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Malinowski N, Morgan MJ, Wylie J, Walsh T, Domingos S, Metcalfe S, Kaksonen AH, Barnhart EP, Mueller R, Peyton BM, Puzon GJ. Prokaryotic microbial ecology as an ecosurveillance tool for eukaryotic pathogen colonisation: Meiothermus and Naegleria fowleri. WATER RESEARCH 2024; 254:121426. [PMID: 38471203 DOI: 10.1016/j.watres.2024.121426] [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: 11/28/2023] [Revised: 02/21/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024]
Abstract
Naegleria fowleri has been detected in drinking water distribution systems (DWDS) in Australia, Pakistan and the United States and is the causative agent of the highly fatal disease primary amoebic meningoencephalitis. Previous small scale field studies have shown that Meiothermus may be a potential biomarker for N. fowleri. However, correlations between predictive biomarkers in small sample sizes often breakdown when applied to larger more representative datasets. This study represents one of the largest and most rigorous temporal investigations of Naegleria fowleri colonisation in an operational DWDS in the world and measured the association of Meiothermus and N. fowleri over a significantly larger space and time in the DWDS. A total of 232 samples were collected from five sites over three-years (2016-2018), which contained 29 positive N. fowleri samples. Two specific operational taxonomic units assigned to M. chliarophilus and M. hypogaeus, were significantly associated with N. fowleri presence. Furthermore, inoculation experiments demonstrated that Meiothermus was required to support N. fowleri growth in field-collected biofilms. This validates Meiothermus as prospective biological tool to aid in the identification and surveillance of N. fowleri colonisable sites.
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Affiliation(s)
- Natalia Malinowski
- CSIRO Environment, Floreat Park, WA, Australia; Water Corporation of Western Australia, Leederville, WA, Australia
| | | | - Jason Wylie
- CSIRO Environment, Floreat Park, WA, Australia
| | - Tom Walsh
- CSIRO Environment, Canberra, ACT, Australia
| | - Sergio Domingos
- Water Corporation of Western Australia, Leederville, WA, Australia
| | | | | | - Elliott P Barnhart
- U.S. Geological Survey, Wyoming-Montana Water Science Center, Helena, Montana (MT), USA
| | - Rebecca Mueller
- Centre for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Brent M Peyton
- Centre for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
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da Silva TCB, Chaúque BJM, Benitez GB, Rott MB. Global prevalence of potentially pathogenic free-living amoebae in sewage and sewage-related environments-systematic review with meta-analysis. Parasitol Res 2024; 123:148. [PMID: 38433138 DOI: 10.1007/s00436-024-08164-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/14/2024] [Indexed: 03/05/2024]
Abstract
Free-living amoebae (FLA) include amphizoic microorganisms important in public health, widely isolated from air, water, and soil. However, its occurrence in sewage-related environments still needs to be systematically documented. This study summarizes the occurrence of FLA in sewage-related environments through a systematic review with meta-analysis. A total of 1983 scientific article were retrieved from different databases, of which 35 were selected and analyzed using a random effects forest plot model with a 95% confidence interval (IC). The pooled overall prevalence of FLA in sewage across 12 countries was 68.96% (95% IC = 58.5-79.42). Subgroup analysis indicates high prevalence in all environments analyzed, including sewage water from the sewage treatment plant (81.19%), treated sewage water (75.57%), sewage-contaminated water (67.70%), sediment contaminated by sewage (48.91%), and sewage water (47.84%). Prevalence values of Acanthamoeba spp., Hartmanella/Vermamoeba spp., and Naegleria spp. are 47.48%, 28.24%, and 16.69%, respectively. Analyzing the species level, the distribution is as follows: Acanthamoeba palestinensis (88%), A. castellanii (23.74%), A. astronyxis (19.18%), A. polyphaga (13.59%), A. culbertsoni (12.5%), A. stevensoni (8.33%), A. tubiashi (4.35%) and A. hatchetti (1.1%), Naegleria fowleri (28.4%), N. gruberi (25%), N. clarki (8.33%), N. australiensis (4.89%) and N. italica (4.29%), Hartmannella/Vermamoeba exundans (40%) and H.V. vermiform (32.61%). Overall, our findings indicate a high risk associated with sewage-related environments, as the prevalence of FLA, including pathogenic strains, is high, even in treated sewage water. The findings of this study may be valuable both for risk remediation actions against amoebic infections and for future research endeavors.
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Affiliation(s)
- Thaisla Cristiane Borella da Silva
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Rio Grande Do Sul, Brazil
| | - Beni Jequicene Mussengue Chaúque
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Rio Grande Do Sul, Brazil
- Postgraduate Program in Biological Sciences: Pharmacology and Therapeutics, UFRGS, Porto Alegre, Rio Grande Do Sul, Brazil
- Center of Studies in Science and Technology (NECET), Biology Course, Universidade Rovuma, Niassa Branch, Lichinga, Mozambique
| | - Guilherme Brittes Benitez
- Industrial and Systems Engineering Graduate Program, Polytechnic School, Pontifical Catholic University of Parana (PUCPR), Curitiba, Paraná, Brazil
| | - Marilise Brittes Rott
- Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Rio Grande Do Sul, Brazil.
- Laboratory 520, Department of Microbiology, Immunology and Parasitology, Institute of Basic Health Sciences, Department of Parasitology, Universidade Federal Do Rio Grande Do Sul, Ramiro Barcelos Street, Porto Alegre, Rio Grande Do Sul, N 2600, Brazil.
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Ward L, Sherchan SP. Surveillance of Naegleria fowleri in Louisiana's public water systems. JOURNAL OF WATER AND HEALTH 2023; 21:1627-1631. [PMID: 38017594 PMCID: wh_2023_040 DOI: 10.2166/wh.2023.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
The free-living amoeba Naegleria fowleri (Nf) inhabits soil and natural waters worldwide: it is thermophilic and thrives at temperatures up to 45 °C and in a multitude of environments. Three deaths in Louisiana were attributed to primary amoebic meningoencephalitis (PAM) caused by Nf infection in 2011 and 2013. Following these incidents, public water systems are now monitored for the presence of Nf in Louisiana. From 2014 to 2018, 29% (27/93) of samples collected showed positive for Nf and 68% (63/93) showed all thermophilic amoeba culture. Ten raw water sources and 17 distribution water systems tested positive. The year 2017 showed the highest number of samples with Nf (n = 10) followed by nine samples in 2015. As climate change increases surface water temperatures, continued testing for Nf prevalence will be an important facet of water monitoring and will need to extend into locations farther north than the current most common range.
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Affiliation(s)
- Lauren Ward
- Department of Environmental Health Sciences, Tulane University, New Orleans, LA, USA; Center of Research Excellence in Wastewater based Epidemiology, Morgan State University, Baltimore, MD, USA E-mail:
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, Tulane University, New Orleans, LA, USA; Center of Research Excellence in Wastewater based Epidemiology, Morgan State University, Baltimore, MD, USA
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Nadeem A, Malik IA, Afridi EK, Shariq F. Naegleria fowleri outbreak in Pakistan: unveiling the crisis and path to recovery. Front Public Health 2023; 11:1266400. [PMID: 37927850 PMCID: PMC10620794 DOI: 10.3389/fpubh.2023.1266400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/29/2023] [Indexed: 11/07/2023] Open
Abstract
The outbreak of Naegleria fowleri in Pakistan presents a significant public health concern due to its high fatality rate and limited treatment options. This review explores the impact of the outbreak on communities and the challenges faced in combating the disease. It evaluates available treatment options and highlights the need for early diagnosis and intervention. The study proposes recommendations to improve public health preparedness, including public awareness campaigns, enhanced healthcare infrastructure, and robust water surveillance systems. Collaboration between research institutions and public health organizations is emphasized to develop effective outbreak response strategies.
