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Zhou M, Ma L, Wang Z, Li S, Cai Y, Li M, Zhang L, Wang C, Wu B, Yan Q, He Z, Shu L. Nano- and microplastics drive the dynamic equilibrium of amoeba-associated bacteria and antibiotic resistance genes. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134958. [PMID: 38905974 DOI: 10.1016/j.jhazmat.2024.134958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 06/12/2024] [Accepted: 06/17/2024] [Indexed: 06/23/2024]
Abstract
As emerging pollutants, microplastics have become pervasive on a global scale, inflicting significant harm upon ecosystems. However, the impact of these microplastics on the symbiotic relationship between protists and bacteria remains poorly understood. In this study, we investigated the mechanisms through which nano- and microplastics of varying sizes and concentrations influence the amoeba-bacterial symbiotic system. The findings reveal that nano- and microplastics exert deleterious effects on the adaptability of the amoeba host, with the magnitude of these effects contingent upon particle size and concentration. Furthermore, nano- and microplastics disrupt the initial equilibrium in the symbiotic relationship between amoeba and bacteria, with nano-plastics demonstrating a reduced ability to colonize symbiotic bacteria within the amoeba host when compared to their microplastic counterparts. Moreover, nano- and microplastics enhance the relative abundance of antibiotic resistance genes and heavy metal resistance genes in the bacteria residing within the amoeba host, which undoubtedly increases the potential transmission risk of both human pathogens and resistance genes within the environment. In sum, the results presented herein provide a novel perspective and theoretical foundation for the study of interactions between microplastics and microbial symbiotic systems, along with the establishment of risk assessment systems for ecological environments and human health.
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Affiliation(s)
- Min Zhou
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Lu Ma
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Zihe Wang
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Shicheng Li
- School of Chemistry, Sun Yat-sen University, Guangzhou 510006, China
| | - Yijun Cai
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Meicheng Li
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Lin Zhang
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Cheng Wang
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Bo Wu
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Qingyun Yan
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhili He
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Longfei Shu
- School of Environmental Science and Engineering, Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China.
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Vingataramin Y, Quétel I, Pons MA, Talarmin A, Marcelino I. Spatiotemporal distribution of thermophilic free-living amoebae in recreational waters: A 5-year survey in Guadeloupe (French West Indies). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 941:173318. [PMID: 38777057 DOI: 10.1016/j.scitotenv.2024.173318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/04/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024]
Abstract
Free-living amoebae (FLA) such as Acanthamoeba, Balamuthia mandrillaris, Naegleria fowleri and Sappinia pedata are naturally widespread in freshwater, causing rare but fatal and debilitating infections in humans. Although recent studies have shown an increase in infection rates, there is a paucity of epidemiological studies regarding the presence of these emerging pathogens in water. Herein, we studied the diversity and relative abundance of thermophilic FLA in different recreational baths in a tropical climate for 5 years. From 2018 to 2022, a total of 96 water samples were collected from 7 recreational baths (natural, tiled, regularly cleaned or not, and with temperatures ranging from 27 to 40 °C). DNA was extracted from FLA cultivated at 37 °C to detect thermophilic culturable FLA. Metabarcoding studies were conducted through FLA 18S rRNA gene amplicons sequencing; amplicon sequence variants (ASV) were extracted from each sample and taxonomy assigned against PR2 database using dada2 and phyloseq tools. We also searched for Naegleria sp. and N. fowleri using PCR targeting ITS and NFITS genes (respectively) and we quantified them using an optimized most probable number (MPN) method for FLA. Our results showed that differences in FLA diversity and abundance were observed amongst the 7 baths, but without a clear seasonal distribution. Naegleria, Vermamoeba and Stenamoeba were the most represented genera, while the genera Acanthamoeba and Vahlkampfia were mainly found in 2 baths. The MPN values for Naegleria sp. (NT/l) increased between 2018 and 2022, but the MPN values for N. fowleri (NF/l) seemed to decrease. Globally, our results showed that since we cannot establish a seasonal distribution of FLA, the regular presence of FLA (namely Naegleria and Acanthamoeba) in recreational waters can pose a potential threat in terms of neuroinfections as well as Acanthamoeba keratitis. It is thus imperious to perform the regular control of these baths as a preventive health measure.
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Affiliation(s)
| | - Isaure Quétel
- Institut Pasteur de la Guadeloupe, Les Abymes, Guadeloupe, France
| | - Marie-Anne Pons
- Agence Régionale de Santé (ARS) Guadeloupe, Les Abymes, France
| | - Antoine Talarmin
- Institut Pasteur de la Guadeloupe, Les Abymes, Guadeloupe, France
| | - Isabel Marcelino
- Institut Pasteur de la Guadeloupe, Les Abymes, Guadeloupe, France.
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Nisar MA, Ross KE, Brown MH, Bentham R, Best G, Eyre NS, Leterme SC, Whiley H. Increased flushing frequency of a model plumbing system initially promoted the formation of viable but non culturable cells but ultimately reduced the concentration of culturable and total Legionella DNA. Heliyon 2024; 10:e32334. [PMID: 38933949 PMCID: PMC11200333 DOI: 10.1016/j.heliyon.2024.e32334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 05/30/2024] [Accepted: 06/02/2024] [Indexed: 06/28/2024] Open
Abstract
Legionella is the causative agent of Legionnaires' disease, and its prevalence in potable water is a significant public health issue. Water stagnation within buildings increases the risk of Legionella. However, there are limited studies investigating how stagnation arising through intermittent usage affects Legionella proliferation and the studies that are available do not consider viable but non culturable (VBNC) Legionella. This study used a model plumbing system to examine how intermittent water stagnation affects both VBNC and culturable Legionella. The model plumbing system contained a water tank supplying two biofilm reactors. The model was initially left stagnant for ≈5 months (147 days), after which one reactor was flushed daily, and the other weekly. Biofilm coupons, and water samples were collected for analysis at days 0, 14 and 28. These samples were analysed for culturable and VBNC Legionella, free-living amoebae, and heterotrophic bacteria. After 28 days, once-a-day flushing significantly (p < 0.001) reduced the amount of biofilm-associated culturable Legionella (1.5 log10 reduction) compared with weekly flushing. However, higher counts of biofilm-associated VBNC Legionella (1 log10 higher) were recovered from the reactor with once-a-day flushing compared with weekly flushing. Likewise, once-a-day flushing increased the population of biofilm-associated Vermamoeba vermiformis (approximately 3 log10 higher) compared with weekly flushing, which indicated a positive relationship between VBNC Legionella and V. vermiformis. This is the first study to investigate the influence of stagnation on VBNC Legionella under environmental conditions. Overall, this study showed that a reduction in water stagnation decreased culturable Legionella but not VBNC Legionella.
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Affiliation(s)
- Muhammad Atif Nisar
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
| | - Kirstin E. Ross
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
| | - Melissa H. Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
- ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, 5042, Australia
| | - Richard Bentham
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
| | - Giles Best
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
- Flow Cytometry Facility, Flinders University, Bedford Park, SA, 5042, Australia
| | - Nicholas S. Eyre
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Sophie C. Leterme
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
- ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, 5042, Australia
- Institute for Nanoscience and Technology, Flinders University, Bedford Park, SA, 5042, Australia
| | - Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
- ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, 5042, Australia
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Gad M, Marouf MA, Abogabal A, Hu A, Nabet N. Commercial reverse osmosis point-of-use systems in Egypt failed to purify tap water. JOURNAL OF WATER AND HEALTH 2024; 22:905-922. [PMID: 38822469 DOI: 10.2166/wh.2024.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 04/10/2024] [Indexed: 06/03/2024]
Abstract
This study addresses the heightened global reliance on point-of-use (PoU) systems driven by water quality concerns, ageing infrastructure, and urbanization. While widely used in Egypt, there is a lack of comprehensive evaluation of these systems. We assessed 10 reverse osmosis point-of-use systems, examining physicochemical, bacteriological, and protozoological aspects of tap water (inlets) and filtered water (outlets), adhering to standard methods for the examination of water and wastewater. Results showed significant reductions in total dissolved solids across most systems, with a decrease from 210 ± 23.6 mg/L in tap water to 21 ± 2.8 mg/L in filtered water for PoU-10. Ammonia nitrogen levels in tap water decreased from 0.05 ± 0.04 to 2.28 ± 1.47 mg/L to 0.02 ± 0.04 to 0.69 ± 0.64 mg/L in filtered water. Despite this, bacterial indicators showed no significant changes, with some systems even increasing coliform levels. Protozoological analysis identified prevalent Acanthamoeba (42.5%), less frequent Naegleria (2.5%), Vermamoeba vermiformis (5%), and potentially pathogenic Acanthamoeba genotypes. Elevated bacterial indicators in filtered water of point-of-use systems, combined with essential mineral removal, indicate non-compliance with water quality standards, posing a public health concern. Further research on the long-term health implications of these filtration systems is essential.
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Affiliation(s)
- Mahmoud Gad
- Environmental Parasitology Laboratory, Water Pollution Research Department, National Research Centre, Giza 12622, Egypt E-mail:
| | - Mohamed A Marouf
- Environmental Parasitology Laboratory, Water Pollution Research Department, National Research Centre, Giza 12622, Egypt
| | - Amr Abogabal
- Reference Laboratory, Holding Company for Water and Wastewater, Cairo 12766, Egypt
| | - Anyi Hu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Noura Nabet
- Zoology Department, Faculty of Science, Menoufia University, Menofia, Egypt
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LeChevallier MW, Prosser T, Stevens M. Opportunistic Pathogens in Drinking Water Distribution Systems-A Review. Microorganisms 2024; 12:916. [PMID: 38792751 PMCID: PMC11124194 DOI: 10.3390/microorganisms12050916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
In contrast to "frank" pathogens, like Salmonella entrocolitica, Shigella dysenteriae, and Vibrio cholerae, that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a host with a weakened immune system and rarely in a healthy host. Historically, drinking water treatment has focused on control of frank pathogens, particularly those from human or animal sources (like Giardia lamblia, Cryptosporidium parvum, or Hepatitis A virus), but in recent years outbreaks from drinking water have increasingly been due to opportunistic pathogens. Characteristics of opportunistic pathogens that make them problematic for water treatment include: (1) they are normally present in aquatic environments, (2) they grow in biofilms that protect the bacteria from disinfectants, and (3) under appropriate conditions in drinking water systems (e.g., warm water, stagnation, low disinfectant levels, etc.), these bacteria can amplify to levels that can pose a public health risk. The three most common opportunistic pathogens in drinking water systems are Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. This report focuses on these organisms to provide information on their public health risk, occurrence in drinking water systems, susceptibility to various disinfectants, and other operational practices (like flushing and cleaning of pipes and storage tanks). In addition, information is provided on a group of nine other opportunistic pathogens that are less commonly found in drinking water systems, including Aeromonas hydrophila, Klebsiella pneumoniae, Serratia marcescens, Burkholderia pseudomallei, Acinetobacter baumannii, Stenotrophomonas maltophilia, Arcobacter butzleri, and several free-living amoebae including Naegleria fowleri and species of Acanthamoeba. The public health risk for these microbes in drinking water is still unclear, but in most cases, efforts to manage Legionella, mycobacteria, and Pseudomonas risks will also be effective for these other opportunistic pathogens. The approach to managing opportunistic pathogens in drinking water supplies focuses on controlling the growth of these organisms. Many of these microbes are normal inhabitants in biofilms in water, so the attention is less on eliminating these organisms from entering the system and more on managing their occurrence and concentrations in the pipe network. With anticipated warming trends associated with climate change, the factors that drive the growth of opportunistic pathogens in drinking water systems will likely increase. It is important, therefore, to evaluate treatment barriers and management activities for control of opportunistic pathogen risks. Controls for primary treatment, particularly for turbidity management and disinfection, should be reviewed to ensure adequacy for opportunistic pathogen control. However, the major focus for the utility's opportunistic pathogen risk reduction plan is the management of biological activity and biofilms in the distribution system. Factors that influence the growth of microbes (primarily in biofilms) in the distribution system include, temperature, disinfectant type and concentration, nutrient levels (measured as AOC or BDOC), stagnation, flushing of pipes and cleaning of storage tank sediments, and corrosion control. Pressure management and distribution system integrity are also important to the microbial quality of water but are related more to the intrusion of contaminants into the distribution system rather than directly related to microbial growth. Summarizing the identified risk from drinking water, the availability and quality of disinfection data for treatment, and guidelines or standards for control showed that adequate information is best available for management of L. pneumophila. For L. pneumophila, the risk for this organism has been clearly established from drinking water, cases have increased worldwide, and it is one of the most identified causes of drinking water outbreaks. Water management best practices (e.g., maintenance of a disinfectant residual throughout the distribution system, flushing and cleaning of sediments in pipelines and storage tanks, among others) have been shown to be effective for control of L. pneumophila in water supplies. In addition, there are well documented management guidelines available for the control of the organism in drinking water distribution systems. By comparison, management of risks for Mycobacteria from water are less clear than for L. pneumophila. Treatment of M. avium is difficult due to its resistance to disinfection, the tendency to form clumps, and attachment to surfaces in biofilms. Additionally, there are no guidelines for management of M. avium in drinking water, and one risk assessment study suggested a low risk of infection. The role of tap water in the transmission of the other opportunistic pathogens is less clear and, in many cases, actions to manage L. pneumophila (e.g., maintenance of a disinfectant residual, flushing, cleaning of storage tanks, etc.) will also be beneficial in helping to manage these organisms as well.
