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Silva AR, Melo LF, Keevil CW, Pereira A. Legionella colonization and 3D spatial location within a Pseudomonas biofilm. Sci Rep 2024; 14:16781. [PMID: 39039267 PMCID: PMC11263398 DOI: 10.1038/s41598-024-67712-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024] Open
Abstract
Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.
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Affiliation(s)
- Ana Rosa Silva
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Luis F Melo
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - C William Keevil
- School of Biological Sciences, University of Southampton, Southampton, UK
| | - Ana Pereira
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
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2
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Song Y, Mena-Aguilar D, Brown CL, Rhoads WJ, Helm RF, Pruden A, Edwards MA. Effects of Copper on Legionella pneumophila Revealed via Viability Assays and Proteomics. Pathogens 2024; 13:563. [PMID: 39057790 PMCID: PMC11279431 DOI: 10.3390/pathogens13070563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/22/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Cu is an antimicrobial that is commonly applied to premise (i.e., building) plumbing systems for Legionella control, but the precise mechanisms of inactivation are not well defined. Here, we applied a suite of viability assays and mass spectrometry-based proteomics to assess the mechanistic effects of Cu on L. pneumophila. Although a five- to six-log reduction in culturability was observed with 5 mg/L Cu2+ exposure, cell membrane integrity only indicated a <50% reduction. Whole-cell proteomic analysis revealed that AhpD, a protein related to oxidative stress, was elevated in Cu-exposed Legionella relative to culturable cells. Other proteins related to cell membrane synthesis and motility were also higher for the Cu-exposed cells relative to controls without Cu. While the proteins related to primary metabolism decreased for the Cu-exposed cells, no significant differences in the abundance of proteins related to virulence or infectivity were found, which was consistent with the ability of VBNC cells to cause infections. Whereas the cell-membrane integrity assay provided an upper-bound measurement of viability, an amoebae co-culture assay provided a lower-bound limit. The findings have important implications for assessing Legionella risk following its exposure to copper in engineered water systems.
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Affiliation(s)
- Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
- Utilities Department, 316 N. Academy St., Town of Cary, Cary, NC 27513, USA
| | - Didier Mena-Aguilar
- Biochemistry, Virginia Tech, 340 W Campus Dr, Blacksburg, VA 24060, USA
- Department of Biochemistry, University of Nebraska-Lincoln, N106, The Beadle Center, Lincoln, NE 68588, USA
| | - Connor L. Brown
- Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Steger Hall, Blacksburg, VA 24061, USA
| | - William J. Rhoads
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
- Black & Veatch, 8400 Ward Pkwy, Kansas City, MO 64114, USA
| | - Richard F. Helm
- Department of Biochemistry, Virginia Tech, 1015 Life Science Circle, 211B Steger Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
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3
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Zhang M, Wang X, Deng X, Zheng S, Zhang W, He JZ, Yu X, Feng M, Ye C. Viable but non-culturable state formation and resuscitation of different antibiotic-resistant Escherichia coli induced by UV/chlorine. WATER RESEARCH 2024; 261:122011. [PMID: 38959654 DOI: 10.1016/j.watres.2024.122011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Revised: 06/12/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024]
Abstract
The presence of "viable but nonculturable" (VBNC) state and bacterial antibiotic resistance (BAR) both pose significant threats to the safety of drinking water. However, limited data was available that explicitly addressed the contribution of bacterial VBNC state in the maintenance and propagation of BAR. Here, the VBNC state induction and resuscitation of two antibiotic-resistant Escherichia coli K12 strains, one carrying multidrug-resistant plasmid (RP4 E. coli) and the other with chromosomal mutation (RIF E. coli) were characterized by subjecting them to different doses of UV/chlorine. The results illustrated that the induction, resuscitation, and associated mechanisms of VBNC ARB exhibit variations based on resistance determinants. RP4 E. coli exhibited a higher susceptibility to enter VBNC state compared to the RIF E. coli., and most VBNC state and resuscitated RP4 E. coli retained original antibiotic resistance. While, reverse mutation in the rpoB gene was observed in VBNC state and recovered RIF E. coli strains induced by high doses of UV/chlorine treatment, leading to the loss of rifampicin resistance. According to RT-qPCR results, ARGs conferring efflux pumps appeared to play a more significant role in the VBNC state formation of RP4 E. coli and the down-regulation of rpoS gene enhanced the speed at which this plasmid-carrying ARB entered into the dormant state. As to RIF E. coli, the induction of VBNC state was supposed to be regulated by the combination of general stress response, SOS response, stringent response, and TA system. Above all, this study highlights that ARB could become VBNC state during UV/chlorine treatments and retain, in some cases, their ability to spread ARGs. Importantly, compared with chromosomal mutation-mediated ARB, both VBNC and resuscitated state ARB that carries multidrug-resistant plasmids poses more serious health risks. Our study provides insights into the relationship between the VBNC state and the propagation of BAR in drinking water systems.
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Affiliation(s)
- Menglu Zhang
- College of Environmental and Resource Science, Fujian Normal University, Fuzhou 350117, China; Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China; Fujian Sanming Forest Ecosystem National Observation and Research Station, Fujian Normal University, Sanming 365002, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou 350117, China
| | - Xuansen Wang
- College of Environmental and Resource Science, Fujian Normal University, Fuzhou 350117, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou 350117, China
| | - Xiaofeng Deng
- Fujian Minhuan Testing and Inspection Co., Fuzhou 350000, China
| | - Suxia Zheng
- College of Environmental and Resource Science, Fujian Normal University, Fuzhou 350117, China
| | - Weifang Zhang
- College of Environmental and Resource Science, Fujian Normal University, Fuzhou 350117, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou 350117, China
| | - Ji-Zheng He
- Fujian Sanming Forest Ecosystem National Observation and Research Station, Fujian Normal University, Sanming 365002, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou 350117, China
| | - Xin Yu
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen, 361102, China
| | - Mingbao Feng
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen, 361102, China
| | - Chengsong Ye
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, College of the Environment & Ecology, Xiamen University, Xiamen, 361102, China.
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4
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Li J, Liu C, Wang S, Mao X. Staphylococcus aureus enters viable-but-nonculturable state in response to chitooligosaccharide stress by altering metabolic pattern and transmembrane transport function. Carbohydr Polym 2024; 330:121772. [PMID: 38368090 DOI: 10.1016/j.carbpol.2023.121772] [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: 11/08/2023] [Revised: 12/17/2023] [Accepted: 12/29/2023] [Indexed: 02/19/2024]
Abstract
Although chitooligosaccharide (COS) has attracted the attention of some researchers due to its good solubility and broad-spectrum antibacterial activity, our study found that Staphylococcus aureus treated with low concentration of COS actively entered the viable-but-nonculturable (VBNC) state to resist this environmental stress. In this study, the transcriptome of VBNC-state S. aureus after COS treatment was analyzed by RNA-sequencing. Compared with the control group, pathway enrichment analysis showed that COS-treated S. aureus adopted a series of adaptive adjustment strategies for survival, including significant up-regulation of the differential genes' expression of such as ABC transporters (metI, tagG), Sec dependent transport pathway (secDF), peptidoglycan synthesis pathway (murG) and alteration of their physiological metabolic patterns, where ATP depletion played a key role in the formation of the VBNC-state S. aureus. Further, by using oxidative phosphorylation uncoupling agent to adjust the initial level of ATP in S. aureus, it was found that the reduction of intracellular ATP level could accelerate the formation of VBNC state. Overall, our results preliminarily elucidated the molecular mechanism of COS inducing the VBNC-state S. aureus. It provided an important theoretical reference for further achieving effective bacterial inactivation by COS.
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Affiliation(s)
- Jiao Li
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Chunhui Liu
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Sai Wang
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
| | - Xiangzhao Mao
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China.
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5
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Borkar SB, Negi M, Jaiswal A, Raj Acharya T, Kaushik N, Choi EH, Kaushik NK. Plasma-generated nitric oxide water: A promising strategy to combat bacterial dormancy (VBNC state) in environmental contaminant Micrococcus luteus. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132634. [PMID: 37793251 DOI: 10.1016/j.jhazmat.2023.132634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/08/2023] [Accepted: 09/24/2023] [Indexed: 10/06/2023]
Abstract
The viable but non-culturable (VBNC) is an inactive state, and certain bacteria can enter under adverse conditions. The VBNC state challenges the environment, food safety, and public health since VBNCs may resuscitate and pose a risk to human health. The aim of this study was to investigate the effect of plasma-generated nitric oxide water (PG-NOW) on airborne contaminant Micrococcus luteus (M. luteus) and examine its potential to induce the VBNC state. The essential conditions for bacteria to enter VBNC state are low metabolic activity and rare or no culturable counts. The results indicated that PG-NOW effectively eliminates M. luteus, and the remaining bacteria are in culturable condition. Moreover, the conventional cultured-based method combined with a propidium iodide monoazide quantitative PCR (PMAxxTM-qPCR) showed no significant VBNC induction and moderate culturable counts. Results from the qPCR revealed that gene levels in PG-NOW treated bacteria related to resuscitation-promoting factors, amino acid biosynthesis, and fatty acid metabolism were notably upregulated. PG-NOW inactivated M. luteus showed negligible VBNC formation and alleviated infection ability in lung cells. This study provides new insights into the potential use of PG-NOW reactive species for the prevention and control of the VBNC state of M. luteus.
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Affiliation(s)
- Shweta B Borkar
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Manorma Negi
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Apurva Jaiswal
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Tirtha Raj Acharya
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea
| | - Neha Kaushik
- Department of Biotechnology, College of Engineering, The University of Suwon, Hwaseong 18323, South Korea.
| | - Eun Ha Choi
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea.
| | - Nagendra Kumar Kaushik
- Department of Electrical and Biological Physics/Plasma Bioscience Research Center, Kwangwoon University, Seoul 01897, South Korea.