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Affiliation(s)
- Abdullah Nadeem
- Department of Medicine, Dow University of Health Sciences, Karachi, Pakistan
| | - Inshal Arshad Malik
- Department of Medicine, Jinnah Sindh Medical University, Karachi, Sindh, Pakistan
| | - Eesha Khan Afridi
- Department of Medicine, Jinnah Sindh Medical University, Karachi, Sindh, Pakistan
| | - Fariha Shariq
- Department of Medicine, Karachi Medical and Dental College, Karachi, Sindh, Pakistan
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Miko S, Cope JR, Hlavsa MC, Ali IKM, Brown TW, Collins JP, Greeley RD, Kahler AM, Moore KO, Roundtree AV, Roy S, Sanders LL, Shah V, Stuteville HD, Mattioli MC. A Case of Primary Amebic Meningoencephalitis Associated with Surfing at an Artificial Surf Venue: Environmental Investigation. ACS ES&T WATER 2023; 3:1126-1133. [PMID: 37213412 PMCID: PMC10193442 DOI: 10.1021/acsestwater.2c00592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. In September 2018, a 29-year-old man died of PAM after traveling to Texas. We conducted an epidemiologic and environmental investigation to identify the water exposure associated with this PAM case. The patient's most probable water exposure occurred while surfing in an artificial surf venue. The surf venue water was not filtered or recirculated; water disinfection and water quality testing were not documented. N. fowleri and thermophilic amebae were detected in recreational water and sediment samples throughout the facility. Codes and standards for treated recreational water venues open to the public could be developed to address these novel venues. Clinicians and public health officials should also consider novel recreational water venues as a potential exposure for this rare amebic infection.
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Affiliation(s)
- Shanna Miko
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Jennifer R. Cope
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Michele C. Hlavsa
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Ibne Karim M. Ali
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Travis W. Brown
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Jennifer P. Collins
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | | | - Amy M. Kahler
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Kathleen O. Moore
- Texas Department of State Health Services, P.O. Box 149347, Austin, TX 78714-9347
| | - Alexis V. Roundtree
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
- Chenega Enterprise System & Solutions, 609 Independence Parkway Suite 210, Chesapeake, VA 23320
| | - Shantanu Roy
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
| | - Lacey L. Sanders
- Waco-McLennan County Public Health District; 225 W Waco Dr, Waco, TX 76707
| | - Vaidehi Shah
- Waco-McLennan County Public Health District; 225 W Waco Dr, Waco, TX 76707
| | - Haylea D. Stuteville
- Texas Department of State Health Services, P.O. Box 149347, Austin, TX 78714-9347
| | - Mia C. Mattioli
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30333
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Ultraviolet – Chlorine combined treatment efficiency to eliminate Naegleria fowleri in artificial surf lagoons. Heliyon 2022; 8:e11625. [PMID: 36439712 PMCID: PMC9691874 DOI: 10.1016/j.heliyon.2022.e11625] [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: 05/11/2022] [Revised: 07/14/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022] Open
Abstract
Naegleria. fowleri, a protozoa belonging to the free-living amoeba group, is the causative agent of a central nervous system affecting disease that is fatal in more than the 95% of the reported cases. This parasite can be found in warm water bodies such as lakes, rivers or inadequately disinfected swimming pools. On the other hand, chlorination and UV light treatment are two of the most extensively used disinfection methods in recreational water facilities. In this study the effect of chlorination and UV light on N. fowleri trophozoites was studied in a close water circuit with the aim to assess the efficacy of this disinfection methods in large pools. The obtained results showed that the chlorination was able to decrease the number of viable cells despite the elimination was not totally achieved. Nonetheless, the combination of the UV light with the chlorination allowed the complete removal of the N. fowleri trophozoites from the water in experimental testing conditions. Absence of an standardized water treatment protocol to eliminate N. fowleri. Treatment based only on chlorine was ineffective to eliminate N. fowleri. Combined chlorination and UV light treatment was effective to completely eliminate N.fowleri. Combination of chlorine - Uv would be a promising method for water disinfection.
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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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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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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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Herman EK, Greninger A, van der Giezen M, Ginger ML, Ramirez-Macias I, Miller HC, Morgan MJ, Tsaousis AD, Velle K, Vargová R, Záhonová K, Najle SR, MacIntyre G, Muller N, Wittwer M, Zysset-Burri DC, Eliáš M, Slamovits CH, Weirauch MT, Fritz-Laylin L, Marciano-Cabral F, Puzon GJ, Walsh T, Chiu C, Dacks JB. Genomics and transcriptomics yields a system-level view of the biology of the pathogen Naegleria fowleri. BMC Biol 2021; 19:142. [PMID: 34294116 PMCID: PMC8296547 DOI: 10.1186/s12915-021-01078-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 06/24/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The opportunistic pathogen Naegleria fowleri establishes infection in the human brain, killing almost invariably within 2 weeks. The amoeba performs piece-meal ingestion, or trogocytosis, of brain material causing direct tissue damage and massive inflammation. The cellular basis distinguishing N. fowleri from other Naegleria species, which are all non-pathogenic, is not known. Yet, with the geographic range of N. fowleri advancing, potentially due to climate change, understanding how this pathogen invades and kills is both important and timely. RESULTS Here, we report an -omics approach to understanding N. fowleri biology and infection at the system level. We sequenced two new strains of N. fowleri and performed a transcriptomic analysis of low- versus high-pathogenicity N. fowleri cultured in a mouse infection model. Comparative analysis provides an in-depth assessment of encoded protein complement between strains, finding high conservation. Molecular evolutionary analyses of multiple diverse cellular systems demonstrate that the N. fowleri genome encodes a similarly complete cellular repertoire to that found in free-living N. gruberi. From transcriptomics, neither stress responses nor traits conferred from lateral gene transfer are suggested as critical for pathogenicity. By contrast, cellular systems such as proteases, lysosomal machinery, and motility, together with metabolic reprogramming and novel N. fowleri proteins, are all implicated in facilitating pathogenicity within the host. Upregulation in mouse-passaged N. fowleri of genes associated with glutamate metabolism and ammonia transport suggests adaptation to available carbon sources in the central nervous system. CONCLUSIONS In-depth analysis of Naegleria genomes and transcriptomes provides a model of cellular systems involved in opportunistic pathogenicity, uncovering new angles to understanding the biology of a rare but highly fatal pathogen.
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Affiliation(s)
- Emily K Herman
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
| | - Alex Greninger
- Laboratory Medicine and Medicine / Infectious Diseases, UCSF-Abbott Viral Diagnostics and Discovery Center, UCSF Clinical Microbiology Laboratory UCSF School of Medicine, San Francisco, USA
- Department of Laboratory Medicine, University of Washington Medical Center, Montlake, USA
| | - Mark van der Giezen
- Centre for Organelle Research, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway
| | - Michael L Ginger
- School of Applied Sciences, Department of Biological and Geographical Sciences, University of Huddersfield, Huddersfield, UK
| | - Inmaculada Ramirez-Macias
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Department of Cardiology, Hospital Clinico Universitario Virgen de la Arrixaca. Instituto Murciano de Investigación Biosanitaria. Centro de Investigación Biomedica en Red-Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Haylea C Miller
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No.5, Wembley, Western Australia 6913, Australia
- CSIRO, Indian Oceans Marine Research Centre, Environomics Future Science Platform, Crawley, WA, Australia
| | - Matthew J Morgan
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | | | - Katrina Velle
- Department of Biology, University of Massachusetts, Amherst, UK
| | - Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Kristína Záhonová
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Sebastian Rodrigo Najle
- Institut de Biologia Evolutiva (UPF-CSIC), Barcelona, Spain
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), 08003, Barcelona, Catalonia, Spain
| | - Georgina MacIntyre
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Norbert Muller
- Institute of Parasitology, Vetsuisse Faculty Bern, University of Bern, Bern, Switzerland
| | - Mattias Wittwer
- Spiez Laboratory, Federal Office for Civil Protection, Austrasse, Spiez, Switzerland
| | - Denise C Zysset-Burri
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Claudio H Slamovits
- Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Canada
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology and Divisions of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, USA
| | | | - Francine Marciano-Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Geoffrey J Puzon
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No.5, Wembley, Western Australia 6913, Australia
| | - Tom Walsh
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | - Charles Chiu
- Laboratory Medicine and Medicine / Infectious Diseases, UCSF-Abbott Viral Diagnostics and Discovery Center, UCSF Clinical Microbiology Laboratory UCSF School of Medicine, San Francisco, USA
| | - Joel B Dacks
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
- Department of Life Sciences, The Natural History Museum, London, UK.