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Affiliation(s)
| | - Toby Prosser
- Melbourne Water, Melbourne, VIC 3001, Australia; (T.P.); (M.S.)
| | - Melita Stevens
- Melbourne Water, Melbourne, VIC 3001, Australia; (T.P.); (M.S.)
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Moreno Y, Moreno-Mesonero L, Soler P, Zornoza A, Soriano A. Influence of drinking water biofilm microbiome on water quality: Insights from a real-scale distribution system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171086. [PMID: 38382601 DOI: 10.1016/j.scitotenv.2024.171086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/07/2024] [Accepted: 02/17/2024] [Indexed: 02/23/2024]
Abstract
Biofilms, constituting over 95 % of the biomass in drinking water distribution systems, form an ecosystem impacting both the aesthetic and microbiological quality of water. This study investigates the microbiome of biofilms within a real-scale drinking water distribution system in eastern Spain, utilizing amplicon-based metagenomics. Forty-one biofilm samples underwent processing and sequencing to analyze both bacterial and eukaryotic microbiomes, with an assessment of active biomass. Genus-level analysis revealed considerable heterogeneity, with Desulfovibrio, Ralstonia, Bradyrhizobium, Methylocystis, and Bacillus identified as predominant genera. Notably, bacteria associated with corrosion processes, including Desulfovibrio, Sulfuricella, Hyphomicrobium, and Methylobacterium, were prevalent. Potentially pathogenic bacteria such as Helicobacter, Pseudomonas, and Legionella were also detected. Among protozoa, Opisthokonta and Archaeplastida were the most abundant groups in biofilm samples, with potential pathogenic eukaryotes (Acanthamoeba, Naegleria, Blastocystis) identified. Interestingly, no direct correlation between microbiota composition and pipe materials was observed. The study suggests that the usual concentration of free chlorine in bulk water proved insufficient to prevent the presence of undesirable bacteria and protozoa in biofilms, which exhibited a high concentration of active biomass.
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Affiliation(s)
- Yolanda Moreno
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
| | - Laura Moreno-Mesonero
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - Patricia Soler
- Empresa Mixta Valenciana de Aguas, S.A. (EMIVASA), Av. del Regne de València, 28, 46005, Valencia, Spain
| | - Andrés Zornoza
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain; H2OCITIES, SL, Arte Mayor de la Seda, 15, 46950 Xirivella, Valencia, Spain
| | - Adela Soriano
- Empresa Mixta Valenciana de Aguas, S.A. (EMIVASA), Av. del Regne de València, 28, 46005, Valencia, Spain
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Kalu CM, Mudau KL, Masindi V, Ijoma GN, Tekere M. Occurrences and implications of pathogenic and antibiotic-resistant bacteria in different stages of drinking water treatment plants and distribution systems. Heliyon 2024; 10:e26380. [PMID: 38434035 PMCID: PMC10906316 DOI: 10.1016/j.heliyon.2024.e26380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 12/05/2023] [Accepted: 02/12/2024] [Indexed: 03/05/2024] Open
Abstract
Different stages of drinking water treatment plants (DWTPs) play specific roles in diverse contaminants' removal present in natural water sources. Although the stages are recorded to promote adequate treatment of water, the occurrence of pathogenic bacteria (PB) and antibiotic-resistant bacteria (ARB) in the treated water and the changes in their diversity and abundance as it passed down to the end users through the drinking water distribution systems (DWDSs), is a great concern, especially to human health. This could imply that the different stages and the distribution system provide a good microenvironment for their growth. Hence, it becomes pertinent to constantly monitor and document the diversity of PB and ARB present at each stage of the treatment and distribution system. This review aimed at documenting the occurrence of PB and ARB at different stages of treatment and distribution systems as well as the implication of their occurrence globally. An exhaustive literature search from Web of Science, Science-Direct database, Google Scholar, Academic Research Databases like the National Center for Biotechnology Information, Scopus, and SpringerLink was done. The obtained information showed that the different treatment stages and distribution systems influence the PB and ARB that proliferate. To minimize the human health risks associated with the occurrence of these PB, the present review, suggests the development of advanced technologies that can promote quick monitoring of PB/ARB at each treatment stage and distribution system as well as reduction of the cost of environomics analysis to promote better microbial analysis.
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Affiliation(s)
- Chimdi M. Kalu
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Khuthadzo L. Mudau
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Vhahangwele Masindi
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
- Magalies Water, Scientific Services, Research & Development Division, Brits, South Africa
| | - Grace N. Ijoma
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
| | - Memory Tekere
- Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa, Florida, 1710, South Africa
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Abkar L, Moghaddam HS, Fowler SJ. Microbial ecology of drinking water from source to tap. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168077. [PMID: 37914126 DOI: 10.1016/j.scitotenv.2023.168077] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 11/03/2023]
Abstract
As drinking water travels from its source, through various treatment processes, hundreds to thousands of kilometres of distribution network pipes, to the taps in private homes and public buildings, it is exposed to numerous environmental changes, as well as other microbes living in both water and on surfaces. This review aims to identify the key locations and factors that are associated with changes in the drinking water microbiome throughout conventional urban drinking water systems from the source to the tap water. Over the past 15 years, improvements in cultivation-independent methods have enabled studies that allow us to answer such questions. As a result, we are beginning to move towards predicting the impacts of disturbances and interventions resulting ultimately in management of drinking water systems and microbial communities rather than mere observation. Many challenges still exist to achieve effective management, particularly within the premise plumbing environment, which exhibits diverse and inconsistent conditions that may lead to alterations in the microbiota, potentially presenting public health risks. Finally, we recommend the establishment of global collaborative projects on the drinking water microbiome that will enhance our current knowledge and lead to tools for operators and researchers alike to improve global access to high-quality drinking water.
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Affiliation(s)
- Leili Abkar
- Civil Engineering Department, University of British Columbia, Canada.
| | | | - S Jane Fowler
- Department of Biological Sciences, Simon Fraser University, Canada.
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Hoogenkamp MA, Mazurel D, Deutekom-Mulder E, de Soet JJ. The consistent application of hydrogen peroxide controls biofilm growth and removes Vermamoeba vermiformis from multi-kingdom in-vitro dental unit water biofilms. Biofilm 2023; 5:100132. [PMID: 37346320 PMCID: PMC10279787 DOI: 10.1016/j.bioflm.2023.100132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/24/2023] [Accepted: 05/24/2023] [Indexed: 06/23/2023] Open
Abstract
The water systems inside a dental unit are known to be contaminated with a multi-kingdom biofilm encompassing bacteria, fungi, viruses and protozoa. Aerosolization of these micro-organisms can potentially create a health hazard for both dental staff and the patient. Very little is known on the efficacy of dental unit disinfection products against amoeba. In this study we have examined the effect of four different treatment regimens, with the hydrogen peroxide (H2O2) containing product Oxygenal, on an in-vitro multi-kingdom dental unit water system (DUWS) biofilm. The treatment efficacy was assessed in time using heterotrophic plate counts, the bacterial 16S rDNA, fungal 18S rDNA gene load and the number of genomic units for Legionella spp. the amoeba Vermamoeba vermiformis. The results indicated that a daily treatment of the DUWS with a low dose H2O2 (0.02% for 5 h), combined with a weekly shock dose (0.25% H2O2, 30 min) is necessary to reduce the heterotrophic plate count of a severely contaminated DUWS (>106 CFU.mL-1) to below 100 CFU.mL-1. A daily treatment with a low dose hydrogen peroxide alone, is sufficient for the statistically significant reduction of the total amount of bacterial 16S rDNA gene, Legionella spp. and Vermamoeba vermiformis load (p < 0.005). Also shown is that even though hydrogen peroxide does not kill the trophozoite nor the cysts of V. vermiformis, it does however result in the detachment of the trophozoite form of this amoeba from the DUWS biofilm and hereby ultimately removing the amoeba from the system.
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Affiliation(s)
- Michel A. Hoogenkamp
- Corresponding author. Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, the Netherlands.
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Delumeau A, Quétel I, Harnais F, Sellin A, Gros O, Talarmin A, Marcelino I. Bacterial microbiota management in free-living amoebae (Heterolobosea lineage) isolated from water: The impact of amoebae identity, grazing conditions, and passage number. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 900:165816. [PMID: 37506913 DOI: 10.1016/j.scitotenv.2023.165816] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 07/30/2023]
Abstract
Free-living amoebae (FLA) are ubiquitous protozoa mainly found in aquatic environments. They are well-known reservoirs and vectors for the transmission of amoeba-resistant bacteria (ARB), most of which are pathogenic to humans. Yet, the natural bacterial microbiota associated with FLA remains largely unknown. Herein, we characterized the natural bacterial microbiota of different FLA species isolated from recreational waters in Guadeloupe. Monoxenic cultures of Naegleria australiensis, Naegleria sp. WTP3, Paravahlkampfia ustiana and Vahlkampfia sp. AK-2007 (Heterolobosea lineage) were cultivated under different grazing conditions, during successive passages. The whole bacterial microbiota of the waters and the amoebal cysts was characterized using 16S rRNA gene metabarcoding. The culturable subset of ARB was analyzed by mass spectrometry (MALDI-TOF MS), conventional 16S PCR, and disk diffusion method (to assess bacterial antibiotic resistance). Transmission electron microscopy was used to locate the ARB inside the amoebae. According to alpha and beta-diversity analyses, FLA bacterial microbiota were significantly different from the ones of their habitat. While Vogesella and Aquabacterium genera were detected in water, the most common ARB belonged to Pseudomonas, Bosea, and Escherichia/Shigella genera. The different FLA species showed both temporary and permanent associations with differentially bacterial taxa, suggesting host specificity. These associations depend on the number of passages and grazing conditions. Additionally, Naegleria, Vahlkampfia and Paravahlkampfia cysts were shown to naturally harbor viable bacteria of the Acinetobacter, Escherichia, Enterobacter, Pseudomonas and Microbacterium genera, all being pathogenic to humans. To our knowledge, this is the first time Paravahlkampfia and Vahlkampfia have been demonstrated as hosts of pathogenic ARB in water. Globally, the persistence of these ARB inside resistant cysts represents a potential health risk. To ensure the continued safety of recreational waters, it is crucial to (i) regularly control both the amoebae and their ARB and (ii) improve knowledge on amoebae-bacteria interactions to establish better water management protocols.
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Affiliation(s)
- Aurélie Delumeau
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Isaure Quétel
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Florian Harnais
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Arantxa Sellin
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Olivier Gros
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Pointe-à-Pitre, Guadeloupe, France
| | - Antoine Talarmin
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Isabel Marcelino
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France.
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11
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Cambronne ED, Ayres C, Dowdell KS, Lawler DF, Saleh NB, Kirisits MJ. Protozoan-Priming and Magnesium Conditioning Enhance Legionella pneumophila Dissemination and Monochloramine Resistance. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:14871-14880. [PMID: 37756220 DOI: 10.1021/acs.est.3c04013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Opportunistic pathogens (OPs) are of concern in drinking water distribution systems because they persist despite disinfectant residuals. While many OPs garner protection from disinfectants via a biofilm lifestyle, Legionella pneumophila (Lp) also gains disinfection resistance by being harbored within free-living amoebae (FLA). It has been long established, but poorly understood, that Lp grown within FLA show increased infectivity toward subsequent FLA or human cells (i.e., macrophage), via a process we previously coined "protozoan-priming". The objectives of this study are (i) to identify in Lp a key genetic determinant of how protozoan-priming increases its infectivity, (ii) to determine the chemical stimulus within FLA to which Lp responds during protozoan-priming, and (iii) to determine if more infectious forms of Lp also exhibit enhanced disinfectant resistance. Using Acanthamoeba castellanii as a FLA host, the priming effect was isolated to Lp's sidGV locus, which is activated upon sensing elevated magnesium concentrations. Supplementing growth medium with 8 mM magnesium is sufficient to produce Lp grown in vitro with an infectivity equivalent to that of Lp grown via the protozoan-primed route. Both Lp forms with increased infectivity (FLA-grown and Mg2+-supplemented) exhibit greater monochloramine resistance than Lp grown in standard media, indicating that passage through FLA not only increases Lp's infectivity but also enhances its monochloramine resistance. Therefore, laboratory-based testing of disinfection strategies should employ conditions that simulate or replicate intracellular growth to accurately assess disinfectant resistance.