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6
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Cheng S, Su R, Song L, Bai X, Yang H, Li Z, Li Z, Zhan X, Xia X, Lü X, Shi C. Citral and trans-cinnamaldehyde, two plant-derived antimicrobial agents can induce Staphylococcus aureus into VBNC state with different characteristics. Food Microbiol 2023; 112:104241. [PMID: 36906323 DOI: 10.1016/j.fm.2023.104241] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 02/19/2023]
Abstract
Viable but nonculturable (VBNC) state bacteria are difficult to detect in the food industry due to their nonculturable nature and their recovery characteristics pose a potential threat to human health. The results of this study indicated that S. aureus was found to enter the VBNC state completely after induced by citral (1 and 2 mg/mL) for 2 h, and after induced by trans-cinnamaldehyde (0.5 and 1 mg/mL) for 1 h and 3 h, respectively. Except for VBNC state cells induced by 2 mg/mL citral, the VBNC state cells induced by the other three conditions (1 mg/mL citral, 0.5 and 1 mg/mL trans-cinnamaldehyde) were able to be resuscitated in TSB media. In the VBNC state cells induced by citral and trans-cinnamaldehyde, the ATP concentration was reduced, the hemolysin-producing ability was significantly decreased, but the intracellular ROS level was elevated. The results of heat and simulated gastric fluid experiments showed different environment resistance on VBNC state cells induced by citral and trans-cinnamaldehyde. In addition, by observing the VBNC state cells showed that irregular folds on the surface, increased electron density inside and vacuoles in the nuclear region. What's more, S. aureus was found to enter the VBNC state completely after induced by meat-based broth containing citral (1 and 2 mg/mL) for 7 h and 5 h, after induced by meat-based broth containing trans-cinnamaldehyde (0.5 and 1 mg/mL) for 8 h and 7 h. In summary, citral and trans-cinnamaldehyde can induce S. aureus into VBNC state and food industry needs to comprehensively evaluate the antibacterial capacity of these two plant-derived antimicrobial agents.
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Affiliation(s)
- Shuai Cheng
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ruiying Su
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Luyi Song
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiangyang Bai
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hui Yang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhuo Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhenye Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiangjun Zhan
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiaodong Xia
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, 116304, China
| | - Xin Lü
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chao Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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Gleason JA, Newby R, Gaynor JJ, Lee LH, Chu T, Bliese AD, Taylor CW, Yoon P, DeLorenzo S, Pranitis D, Bella J. Legionella monitoring results by water quality characteristics in a large public water system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:55974-55988. [PMID: 36913019 DOI: 10.1007/s11356-023-26198-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 02/25/2023] [Indexed: 06/18/2023]
Abstract
Legionella, the causative agent of Legionnaires' disease, is an emerging concern for water utilities. Passaic Valley Water Commission (PVWC) is a public drinking water supplier, which provides treated surface water to approximately 800,000 customers in New Jersey. To evaluate the occurrence of Legionella in the PVWC distribution system, swab, first draw, and flushed cold water samples were collected from total coliform sites (n = 58) during a summer and winter sampling event. Endpoint PCR detection methods were combined with culture for Legionella detection. Among 58 total coliform sites during the summer, 17.2% (10/58) of first draw samples were positive for 16S and mip Legionella DNA markers and 15.5% (9/58) in flushed samples. Across both summer and winter sampling, a total of four out of 58 sites had low-level culture detection of Legionella spp. (0.5-1.6 CFU/mL) among first draw samples. Only one site had both a first and flush draw detection (8.5 CFU/mL and 1.1 CFU/mL) for an estimated culture detection frequency of 0% in the summer and 1.7% in the winter among flushed draw samples. No L. pneumophila was detected by culture. Legionella DNA detection was significantly greater in the summer than in the winter, and detection was greater in samples collected from areas treated with phosphate. No statistical difference was found between first draw and flush sample detection. Total organic carbon, copper, and nitrate were significantly associated with Legionella DNA detection.
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Affiliation(s)
- Jessie A Gleason
- Environmental and Occupational Health Surveillance Program, New Jersey Department of Health, 135 East State Street, P.O. Box 369, Trenton, NJ, 08625, USA.
| | - Robert Newby
- Division of Science, New Jersey Department of Environmental Protection, 428 East State Street, P.O. Box 420, Trenton, NJ, 08625, USA
| | - John J Gaynor
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA
| | - Lee H Lee
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA
| | - Tinchun Chu
- Department of Biological Sciences, Seton Hall University, 400 South Orange Ave, South Orange, NJ, 07076, USA
| | - Alorah D Bliese
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA
| | - Calvin W Taylor
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA
| | - Paul Yoon
- Department of Biological Sciences, Seton Hall University, 400 South Orange Ave, South Orange, NJ, 07076, USA
| | - Suzanne DeLorenzo
- Passaic Valley Water Commission, 1525 Main Avenue, Totowa, NJ, 07512, USA
| | - David Pranitis
- Passaic Valley Water Commission, 1525 Main Avenue, Totowa, NJ, 07512, USA
| | - Joe Bella
- Passaic Valley Water Commission, 1525 Main Avenue, Totowa, NJ, 07512, USA
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Bai K, Xu X, Wang X, Li Y, Yu C, Jiang N, Li J, Luo L. Transcriptional profiling of Xanthomonas campestris pv. campestris in viable but nonculturable state. BMC Genomics 2023; 24:105. [PMID: 36894875 PMCID: PMC9999588 DOI: 10.1186/s12864-023-09200-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 02/21/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Xanthomonas campestris pv. campestris (Xcc) is an important seed-borne plant pathogenic bacteria that can cause a serious threat to cruciferous crops. Bacteria can enter into the viable but non-culturable (VBNC) state under stress conditions, and cause potential risks to agricultural production because the VBNC bacterial cells will evade culture-based detection. However, little is known about the mechanism of VBNC. Our previous study showed that Xcc could be induced into VBNC state by copper ion (Cu2+). RESULTS Here, RNA-seq was performed to explore the mechanism of VBNC state. The results indicated that expression profiling was changed dramatically in the different VBNC stages (0 d, 1 d, 2 d and 10 d). Moreover, metabolism related pathways were enriched according to COG, GO and KEGG analysis of differentially expressed genes (DEGs). The DEGs associated with cell motility were down-regulated, whereas pathogenicity related genes were up-regulated. This study revealed that the high expression of genes related to stress response could trigger the active cells to VBNC state, while the genes involved in transcription and translation category, as well as transport and metabolism category, were ascribed to maintaining the VBNC state. CONCLUSION This study summarized not only the related pathways that might trigger and maintain VBNC state, but also the expression profiling of genes in different survival state of bacteria under stress. It provided a new kind of gene expression profile and new ideas for studying VBNC state mechanism in X. campestris pv. campestris.
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Affiliation(s)
- Kaihong Bai
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China.,Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Xiaoli Xu
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Xudong Wang
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Yao Li
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Chengxuan Yu
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Na Jiang
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Jianqiang Li
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Laixin Luo
- Department of Plant Pathology, Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.
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9
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Pan H, Yang D, Wang Y, Rao L, Liao X. Acid shock protein Asr induces protein aggregation to promote E. coli O157:H7 entering viable but non-culturable state under high pressure carbon dioxide stress. Food Microbiol 2023; 109:104136. [DOI: 10.1016/j.fm.2022.104136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/31/2022] [Accepted: 09/05/2022] [Indexed: 10/14/2022]
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10
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Wagley S. The Viable but Non-Culturable (VBNC) State in Vibrio Species: Why Studying the VBNC State Now Is More Exciting than Ever. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:253-268. [PMID: 36792880 DOI: 10.1007/978-3-031-22997-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
During periods that are not conducive for growth or when facing stressful conditions, Vibrios enter a dormant state called the Viable But Non-Culturable (VBNC) state. In this chapter, I will analyse the role of the VBNC state in Vibrio species survival and pathogenesis and the molecular mechanisms regulating this complex phenomenon. I will emphasise some of the novel findings that make studying the VBNC state now more exciting than ever and its significance in the epidemiology of these pathogens and critical role in food safety.
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Affiliation(s)
- Sariqa Wagley
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, UK.
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11
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Inaccuracies of the ISO 11731 Method for Environmental Validation of Legionella in Building Water Systems: Opportunities to Improve Sensitivity and Detect Viable but Non-Culturable Legionella. Microorganisms 2022; 11:microorganisms11010094. [PMID: 36677386 PMCID: PMC9865130 DOI: 10.3390/microorganisms11010094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/24/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
Current environmental diagnostics for the detection of Legionella fail to detect viable but non-culturable Legionella, have sensitivity limitations and are time-consuming (10-14 days to results). The objective of this study was to compare Legionella detection results between the standard ISO 11731 and an innovative Legionella detection method that utilizes a hybrid methodology of traditional microbiology and molecular detection. In this study, four hundred and seventy-six (476) potable building water samples were analyzed with ISO 11731 and the novel method in parallel. Of the 476 total samples that were tested, a discrepancy of 21% was observed when comparing the ISO 11731 method to the novel method. Separating the samples based on hazard control methods yielded a 15.4% discrepancy for chlorinated systems (n = 284) and a 29% discrepancy for monochloraminated systems (n = 192). The data presented here conclusively show inaccuracies in environmental validation for building water systems based on results returned by the standard ISO 11731 method. This is especially evident in systems primarily disinfected with monochloramines. Overall, these data highlight the need for new and innovative methods to overcome the inaccuracies of the traditional ISO 11731 spread plates to prevent disease and injury caused by Legionella.
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12
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Wake Up! Resuscitation of Viable but Nonculturable Bacteria: Mechanism and Potential Application. Foods 2022; 12:foods12010082. [PMID: 36613298 PMCID: PMC9818539 DOI: 10.3390/foods12010082] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 12/29/2022] Open
Abstract
The viable but nonculturable (VBNC) state is a survival strategy for bacteria when encountered with unfavorable conditions. Under favorable environments such as nutrient supplementation, external stress elimination, or supplementation with resuscitation-promoting substances, bacteria will recover from the VBNC state, which is termed "resuscitation". The resuscitation phenomenon is necessary for proof of VBNC existence, which has been confirmed in different ways to exclude the possibility of culturable-cell regrowth. The resuscitation of VBNC cells has been widely studied for the purpose of risk control of recovered pathogenic or spoilage bacteria. From another aspect, the resuscitation of functional bacteria can also be considered a promising field to explore. To support this point, the resuscitation mechanisms were comprehensively reviewed, which could provide the theoretical foundations for the application of resuscitated VBNC cells. In addition, the proposed applications, as well as the prospects for further applications of resuscitated VBNC bacteria in the food industry are discussed in this review.