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11
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Stahl LM, Olson JB. Environmental abiotic and biotic factors affecting the distribution and abundance of Naegleria fowleri. FEMS Microbiol Ecol 2020; 97:6006869. [PMID: 33242082 PMCID: PMC8068756 DOI: 10.1093/femsec/fiaa238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/23/2020] [Indexed: 12/15/2022] Open
Abstract
Naegleria fowleri is a free-living protozoan that resides in soil and freshwater. Human intranasal amoebae exposure through water or potentially dust particles can culminate in primary amoebic meningoencephalitis, which generally causes death. While many questions remain regarding pathogenesis, the microbial ecology of N. fowleri is even less understood. This review outlines current knowledge of the environmental abiotic and biotic factors that affect the distribution and abundance of N. fowleri. Although the impacts of some abiotic factors remain poorly investigated or inconclusive, N. fowleri appears to have a wide pH range, low salinity tolerance and thermophilic preference. From what is known about biotic factors, the amoebae preferentially feed upon bacteria and are preyed upon by other free-living amoebae. Additional laboratory and environmental studies are needed to fill in knowledge gaps, which are crucial for surveillance and management of N. fowleri in freshwaters. As surface water temperatures increase with climate change, it is likely that this amoeba will pose a greater threat to human health, suggesting that identifying its abiotic and biotic preferences is critical to mitigating this risk.
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Affiliation(s)
- Leigha M Stahl
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Julie B Olson
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
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12
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Julien R, Dreelin E, Whelton AJ, Lee J, Aw TG, Dean K, Mitchell J. Knowledge gaps and risks associated with premise plumbing drinking water quality. ACTA ACUST UNITED AC 2020. [DOI: 10.1002/aws2.1177] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ryan Julien
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
| | - Erin Dreelin
- Department of Fisheries and WildlifeMichigan State University East Lansing Michigan
| | - Andrew J. Whelton
- Lyles School of Civil Engineering and Environmental and Ecological EngineeringPurdue University West Lafayette Indiana
| | - Juneseok Lee
- Department of Civil and Environmental EngineeringManhattan College Riverdale New York
| | - Tiong Gim Aw
- Department of Environmental Health Sciences, School of Public Health and Tropical MedicineTulane University New Orleans Louisiana
| | - Kara Dean
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
| | - Jade Mitchell
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
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13
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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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14
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Cope JR, Murphy J, Kahler A, Gorbett DG, Ali I, Taylor B, Corbitt L, Roy S, Lee N, Roellig D, Brewer S, Hill VR. Primary Amebic Meningoencephalitis Associated With Rafting on an Artificial Whitewater River: Case Report and Environmental Investigation. Clin Infect Dis 2019; 66:548-553. [PMID: 29401275 DOI: 10.1093/cid/cix810] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/13/2017] [Indexed: 11/13/2022] Open
Abstract
Background Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. Patient exposure to water containing the ameba typically occurs in warm freshwater lakes and ponds during recreational water activities. In June 2016, an 18-year-old woman died of PAM after traveling to North Carolina, where she participated in rafting on an artificial whitewater river. Methods We conducted an epidemiologic and environmental investigation to determine the water exposure that led to the death of this patient. Results The case patient's most probable water exposure occurred while rafting on an artificial whitewater river during which she was thrown out of the raft and submerged underwater. The approximately 11.5 million gallons of water in the whitewater facility were partially filtered, subjected to ultraviolet light treatment, and occasionally chlorinated. Heavy algal growth was noted. Eleven water-related samples were collected from the facility; all were positive for N. fowleri. Of 5 samples collected from the nearby natural river, 1 sediment sample was positive for N. fowleri. Conclusions This investigation documents a novel exposure to an artificial whitewater river as the likely exposure causing PAM in this case. Conditions in the whitewater facility (warm, turbid water with little chlorine and heavy algal growth) rendered the water treatment ineffective and provided an ideal environment for N. fowleri to thrive. The combination of natural and engineered elements at the whitewater facility created a challenging environment to control the growth of N. fowleri.
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Affiliation(s)
- Jennifer R Cope
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jennifer Murphy
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Amy Kahler
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Ibne Ali
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Lisa Corbitt
- Mecklenburg County Health Department, Charlotte, North Carolina
| | - Shantanu Roy
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Nicole Lee
- North Carolina Department of Health and Human Services, Raleigh
| | - Dawn Roellig
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Vincent R Hill
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
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15
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Cope JR, Kahler AM, Causey J, Williams JG, Kihlken J, Benjamin C, Ames AP, Forsman J, Zhu Y, Yoder JS, Seidel CJ, Hill VR. Response and remediation actions following the detection of Naegleria fowleri in two treated drinking water distribution systems, Louisiana, 2013-2014. JOURNAL OF WATER AND HEALTH 2019; 17:777-787. [PMID: 31638028 PMCID: PMC7075671 DOI: 10.2166/wh.2019.239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Naegleria fowleri causes the usually fatal disease primary amebic meningoencephalitis (PAM), typically in people who have been swimming in warm, untreated freshwater. Recently, some cases in the United States were associated with exposure to treated drinking water. In 2013, a case of PAM was reported for the first time in association with the exposure to water from a US treated drinking water system colonized with culturable N. fowleri. This system and another were found to have multiple areas with undetectable disinfectant residual levels. In response, the water distribution systems were temporarily converted from chloramine disinfection to chlorine to inactivate N. fowleri and reduced biofilm in the distribution systems. Once >1.0 mg/L free chlorine residual was attained in all systems for 60 days, water testing was performed; N. fowleri was not detected in water samples after the chlorine conversion. This investigation highlights the importance of maintaining adequate residual disinfectant levels in drinking water distribution systems. Water distribution system managers should be knowledgeable about the ecology of their systems, understand potential water quality changes when water temperatures increase, and work to eliminate areas in which biofilm growth may be problematic and affect water quality.