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Affiliation(s)
- Eric D Cambronne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Craig Ayres
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Katherine S Dowdell
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Desmond F Lawler
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Navid B Saleh
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mary Jo Kirisits
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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12
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Song Y, Finkelstein R, Rhoads W, Edwards MA, Pruden A. Shotgun Metagenomics Reveals Impacts of Copper and Water Heater Anodes on Pathogens and Microbiomes in Hot Water Plumbing Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13612-13624. [PMID: 37643149 PMCID: PMC10501123 DOI: 10.1021/acs.est.3c03568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/31/2023]
Abstract
Hot water building plumbing systems are vulnerable to the proliferation of opportunistic pathogens (OPs), including Legionella pneumophila and Mycobacterium avium. Implementation of copper as a disinfectant could help reduce OPs, but a mechanistic understanding of the effects on the microbial community under real-world plumbing conditions is lacking. Here, we carried out a controlled pilot-scale study of hot water systems and applied shotgun metagenomic sequencing to examine the effects of copper dose (0-2 mg/L), orthophosphate corrosion control agent, and water heater anode materials (aluminum vs magnesium vs powered anode) on the bulk water and biofilm microbiome composition. Metagenomic analysis revealed that, even though a copper dose of 1.2 mg/L was required to reduce Legionella and Mycobacterium numbers, lower doses (e.g., ≤0.6 mg/L) measurably impacted the broader microbial community, indicating that the OP strains colonizing these systems were highly copper tolerant. Orthophosphate addition reduced bioavailability of copper, both to OPs and to the broader microbiome. Functional gene analysis indicated that both membrane damage and interruption of nucleic acid replication are likely at play in copper inactivation mechanisms. This study identifies key factors (e.g., orthophosphate, copper resistance, and anode materials) that can confound the efficacy of copper for controlling OPs in hot water plumbing.
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Affiliation(s)
- Yang Song
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- Utilities
Department, Town of Cary, 316 N. Academy St., Cary, North Carolina 27512, United States
| | - Rachel Finkelstein
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- AECOM, 3101 Wilson Boulevard, Arlington, Virginia 22201, United States
| | - William Rhoads
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
- Black
& Veatch, 8400 Ward
Pkwy, Kansas City, Missouri 64114, United States
| | - Marc A. Edwards
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Amy Pruden
- Civil
and Environmental Engineering, Virginia
Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, Virginia 24061, United States
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13
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Wang L, Mai Y, Li S, Shu L, Fang J. Efficient inactivation of amoeba spores and their intraspore bacteria by solar/chlorine: Kinetics and mechanisms. WATER RESEARCH 2023; 242:120288. [PMID: 37419027 DOI: 10.1016/j.watres.2023.120288] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/21/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Amoebae are widespread in water and serve as environment vectors for pathogens, which may threaten public health. This study evaluated the inactivation of amoeba spores and their intraspore bacteria by solar/chlorine. Dictyostelium discoideum and Burkholderia agricolaris B1qs70 were selected as model amoebae and intraspore bacteria, respectively. Compared to solar irradiation and chlorine, solar/chlorine enhanced the inactivation of amoeba spores and intraspore bacteria, with 5.1 and 5.2-log reduction at 20 min, respectively. The enhancement was similar in real drinking water by solar/chlorine under natural sunlight. However, the spore inactivation decreased to 2.97-log by 20 min solar/chlorine under oxygen-free condition, indicating that ozone played a crucial role in the spore inactivation, as also confirmed by the scavenging test using tert‑butanol to scavenge the ground-state atomic oxygen (O(3P)) as a ozone precursor. Moreover, solar/chlorine induced the shape destruction and structural collapse of amoeba spores by scanning electron microscopy. As for intraspore bacteria, their inactivation was likely ascribed to endogenous reactive oxygen species. As pH increased from 5.0 to 9.0, the inactivation of amoeba spores decreased, whereas that of intraspore bacteria was similar at pH 5.0 and 6.5 during solar/chlorine treatment. This study first reports the efficient inactivation of amoeba spores and their intraspore pathogenic bacteria by solar/chlorine in drinking water.
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Affiliation(s)
- Liping Wang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Yingwen Mai
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Shenzhou Li
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Longfei Shu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China.
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China.
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14
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Ashbolt NJ. Conceptual model to inform Legionella-amoebae control, including the roles of extracellular vesicles in engineered water system infections. Front Cell Infect Microbiol 2023; 13:1200478. [PMID: 37274310 PMCID: PMC10232903 DOI: 10.3389/fcimb.2023.1200478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023] Open
Abstract
Extracellular vesicles (EVs or exosomes) are well described for bacterial pathogens associated with our gastrointestinal system, and more recently as a novel mechanism for environmental persistence, dissemination and infection for human enteric viruses. However, the roles played by EVs in the ancient arms race that continues between amoebae and one of their prey, Legionella pneumophila, is poorly understood. At best we know of intracellular vesicles of amoebae containing a mix of bacterial prey species, which also provides an enhanced niche for bacteriophage infection/spread. Free-living amoeba-associated pathogens have recently been recognized to have enhanced resistance to disinfection and environmental stressors, adding to previously understood (but for relatively few species of) bacteria sequestered within amoebal cysts. However, the focus of the current work is to review the likely impacts of large numbers of respiratory-sized EVs containing numerous L. pneumophila cells studied in pure and biofilm systems with mixed prey species. These encapsulated pathogens are orders of magnitude more resistant to disinfection than free cells, and our engineered systems with residual disinfectants could promote evolution of resistance (including AMR), enhanced virulence and EV release. All these are key features for evolution within a dead-end human pathogen post lung infection. Traditional single-hit pathogen infection models used to estimate the probability of infection/disease and critical environmental concentrations via quantitative microbial risk assessments may also need to change. In short, recognizing that EV-packaged cells are highly virulent units for transmission of legionellae, which may also modulate/avoid human host immune responses. Key data gaps are raised and a previous conceptual model expanded upon to clarify where biofilm EVs could play a role promoting risk as well as inform a more wholistic management program to proactively control legionellosis.
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15
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Wang Z, Huang W, Mai Y, Tian Y, Wu B, Wang C, Yan Q, He Z, Shu L. Environmental stress promotes the persistence of facultative bacterial symbionts in amoebae. Ecol Evol 2023; 13:e9899. [PMID: 36937064 PMCID: PMC10019945 DOI: 10.1002/ece3.9899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 02/23/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
Amoebae are one major group of protists that are widely found in natural and engineered environments. They are a significant threat to human health not only because many of them are pathogenic but also due to their unique role as an environmental shelter for pathogens. However, one unsolved issue in the amoeba-bacteria relationship is why so many bacteria live within amoeba hosts while they can also live independently in the environments. By using a facultative amoeba- Paraburkholderia bacteria system, this study shows that facultative bacteria have higher survival rates within amoebae under various environmental stressors. In addition, bacteria survive longer within the amoeba spore than in free living. This study demonstrates that environmental stress can promote the persistence of facultative bacterial symbionts in amoebae. Furthermore, environmental stress may potentially select and produce more amoeba-resisting bacteria, which may increase the biosafety risk related to amoebae and their intracellular bacteria.
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Affiliation(s)
- Zihe Wang
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Wei Huang
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Yingwen Mai
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Yuehui Tian
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Bo Wu
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Cheng Wang
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Qingyun Yan
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Zhili He
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Longfei Shu
- School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
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16
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Nisar MA, Ross KE, Brown MH, Bentham R, Hinds J, Whiley H. Molecular screening and characterization of Legionella pneumophila associated free-living amoebae in domestic and hospital water systems. WATER RESEARCH 2022; 226:119238. [PMID: 36270142 DOI: 10.1016/j.watres.2022.119238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Free-living amoebae are ubiquitous in the environment and cause both opportunistic and non-opportunistic infections in humans. Some genera of amoebae are natural reservoirs of opportunistic plumbing pathogens, such as Legionella pneumophila. In this study, the presence of free-living amoebae and Legionella was investigated in 140 water and biofilm samples collected from Australian domestic (n = 68) and hospital water systems (n = 72). Each sample was screened in parallel using molecular and culture-based methods. Direct quantitative polymerase chain reaction (qPCR) assays showed that 41% samples were positive for Legionella, 33% for L. pneumophila, 11% for Acanthamoeba, and 55% for Vermamoeba vermiformis gene markers. Only 7% of samples contained culturable L. pneumophila serogroup (sg)1, L. pneumophila sg2-14, and non-pneumophila Legionella. In total, 69% of samples were positive for free-living amoebae using any method. Standard culturing found that 41% of the samples were positive for amoeba (either Acanthamoeba, Allovahlkampfia, Stenamoeba, or V. vermiformis). V. vermiformis showed the highest overall frequency of occurrence. Acanthamoeba and V. vermiformis isolates demonstrated high thermotolerance and osmotolerance and strong broad spectrum bacteriogenic activity against Gram-negative and Gram-positive bacteria. Importantly, all Legionella positive samples were also positive for amoeba, and this co-occurrence was statistically significant (p < 0.05). According to qPCR and fluorescence in situ hybridization, V. vermiformis and Allovahlkampfia harboured intracellular L. pneumophila. To our knowledge, this is the first time Allovahlkampfia and Stenamoeba have been demonstrated as hosts of L. pneumophila in potable water. These results demonstrate the importance of amoebae in engineered water systems, both as a pathogen and as a reservoir of Legionella. The high frequency of gymnamoebae detected in this study from Australian engineered water systems identifies an issue of significant public health concern. Future water management protocols should incorporate treatments strategies to control amoebae to reduce the risk to end users.
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Affiliation(s)
- Muhammad Atif Nisar
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Kirstin E Ross
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Melissa H Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Richard Bentham
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Jason Hinds
- Enware Australia Pty Ltd, Caringbah, NSW, Australia
| | - Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia.
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17
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Fechtali-Moute Z, Loiseau PM, Pomel S. Stimulation of Acanthamoeba castellanii excystment by enzyme treatment and consequences on trophozoite growth. Front Cell Dev Biol 2022; 10:982897. [PMID: 36172275 PMCID: PMC9511172 DOI: 10.3389/fcell.2022.982897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Acanthamoeba castellanii is a widespread Free-Living Amoeba (FLA) that can cause severe ocular or cerebral infections in immunocompetent and immunocompromised patients, respectively, besides its capacity to transport diverse pathogens. During their life cycle, FLA can alternate between a vegetative form, called a trophozoite, and a latent and resistant form, called a cyst. This resistant form is characterized by the presence of a cell wall containing two layers, namely the ectocyst and the endocyst, mainly composed of cellulose and proteins. In the present work, we aimed to stimulate Acanthamoeba castellanii excystment by treating their cysts with a cellulolytic enzyme, i.e., cellulase, or two proteolytic enzymes, i.e., collagenase and pepsin. While 11 days were necessary to obtain total excystment in the control at 27°C, only 48 h were sufficient at the same temperature to obtain 100% trophozoites in the presence of 25 U/mL cellulase, 50 U/mL collagenase or 100 U/mL pepsin. Additionally, more than 96% amoebae have excysted after only 24 h with 7.5 U/mL cellulase at 30°C. Nevertheless, no effect of the three enzymes was observed on the excystment of Balamuthia mandrillaris and Vermamoeba vermiformis. Surprisingly, A. castellanii trophozoites excysted in the presence of cellulase displayed a markedly shorter doubling time at 7 h, in comparison to the control at 23 h. Likewise, trophozoites doubled their population in 9 h when both cellulose and cellulase were added to the medium, indicating that Acanthamoeba cyst wall degradation products promote their trophozoite proliferation. The analysis of cysts in epifluorescent microscopy using FITC-lectins and in electron microscopy revealed a disorganized endocyst and a reduction of the intercystic space area after cellulase treatment, implying that these cellular events are preliminary to trophozoite release during excystment. Further studies would be necessary to determine the signaling pathways involved during this amoebal differentiation process to identify new therapeutic targets for the development of anti-acanthamoebal drugs.