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13
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Transcriptome analysis and prediction of the metabolic state of stress-induced viable but non-culturable Bacillus subtilis cells. Sci Rep 2022; 12:18015. [PMID: 36289289 PMCID: PMC9605947 DOI: 10.1038/s41598-022-21102-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/22/2022] [Indexed: 01/24/2023] Open
Abstract
Many bacteria adapt their physiology and enter the viable but non-culturable state to survive prolonged exposure to adverse environmental conditions. The VBNC cells maintain active metabolism, membrane integrity and gene transcription. However, they lose the ability to form colonies on a conventional culture media. Thus, standard colony counting methods cannot detect these alive but dormant cells. The Gram-positive bacterium Bacillus subtilis was found to enter the VBNC state when pre-exposed to osmotic stress and treated with a lethal dose of kanamycin. These cells reduced their metabolic activity, ceased growth and division and became kanamycin-tolerant. Interestingly, despite active metabolism, the majority of the kanamycin tolerant cells could not be revived on LB agar. In this study, we use a robust RNA-Seq technique to elucidate the differences in transcriptional profiles of B. subtilis VBNC cells. A comparative analysis of differently expressed genes and operons performed in this study indicates high similarities in transcriptional responses of VBNC and kanamycin-sensitive cells to antibiotic treatment. Moreover, this work reveals that VBNC cells strongly upregulate genes involved in proline uptake and catabolism, suggesting a putative role of proline as nutrient in VBNC cells.
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14
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Bai K, Jiang N, Chen X, Xu X, Li J, Luo L. RNA-Seq Analysis Discovers the Critical Role of Rel in ppGpp Synthesis, Pathogenicity, and the VBNC State of Clavibacter michiganensis. PHYTOPATHOLOGY 2022; 112:1844-1858. [PMID: 35341314 DOI: 10.1094/phyto-01-22-0023-r] [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: 06/14/2023]
Abstract
The viable but nonculturable (VBNC) state is a unique survival strategy of bacteria in response to stress conditions. It was confirmed that Clavibacter michiganensis, the causal agent of bacterial canker in tomato, could be induced into the VBNC state by exposure to CuSO4 in an oligotrophic solution. RNA-sequencing analysis was used to monitor the mechanisms of the VBNC state during CuSO4 induction in C. michiganensis. The results identified that numerous genes involved in stringent response, copper resistance, and stress resistance were upregulated, and some involved in cell division were downregulated significantly. The study investigated the importance of Rel, which is an essential enzyme in the synthesis of the molecular alarmone ppGpp, via the generation of a Δrel mutant and its complementation strain. Biological characterization revealed that deficiency of rel reduced the bacterial growth, production of exopolysaccharides, and pathogenicity as well as ppGpp production. The Δrel mutant increased the sensitivity to environmental stress, exhibiting reduced growth on minimal media and a propensity to enter the VBNC state in response to CuSO4. These findings have important implications for the understanding of survival mechanism and management of C. michiganensis and other phytopathogenic bacteria.
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Affiliation(s)
- Kaihong Bai
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xing Chen
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xiaoli Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
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15
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Ortí-Lucas RM, Luciano E. New immunomagnetic separation method to analyze risk factors for Legionella colonization in health care centres. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2022; 32:744-750. [PMID: 35264765 PMCID: PMC8906530 DOI: 10.1038/s41370-022-00421-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 02/09/2022] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND It's pivotal to control the presence of legionella in sanitary structures. So, it's important to determine the risk factors associated with Legionella colonization in health care centres. In recent years that is why new diagnostic techniques have been developed. OBJECTIVE To evaluate risks factors for Legionella colonization using a novel and more sensitive Legionella positivity index. METHODS A total of 204 one-litre water samples (102 cold water samples and 102 hot water samples), were collected from 68 different sampling sites of the hospital water system and tested for Legionella spp. by two laboratories using culture, polymerase chain reaction and a method based on immunomagnetic separation (IMS). A Legionella positivity index was defined to evaluate Legionella colonization and associated risk factors in the 68 water samples sites. We performed bivariate analyses and then logistic regression analysis with adjustment of potentially confounding variables. We compared the performance of culture and IMS methods using this index as a new gold standard to determine if rapid IMS method is an acceptable alternative to the use of slower culture method. RESULTS Based on the new Legionella positivity index, no statistically significant differences were found neither between laboratories nor between methods (culture, IMS). Positivity was significantly correlated with ambulatory health assistance (p = 0.05) and frequency of use of the terminal points. The logistic regression model revealed that chlorine (p = 0.009) and the frequency of use of the terminal points (p = 0.001) are predictors of Legionella colonization. Regarding this index, the IMS method proved more sensitive (69%) than culture method (65.4%) in hot water samples. SIGNIFICANCE We showed that the frequency of use of terminal points should be considered when examining environmental Legionella colonization, which can be better evaluated using the provided Legionella positivity index. This study has implications for the prevention of Legionnaires' disease in hospital settings.
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Affiliation(s)
- Rafael Manuel Ortí-Lucas
- Research group on Public Health and Patient Safety, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
- Department of Preventive Medicine, Hospital Clínico Universitario de Valencia, Valencia, Spain.
| | - Eugenio Luciano
- Department of Preventive Medicine, Hospital Clínico Universitario de Valencia, Valencia, Spain.
- Escuela de Doctorado, Universidad Católica de Valencia San Vicente Mártir, Valencia, Spain.
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16
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Niculita-Hirzel H, Vanhove AS, Leclerc L, Girardot F, Pourchez J, Allegra S. Risk Exposure to Legionella pneumophila during Showering: The Difference between a Classical and a Water Saving Shower System. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063285. [PMID: 35328980 PMCID: PMC8955837 DOI: 10.3390/ijerph19063285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/01/2022] [Accepted: 03/08/2022] [Indexed: 02/04/2023]
Abstract
The increase in legionellosis incidence in the general population in recent years calls for a better characterization of the sources of infection, such as showering. Water-efficient shower systems that use water-atomizing technology have been shown to emit slightly more inhalable particles in the range of bacterial sizes than the traditional systems; however, the actual rate of bacterial emission remains poorly documented. The aim of this study was to assess the aerosolisation rate of the opportunistic water pathogen Legionella pneumophila during showering with one shower system representative of each technology. To achieve this objective, we performed controlled experiments inside a glove box and determined the emitted dose and viability of airborne Legionella. The bioaerosols were sampled with a Coriolis® Delta air sampler and the total number of viable (cultivable and noncultivable) Legionella was determined by flow cytometry and culture. We found that the rate of viable and cultivable Legionella aerosolized from the water jet was similar between the two showerheads: the viable fraction represents 0.02% of the overall bacteria present in water, while the cultivable fraction corresponds to only 0.0005%. The two showerhead models emitted a similar ratio of airborne Legionella viable and cultivable per volume of water used. Therefore, the risk of exposure to Legionella is not expected to increase significantly with the new generation of water-efficient showerheads.
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Affiliation(s)
- Hélène Niculita-Hirzel
- Department Work, Heath & Environment, Center for Primary Care and Public Health (Unisanté), University of Lausanne, Route de la Corniche 2, CH-1066 Epalinges-Lausanne, Switzerland
- Correspondence:
| | - Audrey S. Vanhove
- EVS-ISTHME UMR 5600, CNRS, University Jean Monnet of Saint-Etienne, F-42023 Saint-Etienne, France; (A.S.V.); (F.G.); (S.A.)
| | - Lara Leclerc
- Mines Saint-Etienne, University of Lyon, University Jean Monnet of Saint-Etienne, INSERM, U 1059 Sainbiose, Centre CIS, F-42023 Saint-Etienne, France; (L.L.); (J.P.)
| | - Françoise Girardot
- EVS-ISTHME UMR 5600, CNRS, University Jean Monnet of Saint-Etienne, F-42023 Saint-Etienne, France; (A.S.V.); (F.G.); (S.A.)
| | - Jérémie Pourchez
- Mines Saint-Etienne, University of Lyon, University Jean Monnet of Saint-Etienne, INSERM, U 1059 Sainbiose, Centre CIS, F-42023 Saint-Etienne, France; (L.L.); (J.P.)
| | - Séverine Allegra
- EVS-ISTHME UMR 5600, CNRS, University Jean Monnet of Saint-Etienne, F-42023 Saint-Etienne, France; (A.S.V.); (F.G.); (S.A.)
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17
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Progulske-Fox A, Chukkapalli SS, Getachew H, Dunn WA, Oliver JD. VBNC, previously unrecognized in the life cycle of Porphyromonas gingivalis?. J Oral Microbiol 2022; 14:1952838. [PMID: 35035782 PMCID: PMC8759725 DOI: 10.1080/20002297.2021.1952838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Bacteria are exposed to stresses during their growth and multiplication in their ecological systems to which they respond in multiple ways as expert survivalists. One such response mechanism is to convert to a viable but not culturable (VBNC) state. As the name indicates, bacteria in the VBNC state have lost their ability to grow on routine growth medium. A large number of bacteria including many pathogenic species have been reported to be able to enter a VBNC state. VBNC differs from culturable cells in various physiological properties which may result in changes in chemical resistance, adhesion, cellular morphology, metabolism, gene expression, membrane and cell wall composition and/or virulence. The ability of VBNC bacteria to return to the culturable state or resuscitate, when the stressor is removed poses a considerable threat to public health. There have been few publications that overtly describe the ability of oral pathogenic species to enter the VBNC state. However, the presence of VBNCs among oral pathogens such as Porphyromonas gingivalis in human chronic infections may be an important virulence factor and have severe implications for therapy. In this review, we intend to i) define and summarize the significance of the VBNC state in general and ii) discuss the VBNC state of oral bacteria with regard to P. gingivalis. Future studies focused on this phenomenon of intraoral VBNC would provide novel molecular insights on the virulence and persistence of oral pathogens during chronic infections and identify potential novel therapies.