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Affiliation(s)
- Jennifer R Cope
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infections Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, USA E-mail:
| | - Amy M Kahler
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infections Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, USA E-mail:
| | - Jake Causey
- Corona Environmental Consulting, 1001 Hingham St, Suite 102, Rockland, MA 02370, USA
| | - John G Williams
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Jennifer Kihlken
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Caryn Benjamin
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Amanda P Ames
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Johan Forsman
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Yuanda Zhu
- Louisiana Department of Health, 628 North 4th St, Baton Rouge, LA 70802, USA
| | - Jonathan S Yoder
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infections Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, USA E-mail:
| | - Chad J Seidel
- Corona Environmental Consulting, 1001 Hingham St, Suite 102, Rockland, MA 02370, USA
| | - Vincent R Hill
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infections Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, USA E-mail:
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16
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Li RA, McDonald JA, Sathasivan A, Khan SJ. Disinfectant residual stability leading to disinfectant decay and by-product formation in drinking water distribution systems: A systematic review. WATER RESEARCH 2019; 153:335-348. [PMID: 30743084 DOI: 10.1016/j.watres.2019.01.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/02/2019] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Secondary disinfectants, such as chlorine and chloramine, have been widely applied to minimise microbial risks in drinking water during distribution. Key challenges have included the maintenance of stable concentrations of disinfectant residuals and the control of disinfection by-products that may form as a consequence of residual decay processes. Many factors may influence disinfectant residual stability and the consequential formation of by-products. Thus predictions of disinfectant stability and by-product formation are multifactorial problems, complete with numerous complications of parameter co-dependence and feedback amplification of some key parameters. The aim of this review was to derive an understanding of how disinfectant residual stability in drinking water distribution systems is impacted by various influencing factors such as water quality and operational parameters. Factors known to influence disinfectant stability and by-product formation were critically reviewed. A systematic review method was applied to identify 1809 journal articles published in the two decades from January 1998 to December 2017. From the initial screening, 161 papers were selected for detailed assessment. Important factors were identified to include temperature, water age, piping material, corrosion products, pH, hydraulic condition, disinfectant residual type and dosage and microbial activity. Microbial activity is a particularly complex parameter on which to base predictions since many factors are known to influence the degree and nature of such activity. These include temperature, water age, piping material, corrosion products, nutrients, natural organic matter, hydraulic condition and disinfectant residual type and dosage. Disinfectant types and dosages were found to be among the most important factors. Many knowledge gaps and research needs still remain, including the need for a more complete understanding of the factors that influence the production of nitrogenous disinfection by-products.
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Affiliation(s)
- Rebecca A Li
- UNSW Water Research Centre, School of Civil & Environmental Engineering, University of New South Wales, NSW, 2052, Australia.
| | - James A McDonald
- UNSW Water Research Centre, School of Civil & Environmental Engineering, University of New South Wales, NSW, 2052, Australia.
| | - Arumugam Sathasivan
- School of Computing Engineering and Mathematics, University of Western Sydney, Kingswood, NSW, 2747, Australia.
| | - Stuart J Khan
- UNSW Water Research Centre, School of Civil & Environmental Engineering, University of New South Wales, NSW, 2052, Australia.
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17
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Liu L, Xing X, Hu C, Wang H, Lyu L. Effect of sequential UV/free chlorine disinfection on opportunistic pathogens and microbial community structure in simulated drinking water distribution systems. CHEMOSPHERE 2019; 219:971-980. [PMID: 30682762 DOI: 10.1016/j.chemosphere.2018.12.067] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/04/2018] [Accepted: 12/08/2018] [Indexed: 06/09/2023]
Abstract
Drinking water distribution systems (DWDS) may be a "Trojan Horse" for some waterborne diseases caused by opportunistic pathogens (OPs). In this study, two simulated DWDS inoculated with groundwater were treated with chlorine (Cl2) and ultraviolet/chlorine (UV/Cl2) respectively to compare their effects on the OPs distributed in four different phases (bulk water, biofilms, corrosion products, and loose deposits) of DWDS. 16S rRNA genes sequencing and qPCR were used to profile microbial community and quantify target genes of OPs, respectively. Results showed that UV/Cl2 was more effective than single Cl2 to control the regrowth of OPs in the water with the same residual chlorine concentration. However, the OPs inhabiting the biofilms, corrosion products, and loose deposits seemed to be tolerant to UV/Cl2 and Cl2, demonstrating that OPs residing in these phases were resistant to the disinfection processes. Some significant microbial correlations between OPs and Acanthamoeba were found by Spearman correlative analysis (p < 0.05), demonstrating that the ecological interactions may exist in the DWDS. 16S rRNA genes sequencing of water samples revealed a significant different microbial community structure between UV/Cl2 and Cl2. This study may give some implications for controlling the OPs in the DWDS disinfected with UV/Cl2.
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Affiliation(s)
- Lizhong Liu
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang City, Jiangxi 330013, China; School of Water Resource and Environmental Engineering, East China University of Technology, Nanchang City, Jiangxi 330013, China
| | - Xueci Xing
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China.
| | - Chun Hu
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China
| | - Haibo Wang
- Key Laboratory of Aquatic Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lai Lyu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China
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18
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Dean K, Weir MH, Mitchell J. Development of a dose-response model for Naegleria fowleri. JOURNAL OF WATER AND HEALTH 2019; 17:63-71. [PMID: 30758304 DOI: 10.2166/wh.2018.181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This study develops novel dose-response models for Naegleria fowleri from selected peer-reviewed experiments on the virulence based on the intranasal exposure pathway. One data set measured the response of mice intranasally inoculated with the amebae and the other study addressed the response of mice swimming in N. fowleri infected water. The measured response for both studies was death. All experimental data were best fit by the beta-Poisson dose-response model. The three swimming experiments could be pooled, and this is the final recommended model with an LD50 of 13,257 amebae. The results of this study provide a better estimate of the probability of the risk to N. fowleri exposure than the previous models developed based on an intravenous exposure. An accurate dose-response model is the first step in quantifying the risk of free-living amebae like N. fowleri, which pose risks in recreational environments and have been detected in drinking water and premise plumbing systems. A better understanding of this risk will allow for risk management that limits the ability for pathogen growth, proliferation, and exposure.
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Affiliation(s)
- Kara Dean
- College of Engineering, Michigan State University, East Lansing, MI, USA
| | - Mark H Weir
- Environmental Health Sciences, The Ohio State University, College of Public Health, Columbus, OH, USA
| | - Jade Mitchell
- Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI, USA E-mail:
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19
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Liu L, Xing X, Hu C, Wang H. O 3-BAC-Cl 2: A multi-barrier process controlling the regrowth of opportunistic waterborne pathogens in drinking water distribution systems. J Environ Sci (China) 2019; 76:142-153. [PMID: 30528006 DOI: 10.1016/j.jes.2018.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 06/09/2023]
Abstract
Simulated drinking water distribution system (DWDS) treated with O3-BAC-Cl2 (ozone-biological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens (OPs). It was found that O3-BAC-Cl2 could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl2 and O3-Cl2 with the same residual chlorine levels. However, the effect of O3-BAC-Cl2 on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process. The quantification of target OPs in the BAC-filter column demonstrated that OPs decreased with the increase of depth, which was likely due to the organic nutrient gradient and microbial competition inside the BAC-filter. Increase in the ozone dose could further reduce the OPs at the bottom of the BAC-filter. Spearman correlation analysis demonstrated that some significant correlations existed between target microorganisms, suggesting potential microbial ecological relationships. Overall, our results demonstrated that the BAC-filter may act as a "battlefield" suppressing the OPs through microbial competition. O3-BAC-Cl2 could be an effective multi-barrier process to suppress the proliferation of OPs in the bulk water of DWDS. However, OPs protected by the biofilms of DWDS should receive further attention because OPs may be detached and released from the biofilms.
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Affiliation(s)
- Lizhong Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xueci Xing
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Chun Hu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China
| | - Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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20
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Yu Z, Miller HC, Puzon GJ, Clowers BH. Application of untargeted metabolomics for the detection of pathogenic Naegleria fowleri in an operational drinking water distribution system. WATER RESEARCH 2018; 145:678-686. [PMID: 30212806 DOI: 10.1016/j.watres.2018.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/23/2018] [Accepted: 09/02/2018] [Indexed: 06/08/2023]
Abstract
Found in drinking water distribution systems (DWDSs), swimming pools, and recreational waters, N. fowleri, is the causative agent of primary amoebic meningoencephalitis (PAM). Although cases of N. fowleri infections are rare, the fatality is comparatively high (>95%) and surveillance is essential to minimize N. fowleri infections. However, conventional N. fowleri detection methods are less satisfying owing to their time-consuming and lab intensive characteristics as well as the lack of the ability to determine viability. As a result, an alternative detection approach capable of determining viability as well as species identification is required to better ensure public health. Based on our previous research focusing on distinguishing laboratory cultured N. fowleri from N. lovaniensis and N. italica, this study applies untargeted metabolomics methods to field samples from operational DWDSs. A list of diagnostic features was found to preliminarily discriminate the N. fowleri positive from N. fowleri negative and N. lovaniensis positive field samples with satisfying predictive accuracy. The results outlined in this manuscript further validate and improve the metabolite-based N. fowleri detection approach, potentially aiding water utilities in the detection and management of N. fowleri in drinking water.