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Jin C, Mo Y, Zhao L, Xiao Z, Zhu S, He Z, Chen Z, Zhang M, Shu L, Qiu R. Host-Endosymbiont Relationship Impacts the Retention of Bacteria-Containing Amoeba Spores in Porous Media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:12347-12357. [PMID: 35916900 DOI: 10.1021/acs.est.2c02899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, Dictyostelium discoideum, and a representative bacterium, Burkholderia agricolaris B1qs70, were used to prepare amoeba spores that carried bacteria. After interacting with B. agricolaris, the retention of D. discoideum spores was enhanced compared to noninfected spores. Diverse proteins, especially proteins contributing to the looser exosporium structure and cell adhesion functionality, are secreted in higher quantities on the exosporium surface of infected spores compared to that of noninfected ones. Comprehensive examinations using a quartz crystal microbalance with dissipation (QCM-D), a parallel plate chamber, and a single-cell force microscope present coherent evidence that changes in the exosporium of D. discoideum spores due to infection by B. agricolaris enhance the connections between spores in the suspension and the spores that were previously deposited on the collector surface, thus resulting in more retention compared to the uninfected ones in porous media. This work provides novel insight into the retention of amoeba spores after bacterial infection in porous media and suggests that the host-endosymbiont relationship regulates the fate of biocolloids in drinking water systems, groundwater, and other porous environments.
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Affiliation(s)
- Chao Jin
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Yijun Mo
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Lingan Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zihan Xiao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Shishu Zhu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zhenzhen He
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zijian Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Miaoyue Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Longfei Shu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, P. R. China
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, P. R. China
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19
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Zhang M, Altan-Bonnet N, Shen Y, Shuai D. Waterborne Human Pathogenic Viruses in Complex Microbial Communities: Environmental Implication on Virus Infectivity, Persistence, and Disinfection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5381-5389. [PMID: 35434991 PMCID: PMC9073700 DOI: 10.1021/acs.est.2c00233] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Waterborne human pathogenic viruses challenge global health and economy. Viruses were long believed to transmit among hosts as individual, free particles. However, recent evidence indicates that viruses also transmit in populations, so-called en bloc transmission, by either interacting with coexisting bacteria, free-living amoebas, and other higher organisms through endosymbiosis and surface binding, or by being clustered inside membrane-bound vesicles or simply self-aggregating with themselves. En bloc transmission of viruses and virus-microbiome interactions could enable viruses to enhance their infectivity, increase environmental persistence, and resist inactivation from disinfection. Overlooking this type of transmission and virus-microbiome interactions may underestimate the environmental and public health risks of the viruses. We herein provide a critical perspective on waterborne human pathogenic viruses in complex microbial communities to elucidate the environmental implication of virus-microbiome interactions on virus infectivity, persistence, and disinfection. This perspective also provides insights on advancing disinfection and sanitation guidelines and regulations to protect the public health.
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Affiliation(s)
- Mengyang Zhang
- Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052, United States
- Laboratory of Host-Pathogen Dynamics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Nihal Altan-Bonnet
- Laboratory of Host-Pathogen Dynamics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Yun Shen
- Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92521
| | - Danmeng Shuai
- Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052, United States
- Corresponding Author: Danmeng Shuai, Phone: 202-994-0506, Fax: 202-994-0127, , Website: http://materwatersus.weebly.com
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20
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Climate Change: Water Temperature and Invertebrate Propagation in Drinking-Water Distribution Systems, Effects, and Risk Assessment. WATER 2022. [DOI: 10.3390/w14081246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This paper provides a summary of the knowledge of drinking-water temperature increases and present daily, seasonal, and yearly temperature data of drinking-water distribution systems (DWDS). The increasing water temperatures lead to challenges in DWDS management, and we must assume a promotion of invertebrates as pipe inhabitants. Macro-, meio-, and microinvertebrates were found in nearly all DWDS. Data in relation to diversity and abundance clearly point out a high probability of mass development, and invertebrate monitoring must be the focus of any DWDS management. The water temperature of DWDS is increasing due to climate change effects, and as a consequence, the growth and reproduction of invertebrates is increasing. The seasonal development of a chironomid (Paratanytarus grimmii) and longtime development of water lice (Asellus aquaticus) are given. Due to increased water temperatures, a third generation of water lice per year has been observed, which is one reason for the observed mass development. This leads to an impact on drinking-water quality and an increased health risk, as invertebrates can serve as a host or vehicle for potential harmful microbes. More research is needed especially on (i) water temperature monitoring in drinking-water distribution systems, (ii) invertebrate development, and (iii) health risks.
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21
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He Z, Zheng N, Zhang L, Tian Y, Hu Z, Shu L. Efficient inactivation of intracellular bacteria in dormant amoeba spores by FeP. JOURNAL OF HAZARDOUS MATERIALS 2022; 425:127996. [PMID: 34902724 DOI: 10.1016/j.jhazmat.2021.127996] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/26/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Waterborne pathogens and related diseases are a severe public health threat worldwide. Recent studies suggest that microbial interactions among infectious agents can significantly disrupt the disinfection processes, and current disinfection methods cannot inactivate intracellular pathogens effectively, posing an emerging threat to the safety of drinking water. This study developed a novel strategy, the FeP/persulfate (PS) system, to effectively inactivate intracellular bacteria within the amoeba spore. We found that the sulfate radical (SO4•-) produced by the FeP/PS system can be quickly converted into hydroxyl radicals (•OH), and •OH can penetrate the amoeba spores and inactivate the bacteria hidden inside amoeba spores. Therefore, this study proposes a novel technique to overcome the protective effects of microbial interactions and provides a new direction to inactivate intracellular pathogens efficiently.
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Affiliation(s)
- Zhenzhen He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Ningchao Zheng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Lin Zhang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuehui Tian
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhuofeng Hu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
| | - Longfei Shu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
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22
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Proctor C, Garner E, Hamilton KA, Ashbolt NJ, Caverly LJ, Falkinham JO, Haas CN, Prevost M, Prevots DR, Pruden A, Raskin L, Stout J, Haig SJ. Tenets of a holistic approach to drinking water-associated pathogen research, management, and communication. WATER RESEARCH 2022; 211:117997. [PMID: 34999316 PMCID: PMC8821414 DOI: 10.1016/j.watres.2021.117997] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 05/10/2023]
Abstract
In recent years, drinking water-associated pathogens that can cause infections in immunocompromised or otherwise susceptible individuals (henceforth referred to as DWPI), sometimes referred to as opportunistic pathogens or opportunistic premise plumbing pathogens, have received considerable attention. DWPI research has largely been conducted by experts focusing on specific microorganisms or within silos of expertise. The resulting mitigation approaches optimized for a single microorganism may have unintended consequences and trade-offs for other DWPI or other interests (e.g., energy costs and conservation). For example, the ecological and epidemiological issues characteristic of Legionella pneumophila diverge from those relevant for Mycobacterium avium and other nontuberculous mycobacteria. Recent advances in understanding DWPI as part of a complex microbial ecosystem inhabiting drinking water systems continues to reveal additional challenges: namely, how can all microorganisms of concern be managed simultaneously? In order to protect public health, we must take a more holistic approach in all aspects of the field, including basic research, monitoring methods, risk-based mitigation techniques, and policy. A holistic approach will (i) target multiple microorganisms simultaneously, (ii) involve experts across several disciplines, and (iii) communicate results across disciplines and more broadly, proactively addressing source water-to-customer system management.
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Affiliation(s)
- Caitlin Proctor
- Department of Agricultural and Biological Engineering, Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, USA
| | - Emily Garner
- Wadsworth Department of Civil & Environmental Engineering, West Virginia University, Morgantown, WV, USA
| | - Kerry A Hamilton
- School of Sustainable Engineering and the Built Environment and The Biodesign Centre for Environmental Health Engineering, Arizona State University, Tempe, AZ, USA
| | - Nicholas J Ashbolt
- Faculty of Science and Engineering, Southern Cross University, Gold Coast. Queensland, Australia
| | - Lindsay J Caverly
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Charles N Haas
- Department of Civil, Architectural & Environmental Engineering, Drexel University, Philadelphia, PA, USA
| | - Michele Prevost
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, Canada
| | - D Rebecca Prevots
- Epidemiology Unit, Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA USA
| | - Lutgarde Raskin
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Janet Stout
- Department of Civil & Environmental Engineering, University of Pittsburgh, and Special Pathogens Laboratory, Pittsburgh, PA, USA
| | - Sarah-Jane Haig
- Department of Civil & Environmental Engineering, and Department of Environmental & Occupational Health, University of Pittsburgh, Pittsburgh, PA, USA.
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23
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Cazals M, Bédard E, Doberva M, Faucher S, Prévost M. Compromised Effectiveness of Thermal Inactivation of Legionella pneumophila in Water Heater Sediments and Water, and Influence of the Presence of Vermamoeba vermiformis. Microorganisms 2022; 10:microorganisms10020443. [PMID: 35208896 PMCID: PMC8874534 DOI: 10.3390/microorganisms10020443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 11/21/2022] Open
Abstract
Intermittent reduction of temperature set-points and periodic shutdowns of water heaters have been proposed to reduce energy consumption in buildings. However, the consequences of such measures on the occurrence and proliferation of Legionella pneumophila (Lp) in hot water systems have not been documented. The impact of single and repeated heat shocks was investigated using an environmental strain of L. pneumophila and a reference strain of V. vermiformis. Heat shocks at temperatures ranging from 50 °C to 70 °C were applied for 1 h and 4 h in water and water heaters loose deposits (sludge). The regrowth potential of heat-treated culturable L. pneumophila in presence of V. vermiformis in water heaters sludges was evaluated. A 2.5-log loss of culturability of L. pneumophila was observed in simulated drinking water at 60 °C while a 4-log reduction was reached in water heaters loose deposits. Persistence of Lp after 4 h at 55 °C was shown and the presence of V. vermiformis in water heater’s loose deposits resulted in a drastic amplification (5-log). Results show that thermal inactivation by heat shock is only efficient at elevated temperatures (50 °C) in both water and loose deposits. The few remaining organisms can rapidly proliferate during storage at lower temperature in the presence of hosts.
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Affiliation(s)
- Margot Cazals
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
- Correspondence:
| | - Emilie Bédard
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
| | - Margot Doberva
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
| | - Sébastien Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada;
| | - Michèle Prévost
- Department of Civil Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (E.B.); (M.D.); (M.P.)
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24
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Soler P, Moreno-Mesonero L, Zornoza A, Macián VJ, Moreno Y. Characterization of eukaryotic microbiome and associated bacteria communities in a drinking water treatment plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:149070. [PMID: 34303230 DOI: 10.1016/j.scitotenv.2021.149070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
The effectiveness of drinking water treatment is critical to achieve an optimal and safe drinking water. Disinfection is one of the most important steps to eliminate the health concern caused by the microbial population in this type of water. However, no study has evaluated the changes in its microbiome, specially the eukaryotic microbiome, and the fates of opportunistic pathogens generated by UV disinfection with medium-pressure mercury lamps in drinking water treatment plants (DWTPs). In this work, the eukaryotic community composition of a DWTP with UV disinfection was evaluated before and after a UV disinfection treatment by means of Illumina 18S rRNA amplicon-based sequencing. Among the physicochemical parameters analysed, flow and nitrate appeared to be related with the changes in the eukaryotic microbiome shape. Public health concern eukaryotic organisms such as Blastocystis, Entamoeba, Acanthamoeba, Hartmannella, Naegleria, Microsporidium or Caenorhabditis were identified. Additionally, the relation between the occurrence of some human bacterial pathogens and the presence of some eukaryotic organisms has been studied. The presence of some human bacterial pathogens such as Arcobacter, Mycobacterium, Pseudomonas and Parachlamydia were statistically correlated with the presence of some eukaryotic carriers showing the public health risk due to the bacterial pathogens they could shelter.