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Affiliation(s)
- A Progulske-Fox
- Department of Oral Biology, Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA.,Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA
| | - S S Chukkapalli
- Department of Oral Biology, Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA.,Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA
| | - H Getachew
- Department of Oral Biology, Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA.,Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA
| | - W A Dunn
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL, USA
| | - J D Oliver
- Department of Biological Sciences, University of North Carolina, Charlotte, NC, USA
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18
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Atwill ER, Jeamsripong S. Bacterial diversity and potential risk factors associated with Salmonella contamination of seafood products sold in retail markets in Bangkok, Thailand. PeerJ 2022; 9:e12694. [PMID: 35036165 PMCID: PMC8711275 DOI: 10.7717/peerj.12694] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 12/06/2021] [Indexed: 11/20/2022] Open
Abstract
Consumption of contaminated food causes 600 million cases, including 420,000 of fatal infections every year. Estimated cost from food-borne illnesses is USD 110 billion per year, which is an economic burden to low- and middle-income countries. Thailand is a leading producer and consumer of seafood, but little is known about bacterial contamination in seafood. In particular, public health agencies need to know the relationship between Salmonella contamination in seafood and risk factors, as assessed with readily available culture-dependent and bacterial phenotyping methods. To address this, levels of indicator bacteria, Salmonella and Vibrio in various seafood products were determined to identify risk factors associated with Salmonella contamination. A total of 335 samples were collected from October 2018 to July 2019 at seafood markets throughout Bangkok, Thailand; overall sample composition was Pacific white shrimp (n = 85), oysters (n = 82), blood cockles (n = 84), and Asian seabass (n = 84). Prevalence was 100% for fecal coliforms and 85% for E. coli. In contrast, prevalence was 59% for V. parahaemolyticus, 49% for V. cholerae, 19% for V. alginolyticus, 18% for V. vulnificus, and 36% for Salmonella. Highest concentrations of fecal coliforms and E. coli were in oysters. Highest concentrations of Salmonella with Matopeni (31%) being the predominant serotype were in shrimp. Salmonella contamination was significantly associated with type of seafood, sampling location, retail conditions, and the presence of E. coli, V. alginolyticus and V. vulnificus. A cutoff value for E. coli concentration of 1.3 × 104 MPN/g predicted contamination of Salmonella, with a sensitivity of 84% and specificity of 61%. Displaying seafood products on ice, presence of E. coli and Vibrio, and seafood derived from Eastern Thailand were associated with an increased risk of Salmonella contamination.
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Affiliation(s)
- Edward R Atwill
- School of Veterinary Medicine, University of California, Davis, Department of Population Health and Reproduction, Davis, CA, USA
| | - Saharuetai Jeamsripong
- Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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19
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Zhang C, Lu J. Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems. FRONTIERS IN ENVIRONMENTAL SCIENCE 2021; 9:1-22. [PMID: 35004706 PMCID: PMC8740890 DOI: 10.3389/fenvs.2021.684319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Opportunistic pathogens (OPs) are natural inhabitants and the predominant disease causative biotic agents in municipal engineered water systems (EWSs). In EWSs, OPs occur at high frequencies and concentrations, cause drinking-water-related disease outbreaks, and are a major factor threatening public health. Therefore, the prevalence of OPs in EWSs represents microbial drinking water quality. Closely or routinely monitoring the dynamics of OPs in municipal EWSs is thus critical to ensuring drinking water quality and protecting public health. Monitoring the dynamics of conventional (fecal) indicators (e.g., total coliforms, fecal coliforms, and Escherichia coli) is the customary or even exclusive means of assessing microbial drinking water quality. However, those indicators infer only fecal contamination due to treatment (e.g., disinfection within water utilities) failure and EWS infrastructure issues (e.g., water main breaks and infiltration), whereas OPs are not contaminants in drinking water. In addition, those indicators appear in EWSs at low concentrations (often absent in well-maintained EWSs) and are uncorrelated with OPs. For instance, conventional indicators decay, while OPs regrow with increasing hydraulic residence time. As a result, conventional indicators are poor indicators of OPs (the major aspect of microbial drinking water quality) in EWSs. An additional or supplementary indicator that can well infer the prevalence of OPs in EWSs is highly needed. This systematic review argues that Legionella as a dominant OP-containing genus and natural inhabitant in EWSs is a promising candidate for such a supplementary indicator. Through comprehensively comparing the behavior (i.e., occurrence, growth and regrowth, spatiotemporal variations in concentrations, resistance to disinfectant residuals, and responses to physicochemical water quality parameters) of major OPs (e.g., Legionella especially L. pneumophila, Mycobacterium, and Pseudomonas especially P. aeruginosa), this review proves that Legionella is a promising supplementary indicator for the prevalence of OPs in EWSs while other OPs lack this indication feature. Legionella as a dominant natural inhabitant in EWSs occurs frequently, has a high concentration, and correlates with more microbial and physicochemical water quality parameters than other common OPs. Legionella and OPs in EWSs share multiple key features such as high disinfectant resistance, biofilm formation, proliferation within amoebae, and significant spatiotemporal variations in concentrations. Therefore, the presence and concentration of Legionella well indicate the presence and concentrations of OPs (especially L. pneumophila) and microbial drinking water quality in EWSs. In addition, Legionella concentration indicates the efficacies of disinfectant residuals in EWSs. Furthermore, with the development of modern Legionella quantification methods (especially quantitative polymerase chain reactions), monitoring Legionella in ESWs is becoming easier, more affordable, and less labor-intensive. Those features make Legionella a proper supplementary indicator for microbial drinking water quality (especially the prevalence of OPs) in EWSs. Water authorities may use Legionella and conventional indicators in combination to more comprehensively assess microbial drinking water quality in municipal EWSs. Future work should further explore the indication role of Legionella in EWSs and propose drinking water Legionella concentration limits that indicate serious public health effects and require enhanced treatment (e.g., booster disinfection).
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Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH, United States
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, United States
- Correspondence: Jingrang Lu,
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20
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Zhang C, Struewing I, Mistry JH, Wahman DG, Pressman J, Lu J. Legionella and other opportunistic pathogens in full-scale chloraminated municipal drinking water distribution systems. WATER RESEARCH 2021; 205:117571. [PMID: 34628111 PMCID: PMC8629321 DOI: 10.1016/j.watres.2021.117571] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 08/02/2021] [Accepted: 08/13/2021] [Indexed: 05/06/2023]
Abstract
Water-based opportunistic pathogens (OPs) are a leading cause of drinking-water-related disease outbreaks, especially in developed countries such as the United States (US). Physicochemical water quality parameters, especially disinfectant residuals, control the (re)growth, presence, colonization, and concentrations of OPs in drinking water distribution systems (DWDSs), while the relationship between OPs and those parameters remain unclear. This study aimed to quantify how physicochemical parameters, mainly monochloramine residual concentration, hydraulic residence time (HRT), and seasonality, affected the occurrence and concentrations of four common OPs (Legionella, Mycobacterium, Pseudomonas, and Vermamoeba vermiformis) in four full-scale DWDSs in the US. Legionella as a dominant OP occurred in 93.8% of the 64 sampling events and had a mean density of 4.27 × 105 genome copies per liter. Legionella positively correlated with Mycobacterium, Pseudomonas, and total bacteria. Multiple regression with data from the four DWDSs showed that Legionella had significant correlations with total chlorine residual level, free ammonia concentration, and trihalomethane concentration. Therefore, Legionella is a promising indicator of water-based OPs, reflecting microbial water quality in chloraminated DWDSs. The OP concentrations had strong seasonal variations and peaked in winter and/or spring possibly because of reduced water usage (i.e., increased water stagnation or HRT) during cold seasons. The OP concentrations generally increased with HRT presumably because of disinfectant residual decay, indicating the importance of well-maintaining disinfectant residuals in DWDSs for OP control. The concentrations of Mycobacterium, Pseudomonas, and V. vermiformis were significantly associated with total chlorine residual concentration, free ammonia concentration, and pH and trihalomethane concentration, respectively. Overall, this study demonstrates how the significant spatiotemporal variations of OP concentrations in chloraminated DWDSs correlated with critical physicochemical water quality parameters such as disinfectant residual levels. This work also indicates that Legionella is a promising indicator of OPs and microbial water quality in chloraminated DWDSs.
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Affiliation(s)
- Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, Ohio, USA
| | - Ian Struewing
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Jatin H Mistry
- United States Environmental Protection Agency, Region 6, Dallas, Texas, USA
| | - David G Wahman
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Jonathan Pressman
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, Ohio, USA.
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21
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Oliveira MM, de Almeida FA, Baglinière F, de Oliveira LL, Vanetti MCD. Behavior of Salmonella Enteritidis and Shigella flexneri during induction and recovery of the viable but nonculturable state. FEMS Microbiol Lett 2021; 368:6316107. [PMID: 34227668 DOI: 10.1093/femsle/fnab087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 07/02/2021] [Indexed: 11/12/2022] Open
Abstract
Bacteria may enter into a viable but nonculturable (VBNC) state as a response to stresses, such as those found in food processing. Cells in the VBNC state lose the ability to grow in a conventional culture medium but man recover culturability. The viability, culturability and intracellular reactive oxygen species (ROS) of Salmonella Enteritidis and Shigella flexneri were evaluated under stress conditions to induce a VBNC state. Cells were maintained under nutritional, osmotic and cold stresses (long-term induction) in Butterfield's phosphate solution plus 1.2 M of NaCl at 4°C and under nutritional and oxidative stresses (short-term induction) in 10 mM of H2O2. Culture media, recovery agents, sterilization methods of media and incubation temperature, were combined and applied to recover the culturability of the VBNC cells. Salmonella entered in the VBNC state after 135 days under long-term induction, while Shigella maintained culturability after 240 days. Under short-term induction, Salmonella and Shigella lose culturability after 135 and 240 min, respectively. Flow cytometric analysis revealed viable cells and intracellular ROS in both species in VBNC. It was not possible to recover the culturability of VBNC cells using the 42 combinations of different factors.
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Affiliation(s)
- Mayara Messias Oliveira
- Department of Microbiology, Universidade Federal de Viçosa (UFV), Viçosa, MG, 36570-450, Brazil.,Department of Food Science, Universidade Estadual de Campinas (Unicamp), Campinas, SP, 13084-654, Brazil
| | - Felipe Alves de Almeida
- Department of Nutrition, Universidade Federal de Juiz de Fora (UFJF), Governador Valadares, MG, 35032-620, Brazil
| | - François Baglinière
- Department of Microbiology, Universidade Federal de Viçosa (UFV), Viçosa, MG, 36570-450, Brazil
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22
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Zhou A, Wang L, Zhang J, Yang X, Ou Z, Zhao L. Survival of viable but nonculturable Cronobacter sakazakii in macrophages contributes to infections. Microb Pathog 2021; 158:105064. [PMID: 34171399 DOI: 10.1016/j.micpath.2021.105064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/09/2021] [Accepted: 06/16/2021] [Indexed: 02/04/2023]
Abstract
Cronobacter sakazakii (C. sakazakii), a pathogen that exists in dry and low-moisture environments, such as powder infant formula (PIF), can enter a viable but nonculturable (VBNC) state under harsh conditions, which enables it to escape traditional detection methods and thus poses a potential public health risk. This study aimed at assessing the virulent nature of VBNC C. sakazakii. Our results showed that VBNC C. sakazakii induced intestinal inflammation in neonatal rats. However, the degree of inflammation was significantly lower than that of culturable bacteria due to decreasing endotoxin production, motility, adhesion, and invasion ability in the VBNC state. From the perspective of bacterial translocation, the numbers of C. sakazakii in the blood, liver, and spleen of rats treated with VBNC cells were in the same order of magnitude as those treated with its culturable counterpart and may lead to the same degree of bacteremia. According to the macrophage survival assays, the survival rate of VBNC C. sakazakii within macrophages was 4.7 times higher than that of culturable cells. Based on these findings, we hypothesize that VBNC C. sakazakii evaded the host immune defense system, penetrated the tissue barrier, and translocated to the bloodstream, liver, and spleen through macrophages. Thus, our study reveals that VBNC C. sakazakii could be a potential risk for infants' health.