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Affiliation(s)
- Zhihao Yu
- Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, WA, 99164, USA
| | - Haylea C Miller
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia, 6913, Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia, 6913, Australia
| | - Brian H Clowers
- Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, WA, 99164, USA.
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21
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Wang H, Hu C, Zhang S, Liu L, Xing X. Effects of O 3/Cl 2 disinfection on corrosion and opportunistic pathogens growth in drinking water distribution systems. J Environ Sci (China) 2018; 73:38-46. [PMID: 30290870 DOI: 10.1016/j.jes.2018.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 01/11/2018] [Accepted: 01/11/2018] [Indexed: 06/08/2023]
Abstract
The effects of O3/Cl2 disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors (ARs). The corrosion process and most probable number (MPN) analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O3/Cl2 induced higher Fe3O4 formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl2 alone. O3/Cl2 disinfection inhibited corrosion and iron release efficiently by changing the content of corrosion-related bacteria. Moreover, ozone disinfection inactivated or damaged the opportunistic pathogens due to its strong oxidizing properties. The damaged bacteria resulting from initial ozone treatment were inactivated by the subsequent chlorine disinfection. Compared with the AR treated with Cl2 alone, the opportunistic pathogens M. avium and L. pneumophila were not detectable in effluents of the AR treated with O3/Cl2, and decreased to (4.60±0.14) and (3.09±0.12) log10 (gene copies/g corrosion scales) in biofilms, respectively. The amoeba counts were also lower in the AR treated with O3/Cl2. Therefore, O3/Cl2 disinfection can effectively control opportunistic pathogens in effluents and biofilms of an AR used as a model for a drinking water distribution system.
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Affiliation(s)
- Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Chun Hu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Research Institute of Environmental Studies at Greater Bay, School of Environmental Sciences and Engineering, Guangzhou University, Guangzhou 510006, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Suona Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lizhong Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xueci Xing
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Miller HC, Morgan MJ, Walsh T, Wylie JT, Kaksonen AH, Puzon GJ. Preferential feeding in Naegleria fowleri; intracellular bacteria isolated from amoebae in operational drinking water distribution systems. WATER RESEARCH 2018; 141:126-134. [PMID: 29783165 DOI: 10.1016/j.watres.2018.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/04/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
The amoeba Naegleria fowleri is the causative agent of the highly fatal disease, primary amoebic meningoencephalitis, and estimated to cause 16 deaths per year in the United States alone. Colonisation of drinking water distribution systems (DWDSs) by the N. fowleri is a significant public health issue. Understanding the factors which enable this pathogen to colonise and thrive in DWDSs is critical for proper management. The microbial ecology within DWDSs may influence the ability of N. fowleri to colonise DWDSs by facilitating the availability of an appropriate food source. Using biofilm samples obtained from operational DWDSs, 16S rRNA amplicon metabarcoding was combined with genus-specific PCR and Sanger sequencing of intracellular associated bacteria from isolated amoeba and their parental biofilms to identify Meiothermus chliarophilus as a potential food source for N. fowleri. Meiothermus was confirmed as a food source for N. fowleri following successful serial culturing of axenic N. fowleri with M. chliarophilus or M. ruber as the sole food source. The ability to identify environmental and ecological conditions favourable to N. fowleri colonisation, including the detection of appropriate food sources such as Meiothermus, could provide water utilities with a predictive tool for managing N. fowleri colonisation within the DWDS.
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Affiliation(s)
- Haylea C Miller
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia; School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Matthew J Morgan
- CSIRO Land and Water, Black Mountain Laboratories, P.O. Box 1700, Canberra, ACT, 2601, Australia
| | - Tom Walsh
- CSIRO Land and Water, Black Mountain Laboratories, P.O. Box 1700, Canberra, ACT, 2601, Australia
| | - Jason T Wylie
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia; School of Biomedical Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia.
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Miller HC, Wylie JT, Kaksonen AH, Sutton D, Puzon GJ. Competition between Naegleria fowleri and Free Living Amoeba Colonizing Laboratory Scale and Operational Drinking Water Distribution Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2549-2557. [PMID: 29390181 DOI: 10.1021/acs.est.7b05717] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Free living amoebae (FLA), including pathogenic Naegleria fowleri, can colonize and grow within pipe wall biofilms of drinking water distribution systems (DWDSs). Studies on the interactions between various FLA species in biofilms are limited. Understanding the interaction between FLA and the broader biofilm ecology could help better predict DWDS susceptibility to N. fowleri colonization. The aim of this study was to determine if N. fowleri and other FLAs ( Naegleria, Vermamoeba, Willaertia, and Vahlkampfia spp.) cocolonize DWDS biofilm. FLAs commonly isolated from DWDSs ( N. fowleri, V. vermiformis, and N. lovaniensis) were introduced into laboratory-scale biomonitors to determine the impact of these amoebae on N. fowleri's presence and viability. Over 18 months, a single viable amoebae ( N. fowleri, N. lovaniensis, or V. vermiformis) was detected in each biofilm sample, with the exception of N. lovaniensis and N. fowleri, which briefly cocolonized biofilm following their coinoculation. The analysis of biofilm and bulk water samples from operational DWDSs revealed a similar lack of cocolonization with a single FLA detected in 99% ( n = 242) of samples. Interestingly, various Naegleria spp. did colonize the same DWDS locations but at different times. This knowledge furthers the understanding of ecological factors which enable N. fowleri to colonize and survive within operational DWDSs and could aid water utilities to control its occurrence.
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Affiliation(s)
- Haylea C Miller
- CSIRO Land and Water , Private Bag No. 5 , Wembley , Western Australia 6913 , Australia
- School of Biomedical Sciences , University of Western Australia , 35 Stirling Highway , Crawley , Western Australia 6009 , Australia
| | - Jason T Wylie
- CSIRO Land and Water , Private Bag No. 5 , Wembley , Western Australia 6913 , Australia
| | - Anna H Kaksonen
- CSIRO Land and Water , Private Bag No. 5 , Wembley , Western Australia 6913 , Australia
- School of Biomedical Sciences , University of Western Australia , 35 Stirling Highway , Crawley , Western Australia 6009 , Australia
| | - David Sutton
- School of Biomedical Sciences , University of Western Australia , 35 Stirling Highway , Crawley , Western Australia 6009 , Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water , Private Bag No. 5 , Wembley , Western Australia 6913 , Australia
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Wang H, Shen Y, Hu C, Xing X, Zhao D. Sulfadiazine/ciprofloxacin promote opportunistic pathogens occurrence in bulk water of drinking water distribution systems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 234:71-78. [PMID: 29161575 DOI: 10.1016/j.envpol.2017.11.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 05/19/2023]
Abstract
Effects of sulfadiazine and ciprofloxacin on the occurrence of free-living and particle-associated opportunistic pathogens in bulk water of simulated drinking water distribution systems (DWDSs) were investigated. It was found that sulfadiazine and ciprofloxacin greatly promoted the occurrence of opportunistic pathogens including Pseudomonas aeruginosa, Legionella pneumophila, Mycobacterium avium and its broader genus Mycobacterium spp., as well as the amoebae Acanthamoeba spp. and Hartmanella vermiformis, in bulk water of DWDSs. Moreover, sulfadiazine and ciprofloxacin exhibited much stronger combined effects on the increase of these opportunistic pathogens. Based on the analysis of the antibiotic resistance genes (ARGs) and extracellular polymeric substances (EPS), it was verified that EPS production was increased by the antibiotic resistant bacteria arising from the effects of sulfadiazine/ciprofloxacin. The combined effects of sulfadiazine and ciprofloxacin induced the greatest increase of EPS production in DWDSs. Furthermore, the increased EPS with higher contents of proteins and secondary structure β-sheet led to greater bacterial aggregation and adsorption. Meanwhile, large numbers of suspended particles were formed, increasing the chlorine-resistance capability, which was responsible for the enhancement of the particle-associated opportunistic pathogens in bulk water of DWDSs with sulfadiazine/ciprofloxacin. Therefore, sulfadiazine and ciprofloxacin promoted the occurrence of particle-associated opportunistic pathogens in bulk water of DWDSs due to the role of EPS produced by the bacteria with ARGs.