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Affiliation(s)
- Patricia Soler
- Empresa Mixta Valenciana de Aguas, S.A. (EMIVASA), Av. del Regne de València, 28, 46005, Valencia, Spain.
| | - Laura Moreno-Mesonero
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
| | - Andrés Zornoza
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain; H2OCITIES, SL. Arte Mayor de la Seda, 15, 46950 Xirivella, Valencia, Spain.
| | - V Javier Macián
- Empresa Mixta Valenciana de Aguas, S.A. (EMIVASA), Av. del Regne de València, 28, 46005, Valencia, Spain; Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
| | - Yolanda Moreno
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
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25
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Zhang C, Lu J. Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems. FRONTIERS IN ENVIRONMENTAL SCIENCE 2021; 9:1-22. [PMID: 35004706 PMCID: PMC8740890 DOI: 10.3389/fenvs.2021.684319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Opportunistic pathogens (OPs) are natural inhabitants and the predominant disease causative biotic agents in municipal engineered water systems (EWSs). In EWSs, OPs occur at high frequencies and concentrations, cause drinking-water-related disease outbreaks, and are a major factor threatening public health. Therefore, the prevalence of OPs in EWSs represents microbial drinking water quality. Closely or routinely monitoring the dynamics of OPs in municipal EWSs is thus critical to ensuring drinking water quality and protecting public health. Monitoring the dynamics of conventional (fecal) indicators (e.g., total coliforms, fecal coliforms, and Escherichia coli) is the customary or even exclusive means of assessing microbial drinking water quality. However, those indicators infer only fecal contamination due to treatment (e.g., disinfection within water utilities) failure and EWS infrastructure issues (e.g., water main breaks and infiltration), whereas OPs are not contaminants in drinking water. In addition, those indicators appear in EWSs at low concentrations (often absent in well-maintained EWSs) and are uncorrelated with OPs. For instance, conventional indicators decay, while OPs regrow with increasing hydraulic residence time. As a result, conventional indicators are poor indicators of OPs (the major aspect of microbial drinking water quality) in EWSs. An additional or supplementary indicator that can well infer the prevalence of OPs in EWSs is highly needed. This systematic review argues that Legionella as a dominant OP-containing genus and natural inhabitant in EWSs is a promising candidate for such a supplementary indicator. Through comprehensively comparing the behavior (i.e., occurrence, growth and regrowth, spatiotemporal variations in concentrations, resistance to disinfectant residuals, and responses to physicochemical water quality parameters) of major OPs (e.g., Legionella especially L. pneumophila, Mycobacterium, and Pseudomonas especially P. aeruginosa), this review proves that Legionella is a promising supplementary indicator for the prevalence of OPs in EWSs while other OPs lack this indication feature. Legionella as a dominant natural inhabitant in EWSs occurs frequently, has a high concentration, and correlates with more microbial and physicochemical water quality parameters than other common OPs. Legionella and OPs in EWSs share multiple key features such as high disinfectant resistance, biofilm formation, proliferation within amoebae, and significant spatiotemporal variations in concentrations. Therefore, the presence and concentration of Legionella well indicate the presence and concentrations of OPs (especially L. pneumophila) and microbial drinking water quality in EWSs. In addition, Legionella concentration indicates the efficacies of disinfectant residuals in EWSs. Furthermore, with the development of modern Legionella quantification methods (especially quantitative polymerase chain reactions), monitoring Legionella in ESWs is becoming easier, more affordable, and less labor-intensive. Those features make Legionella a proper supplementary indicator for microbial drinking water quality (especially the prevalence of OPs) in EWSs. Water authorities may use Legionella and conventional indicators in combination to more comprehensively assess microbial drinking water quality in municipal EWSs. Future work should further explore the indication role of Legionella in EWSs and propose drinking water Legionella concentration limits that indicate serious public health effects and require enhanced treatment (e.g., booster disinfection).
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Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH, United States
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
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26
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Chaúque BJM, Rott MB. Solar disinfection (SODIS) technologies as alternative for large-scale public drinking water supply: Advances and challenges. CHEMOSPHERE 2021; 281:130754. [PMID: 34029967 DOI: 10.1016/j.chemosphere.2021.130754] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/25/2021] [Accepted: 04/29/2021] [Indexed: 06/12/2023]
Abstract
Gastrointestinal waterborne diseases, continue to stand out among the most lethal diseases in developing countries, because of consuming contaminated water taken from unsafe sources. Advances made in recent decades in methods of solar water disinfection (SODIS) have shown that SODIS is an effective and inexpensive method of providing drinking water, capable of substantially reducing the prevalence and mortality of waterborne diseases. The increased impact of SODIS in communities lacking drinking water services depends on a successful upgrade from conventional SODIS (based on PET bottle reactors) in high flow continuous flow systems for solar water disinfection (CFSSWD). This review aimed to identify the main limitations of conventional SODIS that hinder its application as a large-scale drinking water supply strategy, and to propose ways to overcome these limitations (without making it economically inaccessible) based on the current frontier of advances technological. It was found that the successful development of the CFSSWD depends on overcoming the current limitations of conventional SODIS and the development of systems whose configurations allow combining the properties of solar pasteurization (SOPAS) and SODIS. Different improvements need to be made to the main components of the CFSSWD, such as increasing the performance of solar radiation collectors, photo and thermal reactors and heat exchangers. The integration of disinfection technologies based on photocatalytic and photothermal nanomaterials also needs to be achieved. The performance evaluation of the CFSSWD should be made considering resistant microorganisms, such as the environmental resistance structures of bacteria or protozoa (spores or (oo)cysts) as targets of disinfection approaches.
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Affiliation(s)
- Beni Jequicene Mussengue Chaúque
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Brazil; Department of Science, Technology, Engineering and Mathematics, Universidade Rovuma, Niassa Branch, Mozambique.
| | - Marilise Brittes Rott
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Brazil.
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27
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Zhang X, Xia S, Ye Y, Wang H. Opportunistic pathogens exhibit distinct growth dynamics in rainwater and tap water storage systems. WATER RESEARCH 2021; 204:117581. [PMID: 34461496 DOI: 10.1016/j.watres.2021.117581] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/09/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Opportunistic pathogens (OPs) are emerging microbial contaminants in engineered water systems, yet their growth potential in rainwater systems has not been evaluated. The purpose of this study was to compare the growth dynamics of bacterial OPs and related genera (Pseudomonas aeruginosa, Legionella spp., L. pneumophila, Mycobacterium spp., and M. avium), two amoebal hosts (Acanthamoeba spp. and Vermamoeba vermiformis), and the fecal indicator Escherichia coli in simulated rainwater and tap water storage systems (SWSSs). Quantitative polymerase chain reaction (q-PCR) analysis of target microorganisms in SWSS influents and effluents demonstrated that P. aeruginosa and Legionella thrived in rainwater, but not in tap water. V. vermiformis proliferated in both rainwater and tap water polyvinyl chloride (PVC) SWSSs, while mycobacteria were largely absent in rainwater SWSSs. Tank materials exerted stronger influence on target microorganisms in rainwater SWSSs relative to tap water SWSSs, with species-specific responses noted in bulk water and biofilm. For instance, P. aeruginosa and V. vermiformis had the highest gene copy numbers in PVC rainwater SWSS effluents and biofilm, while Legionella peaked in stainless steel rainwater SWSS effluents and PVC rainwater SWSS biofilm. These results highlighted the OP contamination risks in rainwater storage systems and provided insights into rainwater system design and operation in terms of OP control.
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Affiliation(s)
- Xiaodong Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Chengtou Water Group Corporation, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Yinyin Ye
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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28
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Ghosh S, Zhu NJ, Milligan E, Falkinham JO, Pruden A, Edwards MA. Mapping the Terrain for Pathogen Persistence and Proliferation in Non-potable Reuse Distribution Systems: Interactive Effects of Biofiltration, Disinfection, and Water Age. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12561-12573. [PMID: 34448580 DOI: 10.1021/acs.est.1c02121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Diverse pathogens can potentially persist and proliferate in reclaimed water distribution systems (RWDSs). The goal of this study was to evaluate interactive effects of reclaimed water treatments and water age on persistence and proliferation of multiple fecal (e.g., Klebsiella, Enterobacter) and non-fecal (e.g., Legionella, mycobacteria) gene markers in RWDSs. Six laboratory-scale RWDSs were operated in parallel receiving the influent with or without biologically active carbon (BAC) filtration + chlorination, chloramination, or no disinfectant residual. After 3 years of operation, the RWDSs were subject to sacrificial sampling and shotgun metagenomic sequencing. We developed an in-house metagenome-derived pathogen quantification pipeline, validated by quantitative polymerase chain reaction and mock community analysis, to estimate changes in abundance of ∼30 genera containing waterborne pathogens. Microbial community composition in the RWDS bulk water, biofilm, and sediments was clearly shaped by BAC filtration, disinfectant conditions, and water age. Key commonalities were noted in the ecological niches occupied by fecal pathogen markers in the RWDSs, while non-fecal pathogen markers were more varied in their distribution. BAC-filtration + chlorine was found to most effectively control the widest range of target genera. However, filtration alone or chlorine secondary disinfection alone resulted in proliferation of some of these genera containing waterborne pathogens.
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Affiliation(s)
- Sudeshna Ghosh
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Ni Joyce Zhu
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Erin Milligan
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Joseph O Falkinham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Marc A Edwards
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
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29
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He Z, Wang L, Ge Y, Zhang S, Tian Y, Yang X, Shu L. Both viable and inactivated amoeba spores protect their intracellular bacteria from drinking water disinfection. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126006. [PMID: 33984787 DOI: 10.1016/j.jhazmat.2021.126006] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/29/2021] [Accepted: 04/29/2021] [Indexed: 05/21/2023]
Abstract
In drinking water systems, waterborne pathogens constitute a significant threat. While most studies focus on a single infectious agent, such as bacteria, fungi, viruses, and protists, the effect of interactions among these infectious agents on disinfection treatment has largely been ignored. In this study, we find that dormant amoeba spores, a frequently found protist in drinking water systems, can protect their intracellular bacteria from drinking water disinfection. Bacteria-containing amoeba spores were constructed and treated with various disinfection techniques (Cl2, ClO2, and UV254). The three disinfection methods could kill the bacteria alone efficiently (6-log inactivation). However, the inactivation efficiency of bacteria that hid within amoeba spore was significantly inhibited (2-3-log inactivation). We also found that inactivated amoeba spores can still protect their intracellular bacteria. This study provides direct evidence that viable and inactivated amoeba spores can protect their hitchhiking bacteria from disinfection treatment, which is crucial for future decision-making about the dosage for sufficient bacterial disinfection in drinking water systems.
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Affiliation(s)
- Zhenzhen He
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Luting Wang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Yuexian Ge
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Siyi Zhang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Yuehui Tian
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
| | - Longfei Shu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, China.
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Petitjean M, Juarez P, Meunier A, Daguindau E, Puja H, Bertrand X, Valot B, Hocquet D. The rise and the fall of a Pseudomonas aeruginosa endemic lineage in a hospital. Microb Genom 2021; 7. [PMID: 34473016 PMCID: PMC8715434 DOI: 10.1099/mgen.0.000629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The biological features that allow a pathogen to survive in the hospital environment are mostly unknown. The extinction of bacterial epidemics in hospitals is mostly attributed to changes in medical practice, including infection control, but the role of bacterial adaptation has never been documented. We analysed a collection of Pseudomonas aeruginosa isolates belonging to the Besançon Epidemic Strain (BES), responsible for a 12year nosocomial outbreak, using a genotype-to-phenotype approach. Bayesian analysis estimated the emergence of the clone in the hospital 5 years before its opening, during the creation of its water distribution network made of copper. BES survived better than the reference strains PAO1 and PA14 in a copper solution due to a genomic island containing 13 metal-resistance genes and was specifically able to proliferate in the ubiquitous amoeba Vermamoeba vermiformis. Mutations affecting amino-acid metabolism, antibiotic resistance, lipopolysaccharide biosynthesis, and regulation were enriched during the spread of BES. Seven distinct regulatory mutations attenuated the overexpression of the genes encoding the efflux pump MexAB-OprM over time. The fitness of BES decreased over time in correlation with its genome size. Overall, the resistance to inhibitors and predators presumably aided the proliferation and propagation of BES in the plumbing system of the hospital. The pathogen further spread among patients via multiple routes of contamination. The decreased prevalence of patients infected by BES mirrored the parallel and convergent genomic evolution and reduction that affected bacterial fitness. Along with infection control measures, this may have participated in the extinction of BES in the hospital setting.