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Affiliation(s)
- Aidi Zhou
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, PR China
| | - Li Wang
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China.
| | - Jingfeng Zhang
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, PR China
| | - Xiaoqing Yang
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China
| | - Zhihua Ou
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China
| | - Lichao Zhao
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Wu Shan Road 483, Guangzhou 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, PR China.
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23
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Kirschner AKT, Vierheilig J, Flemming HC, Wingender J, Farnleitner AH. How dead is dead? Viable but non-culturable versus persister cells. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:243-245. [PMID: 33904249 DOI: 10.1111/1758-2229.12949] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Alexander K T Kirschner
- Medical University Vienna, Institute for Hygiene and Applied Immunology - Water Microbiology, Vienna, A-1090, Austria
- Karl Landsteiner University for Health Sciences, Research Division Water Quality and Health, Krems, A-3500, Austria
- Interuniversity Cooperation Centre Water and Health, www.waterandhealth.at, Austria
| | - Julia Vierheilig
- Karl Landsteiner University for Health Sciences, Research Division Water Quality and Health, Krems, A-3500, Austria
- Interuniversity Cooperation Centre Water and Health, www.waterandhealth.at, Austria
| | - Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 637551, Singapore
- University of Duisburg-Essen, Biofilm Centre, Universitätsstrasse 5, Essen, 45131, Germany
- Water Academy, Friedrichshafen, 88045, Germany
| | - Jost Wingender
- University of Duisburg-Essen, Biofilm Centre, Universitätsstrasse 5, Essen, 45131, Germany
| | - Andreas H Farnleitner
- Karl Landsteiner University for Health Sciences, Research Division Water Quality and Health, Krems, A-3500, Austria
- Interuniversity Cooperation Centre Water and Health, www.waterandhealth.at, Austria
- Technische Universität Wien, Institute of Chemical, Environmental and Bioscience Engineering, Vienna, A-1060, Austria
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24
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Tan MF, Zou G, Wei Y, Liu WQ, Li HQ, Hu Q, Zhang LS, Zhou R. Protein-protein interaction network and potential drug target candidates of Streptococcus suis. J Appl Microbiol 2021; 131:658-670. [PMID: 33249680 DOI: 10.1111/jam.14950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/15/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023]
Abstract
AIMS This study aimed to explore potential drug targets of Streptococcus suis at the system level. METHODS AND RESULTS A homologous protein mapping method was used in the construction of a protein-protein interaction (PPI) network of S. suis, which presented 1147 non-redundant interaction pairs among 286 proteins. The parameters of PPI networks were calculated and showed scale-free network properties. In all, 41 possibly essential proteins identified from 47 highly connected proteins were selected as potential drug target candidates. Of these proteins, 30 were already regarded as drug targets in other bacterial species. Six transporters with high connections to other functional proteins were identified as probably not essential but important functional proteins. Afterward, the subnetwork centred with cell division protein FtsZ was used in confirming the PPI network through bacterial two-hybrid analysis. CONCLUSIONS The predicted PPI network covers 13·04% of the proteome in S. suis. The selected 41 potential drug target candidates are conserved between S. suis and several model bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY The predictions included proteins known to be drug targets, and a verifying experiment confirmed the reliability of predicted interactions. This work is the first to present systematic computational PPI data for S. suis and provides potential drug targets, which are valuable in exploring novel anti-streptococcus drugs.
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Affiliation(s)
- M-F Tan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China.,Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, China
| | - G Zou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - Y Wei
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, China
| | - W-Q Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - H-Q Li
- Institute of Animal Husbandry and Veterinary Medicine, Jiangxi Academy of Agricultural Sciences, Nanchang, China
| | - Q Hu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - L-S Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - R Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China.,International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China
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25
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Bacterial dormancy: A subpopulation of viable but non-culturable cells demonstrates better fitness for revival. PLoS Pathog 2021; 17:e1009194. [PMID: 33439894 PMCID: PMC7837498 DOI: 10.1371/journal.ppat.1009194] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/26/2021] [Accepted: 11/27/2020] [Indexed: 01/08/2023] Open
Abstract
The viable but non culturable (VBNC) state is a condition in which bacterial cells are viable and metabolically active, but resistant to cultivation using a routine growth medium. We investigated the ability of V. parahaemolyticus to form VBNC cells, and to subsequently become resuscitated. The ability to control VBNC cell formation in the laboratory allowed us to selectively isolate VBNC cells using fluorescence activated cell sorting, and to differentiate subpopulations based on their metabolic activity, cell shape and the ability to cause disease in Galleria mellonella. Our results showed that two subpopulations (P1 and P2) of V. parahaemolyticus VBNC cells exist and can remain dormant in the VBNC state for long periods. VBNC subpopulation P2, had a better fitness for survival under stressful conditions and showed 100% revival under favourable conditions. Proteomic analysis of these subpopulations (at two different time points: 12 days (T12) and 50 days (T50) post VBNC) revealed that the proteome of P2 was more similar to that of the starting microcosm culture (T0) than the proteome of P1. Proteins that were significantly up or down-regulated between the different VBNC populations were identified and differentially regulated proteins were assigned into 23 functional groups, the majority being assigned to metabolism functional categories. A lactate dehydrogenase (lldD) protein, responsible for converting lactate to pyruvate, was significantly upregulated in all subpopulations of VBNC cells. Deletion of the lactate dehydrogenase (RIMD2210633:ΔlldD) gene caused cells to enter the VBNC state significantly more quickly compared to the wild-type, and adding lactate to VBNC cells aided their resuscitation and extended the resuscitation window. Addition of pyruvate to the RIMD2210633:ΔlldD strain restored the wild-type VBNC formation profile. This study suggests that lactate dehydrogenase may play a role in regulating the VBNC state.
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26
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Cullom AC, Martin RL, Song Y, Williams K, Williams A, Pruden A, Edwards MA. Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens. Pathogens 2020; 9:E957. [PMID: 33212943 PMCID: PMC7698398 DOI: 10.3390/pathogens9110957] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/20/2022] Open
Abstract
Growth of Legionella pneumophila and other opportunistic pathogens (OPs) in drinking water premise plumbing poses an increasing public health concern. Premise plumbing is constructed of a variety of materials, creating complex environments that vary chemically, microbiologically, spatially, and temporally in a manner likely to influence survival and growth of OPs. Here we systematically review the literature to critically examine the varied effects of common metallic (copper, iron) and plastic (PVC, cross-linked polyethylene (PEX)) pipe materials on factors influencing OP growth in drinking water, including nutrient availability, disinfectant levels, and the composition of the broader microbiome. Plastic pipes can leach organic carbon, but demonstrate a lower disinfectant demand and fewer water chemistry interactions. Iron pipes may provide OPs with nutrients directly or indirectly, exhibiting a high disinfectant demand and potential to form scales with high surface areas suitable for biofilm colonization. While copper pipes are known for their antimicrobial properties, evidence of their efficacy for OP control is inconsistent. Under some circumstances, copper's interactions with premise plumbing water chemistry and resident microbes can encourage growth of OPs. Plumbing design, configuration, and operation can be manipulated to control such interactions and health outcomes. Influences of pipe materials on OP physiology should also be considered, including the possibility of influencing virulence and antibiotic resistance. In conclusion, all known pipe materials have a potential to either stimulate or inhibit OP growth, depending on the circumstances. This review delineates some of these circumstances and informs future research and guidance towards effective deployment of pipe materials for control of OPs.
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Affiliation(s)
- Abraham C. Cullom
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Rebekah L. Martin
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
- Civil and Environmental Engineering, Virginia Military Institute, Lexington, VA 24450, USA
| | - Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | | | - Amanda Williams
- c/o Marc Edwards, Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA; (A.C.C.); (R.L.M.); (Y.S.); (A.P.)
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27
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Chen S, Zeng J, Wang Y, Ye C, Zhu S, Feng L, Zhang S, Yu X. Modelling the effect of chlorination/chloramination on induction of viable but non-culturable (VBNC) Escherichia coli. ENVIRONMENTAL TECHNOLOGY 2020; 41:3443-3455. [PMID: 31018776 DOI: 10.1080/09593330.2019.1611939] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/19/2019] [Indexed: 06/09/2023]
Abstract
Many bacteria, including Escherichia coli, are known to enter into a viable but non-culturable (VBNC) state when exposed to harsh environmental stresses. The VBNC cells introduced by chlorination/chloramination have raised increasing concern about biological safety of drinking water. A quantitative relationship between chlorination/chloramination and number of VBNC cells has not been found. In this study, a mathematical model was developed to quantify the effect of chlorination/chloramination on induction of viable but non-culturable (VBNC) Escherichia coli. the model was generated based on a first order kinetics of chlorination/chloramination using the data collected from laboratory disinfection experiments. The disinfection rates of culturable cells (kc ) and viable cells (kv ) were dose-dependent, and they were also modelled in different initial concentrations by regression analysis to overcome the shortcoming of dose-dependent. In general, the kc and kv values for chlorination (kc , 2.59-29.89 h-1; kv , 19.52-26.74 h-1) was 2-58 times greater than that for chloramination (kc , 0.5446-10.81 h-1; kv , 0.3398-14.57 h-1), suggesting that chlorine was more effective than chloramine in reducing the number of culturable and VBNC cells at same dose of disinfectant. Ultimately, the generated models, which could describe the dynamics of VBNC cells formation in chlorination/chloramination, can provide practical guidance in drinking water treatment and it can also be applied to risk assessment of drinking water management systems.