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Affiliation(s)
- Haibo Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yi Shen
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China
| | - Chun Hu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environmental Sciences and Engineering, Guangzhou University, Guangzhou, 510006, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xueci Xing
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dan Zhao
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China
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Waso M, Dobrowsky PH, Hamilton KA, Puzon G, Miller H, Khan W, Ahmed W. Abundance of Naegleria fowleri in roof-harvested rainwater tank samples from two continents. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:5700-5710. [PMID: 29230646 DOI: 10.1007/s11356-017-0870-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 11/28/2017] [Indexed: 05/24/2023]
Abstract
Roof-harvested rainwater (RHRW) has been used as an alternative source of water in water scarce regions of many countries. The microbiological and chemical quality of RHRW has been questioned due to the presence of bacterial and protozoan pathogens. However, information on the occurrence of pathogenic amoeba in RHRW tank samples is needed due to their health risk potential and known associations with opportunistic pathogens. Therefore, this study aims to determine the quantitative occurrence of Naegleria fowleri in RHRW tank samples from Southeast Queensland (SEQ), Australia (AU), and the Kleinmond Housing Scheme located in Kleinmond, South Africa (SA). In all, 134 and 80 RHRW tank samples were collected from SEQ, and the Kleinmond Housing Scheme, Western Cape, SA, respectively. Quantitative PCR (qPCR) assays were used to measure the concentrations of N. fowleri, and culture-based methods were used to measure fecal indicator bacteria (FIB) Escherichia coli (E. coli) and Enterococcus spp. Of the 134 tank water samples tested from AU, 69 and 62.7% were positive for E. coli, and Enterococcus spp., respectively. For the SA tank water samples, FIB analysis was conducted for samples SA-T41 to SA-T80 (n = 40). Of the 40 samples analyzed from SA, 95 and 35% were positive for E. coli and Enterococcus spp., respectively. Of the 134 water samples tested in AU, 15 (11.2%) water samples were positive for N. fowleri, and the concentrations ranged from 1.7 × 102 to 3.6 × 104 gene copies per 100 mL of water. Of the 80 SA tank water samples screened for N. fowleri, 15 (18.8%) tank water samples were positive for N. fowleri and the concentrations ranged from 2.1 × 101 to 7.8 × 104 gene copies per 100 mL of tank water. The prevalence of N. fowleri in RHRW tank samples from AU and SA thus warrants further development of dose-response models for N. fowleri and a quantitative microbial risk assessment (QMRA) to inform and prioritize strategies for reducing associated public health risks.
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Affiliation(s)
- Monique Waso
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Penelope Heather Dobrowsky
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Kerry Ann Hamilton
- Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, QLD, 4102, Australia
| | - Geoffrey Puzon
- CSIRO Land and Water, Private Bag No.5, Wembley, WA, 6913, Australia
| | - Haylea Miller
- CSIRO Land and Water, Private Bag No.5, Wembley, WA, 6913, Australia
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, QLD, 4102, Australia.
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Cai W, Arias CR. Biofilm Formation on Aquaculture Substrates by Selected Bacterial Fish Pathogens. JOURNAL OF AQUATIC ANIMAL HEALTH 2017; 29:95-104. [PMID: 28406736 DOI: 10.1080/08997659.2017.1290711] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The objective of this study was to determine whether common bacterial catfish pathogens could attach and colonize surfaces commonly found in aquaculture facilities. In addition, we evaluated the role of calcium in biofilm formation. Attachment to polystyrene plates was used to quantify biofilm formation by five bacterial pathogens (i.e., Flavobacterium columnare, Aeromonas hydrophila, Edwardsiella ictaluri, E. tarda, and E. piscicida). Flavobacterium columnare and A. hydrophila formed thick biofilms that were enhanced by calcium supplementation. Biofilm formation was significantly lower in all Edwardsiella species tested and calcium had little to no effect on Edwardsiella biofilm formation. Attachment to natural and artificial surfaces was quantified by a standard plate count method. Scanning electron microscopy (SEM) was used to confirm biofilm formation on the substrates. Flavobacterium columnare formed biofilm on the liner, flexible PVC, and nets. Bamboo prevented F. columnare attachment and inhibited cell growth. Aeromonas hydrophila and E. ictaluri formed biofilm on all materials tested, although significant differences were found among substrates. While E. ictaluri failed to form biofilm on microtiter polystyrene plates, it was able to colonize and multiply on all aquaculture materials tested. Our results demonstrated that common bacterial pathogens had the potential of colonizing surfaces and may use biofilm as reservoirs in fish farms. Received July 19, 2016; accepted January 19, 2017.
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Affiliation(s)
- Wenlong Cai
- a Aquatic Microbiology Laboratory, School of Fisheries, Aquaculture, and Aquatic Sciences,Auburn University , 203 Swingle Hall, Auburn , Alabama 36832 , USA
| | - Covadonga R Arias
- a Aquatic Microbiology Laboratory, School of Fisheries, Aquaculture, and Aquatic Sciences,Auburn University , 203 Swingle Hall, Auburn , Alabama 36832 , USA
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Yu Z, Miller HC, Puzon GJ, Clowers BH. Development of Untargeted Metabolomics Methods for the Rapid Detection of Pathogenic Naegleria fowleri. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4210-4219. [PMID: 28290675 DOI: 10.1021/acs.est.6b05969] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Despite comparatively low levels of infection, primary amoebic meningoencephalitis (PAM) induced by Naegleria fowleri is extremely lethal, with mortality rates above 95%. As a thermophile, this organism is often found in moderate-to-warm climates and has the potential to colonize drinking water distribution systems (DWDSs). Current detection approaches require days to obtain results, whereas swift corrective action can maximize the benefit of public health. Presently, there is little information regarding the underlying in situ metabolism for this amoeba but the potential exists to exploit differentially expressed metabolic signatures as a rapid detection technique. This research outlines the biochemical profiles of selected pathogenic and nonpathogenic Naegleria in vitro using an untargeted metabolomics approach to identify a panel of diagnostically meaningful compounds that may enable rapid detection of viable pathogenic N. fowleri and augment results from traditional monitoring approaches.