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Affiliation(s)
- Marie Petitjean
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Paulo Juarez
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Alexandre Meunier
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France
| | - Etienne Daguindau
- UMR INSERM 1098, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Hélène Puja
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Xavier Bertrand
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Benoit Valot
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Bioinformatique et Big Data au Service de la Santé, UFR Science de la Santé, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Didier Hocquet
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Bioinformatique et Big Data au Service de la Santé, UFR Science de la Santé, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Centre de Ressources Biologiques - Filière Microbiologique de Besançon, Centre Hospitalier Universitaire, 25030 Besançon, France
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31
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Drigo B, Brunetti G, Aleer SC, Bell JM, Short MD, Vasileiadis S, Turnidge J, Monis P, Cunliffe D, Donner E. Inactivation, removal, and regrowth potential of opportunistic pathogens and antimicrobial resistance genes in recycled water systems. WATER RESEARCH 2021; 201:117324. [PMID: 34242935 DOI: 10.1016/j.watres.2021.117324] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 04/30/2021] [Accepted: 05/30/2021] [Indexed: 06/13/2023]
Abstract
With two thirds of the global population living in areas affected by water scarcity, wastewater reuse is actively being implemented or explored by many nations. There is a need to better understand the efficacy of recycled water treatment plants (RWTPs) for removal of human opportunistic pathogens and antimicrobial resistant microorganisms. Here, we used a suite of probe-based multiplex and SYBR green real-time PCR assays to monitor enteric opportunistic pathogens (EOPs; Acinetobacter baumannii, Arcobacter butzlieri, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Legionella spp., Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Enteritidis, Streptococcus spp.) and antimicrobial resistance genes (ARGs; qnrS, blaSHV, blaTEM, blaGES, blaKPC, blaIMI, blaSME, blaNDM, blaVIM, blaIMP, blaOXA-48-like, mcr-1 and mcr-3) of key concern from an antimicrobial resistance (AMR), waterborne and foodborne disease perspective. The class 1 integron-integrase gene (intl1) was quantified as a proxy for multi-drug resistance. EOPs, intl1 and ARGs absolute abundance (DNA and RNA) and metabolic activity (RNA) was assessed through three RWTPs with differing treatment trains. Our results indicate that RWTPs produced high quality recycled water for non-potable reuse by removing >95% of EOPs and ARGs, however, subpopulations of EOPs and ARGs survived disinfection and demonstrated potential to become actively growing members of the recycled water and distribution system microbiomes. The persistence of functional intl1 suggests that significant genetic recombination capacity remains in the recycled water, along with the likely presence of multi-drug resistant bacteria. Results provide new insights into the persistence and growth of EOPs, and prevalence and removal of ARGs in recycled water systems. These data will contribute towards the emerging evidence base of AMR risks in recycled water to inform quantitative risk-based policy development regarding water recycling schemes.
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Affiliation(s)
- Barbara Drigo
- Future Industries Institute, University of South Australia, Adelaide, SA 5001, Australia.
| | - Gianluca Brunetti
- Future Industries Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Samuel C Aleer
- Future Industries Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Jan M Bell
- Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Michael D Short
- Future Industries Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Sotirios Vasileiadis
- Laboratory of Plant and Environmental Biotechnology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - John Turnidge
- Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Paul Monis
- South Australian Water Corporation, Adelaide, SA 5000, Australia; Future Industries Institute and ARC Centre of Excellence for Convergent Bio and Nano Science, University of South Australia, Adelaide, SA 5095, Australia
| | - David Cunliffe
- Department for Health and Wellbeing, Adelaide, 5000, South Australia, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Adelaide, SA 5001, Australia
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32
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The role of Acanthamoeba spp. in biofilm communities: a systematic review. Parasitol Res 2021; 120:2717-2729. [PMID: 34292376 DOI: 10.1007/s00436-021-07240-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/01/2021] [Indexed: 12/16/2022]
Abstract
Acanthamoeba spp. have always caused disease in immunosuppressed patients, but since 1986, they have become a worldwide public health issue by causing infection in healthy contact lens wearers. Amoebae of the Acanthamoeba genus are broadly distributed in nature, living either freely or as parasites, and are frequently associated with biofilms throughout the environment. These biofilms provide the parasite with protection against external aggression, thus favoring its increased pathogeny. This review aims to assess observational studies on the association between Acanthamoeba spp. and biofilms, opening potential lines of research on this severe ocular infection. A systematic literature search was conducted in May 2020 in the following databases: PubMed Central®/Medline, LILACS, The Cochrane Library, and EMBASE®. The studies were selected following the inclusion and exclusion criteria specifically defined for this review. Electronic research recovered 353 publications in the literature. However, none of the studies met the inclusion criterion of biofilm-producing Acanthamoeba spp., inferring that the parasite does not produce biofilms. Nonetheless, 78 studies were classified as potentially included regarding any association of Acanthamoeba spp. and biofilms. These studies were allocated across six different locations (hospital, aquatic, ophthalmic and dental environments, biofilms produced by bacteria, and other places). Acanthamoeba species use biofilms produced by other microorganisms for their benefit, in addition to them providing protection to and facilitating the dissemination of pathogens residing in them.
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33
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Jin C, Zhao L, Zhao W, Wang L, Zhu S, Xiao Z, Mo Y, Zhang M, Shu L, Qiu R. Transport and Retention of Free-Living Amoeba Spores in Porous Media: Effects of Operational Parameters and Extracellular Polymeric Substances. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8709-8720. [PMID: 34138552 DOI: 10.1021/acs.est.1c00785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Amoebas are protists that are widespread in water and soil environments. Some species are pathogenic, inducing potentially lethal effects on humans, making them a major threat to public health. Nonpathogenic amoebas are also of concern because they have the potential to carry a mini-microbiome of bacteria, either transiently or via more long-term stable transport. Due to their resistance to disinfection processes, the physical removal of amoeba by filtration is necessary to prevent their propagation throughout drinking water distribution networks and occurrence in tap water. In this study, a model amoeba species Dictyostelium discoideum was used to study the transport and retention behavior of amoeba spores in porous media. The key factors affecting the transport behavior of amoeba spores in fully saturated media were comprehensively evaluated, with experiments performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and parallel plate chamber system. The effects of ionic strength (IS) on the deposition of spores were found to be in contrast to the predicted Derjaguin-Landau-Verwey-Overbeek (DLVO) theory that more deposition is observed under lower-IS conditions. The presence of extracellular polymeric substances (EPS) was found to be the main contributor to deposition behavior. Overall, these results provide plausible evidence for the presence of amoeba in tap water. Furthermore, this is one of the first studies to examine the mechanisms affecting the fate of amoeba spores in porous media, providing a significant baseline for future research to minimize the safety risk presented by amoeba in drinking water systems.
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Affiliation(s)
- Chao Jin
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Lingan Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Weigao Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Department of Environmental Engineering, Tianjin University, Tianjin 300072, China
| | - Luting Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Shishu Zhu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zihan Xiao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yijun Mo
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Miaoyue Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Longfei Shu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
- Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
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34
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Causes, Factors, and Control Measures of Opportunistic Premise Plumbing Pathogens—A Critical Review. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11104474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review critically analyses the chemical and physical parameters that influence the occurrence of opportunistic pathogens in the drinking water distribution system, specifically in premise plumbing. A comprehensive literature review reveals significant impacts of water age, disinfectant residual (type and concentration), temperature, pH, and pipe materials. Evidence suggests that there is substantial interplay between these parameters; however, the dynamics of such relationships is yet to be elucidated. There is a correlation between premise plumbing system characteristics, including those featuring water and energy conservation measures, and increased water quality issues and public health concerns. Other interconnected issues exacerbated by high water age, such as disinfectant decay and reduced corrosion control efficiency, deserve closer attention. Some common features and trends in the occurrence of opportunistic pathogens have been identified through a thorough analysis of the available literature. It is proposed that the efforts to reduce or eliminate their incidence might best focus on these common features.
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35
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Li Q, Yu S, Yang S, Yang W, Que S, Li W, Qin Y, Yu W, Jiang H, Zhao D. Eukaryotic community diversity and pathogenic eukaryotes in a full-scale drinking water treatment plant determined by 18S rRNA and metagenomic sequencing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:17417-17430. [PMID: 33394404 DOI: 10.1007/s11356-020-12079-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
In this study, 18S rRNA high-throughput sequencing was applied to investigate the eukaryotic community in a full-scale drinking water treatment plant. Eukaryotic species and microbial functions in raw water and filter biofilms were identified by metagenomic sequencing. The eukaryotic species richness and diversity presented declining trends throughout the treatment process. The lowest eukaryotic species richness was observed in disinfected water. Arthropoda, Ciliophora, Ochrophyta, and Rotifera were the dominant eukaryotic phyla and exhibited high variations in relative abundance among the different treatment units. Sedimentation significantly decreased the abundance of all eukaryotes except Arthropoda. Biological activated carbon (BAC) filtration and chlorine disinfection exerted strong effects on community composition. The eukaryotic communities in water were distinct from those in filter biofilms, as were the communities of different filter biofilms from each other. In contrast, communities were functionally similar among different filter biofilms, with the category metabolism being the dominant category represented, within which amino acid transport and metabolism (E) and energy production and conversion (C) dominated among subcategories. Seventy-one eukaryotic species pathogenic to humans were identified in raw water and filter biofilms. Quantitative PCR (qPCR) results showed that Acanthamoeba spp. and Vermamoeba vermiformis were present during some treatment processes, with concentrations of 12-1.2 × 105 copies/mL and 1 copy/mL, respectively. Neither of the two pathogenic amoebae was found in disinfected water. Canonical correspondence analysis (CCA) showed that pH was the most important environmental factor affecting eukaryotic community composition. Overall, the results provide insights into the eukaryotic community diversity in drinking water treatment plants and the potential eukaryotic hazards involved in drinking water production.
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Affiliation(s)
- Qi Li
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China.
| | - Shuili Yu
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Shengfa Yang
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Wei Yang
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Sisi Que
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Wenjie Li
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Yu Qin
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Weiwei Yu
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Hui Jiang
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Deqiang Zhao
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
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36
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Dey R, Rieger A, Banting G, Ashbolt NJ. Role of amoebae for survival and recovery of 'non-culturable' Helicobacter pylori cells in aquatic environments. FEMS Microbiol Ecol 2021; 96:5902844. [PMID: 32897313 PMCID: PMC7494403 DOI: 10.1093/femsec/fiaa182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori is a fastidious Gram-negative bacterium that infects over half of the world's population, causing chronic gastritis and is a risk factor for stomach cancer. In developing and rural regions where prevalence rate exceeds 60%, persistence and waterborne transmission are often linked to poor sanitation conditions. Here we demonstrate that H. pylori not only survives but also replicates within acidified free-living amoebal phagosomes. Bacterial counts of the clinical isolate H. pylori G27 increased over 50-fold after three days in co-culture with amoebae. In contrast, a H. pylori mutant deficient in a cagPAI gene (cagE) showed little growth within amoebae, demonstrating the likely importance of a type IV secretion system in H. pylori for amoebal infection. We also demonstrate that H. pylori can be packaged by amoebae and released in extracellular vesicles. Furthermore, and for the first time, we successfully demonstrate the ability of two free-living amoebae to revert and recover viable but non-cultivable coccoid (VBNC)-H. pylori to a culturable state. Our studies provide evidence to support the hypothesis that amoebae and perhaps other free-living protozoa contribute to the replication and persistence of human-pathogenic H. pylori by providing a protected intracellular microenvironment for this pathogen to persist in natural aquatic environments and engineered water systems, thereby H. pylori potentially uses amoeba as a carrier and a vector of transmission.
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Affiliation(s)
- Rafik Dey
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada.,Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Aja Rieger
- Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Graham Banting
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta,11405-87 Avenue, Edmonton, Alberta T6G 1C9, Canada.,Deparment of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.,Provincial Laboratory for Public Health (ProvLab), Alberta Health Services, Edmonton, Canada.,School of Environmental, Sciense and Engineering, Southern Cross University, Lismore NSW, Australia
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37
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Shaheen M, Ashbolt NJ. Differential Bacterial Predation by Free-Living Amoebae May Result in Blooms of Legionella in Drinking Water Systems. Microorganisms 2021; 9:microorganisms9010174. [PMID: 33467483 PMCID: PMC7829821 DOI: 10.3390/microorganisms9010174] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/05/2021] [Accepted: 01/12/2021] [Indexed: 11/17/2022] Open
Abstract
Intracellular growth of pathogenic Legionella in free-living amoebae (FLA) results in the critical concentrations that are problematic in engineered water systems (EWS). However, being amoeba-resistant bacteria (ARB), how Legionella spp. becomes internalized within FLA is still poorly understood. Using fluorescent microscopy, we investigated in real-time the preferential feeding behavior of three water-related FLA species, Willaertia magna, Acanthamoeba polyphaga, and Vermamoeba vermiformis regarding Legionella pneumophila and two Escherichia coli strains. Although all the studied FLA species supported intracellular growth of L. pneumophila, they avoided this bacterium to a certain degree in the presence of E. coli and mostly fed on it when the preferred bacterial food-sources were limited. Moreover, once L. pneumophila were intracellular, it inhibited digestion of co-occurring E. coli within the same trophozoites. Altogether, based on FLA–bacteria interactions and the shifts in microbial population dynamics, we propose that FLA’s feeding preference leads to an initial growth of FLA and depletion of prey bacteria, thus increases the relative abundance of Legionella and creates a “forced-feeding” condition facilitating the internalization of Legionella into FLA to initiate the cycles of intracellular multiplication. These findings imply that monitoring of FLA levels in EWS could be useful in predicting possible imminent high occurrence of Legionella.