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Affiliation(s)
- Sheng Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Jie Zeng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yahong Wang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Chengsong Ye
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
| | - Shuai Zhu
- Beijing Guohuan Tsinghua Environmental Engineering Design & Research Institute Co., Ltd, Beijing, People's Republic of China
| | - Lin Feng
- School of the Environment, China Renmin University, Beijing, People's Republic of China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
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28
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Laribi A, Allegra S, Souiri M, Mzoughi R, Othmane A, Girardot F. Legionella pneumophila sg1-sensing signal enhancement using a novel electrochemical immunosensor in dynamic detection mode. Talanta 2020; 215:120904. [PMID: 32312449 DOI: 10.1016/j.talanta.2020.120904] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 03/03/2020] [Accepted: 03/05/2020] [Indexed: 01/20/2023]
Abstract
This work presents a comparison between static and dynamic modes of biosensing using a novel microfluidic assay for continuous and quantitative detection of Legionella pneumophila sg1 in artificial water samples. A self-assembled monolayer of 16-amino-1-hexadecanethiol (16-AHT) was covalently linked to a gold substrate, and the resulting modified surface was used to immobilize an anti-Legionella pneumophila monoclonal antibody (mAb). The modified surfaces formed during the biosensor functionalization steps were characterized using electrochemical measurements and microscopic imaging techniques. Under static conditions, the biosensor exhibited a wide linear response range from 10 to 108 CFU/mL and a detection limit of 10 CFU/mL. Using a microfluidic system, the biosensor responses exhibited a linear relationship for low bacterial concentrations ranging from 10 to 103 CFU/mL under dynamic conditions and an enhancement of sensing signals by a factor of 4.5 compared to the sensing signals obtained under static conditions with the same biosensor for the detection of Legionella cells in artificially contaminated samples.
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Affiliation(s)
- Ahlem Laribi
- Environments, Territories, Societies (EVS) Lab, Mixed Research Unit (Jean Monnet University - French National Centre for Scientific Research) 5600, University of Lyon, F42023, France; Laboratory of Advanced Materials and Interfaces, Faculty of Medicine, University of Monastir, 5019, Monastir, Tunisia.
| | - Séverine Allegra
- Environments, Territories, Societies (EVS) Lab, Mixed Research Unit (Jean Monnet University - French National Centre for Scientific Research) 5600, University of Lyon, F42023, France
| | - Mina Souiri
- Laboratory of Advanced Materials and Interfaces, Faculty of Medicine, University of Monastir, 5019, Monastir, Tunisia
| | - Ridha Mzoughi
- Regional Laboratory of Hygiene, University Hospital Farhat Hached, 4000 Sousse, Tunisia and Laboratory of Analysis Treatment and Valorization of Pollutants and Products, Faculty of Pharmacy, 5000, Monastir, Tunisia
| | - Ali Othmane
- Laboratory of Advanced Materials and Interfaces, Faculty of Medicine, University of Monastir, 5019, Monastir, Tunisia
| | - Françoise Girardot
- Environments, Territories, Societies (EVS) Lab, Mixed Research Unit (Jean Monnet University - French National Centre for Scientific Research) 5600, University of Lyon, F42023, France
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29
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Fisher KE, Wickenberg LP, Leonidas LF, Ranz AA, Habib MA, Buford RM, McCoy WF. Next Day Legionella PCR: a highly reliable negative screen for Legionella in the built environment. JOURNAL OF WATER AND HEALTH 2020; 18:345-357. [PMID: 32589620 DOI: 10.2166/wh.2020.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The opportunistic, waterborne pathogen Legionella caused 9,933 cases of Legionnaires' disease in 2018 in the United States (CDC.gov). The incidence of Legionnaires' disease can be reduced by maintaining clean building water systems through water management programs (WMPs). WMPs often include validation testing to confirm the control of bacteria, but the traditional culture method for enumerating Legionella requires 10-14 days to obtain results. A rapid DNA extraction developed by Phigenics and a real-time PCR negative screen for the genus Legionella provided results the day after sampling. This study evaluated the Next Day Legionella PCR (Phigenics, LLC) compared with the traditional culture method (ISO 11731) on 11,125 building water samples for approximately 1 year. Two DNA extraction methods (Methods 1 and 2) were compared. The negative predictive value (NPV) of the Next Day Legionella PCR in comparison to traditional culture for Method 1 was 99.95%, 99.92%, 99.85%, and 99.17% at >10, >2, >1, and >0.1 CFU/ml limits of detection, respectively. The improved DNA extraction (Method 2) increased the NPV to 100% and 99.88% at >1 and >0.1 CFU/ml, respectively. These results demonstrate the reliability of the genus-level Legionella PCR negative screen to predict culture-negative water samples.
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Affiliation(s)
- Katherine E Fisher
- Phigenics Research and Innovation Team, Nevada Center for Applied Research, Reno, NV, USA E-mail:
| | - Leah P Wickenberg
- Phigenics Research and Innovation Team, Nevada Center for Applied Research, Reno, NV, USA E-mail:
| | - Lesley F Leonidas
- Phigenics Analytical Services Laboratory (PASL), Warrenville, IL, USA
| | - Anna A Ranz
- Phigenics Analytical Services Laboratory (PASL), Fayetteville, AR, USA
| | - Michelle A Habib
- Phigenics Analytical Services Laboratory (PASL), Warrenville, IL, USA
| | - Rafael M Buford
- Phigenics Analytical Services Laboratory (PASL), Fayetteville, AR, USA
| | - William F McCoy
- Phigenics Research and Innovation Team, Nevada Center for Applied Research, Reno, NV, USA E-mail:
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30
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Quantitative detection of viable but nonculturable state Escherichia coli O157:H7 by ddPCR combined with propidium monoazide. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107140] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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31
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Dong K, Pan H, Yang D, Rao L, Zhao L, Wang Y, Liao X. Induction, detection, formation, and resuscitation of viable but non‐culturable state microorganisms. Compr Rev Food Sci Food Saf 2019; 19:149-183. [DOI: 10.1111/1541-4337.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Kai Dong
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Hanxu Pan
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Dong Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Lei Rao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Liang Zhao
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Yongtao Wang
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human HealthCollege of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- College of Food Science and Nutritional EngineeringChina Agricultural University Beijing China
- Key Lab of Fruit and Vegetable ProcessingMinistry of Agriculture and Rural Affairs Beijing China
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32
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Paniel N, Noguer T. Detection of Salmonella in Food Matrices, from Conventional Methods to Recent Aptamer-Sensing Technologies. Foods 2019; 8:E371. [PMID: 31480504 PMCID: PMC6770675 DOI: 10.3390/foods8090371] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 01/01/2023] Open
Abstract
Rapid detection of the foodborne pathogen Salmonella in food processing is of crucial importance to prevent food outbreaks and to ensure consumer safety. Detection and quantification of Salmonella species in food samples is routinely performed using conventional culture-based techniques, which are labor intensive, involve well-trained personnel, and are unsuitable for on-site and high-throughput analysis. To overcome these drawbacks, many research teams have developed alternative methods like biosensors, and more particularly aptasensors, were a nucleic acid is used as biorecognition element. The increasing interest in these devices is related to their high specificity, convenience, and relative rapid response. This review aims to present the advances made in these last years in the development of biosensors for the detection and the quantification of Salmonella, highlighting applications on meat from the chicken food chain.
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Affiliation(s)
- Nathalie Paniel
- Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan, France.
- Unité EMaiRIT'S, Centre Technique de la Conservation des Produits Agricoles (CTCPA), Site Agroparc, 449 Avenue Clément Ader, BP21203, 84911 Avignon, France.
| | - Thierry Noguer
- Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan, France.
- Laboratoire de Biodiversité et Biotechnologies Microbiennes, USR 3579, Sorbonne Universités (UPMC) Paris 6 et CNRS, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France.
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33
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Cervero-Aragó S, Schrammel B, Dietersdorfer E, Sommer R, Lück C, Walochnik J, Kirschner A. Viability and infectivity of viable but nonculturable Legionella pneumophila strains induced at high temperatures. WATER RESEARCH 2019; 158:268-279. [PMID: 31048196 PMCID: PMC6520252 DOI: 10.1016/j.watres.2019.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/05/2019] [Accepted: 04/06/2019] [Indexed: 06/09/2023]
Abstract
Thermal disinfection is commonly used to prevent the proliferation of culturable Legionella in engineered water systems (EWS). In response to such stress, culturable Legionella populations can switch into a viable but nonculturable (VBNC) state. The importance of such VBNC Legionella cells is currently hotly debated. Here, we investigated the stress response patterns and transitions of the bacteria to the VBNC state at 55 °C, 60 °C and 70 °C on two L. pneumophila strains for >80 days using a combination of cell-based viability indicators. Complete loss of culturability at 55 °C, 60 °C and 70 °C occurred after 3-8 h, 60 min and <2 min, respectively. In contrast, L. pneumophila strains required 9 days at 55 °C, 8 h at 60 °C and 20 min at 70 °C to achieve a 2 log reduction in cells with intact membranes and high esterase activity; a 4 log reduction was achieved only after 150, 8-15 and 1-4 days, respectively. In parallel, the presence of diagnostic outer-membrane epitopes (OMEs) and changes in the infectivity patterns of the two strains towards amoebae and THP-1 cells were assessed. OMEs were more persistent than viability indicators, showing their potential as targets for VBNC Legionella detection. L. pneumophila strains infected amoebae and THP-1 cells for at least 85 days at 55 °C and 60 °C and for up to 8 days at 70 °C. However, they did so with reduced efficiency, requiring prolonged co-incubation times with the hosts and higher Legionella cell numbers in comparison to culturable cells. Consequently, infection of amoebae by thermally induced VBNC L. pneumophila with lowered virulence can be expected in EWS. Although the gold standard method cannot detect VBNC Legionella, it provides important information about the most virulent bacterial subpopulations. Our results indicate that a prolonged thermal regime ≥60 °C at the central parts of warm water systems is not only effective against culturable L. pneumophila but in the long run even against VBNC cells.