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Affiliation(s)
- Zhihao Yu
- Department of Chemistry, Washington State University , P.O. Box 644630, Pullman, Washington 99164, United States
| | - Haylea C Miller
- CSIRO Land and Water, Centre for Environment and Life Sciences , Private Bag No. 5, Wembley, Western Australia 6913, Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water, Centre for Environment and Life Sciences , Private Bag No. 5, Wembley, Western Australia 6913, Australia
| | - Brian H Clowers
- Department of Chemistry, Washington State University , P.O. Box 644630, Pullman, Washington 99164, United States
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Miller HC, Morgan MJ, Wylie JT, Kaksonen AH, Sutton D, Braun K, Puzon GJ. Elimination of Naegleria fowleri from bulk water and biofilm in an operational drinking water distribution system. WATER RESEARCH 2017; 110:15-26. [PMID: 27974249 DOI: 10.1016/j.watres.2016.11.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/07/2016] [Accepted: 11/25/2016] [Indexed: 06/06/2023]
Abstract
Global incidence of primary amoebic meningoencephalitis cases associated with domestic drinking water is increasing. The need for understanding disinfectant regimes capable of eliminating the causative microorganism, Naegleria fowleri, from bulk water and pipe wall biofilms is critical. This field study demonstrated the successful elimination of N. fowleri from the bulk water and pipe wall biofilm of a persistently colonised operational drinking water distribution system (DWDS), and the prevention of further re-colonisation. A new chlorination unit was installed along the pipe line to boost the free chlorine residual to combat the persistence of N. fowleri. Biofilm and bulk water were monitored prior to and after re-chlorination (RCl), pre-rechlorination (pre-RCl) and post-rechlorination (post-RCl), respectively, for one year. A constant free chlorine concentration of > 1 mg/L resulted in the elimination of N. fowleri from both the bulk water and biofilm at the post-RCl site. Other amoeba species were detected during the first two months of chlorination, but all amoebae were eliminated from both the bulk water and biofilm at post-RCl after 60 days of chlorination with free chlorine concentrations > 1 mg/L. In addition, a dynamic change in the biofilm community composition and a four log reduction in biofilm cell density occurred post-RCl. The pre-RCl site continued to be seasonally colonised by N. fowleri, but the constant free chlorine residual of > 1 mg/L prevented N. fowleri from recolonising the bulk and pipe wall biofilm at the post-RCl site. To our knowledge, this is the first study to demonstrate successful removal of N. fowleri from both the bulk and pipe wall biofilm and prevention of re-colonisation of N. fowleri in an operational DWDS. The findings of this study are of importance to water utilities in addressing the presence of N. fowleri and other amoeba in susceptible DWDSs.
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Affiliation(s)
- Haylea C Miller
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Matthew J Morgan
- CSIRO Land and Water, Black Mountain Laboratories, P.O. Box 1700, Canberra, ACT 2601, Australia
| | - Jason T Wylie
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia; School of Pathology and Laboratory Medicine, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - David Sutton
- School of Pathology and Laboratory Medicine, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Kalan Braun
- Water Corporation of Western Australia, 629 Newcastle Street, Leederville, Western Australia 6007, Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water, Private Bag No.5, Wembley, Western Australia 6913, Australia.
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Puzon GJ, Wylie JT, Walsh T, Braun K, Morgan MJ. Comparison of biofilm ecology supporting growth of individual Naegleria species in a drinking water distribution system. FEMS Microbiol Ecol 2017; 93:3044201. [DOI: 10.1093/femsec/fix017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 02/20/2017] [Indexed: 01/06/2023] Open
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Shen Y, Huang C, Lin J, Wu W, Ashbolt NJ, Liu WT, Nguyen TH. Effect of Disinfectant Exposure on Legionella pneumophila Associated with Simulated Drinking Water Biofilms: Release, Inactivation, and Infectivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2087-2095. [PMID: 28085262 DOI: 10.1021/acs.est.6b04754] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Legionella pneumophila, the most commonly identified causative agent in drinking water associated with disease outbreaks, can be harbored by and released from drinking water biofilms. In this study, the release of biofilm-associated L. pneumophila under simulated drinking water flow containing a disinfectant residual was examined. Meanwhile, the inactivation and infectivity (to amoebae) of the released L. pneumophila were studied. To simulate drinking water system conditions, biofilms were prepared under either disinfectant exposure (predisinfected biofilms) or disinfectant-free (untreated biofilms) conditions, respectively. For experiments with water flow containing a disinfectant to release the biofilm-associated L. pneumophila from these two types of biofilms, the L. pneumophila release kinetics values from predisinfected and untreated biofilms under flow condition were not statistically different (one-way ANOVA, p > 0.05). However, inactivation of the L. pneumophila released from predisinfected biofilms was 1-2 times higher and amoeba infectivity was 2-29 times lower than that from untreated biofilms. The higher disinfectant resistance of L. pneumophila released from untreated biofilms was presumably influenced by the detachment of a larger amount of biofilm material (determined by 16S rRNA qPCR) surrounding the released L. pneumophila. This study highlights the interaction among disinfectant residual, biofilms, and L. pneumophila, which provides guidelines to assess and control pathogen risk.
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Affiliation(s)
- Yun Shen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
| | - Conghui Huang
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
| | - Jie Lin
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
| | - Wenjing Wu
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
| | - Nicholas J Ashbolt
- School of Public Health, University of Alberta , Edminton, Alberta AB T6G 2G7, Canada
| | - Wen-Tso Liu
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States
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Effectiveness of Devices to Monitor Biofouling and Metals Deposition on Plumbing Materials Exposed to a Full-Scale Drinking Water Distribution System. PLoS One 2017; 12:e0169140. [PMID: 28060947 PMCID: PMC5218461 DOI: 10.1371/journal.pone.0169140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/12/2016] [Indexed: 11/19/2022] Open
Abstract
A Modified Robbins Device (MRD) was installed in a full-scale water distribution system to investigate biofouling and metal depositions on concrete, high-density polyethylene (HDPE) and stainless steel surfaces. Bulk water monitoring and a KIWA monitor (with glass media) were used to offline monitor biofilm development on pipe wall surfaces. Results indicated that adenosine triphosphate (ATP) and metal concentrations on coupons increased with time. However, bacterial diversities decreased. There was a positive correlation between increase of ATP and metal deposition on pipe surfaces of stainless steel and HDPE and no correlation was observed on concrete and glass surfaces. The shared bacterial diversity between bulk water and MRD was less than 20% and the diversity shared between the MRD and KIWA monitor was only 10%. The bacterial diversity on biofilm of plumbing material of MRD however, did not show a significant difference suggesting a lack of influence from plumbing material during early stage of biofilm development.
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Siddiqui R, Ali IKM, Cope JR, Khan NA. Biology and pathogenesis of Naegleria fowleri. Acta Trop 2016; 164:375-394. [PMID: 27616699 DOI: 10.1016/j.actatropica.2016.09.009] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/06/2016] [Accepted: 09/06/2016] [Indexed: 12/13/2022]
Abstract
Naegleria fowleri is a protist pathogen that can cause lethal brain infection. Despite decades of research, the mortality rate related with primary amoebic meningoencephalitis owing to N. fowleri remains more than 90%. The amoebae pass through the nose to enter the central nervous system killing the host within days, making it one of the deadliest opportunistic parasites. Accordingly, we present an up to date review of the biology and pathogenesis of N. fowleri and discuss needs for future research against this fatal infection.
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Gonzalez D, Tjandraatmadja G, Barry K, Vanderzalm J, Kaksonen AH, Dillon P, Puzon GJ, Sidhu J, Wylie J, Goodman N, Low J. Biofouling potential and material reactivity in a simulated water distribution network supplied with stormwater recycled via managed aquifer recharge. WATER RESEARCH 2016; 105:110-118. [PMID: 27607597 DOI: 10.1016/j.watres.2016.08.066] [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: 04/10/2016] [Revised: 07/29/2016] [Accepted: 08/30/2016] [Indexed: 06/06/2023]
Abstract
The injection of stormwater into aquifers for storage and recovery during high water demand periods is a promising technology for augmenting conventional water reserves. Limited information exists regarding the potential impact of aquifer treated stormwater in distribution system infrastructure. This study describes a one year pilot distribution pipe network trial to determine the biofouling potential for cement, copper and polyvinyl chloride pipe materials exposed to stormwater stored in a limestone aquifer compared to an identical drinking water rig. Median alkalinity (123 mg/L) and colour (12 HU) in stormwater was significantly higher than in drinking water (82 mg/L and 1 HU) and pipe discolouration was more evident for stormwater samples. X-ray Diffraction and Fluorescence analyses confirmed this was driven by the presence of iron rich amorphous compounds in more thickly deposited sediments also consistent with significantly higher median levels of iron (∼0.56 mg/L) in stormwater compared to drinking water (∼0.17 mg/L). Water type did not influence biofilm development as determined by microbial density but faecal indicators were significantly higher for polyvinyl chloride and cement exposed to stormwater. Treatment to remove iron through aeration and filtration would reduce the potential for sediment accumulation. Operational and verification monitoring parameters to manage scaling, corrosion, colour, turbidity and microbial growth in recycled stormwater distribution networks are discussed.