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Affiliation(s)
- Mohamed Shaheen
- School of Public Health, University of Alberta, Edmonton, AB T6G 1C9, Canada;
| | - Nicholas J. Ashbolt
- School of Environment, Science & Engineering, Southern Cross University, Lismore Campus, PO Box 157, Lismore, NSW 2480, Australia
- Correspondence:
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Abstract
Amoebae are protists that have complicated relationships with bacteria, covering the whole spectrum of symbiosis. Amoeba-bacterium interactions contribute to the study of predation, symbiosis, pathogenesis, and human health. Given the complexity of their relationships, it is necessary to understand the ecology and evolution of their interactions. In this paper, we provide an updated review of the current understanding of amoeba-bacterium interactions. We start by discussing the diversity of amoebae and their bacterial partners. We also define three types of ecological interactions between amoebae and bacteria and discuss their different outcomes. Finally, we focus on the implications of amoeba-bacterium interactions on human health, horizontal gene transfer, drinking water safety, and the evolution of symbiosis. In conclusion, amoeba-bacterium interactions are excellent model systems to investigate a wide range of scientific questions. Future studies should utilize advanced techniques to address research gaps, such as detecting hidden diversity, lack of amoeba genomes, and the impacts of amoeba predation on the microbiome.
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Dean K, Tamrakar S, Huang Y, Rose JB, Mitchell J. Modeling the Dose Response Relationship of Waterborne Acanthamoeba. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2021; 41:79-91. [PMID: 33047815 DOI: 10.1111/risa.13603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/30/2020] [Accepted: 07/26/2020] [Indexed: 06/11/2023]
Abstract
This study developed dose response models for determining the probability of eye or central nervous system infections from previously conducted studies using different strains of Acanthamoeba spp. The data were a result of animal experiments using mice and rats exposed corneally and intranasally to the pathogens. The corneal inoculations of Acanthamoeba isolate Ac 118 included varied amounts of Corynebacterium xerosis and were best fit by the exponential model. Virulence increased with higher levels of C. xerosis. The Acanthamoeba culbertsoni intranasal study with death as an endpoint of response was best fit by the beta-Poisson model. The HN-3 strain of A. castellanii was studied with an intranasal exposure and three different endpoints of response. For all three studies, the exponential model was the best fit. A model based on pooling data sets of the intranasal exposure and death endpoint resulted in an LD50 of 19,357 amebae. The dose response models developed in this study are an important step towards characterizing the risk associated with free-living amoeba like Acanthamoeba in drinking water distribution systems. Understanding the human health risk posed by free-living amoeba will allow for quantitative microbial risk assessments that support building design decisions to minimize opportunities for pathogen growth and survival.
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Affiliation(s)
- Kara Dean
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI, USA
| | - Sushil Tamrakar
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
- Freelancer
| | - Yin Huang
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
- Current address: Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Joan B Rose
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
| | - Jade Mitchell
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI, USA
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40
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Ohkouchi Y, Ase T. Determination of log removal values of bacteria by spiral-wound reverse osmosis modules and a hollow fiber ultrafiltration module using Escherichia coli and indigenous heterotrophic bacteria as indicators. JOURNAL OF WATER AND HEALTH 2020; 18:956-967. [PMID: 33328367 DOI: 10.2166/wh.2020.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The use of reverse osmosis (RO) membranes has been expanding not only to medical applications but also to water supply and reclaimed water applications due to its strong ability to remove a wide range of contaminants. Many researchers reported RO performance as a barrier against waterborne viruses; however, there are limited reports on its ability to remove bacteria from water. This investigation evaluated the removal performances of several spiral-wound RO modules and a hollow fiber ultrafiltration (UF) module in two different ways: dosing tests in batch-wise mode operation and in continuous-mode operation. The dosing tests of Escherichia coli using RO modules confirmed that E. coli could leak from the feed-side into the permeate. The log removal values (LRVs) (4.21- to >7.44-log10) by the RO modules from different production lots were found to vary greatly. In continuous-mode operation of the RO module, the LRVs for indigenous heterotrophic bacteria decreased over the operation period. These results clearly illustrate that bacteria, which originate on the feed-side, can leak into the permeate-side and then begin to proliferate in the permeate. On the other hand, using a UF module, E. coli was not detected in the permeate regardless of the operation mode.
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Affiliation(s)
- Yumiko Ohkouchi
- Department of Environmental Science, School of Life and Environmental Science, Azabu University, Fuchinobe 1-17-71, Chuo-ku, Sagamihara, 252-5201 Kanagawa, Japan E-mail:
| | - Tomonobu Ase
- Medical Division, Daicen Membrane-Systems Ltd, JR Shinagawa East Building 14F, Konan 2-18-1, Minato-ku, 108-8230 Tokyo, Japan; † Present address: Technology Management Division, Chuou Sekkei Engineering Co., Ltd, Yokohama Bashamichi Bldg.,4-55 Otamachi, Naka-ku, Yokohama, 231-0011 Kanagawa, Japan
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Cullom AC, Martin RL, Song Y, Williams K, Williams A, Pruden A, Edwards MA. Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens. Pathogens 2020; 9:E957. [PMID: 33212943 PMCID: PMC7698398 DOI: 10.3390/pathogens9110957] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022] Open
Abstract
Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper's interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.
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Affiliation(s)
- Abraham C. Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Rebekah L. Martin
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
- Civil and Environmental Engineering, Virginia Military Institute, Lexington, VA 24450, USA
| | - Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | | | - Amanda Williams
- c/o Marc Edwards, Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
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42
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Moreno-Mesonero L, Ferrús MA, Moreno Y. Determination of the bacterial microbiome of free-living amoebae isolated from wastewater by 16S rRNA amplicon-based sequencing. ENVIRONMENTAL RESEARCH 2020; 190:109987. [PMID: 32771367 DOI: 10.1016/j.envres.2020.109987] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Free-living amoebae (FLA) are ubiquitous protozoa commonly found in water. FLA are well-established hosts for amoeba-resistant bacteria, most of which are pathogenic, and offer them shelter from adverse environmental conditions or water treatments. Since there is very little knowledge about the complete bacterial microbiome of FLA, in this work the bacterial microbiome of FLA isolated from wastewater both after secondary and tertiary treatments was studied by amplicon-based sequencing. FLA were detected in 87.5% and 50.0% of wastewater samples taken after secondary and tertiary disinfection treatments, respectively. The most abundant bacterial phyla were Proteobacteria, Planctomycetes, Bacteroidetes and Firmicutes, which represented 83.77% of the total bacterial FLA microbiome. The most abundant class of bacteria was Gammaproteobacteria, which contains an important number of relevant pathogenic bacteria. The bacteria of public health concern Aeromonas, Arcobacter, Campylobacter, Helicobacter, Klebsiella, Legionella, Mycobacterium, Pseudomonas and Salmonella were detected as part of the FLA microbiome. Although different microbial communities were identified in each sample, there is no correlation between the microbiome of FLA and the extent of wastewater treatment. To our knowledge, this is the first work in which the bacterial microbiome of FLA isolated from wastewater is studied. Obtained results indicate that FLA are hosts of potentially pathogenic bacteria in treated wastewater used for irrigation, which may pose a public health threat.
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Affiliation(s)
- Laura Moreno-Mesonero
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, 46022, Valencia, Spain.
| | - María Antonia Ferrús
- Biotechnology Department, Universitat Politècnica de València, 46022, Valencia, Spain.
| | - Yolanda Moreno
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, 46022, Valencia, Spain.
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43
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Miyazaki D, Eguchi H, Kuwahara T, Nakayama-Imaohji H, Inaba M, Itoi M, Ueda K, Ohashi Y, Sado K, Mizutani S, Miyamoto H, Sasaki SI, Shimizu Y, Inoue Y. Presence of Acanthamoeba and diversified bacterial flora in poorly maintained contact lens cases. Sci Rep 2020; 10:12595. [PMID: 32724150 PMCID: PMC7387515 DOI: 10.1038/s41598-020-69554-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/08/2020] [Indexed: 01/11/2023] Open
Abstract
Acanthamoeba can cause visually destructive Acanthamoeba keratitis (AK) in contact lens (CL) users. The purpose of this study was to determine whether Acanthamoeba was present in the CL cases of CL wearers and to develop techniques to prevent the contaminations. To accomplish this, 512 CL case samples were collected from 305 healthy CL wearers. Using real-time PCR, Acanthamoeba DNA was detected in 19.1% of CL cases, however their presence was not directly associated with poor CL case care. Instead, the presence of Acanthamoeba DNA was associated with significant levels of many different bacterial species. When the CL cases underwent metagenomic analysis, the most abundant bacterial orders were Enterobacteriales followed by Burkholderiales, Pseudomonadales, and Flavobacteriales. The presence of Acanthamoeba was characterized by Propionibacterium acnes and Rothia aeria and was also associated with an increase in the α diversity. Collectively, Acanthamoeba contamination occurs when a diversified bacterial flora is present in CL cases. This can effectively be prevented by careful and thorough CL case care.
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Affiliation(s)
- Dai Miyazaki
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan.
| | - Hiroshi Eguchi
- Department of Ophthalmology, Faculty of Medicine, Kindai University, Higashiōsaka, Japan
| | - Tomomi Kuwahara
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | - Haruyuki Nakayama-Imaohji
- Department of Microbiology, Faculty of Medicine, Kagawa University, 1750-1 Miki, Kagawa, 761-0793, Japan
| | | | - Motozumi Itoi
- Dougenzaka Itoi Eye Clinic, Dogenzaka Shibuya-ku, Tokyo, Japan
| | - Kiichi Ueda
- Ueda Eye Clinic, Shimonoseki, Yamaguchi, Japan
| | - Yuichi Ohashi
- School of Medicine, Faculty of Medicine, Ehime University, Matsuyama, Japan
| | | | | | - Hitoshi Miyamoto
- Department of Clinical Laboratory, Ehime University Hospital, Matsuyama, Japan
| | - Shin-Ichi Sasaki
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan
| | - Yumiko Shimizu
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan
| | - Yoshitsugu Inoue
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan
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Bugge Harder C, Nyrop Albers C, Rosendahl S, Aamand J, Ellegaard-Jensen L, Ekelund F. Successional trophic complexity and biogeographical structure of eukaryotic communities in waterworks' rapid sand filters. FEMS Microbiol Ecol 2020; 95:5569652. [PMID: 31518408 DOI: 10.1093/femsec/fiz148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
As groundwater-fed waterworks clean their raw inlet water with sand filters, a variety of pro- and eukaryotic microbial communities develop on these filters. While several studies have targeted the prokaryotic sand filter communities, little is known about the eukaryotic communities, despite the obvious need for knowledge of microorganisms that get in contact with human drinking water. With a new general eukaryotic primer set (18S, V1-V3 region), we performed FLX-454 sequencing of material from 21 waterworks' sand filters varying in age (3-40 years) and geographical location on a 250 km east-west axis in Denmark, and put the data in context of their previously published prokaryotic communities. We find that filters vary highly in trophic complexity depending on age, from simple systems with bacteria and protozoa (3-6 years) to complex, mature systems with nematodes, rotifers and turbellarians as apex predators (40 years). Unlike the bacterial communities, the eukaryotic communities display a clear distance-decay relationship that predominates over environmental variations, indicating that the underlying aquifers feeding the filters harbor distinct eukaryotic communities with limited dispersal in between. Our findings have implications for waterworks' filter management, and offer a window down to the largely unexplored eukaryotic microbiology of groundwater aquifers.