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Affiliation(s)
- Sílvia Cervero-Aragó
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria.
| | - Barbara Schrammel
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Elisabeth Dietersdorfer
- Medical University of Vienna, Institute of Specific Prophylaxis and Tropical Medicine, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Regina Sommer
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria
| | - Christian Lück
- Technical University Dresden, Institute for Medical Microbiology and Hygiene, Medical Faculty "Carl Gustav Carus", Helmholtzstr. 10, D 01069, Dresden, Germany
| | - Julia Walochnik
- Medical University of Vienna, Institute of Specific Prophylaxis and Tropical Medicine, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Alexander Kirschner
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria; Karl Landsteiner University of Health Sciences, Division Water Quality and Health, Dr. Karl Dorrekstraße 30, A-3400, Krems, Austria
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34
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Kan Y, Jiang N, Xu X, Lyu Q, Gopalakrishnan V, Walcott R, Burdman S, Li J, Luo L. Induction and Resuscitation of the Viable but Non-culturable (VBNC) State in Acidovorax citrulli, the Causal Agent of Bacterial Fruit Blotch of Cucurbitaceous Crops. Front Microbiol 2019; 10:1081. [PMID: 31156591 PMCID: PMC6529555 DOI: 10.3389/fmicb.2019.01081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/29/2019] [Indexed: 01/14/2023] Open
Abstract
Acidovorax citrulli is a gram-negative bacterium that infects a wide range of cucurbits causing bacterial fruit blotch (BFB) disease. Copper-based compounds are the most widely-used chemicals for managing BFB and other bacterial diseases in the field. Many bacteria can enter a viable but non-culturable (VBNC) state in response to stress, including exposure to copper, and recover the culturability when favorable conditions return. The present study demonstrates that A. citrulli strain AAC00-1 is able to enter into the VBNC state by treatment with different concentrations of copper sulfate. It took 3 h, 5 and 15 days for all viable cells to lose culturability upon exposure to copper sulfate concentrations of 50, 10, and 5 μM, respectively. The VBNC A. citrulli cells regained culturability when the Cu2+ ions were removed by chelation with EDTA or by transfer of cells to LB broth, a cell-free supernatant from a suspension of AAC00-1, oligotrophic media amended with casein hydrolysate or watermelon seedling juice. We also found that the VBNC cells induced by Cu2+ were unable to colonize or infect watermelon seedlings directly, but the resuscitated cells recovered full virulence equivalent to untreated bacterial cells in the log phase. To the best of our knowledge, this is the first report on the VBNC state in A. citrulli and the factors that facilitate resuscitation and restoration of pathogenicity.
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Affiliation(s)
- Yumin Kan
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Xin Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Qingyang Lyu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Vinoj Gopalakrishnan
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Ronald Walcott
- Department of Plant Pathology, University of Georgia, Athens, GA, United States
| | - Saul Burdman
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
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Schnabel U, Handorf O, Yarova K, Zessin B, Zechlin S, Sydow D, Zellmer E, Stachowiak J, Andrasch M, Below H, Ehlbeck J. Plasma-Treated Air and Water-Assessment of Synergistic Antimicrobial Effects for Sanitation of Food Processing Surfaces and Environment. Foods 2019; 8:foods8020055. [PMID: 30717375 PMCID: PMC6406376 DOI: 10.3390/foods8020055] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 01/28/2023] Open
Abstract
The synergistic antimicrobial effects of plasma-processed air (PPA) and plasma-treated water (PTW), which are indirectly generated by a microwave-induced non-atmospheric pressure plasma, were investigated with the aid of proliferation assays. For this purpose, microorganisms (Listeria monocytogenes, Escherichia coli, Pectobacterium carotovorum, sporulated Bacillus atrophaeus) were cultivated as monocultures on specimens with polymeric surface structures. Both the distinct and synergistic antimicrobial potential of PPA and PTW were governed by the plasma-on time (5⁻50 s) and the treatment time of the specimens with PPA/PTW (1⁻5 min). In single PTW treatment of the bacteria, an elevation of the reduction factor with increasing treatment time could be observed (e.g., reduction factor of 2.4 to 3.0 for P. carotovorum). In comparison, the combination of PTW and subsequent PPA treatment leads to synergistic effects that are clearly not induced by longer treatment times. These findings have been valid for all bacteria (L. monocytogenes > P. carotovorum = E. coli). Controversially, the effect is reversed for endospores of B. atrophaeus. With pure PPA treatment, a strong inactivation at 50 s plasma-on time is detectable, whereas single PTW treatment shows no effect even with increasing treatment parameters. The use of synergistic effects of PTW for cleaning and PPA for drying shows a clear alternative for currently used sanitation methods in production plants. Highlights: Non-thermal atmospheric pressure microwave plasma source used indirect in two different modes-gaseous and liquid; Measurement of short and long-living nitrite and nitrate in corrosive gas PPA (plasma-processed air) and complex liquid PTW (plasma-treated water); Application of PTW and PPA in single and combined use for biological decontamination of different microorganisms.
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Affiliation(s)
- Uta Schnabel
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, D01 HV58 Dublin, Ireland.
| | - Oliver Handorf
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Kateryna Yarova
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Björn Zessin
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Susann Zechlin
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Diana Sydow
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Elke Zellmer
- Institute for Hygiene and Environmental Medicine, Faculty of Medicine, University of Greifswald, Walter-Rathenau-Straße 49A, 17475 Greifswald, Germany.
| | - Jörg Stachowiak
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Mathias Andrasch
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
| | - Harald Below
- Institute for Hygiene and Environmental Medicine, Faculty of Medicine, University of Greifswald, Walter-Rathenau-Straße 49A, 17475 Greifswald, Germany.
| | - Jörg Ehlbeck
- Plasma Bioengineering, Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2, 17491 Greifswald, Germany.
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Braun RS, Mendis N, Li L, Faucher SP. Quantification of Viable but Non-Culturable Cells of Legionella pneumophila. Methods Mol Biol 2019; 1921:45-53. [PMID: 30694484 DOI: 10.1007/978-1-4939-9048-1_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Legionella pneumophila, among other bacteria, may enter a viable but non-culturable state as a means for survival in stressful conditions. Bacterial cells in the viable but non-culturable state cannot grow on standard medium; however, they continue to exhibit characteristics that are associated with live cells, such as respiration, transcription, and cell wall integrity. The present paper outlines a detailed protocol for the detection of viable but non-culturable L. pneumophila cells via Syto® 9 and propidium iodide staining coupled with flow cytometry.
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Affiliation(s)
- Rosalie S Braun
- New York University College of Dentistry, New York, NY, USA
- Faculty of Agricultural and Environmental Sciences, Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Nilmini Mendis
- Faculty of Agricultural and Environmental Sciences, Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
| | - Laam Li
- Faculty of Agricultural and Environmental Sciences, Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Sebastien P Faucher
- Faculty of Agricultural and Environmental Sciences, Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, QC, Canada.
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Cebrián F, Montero JC, Fernández PJ. New approach to environmental investigation of an explosive legionnaires´ disease outbreak in Spain: early identification of potential risk sources by rapid Legionella spp immunosensing technique. BMC Infect Dis 2018; 18:696. [PMID: 30587144 PMCID: PMC6307211 DOI: 10.1186/s12879-018-3605-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 12/10/2018] [Indexed: 02/05/2023] Open
Abstract
Background An explosive outbreak of Legionnaires’ disease (LD) was identified on 11 December 2015 in Manzanares, Ciudad Real, Spain, and was declared closed by 03 February 2016. The number of declared cases was 593 with 277 confirmed cases so that it can be considered as one of the outbreaks with highest attack rate. This rate could be attributed to the ageing of the population, among others, in addition to various risk factors and habits, and the meteorological conditions (thermal inversion) maintained in this municipality at the time. The Public Health Services succeeded in breaking the bacterial transmission. Several facilities were early identified by microbiological analysis, including a cooling tower and a decorative fountain, as possible infectious sources. Rapid analytical techniques for rapid Legionella detection and the shutdown and preventative closure of positive installations have been considered key elements in the control of this outbreak. Results Rapid microbiological analysis helped to the early identification of potential risk sources in a Legionnaires´ disease outbreak, reducing decision-making processes according to the actual needs of the intervention in public health and shortening the exposure of the population. Conclusions Protocolized and immediate intervention in an outbreak is a crucial issue to reduce their effects on public health. For this, identification and control of the suspicious sources able to disseminate the bacteria and cause the illness is required. Rapid analytical techniques like immunomagnetic separation (IMS) method based on the whole bacterial cell detection are shown as excellent tools to investigate all the potential sources of risk.
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Affiliation(s)
- Fernando Cebrián
- Ministry of Health of the Council of Communities of Castilla - La Mancha, Av. de Madrid s/n, 45600 Talavera de la Reina, Toledo, Spain
| | - Juan C Montero
- Ministry of Health of the Council of Communities of Castilla - La Mancha, Av. de Madrid s/n, 45600 Talavera de la Reina, Toledo, Spain.
| | - Pedro J Fernández
- Ministry of Health of the Council of Communities of Castilla - La Mancha, Av. de Madrid s/n, 45600 Talavera de la Reina, Toledo, Spain
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38
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Robben C, Fister S, Witte AK, Schoder D, Rossmanith P, Mester P. Induction of the viable but non-culturable state in bacterial pathogens by household cleaners and inorganic salts. Sci Rep 2018; 8:15132. [PMID: 30310128 PMCID: PMC6181970 DOI: 10.1038/s41598-018-33595-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
Effective monitoring of microbial pathogens is essential for a successful preventive food safety and hygiene strategy. However, as most monitoring strategies are growth-based, these tests fail to detect pathogenic bacteria that have entered the viable but non-culturable (VBNC) state. The present study reports the induction of the VBNC state in five human pathogens by commercially available household cleaners in combination with inorganic salts. We determined that non-ionic surfactants, a common ingredient in household cleaners, can induce the VBNC state, when combined with salts. A screening study with 630 surfactant/salt combinations indicates a correlation between the hydrophobicity of the surfactant and VBNC induction in L. monocytogenes, E. coli, S. enterica serovar Typhimurium, S. aureus and toxin-producing enteropathogenic E. coli. Cells that were exposed to combinations of surfactants and salts for 5 min and up to 1 h lost their culturability on standard growth media while retaining their ATP production, fermentation of sugars and membrane integrity, which suggests intact and active metabolism. Screening also revealed major differences between Gram-negative and Gram-positive bacteria; the latter being more susceptible to VBNC induction. Combinations of such detergents and salts are found in many different environments and reflect realistic conditions in industrial and domestic surroundings. VBNC cells present in industrial environments, food-processing plants and even our daily routine represent a serious health risk due to possible resuscitation, unknown spreading, production of toxins and especially their invisibility to routine detection methods, which rely on culturability of cells and fail to detect VBNC pathogens.