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Affiliation(s)
- Dennis Gonzalez
- CSIRO Land and Water, Private Bag 2, Glen Osmond, SA, 5064, Australia.
| | - Grace Tjandraatmadja
- CSIRO Land and Water, CSIRO, Private Bag 10, Clayton South, Vic, 3169, Australia
| | - Karen Barry
- CSIRO Land and Water, Private Bag 2, Glen Osmond, SA, 5064, Australia
| | - Joanne Vanderzalm
- CSIRO Land and Water, Private Bag 2, Glen Osmond, SA, 5064, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water, CSIRO, Private Bag 5, Wembley, WA, 6913, Australia
| | - Peter Dillon
- CSIRO Land and Water, Private Bag 2, Glen Osmond, SA, 5064, Australia
| | - Geoff J Puzon
- CSIRO Land and Water, CSIRO, Private Bag 5, Wembley, WA, 6913, Australia
| | - Jatinder Sidhu
- CSIRO Land and Water, CSIRO, GPO Box 2583, Brisbane, Qld, 4001, Australia
| | - Jason Wylie
- CSIRO Land and Water, CSIRO, Private Bag 5, Wembley, WA, 6913, Australia
| | - Nigel Goodman
- CSIRO Land and Water, CSIRO, Private Bag 10, Clayton South, Vic, 3169, Australia
| | - Jason Low
- CSIRO Land and Water, CSIRO, Private Bag 10, Clayton South, Vic, 3169, Australia
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Morgan MJ, Halstrom S, Wylie JT, Walsh T, Kaksonen AH, Sutton D, Braun K, Puzon GJ. Characterization of a Drinking Water Distribution Pipeline Terminally Colonized by Naegleria fowleri. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2890-2898. [PMID: 26853055 DOI: 10.1021/acs.est.5b05657] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Free-living amoebae, such as Naegleria fowleri, Acanthamoeba spp., and Vermamoeba spp., have been identified as organisms of concern due to their role as hosts for pathogenic bacteria and as agents of human disease. In particular, N. fowleri is known to cause the disease primary amoebic meningoencephalitis (PAM) and can be found in drinking water systems in many countries. Understanding the temporal dynamics in relation to environmental and biological factors is vital for developing management tools for mitigating the risks of PAM. Characterizing drinking water systems in Western Australia with a combination of physical, chemical and biological measurements over the course of a year showed a close association of N. fowleri with free chlorine and distance from treatment over the course of a year. This information can be used to help design optimal management strategies for the control of N. fowleri in drinking-water-distribution systems.
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Affiliation(s)
- Matthew J Morgan
- CSIRO Land and Water , Black Mountain Laboratories, P.O. Box 1700, Canberra, ACT, 2601, Australia
| | - Samuel Halstrom
- CSIRO Land and Water , Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia 6913, Australia
- School of Pathology and Laboratory Medicine and Oceans Institute, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Jason T Wylie
- CSIRO Land and Water , Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia 6913, Australia
| | - Tom Walsh
- CSIRO Land and Water , Black Mountain Laboratories, P.O. Box 1700, Canberra, ACT, 2601, Australia
| | - Anna H Kaksonen
- CSIRO Land and Water , Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia 6913, Australia
- School of Pathology and Laboratory Medicine and Oceans Institute, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - David Sutton
- School of Pathology and Laboratory Medicine and Oceans Institute, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Kalan Braun
- Water Corporation of Western Australia , 629 Newcastle Street, Leederville, Western Australia 6007, Australia
| | - Geoffrey J Puzon
- CSIRO Land and Water , Centre for Environment and Life Sciences, Private Bag No. 5, Wembley, Western Australia 6913, Australia
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Shen Y, Huang C, Monroy GL, Janjaroen D, Derlon N, Lin J, Espinosa-Marzal R, Morgenroth E, Boppart SA, Ashbolt NJ, Liu WT, Nguyen TH. Response of Simulated Drinking Water Biofilm Mechanical and Structural Properties to Long-Term Disinfectant Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1779-87. [PMID: 26756120 PMCID: PMC5135099 DOI: 10.1021/acs.est.5b04653] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mechanical and structural properties of biofilms influence the accumulation and release of pathogens in drinking water distribution systems (DWDS). Thus, understanding how long-term residual disinfectants exposure affects biofilm mechanical and structural properties is a necessary aspect for pathogen risk assessment and control. In this study, elastic modulus and structure of groundwater biofilms was monitored by atomic force microscopy (AFM) and optical coherence tomography (OCT) during three months of exposure to monochloramine or free chlorine. After the first month of disinfectant exposure, the mean stiffness of monochloramine- or free-chlorine-treated biofilms was 4 to 9 times higher than those before treatment. Meanwhile, the biofilm thickness decreased from 120 ± 8 μm to 93 ± 6-107 ± 11 μm. The increased surface stiffness and decreased biofilm thickness within the first month of disinfectant exposure was presumably due to the consumption of biomass. However, by the second to third month during disinfectant exposure, the biofilm mean stiffness showed a 2- to 4-fold decrease, and the biofilm thickness increased to 110 ± 7-129 ± 8 μm, suggesting that the biofilms adapted to disinfectant exposure. After three months of the disinfectant exposure process, the disinfected biofilms showed 2-5 times higher mean stiffness (as determined by AFM) and 6-13-fold higher ratios of protein over polysaccharide, as determined by differential staining and confocal laser scanning microscopy (CLSM), than the nondisinfected groundwater biofilms. However, the disinfected biofilms and nondisinfected biofilms showed statistically similar thicknesses (t test, p > 0.05), suggesting that long-term disinfection may not significantly remove net biomass. This study showed how biofilm mechanical and structural properties vary in response to a complex DWDS environment, which will contribute to further research on the risk assessment and control of biofilm-associated-pathogens in DWDS.
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Affiliation(s)
| | | | | | | | - Nicolas Derlon
- Eawag: Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
| | | | | | - Eberhard Morgenroth
- Eawag: Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
- Institute of Environmental Engineering, ETH Zürich , 8093 Zürich, Switzerland
| | | | - Nicholas J Ashbolt
- School of Public Health, University of Alberta , Edmonton, AB T6G 2G7 Canada
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Lu J, Struewing I, Vereen E, Kirby AE, Levy K, Moe C, Ashbolt N. Molecular Detection of Legionella
spp. and their associations with Mycobacterium
spp., Pseudomonas aeruginosa
and amoeba hosts in a drinking water distribution system. J Appl Microbiol 2016; 120:509-21. [DOI: 10.1111/jam.12996] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 01/12/2023]
Affiliation(s)
- J. Lu
- U.S. EPA National Exposure Research Laboratory; Cincinnati OH USA
| | | | - E. Vereen
- Center for Global Safe Water; Sanitation and Hygiene; Emory University; Atlanta GA USA
| | - A. E. Kirby
- Center for Global Safe Water; Sanitation and Hygiene; Emory University; Atlanta GA USA
| | - K. Levy
- Center for Global Safe Water; Sanitation and Hygiene; Emory University; Atlanta GA USA
| | - C. Moe
- Center for Global Safe Water; Sanitation and Hygiene; Emory University; Atlanta GA USA
| | - N. Ashbolt
- School of Public Health; University of Alberta; Edmonton AB Canada
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