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Affiliation(s)
- Christoffer Bugge Harder
- Department of Biology, Copenhagen University, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark.,Department of Biology, Microbial Ecology Group, Lund University, Ecology Building, Solvegatan 37, SE 223-62, Lund, Sweden.,Department of Plant and Soil Science, Texas Tech University, Bayer Plant Science Building, 2911 15th Street, Lubbock, TX 79409, USA
| | - Christian Nyrop Albers
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Ø Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Søren Rosendahl
- Department of Biology, Copenhagen University, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark
| | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Ø Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Lea Ellegaard-Jensen
- Department of Geochemistry, Geological Survey of Denmark & Greenland, Ø Voldgade 10, DK-1350, Copenhagen, Denmark.,Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Flemming Ekelund
- Department of Biology, Copenhagen University, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark
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45
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Cartography of Free-Living Amoebae in Soil in Guadeloupe (French West Indies) Using DNA Metabarcoding. Pathogens 2020; 9:pathogens9060440. [PMID: 32512696 PMCID: PMC7350318 DOI: 10.3390/pathogens9060440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/02/2020] [Accepted: 05/03/2020] [Indexed: 12/20/2022] Open
Abstract
Free-living amoebae (FLA) are ubiquitous protists. Pathogenic FLA such as N. fowleri can be found in hot springs in Guadeloupe, soil being the origin of this contamination. Herein, we analyzed the diversity and distribution of FLA in soil using a targeted metataxonomic analysis. Soil samples (n = 107) were collected from 40 sites. DNA was extracted directly from soil samples or from FLA cultivated at different temperatures (30, 37 and 44 °C). Metabarcoding studies were then conducted through FLA 18SrDNA amplicons sequencing; amplicon sequence variants (ASV) were extracted from each sample and taxonomy assigned against SILVA database using QIIME2 and SHAMAN pipelines. Vermamoeba were detected in DNA extracted directly from the soil, but to detect other FLA an amoebal enrichment step was necessary. V. vermiformis was by far the most represented species of FLA, being detected throughout the islands. Although Naegleria were mainly found in Basse-Terre region, N. fowleri was also detected in Grand Terre and Les Saintes Islands. Acanthamoeba were mainly found in areas where temperature is approx. 30 °C. Vannella and Vahlkampfia were randomly found in Guadeloupe islands. FLA detected in Guadeloupe include both pathogenic genera and genera that can putatively harbor microbial pathogens, therefore posing a potential threat to human health.
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46
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Zhao L, Liu YW, Li N, Fan XY, Li X. Response of bacterial regrowth, abundant and rare bacteria and potential pathogens to secondary chlorination in secondary water supply system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 719:137499. [PMID: 32120107 DOI: 10.1016/j.scitotenv.2020.137499] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 06/10/2023]
Abstract
This study investigated the effects of secondary chlorination on bacterial regrowth, microbial communities (abundant and rare taxa) and bacterial functions of pipe wall biofilm and bulk water in simulated secondary water supply system (SWSS). Continuous secondary chlorination was more effective than short-term secondary chlorination to control the bacterial regrowth in both biofilm and water samples. Bacterial diversity slightly reduced after continuous secondary chlorination, and 19.27% of the total operational taxonomic units (OTUs) were shared by biofilm and water samples, with Bacillus as the dominant genus. Abundant and rare taxa exhibited different community structures. Proteobacteria and candidate division WPS-1 predominated in abundant and rare phyla were sensitive to chlorine, while Firmicutes, Acidobacteria and Bacteroidetes, exhibited relative strong chlorine resistance. The abundant genera in control sample (e.g., Bosea, Sphingobium and Gemmata) exhibited poor tolerance to chlorine, while Bacillus in biofilm and Defluviimonas in water were the main chlorine-resistant genera. Moreover, the composition of rare genera in each sample was obviously different. Furthermore, a total of 18 potential pathogens were detected with Pseudomonas as the dominant genus, most of which were significantly reduced after disinfection. There were mainly positive interactions among potential pathogenic bacteria, with Enterococcus, Legionella and Vibrio as the hub genera as revealed by network analysis. Similar bacterial functions in both biofilm and water were observed with metabolism as the predominant bacterial function, while, human disease function only accounted for 1.07% of bacterial functions. These results highlighted the importance of continuous secondary chlorination for controlling biosafety of SWSS and identified the dissimilar responses of abundant and rare bacteria to the disinfection, as well as the co-occurrence patterns among potential pathogens, improving our understanding of bacterial communities in SWSS.
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Affiliation(s)
- Li Zhao
- China Architecture Design and Research Group, Beijing 100044, PR China
| | - Yong-Wang Liu
- China Architecture Design and Research Group, Beijing 100044, PR China; College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, PR China.
| | - Na Li
- College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xiao-Yan Fan
- College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xing Li
- College of Architecture and Civil engineering, Beijing University of Technology, Beijing 100124, PR China
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47
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Nisar MA, Ross KE, Brown MH, Bentham R, Whiley H. Legionella pneumophila and Protozoan Hosts: Implications for the Control of Hospital and Potable Water Systems. Pathogens 2020; 9:pathogens9040286. [PMID: 32326561 PMCID: PMC7238060 DOI: 10.3390/pathogens9040286] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 12/12/2022] Open
Abstract
Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is the causative agent of Legionnaires’ disease (LD) and Pontiac fever and is ubiquitous in manufactured water systems, where protozoan hosts and complex microbial communities provide protection from disinfection procedures. This review collates the literature describing interactions between L. pneumophila and protozoan hosts in hospital and municipal potable water distribution systems. The effectiveness of currently available water disinfection protocols to control L. pneumophila and its protozoan hosts is explored. The studies identified in this systematic literature review demonstrated the failure of common disinfection procedures to achieve long term elimination of L. pneumophila and protozoan hosts from potable water. It has been demonstrated that protozoan hosts facilitate the intracellular replication and packaging of viable L. pneumophila in infectious vesicles; whereas, cyst-forming protozoans provide protection from prolonged environmental stress. Disinfection procedures and protozoan hosts also facilitate biogenesis of viable but non-culturable (VBNC) L. pneumophila which have been shown to be highly resistant to many water disinfection protocols. In conclusion, a better understanding of L. pneumophila-protozoan interactions and the structure of complex microbial biofilms is required for the improved management of L. pneumophila and the prevention of LD.
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48
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Retana Moreira L, Vargas Ramírez D, Linares F, Prescilla Ledezma A, Vaglio Garro A, Osuna A, Lorenzo Morales J, Abrahams Sandí E. Isolation of Acanthamoeba T5 from Water: Characterization of Its Pathogenic Potential, Including the Production of Extracellular Vesicles. Pathogens 2020; 9:pathogens9020144. [PMID: 32098034 PMCID: PMC7168589 DOI: 10.3390/pathogens9020144] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/12/2020] [Accepted: 02/19/2020] [Indexed: 12/12/2022] Open
Abstract
Acanthamoeba is a genus of free-living amoebae widely distributed in nature, associated with the development of encephalitis and keratitis. Despite the fact that it is common to find genotype T5 in environmental samples, only a few cases have been associated with clinical cases in humans. The wide distribution of Acanthamoeba, the characteristic of being amphizoic and the severity of the disease motivate researchers to focus on the isolation of these organisms, but also in demonstrating direct and indirect factors that could indicate a possible pathogenic potential. Here, we performed the characterization of the pathogenic potential of an Acanthamoeba T5 isolate collected from a water source in a hospital. Osmo- and thermotolerance, the secretion of proteases and the effect of trophozoites over cell monolayers were analyzed by different methodologies. Additionally, we confirm the secretion of extracellular vesicles (EVs) of this isolate incubated at two different temperatures, and the presence of serine and cysteine proteases in these vesicles. Finally, using atomic force microscopy, we determined some nanomechanical properties of the secreted vesicles and found a higher value of adhesion in the EVs obtained at 37 °C, which could have implications in the parasite´s survival and damaging potential in two different biological environments.
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Affiliation(s)
- Lissette Retana Moreira
- Departamento de Parasitología, Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
- Correspondence: (L.R.M.); (E.A.S.)
| | - Daniel Vargas Ramírez
- Departamento de Parasitología, Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
| | - Fátima Linares
- Centro de Instrumentación Científica (CIC), Universidad de Granada, Granada 18071, Spain;
| | - Alexa Prescilla Ledezma
- Departamento de Parasitología, Grupo de Bioquímica y Parasitología Molecular (CTS 183), Instituto de Biotecnología, Campus de Fuentenueva, Universidad de Granada, Granada 18071, Spain; (A.P.L.); (A.O.)
| | - Annette Vaglio Garro
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
| | - Antonio Osuna
- Departamento de Parasitología, Grupo de Bioquímica y Parasitología Molecular (CTS 183), Instituto de Biotecnología, Campus de Fuentenueva, Universidad de Granada, Granada 18071, Spain; (A.P.L.); (A.O.)
| | - Jacob Lorenzo Morales
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna, Tenerife, Islas Canarias 38203, Spain;
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad de La Laguna, Avda. Astrofísico Fco. Sánchez, S/N, La Laguna, Tenerife, Islas Canarias 38203, Spain
| | - Elizabeth Abrahams Sandí
- Departamento de Parasitología, Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San Pedro, Montes de Oca 2060, Costa Rica;
- Correspondence: (L.R.M.); (E.A.S.)
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49
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Gabriel AA, Panaligan DC. Heat and chlorine resistance of a soil Acanthamoeba sp. cysts in water. J Appl Microbiol 2020; 129:453-464. [PMID: 32012390 DOI: 10.1111/jam.14600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/28/2020] [Accepted: 01/28/2020] [Indexed: 12/24/2022]
Abstract
AIMS The study established the inactivation kinetic parameters of an Acanthamoeba cyst isolate subjected to heating and chlorination. METHODS AND RESULTS A strain of Acanthamoeba was isolated and purified from an area surrounding a pilot food plant. Mature cysts (14 days) were subjected to heat inactivation studies at 71, 76, 81, 86 and 91°C; and chlorination at 100, 200, 300, 400 and 500 ppm. The decimal reduction times (D-values) at 71, 76, 81, 86 and 91°C were 18·31, 9·26, 7·35, 4·52 and 1·81 min respectively. The calculated thermal resistance constant (z-value) was 21·32°C (R2 = 0·96-0·97). The D-value in 100, 200, 300, 400 and 500 ppm chlorine-treated water were 47·17, 25·06, 24·51, 23·70 and 18·55 min respectively. The chlorine resistance constant (z-value) was 1179 ppm chlorine (R2 = 0·65-0·74). CONCLUSIONS Results demonstrated high resistance of the isolated Acanthamoeba cysts towards the common methods applied in ensuring food and food processing environment sanitation. SIGNIFICANCE AND IMPACT OF THE STUDY The resistance parameters of the test organisms established in this study may be used in the establishment of Sanitation Standard Operating Procedures (SSOPs), which are often based on inactivation of bacteria. These SSOPs could render better protection to food and food processing environments.
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Affiliation(s)
- A A Gabriel
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Nutrition, College of Home Economics, University of the Philippines, Quezon City, Philippines
| | - D C Panaligan
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Nutrition, College of Home Economics, University of the Philippines, Quezon City, Philippines
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50
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Isaac TS, Sherchan SP. Molecular detection of opportunistic premise plumbing pathogens in rural Louisiana's drinking water distribution system. ENVIRONMENTAL RESEARCH 2020; 181:108847. [PMID: 31740037 DOI: 10.1016/j.envres.2019.108847] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 05/21/2023]
Abstract
Opportunistic premise plumbing pathogens (OPPPs) in drinking water distribution systems are responsible for causing numerous infections such as Legionnaires' disease and pneumonia through the consumption of contaminated drinking water. The incidence of opportunistic pathogens and the number of individuals at risk of contracting infections caused by these OPPPs in drinking water has risen drastically in the past decade. Preflush and postflush water samples were collected from 64 houses in a rural town in northeast Louisiana to determine drinking water quality in terms of understanding abiotic and biotic factors on potential proliferation of OPPPs. Physical and chemical water quality parameters, such as pH, temperature, dissolved oxygen, salinity, and specific conductance were also measured. The quantitative polymerase chain reaction (qPCR) results indicated that Legionella spp. had the highest prevalence and was found in 46/64 samples (72%), followed by Mycobacterium spp. which was found in 43/64 samples (67%), E. coli in 31/64 samples (48%) and, Naegleria fowleri in 4/64 samples (6%) respectively. The results indicate the persistence of Legionella spp. DNA marker in these water samples.
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Affiliation(s)
- Tanya S Isaac
- Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, 70112, USA
| | - Samendra P Sherchan
- Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, 70112, USA.
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