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Affiliation(s)
- Christian Robben
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Susanne Fister
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Anna Kristina Witte
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Dagmar Schoder
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Peter Rossmanith
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.,Institute of Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Patrick Mester
- Christian Doppler-Laboratory for Monitoring of Microbial Contaminants, Institute for Milk Hygiene, Milk Technology and Food Science, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
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Relationship between the Viable but Nonculturable State and Antibiotic Persister Cells. J Bacteriol 2018; 200:JB.00249-18. [PMID: 30082460 DOI: 10.1128/jb.00249-18] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria have evolved numerous means of survival in adverse environments with dormancy, as represented by "persistence" and the "viable but nonculturable" (VBNC) state, now recognized to be common modes for such survival. VBNC cells have been defined as cells which, induced by some stress, become nonculturable on media that would normally support their growth but which can be demonstrated by various methods to be alive and capable of returning to a metabolically active and culturable state. Persister cells have been described as a population of cells which, while not being antibiotic resistant, are antibiotic tolerant. This drug-tolerant phenotype is thought to be a result of stress-induced and stochastic physiological changes as opposed to mutational events leading to true resistance. In this review, we describe these two dormancy strategies, characterize the molecular underpinnings of each state, and highlight the similarities and differences between them. We believe these survival modes represent a continuum between actively growing and dead cells, with VBNC cells being in a deeper state of dormancy than persister cells.
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40
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Dietersdorfer E, Kirschner A, Schrammel B, Ohradanova-Repic A, Stockinger H, Sommer R, Walochnik J, Cervero-Aragó S. Starved viable but non-culturable (VBNC) Legionella strains can infect and replicate in amoebae and human macrophages. WATER RESEARCH 2018; 141:428-438. [PMID: 29409685 DOI: 10.1016/j.watres.2018.01.058] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/24/2018] [Accepted: 01/24/2018] [Indexed: 05/22/2023]
Abstract
Legionella infections are among the most important waterborne infections with constantly increasing numbers of cases in industrialized countries, as a result of aging populations, rising numbers of immunocompromised individuals and increased need for conditioned water due to climate change. Surveillance of water systems is based on microbiological culture-based techniques; however, it has been shown that high percentages of the Legionella populations in water systems are not culturable. In the past two decades, the relevance of such viable but non-culturable (VBNC) legionellae has been controversially discussed, and whether VBNC legionellae can directly infect human macrophages, the primary targets of Legionella infections, remains unclear. In this study, it was demonstrated for the first time that several starved VBNC Legionella strains (four L. pneumophila serogroup 1 strains, a serogroup 6 strain and a L. micdadei strain) can directly infect different types of human macrophages and amoebae even after one year of starvation in ultrapure water. However, under these conditions, the strains caused infection with reduced efficacy, as represented by the lower percentages of infected cells, prolonged time in co-culture and higher multiplicities of infection required. Interestingly, the VBNC cells remained mostly non-culturable even after multiplication within the host cells. Amoebal infection by starved VBNC Legionella, which likely occurs in oligotrophic biofilms, would result in an increase in the bacterial concentration in drinking-water systems. If cells remain in the VBNC state, the real number of active legionellae will be underestimated by the use of culture-based standard techniques. Thus, further quantitative research is needed in order to determine, whether and how many starved VBNC Legionella cells are able to cause disease in humans.
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Affiliation(s)
- Elisabeth Dietersdorfer
- Medical University of Vienna, Institute of Specific Prophylaxis and Tropical Medicine, Department of Medical Parasitology, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Alexander Kirschner
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria.
| | - Barbara Schrammel
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria
| | - Anna Ohradanova-Repic
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Lazarettgasse 19, A-1090 Vienna, Austria
| | - Hannes Stockinger
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Lazarettgasse 19, A-1090 Vienna, Austria
| | - Regina Sommer
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria
| | - Julia Walochnik
- Medical University of Vienna, Institute of Specific Prophylaxis and Tropical Medicine, Department of Medical Parasitology, Kinderspitalgasse 15, A-1090, Vienna, Austria.
| | - Sílvia Cervero-Aragó
- Medical University of Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090, Vienna, Austria; Interuniversity Cooperation Centre for Water & Health, Vienna, Austria
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41
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Role of food sanitising treatments in inducing the ‘viable but nonculturable’ state of microorganisms. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.04.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Liu Y, Zhong Q, Wang J, Lei S. Enumeration of Vibrio parahaemolyticus in VBNC state by PMA-combined real-time quantitative PCR coupled with confirmation of respiratory activity. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.03.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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43
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Xu L, Zhang C, Xu P, Wang XC. Mechanisms of ultraviolet disinfection and chlorination of Escherichia coli: Culturability, membrane permeability, metabolism, and genetic damage. J Environ Sci (China) 2018; 65:356-366. [PMID: 29548407 DOI: 10.1016/j.jes.2017.07.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 06/13/2017] [Accepted: 07/06/2017] [Indexed: 06/08/2023]
Abstract
Traditional culture methods may underestimate the tolerance of microorganisms to disinfectants because of the existence of viable but nonculturable or sublethally injured cells after disinfection. The selection of a strict method is crucial for the evaluation of disinfection performance. The actions of 2 typical disinfectants - ultraviolet (UV) and chlorine - on the fecal indicator Escherichia coli were investigated by the detection of culturability, membrane permeability, metabolic activity, deoxyribonucleic acid (DNA), and messenger ribonucleic acid (mRNA). During UV disinfection, the irreversible damages in the cell membrane and cellular adenosine triphosphate (ATP) were negligible at low UV doses (<80mJ/cm2). However, membrane permeability was damaged at low doses of chlorine (<5mg/L), leading to leakage of cellular ATP. Our study showed that a slight lesion in DNA was detected even at high doses of UV (400mJ/cm2) and chlorine (>5mg/L) treatments. The decay of mRNA was more rapid than that of DNA. The degradation level of mRNA depended on the choice of target genes. After exposure to 50mJ/cm2 UV dose or 5mg/L chlorine for 30min, the DNA damage repair function (RecA mRNA) was inhibited. The mRNA involved in the DNA damage repair function can be a potential indicator of bacterial viability.
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Affiliation(s)
- Limei Xu
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, China; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Chongmiao Zhang
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, China; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Pengcheng Xu
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, China; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xiaochang C Wang
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, China; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
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Knowledge to Predict Pathogens: Legionella pneumophila Lifecycle Critical Review Part I Uptake into Host Cells. WATER 2018. [DOI: 10.3390/w10020132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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45
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Goncharuk VV, Rudenko AV, Saprykina MN, Bolgova ES. Detection of Microorganisms in Nonculturable State in Chlorinated Water. J WATER CHEM TECHNO+ 2018. [DOI: 10.3103/s1063455x18010071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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46
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Li Y, Yang L, Fu J, Yan M, Chen D, Zhang L. The novel loop-mediated isothermal amplification based confirmation methodology on the bacteria in Viable but Non-Culturable (VBNC) state. Microb Pathog 2017; 111:280-284. [DOI: 10.1016/j.micpath.2017.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/03/2017] [Accepted: 09/05/2017] [Indexed: 01/28/2023]
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47
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Prussin AJ, Schwake DO, Marr LC. Ten Questions Concerning the Aerosolization and Transmission of Legionella in the Built Environment. BUILDING AND ENVIRONMENT 2017; 123:684-695. [PMID: 29104349 PMCID: PMC5665586 DOI: 10.1016/j.buildenv.2017.06.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Legionella is a genus of pathogenic Gram-negative bacteria responsible for a serious disease known as legionellosis, which is transmitted via inhalation of this pathogen in aerosol form. There are two forms of legionellosis: Legionnaires' disease, which causes pneumonia-like symptoms, and Pontiac fever, which causes influenza-like symptoms. Legionella can be aerosolized from various water sources in the built environment including showers, faucets, hot tubs/swimming pools, cooling towers, and fountains. Incidence of the disease is higher in the summertime, possibly because of increased use of cooling towers for air conditioning systems and differences in water chemistry when outdoor temperatures are higher. Although there have been decades of research related to Legionella transmission, many knowledge gaps remain. While conventional wisdom suggests that showering is an important source of exposure in buildings, existing measurements do not provide strong support for this idea. There has been limited research on the potential for Legionella transmission through heating, ventilation, and air conditioning (HVAC) systems. Epidemiological data suggest a large proportion of legionellosis cases go unreported, as most people who are infected do not seek medical attention. Additionally, controlled laboratory studies examining water-to-air transfer and source tracking are still needed. Herein, we discuss ten questions that spotlight current knowledge about Legionella transmission in the built environment, engineering controls that might prevent future disease outbreaks, and future research that is needed to advance understanding of transmission and control of legionellosis.
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Affiliation(s)
- Aaron J. Prussin
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
- Corresponding Author:
| | - David Otto Schwake
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Linsey C. Marr
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
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48
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Li L, Faucher SP. Role of the LuxR family transcriptional regulator Lpg2524 in the survival of Legionella pneumophila in water. Can J Microbiol 2017; 63:535-545. [PMID: 28264171 DOI: 10.1139/cjm-2016-0780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The water-borne Gram-negative bacterium Legionella pneumophila (Lp) is the causative agent of Legionnaires' disease. Lp is typically transmitted to humans from water systems, where it grows inside amoebae. Survival of Lp in water is central to its transmission to humans. A transcriptomic study previously identified many genes induced by Lp in water. One such gene, lpg2524, encodes a putative LuxR family transcriptional regulator. It was hypothesized that this gene could be involved in the survival of Lp in water. Deletion of lpg2524 does not affect the growth of Lp in rich medium, in the amoeba Acanthamoeba castellanii, or in human macrophage-like THP-1 cells, showing that Lpg2524 is not required for growth in vitro and in vivo. Nevertheless, deletion of lpg2524 results in a faster colony-forming unit (CFU) reduction in an artificial freshwater medium, Fraquil, indicating that Lpg2524 is important for Lp to survive in water. Overexpression of Lpg2524 also results in a survival defect, suggesting that a precise level of this transcriptional regulator is essential for its function. However, our result shows that Lpg2524 is dispensable for survival in water when Lp is at a high cell density (109 CFU/mL), suggesting that its regulon is regulated by another regulator activated at high cell density.
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Affiliation(s)
- Laam Li
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Montréal, QC H9X 3V9, Canada.,Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Montréal, QC H9X 3V9, Canada
| | - Sébastien P Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Montréal, QC H9X 3V9, Canada
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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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Saprykina MN, Bolgova ES, Goncharuk VV. Formation of viable noncultural state of Candida Albicans. J WATER CHEM TECHNO+ 2016. [DOI: 10.3103/s1063455x16030103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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