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Hassan J, Awasthi SP, Hatanaka N, Hoang PH, Nagita A, Hinenoya A, Faruque SM, Yamasaki S. Presence of Functionally Active Cytolethal Distending Toxin Genes on a Conjugative Plasmid in a Clinical Isolate of Providencia rustigianii. Infect Immun 2023; 91:e0012122. [PMID: 37158737 PMCID: PMC10269090 DOI: 10.1128/iai.00121-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/14/2023] [Indexed: 05/10/2023] Open
Abstract
Providencia rustigianii is potentially enteropathogenic in humans. Recently, we identified a P. rustigianii strain carrying a part of the cdtB gene homologous to that of Providencia alcalifacines that produces an exotoxin called cytolethal distending toxin (CDT), encoded by three subunit genes (cdtA, cdtB, and cdtC). In this study, we analyzed the P. rustigianii strain for possible presence of the entire cdt gene cluster and its organization, location, and mobility, as well as expression of the toxin as a putative virulence factor of P. rustigianii. Nucleotide sequence analysis revealed the presence of the three cdt subunit genes in tandem, and over 94% homology to the corresponding genes carried by P. alcalifaciens both at nucleotide and amino acid sequence levels. The P. rustigianii strain produced biologically active CDT, which caused distension of eukaryotic cell lines with characteristic tropism of CHO and Caco-2 cells but not of Vero cells. S1-nuclease digested pulsed-field gel electrophoresis followed by Southern hybridization analysis demonstrated that the cdt genes in both P. rustigianii and P. alcalifaciens strains are located on large plasmids (140 to 170 kb). Subsequently, conjugation assays using a genetically marked derivative of the P. rustigianii strain showed that the plasmid carrying cdt genes in the P. rustigianii was transferable to cdt gene-negative recipient strains of P. rustigianii, Providencia rettgeri, and Escherichia coli. Our results demonstrated the presence of cdt genes in P. rustigianii for the first time, and further showed that the genes are located on a transferable plasmid, which can potentially spread to other bacterial species.
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Affiliation(s)
- Jayedul Hassan
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Sharda Prasad Awasthi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Noritoshi Hatanaka
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Phuong Hoai Hoang
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Akira Nagita
- Department of Pediatrics, Mizushima Central Hospital, Okayama, Japan
| | - Atsushi Hinenoya
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Shah M. Faruque
- School of Environment and Life Sciences, Independent University Bangladesh (IUB), Bashundhara, Dhaka, Bangladesh
| | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
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Islam MM, Faruque SM, Das D, Ranjan R, Ahmed SM, Adhikary AB. Diagnostic Dilemma of Frozen Shoulder in Post CABG Patient: A Case Report. Mymensingh Med J 2023; 32:593-598. [PMID: 37002777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
Abstract
Frozen shoulder, also known as adhesive capsulitis, is a condition featured by stiffness and pain in shoulder joint. In this report, we present a case of 58 years old diabetic male patient with the history of coronary artery bypass grafting (CABG) 06 months back. He presented with persistent right shoulder pain for 05 months. Clinical examinations reveal restriction of the right shoulder joint movement in all directions and wasting of the right supraspinatus, infraspinatus and trapezius muscles. Both active and passive range of motions was restricted with painful right shoulder joint. Pain free abduction range was about 40 degrees in right shoulder. Plain X-ray of right shoulder joint and other relevant investigations show normal findings. Considering the clinical and laboratory findings decision was taken to treat the patient with exercise, pain killer and ultrasound therapy which were found to be optimistic.
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Affiliation(s)
- M M Islam
- Dr Md Mahbubul Islam, MD (Physical Medicine) Phase B Student, Department of Physical Medicine & Rehabilitation, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh
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Naser IB, Shishir TA, Faruque SN, Hoque MM, Hasan A, Faruque SM. Environmental prevalence of toxigenic Vibrio cholerae O1 in Bangladesh coincides with V. cholerae non-O1 non-O139 genetic variants which overproduce autoinducer-2. PLoS One 2021; 16:e0254068. [PMID: 34214115 PMCID: PMC8253391 DOI: 10.1371/journal.pone.0254068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/19/2021] [Indexed: 12/02/2022] Open
Abstract
Prevalence of toxigenic Vibrio cholerae O1 in aquatic reservoirs in Bangladesh apparently increases coinciding with the occurrence of seasonal cholera epidemics. In between epidemics, these bacteria persist in water mostly as dormant cells, known as viable but non-culturable cells (VBNC), or conditionally viable environmental cells (CVEC), that fail to grow in routine culture. CVEC resuscitate to active cells when enriched in culture medium supplemented with quorum sensing autoinducers CAI-1 or AI-2 which are signal molecules that regulate gene expression dependent on cell density. V. cholerae O1 mutant strains with inactivated cqsS gene encoding the CAI-1 receptor has been shown to overproduce AI-2 that enhance CVEC resuscitation in water samples. Since V. cholerae non-O1 non-O139 (non-cholera-vibrios) are abundant in aquatic ecosystems, we identified and characterized naturally occurring variant strains of V. cholerae non-O1 non-O139 which overproduce AI-2, and monitored their co-occurrence with V. cholerae O1 in water samples. The nucleotide sequence and predicted protein products of the cqsS gene carried by AI-2 overproducing variant strains showed divergence from that of typical V. cholerae O1 or non-O1 strains, and their culture supernatants enhanced resuscitation of CVEC in water samples. Furthermore, prevalence of V. cholerae O1 in the aquatic environment was found to coincide with an increase in AI-2 overproducing non-O1 non-O139 strains. These results suggest a possible role of non-cholera vibrios in the environmental biology of the cholera pathogen, in which non-O1 non-O139 variant strains overproducing AI-2 presumably contribute in resuscitation of the latent pathogen, leading to seasonal cholera epidemics. Importance. Toxigenic Vibrio cholerae which causes seasonal epidemics of cholera persists in aquatic reservoirs in endemic areas. The bacteria mostly exist in a dormant state during inter-epidemic periods, but periodically resuscitate to the active form. The resuscitation is enhanced by signal molecules called autoinducers (AIs). Toxigenic V. cholerae can be recovered from water samples that normally test negative for the organism in conventional culture, by supplementing the culture medium with exogenous AIs. V. cholerae belonging to the non-O1 non-O139 serogroups which do not cause cholera are also abundant in natural waters, and they are capable of producing AIs. In this study we characterized V. cholerae non-O1 non-O139 variant strains which overproduce an autoinducer called AI-2, and found that the abundance of the cholera pathogen in aquatic reservoirs correlates with an increase in the AI-2 overproducing strains. Our results suggest a probable role of these variant strains in the environmental biology and epidemiology of toxigenic V. cholerae, and may lead to novel means for surveillance, prevention and control of cholera.
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Affiliation(s)
- Iftekhar Bin Naser
- School of Environment and Life Sciences, Independent University Bangladesh, Bashundhara, Dhaka, Bangladesh
- Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Tushar Ahmed Shishir
- Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
| | - Shah Nayeem Faruque
- Department of Biochemistry and Microbiology, North South University, Dhaka, Bangladesh
| | - M. Mozammel Hoque
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Anamul Hasan
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shah M. Faruque
- School of Environment and Life Sciences, Independent University Bangladesh, Bashundhara, Dhaka, Bangladesh
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- * E-mail: ,
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Nguyen DTA, Awasthi SP, Hoang PH, Nguyen PD, Jayedul H, Hatanaka N, Hinenoya A, Van Dang C, Faruque SM, Yamasaki S. Prevalence, Serovar, and Antimicrobial Resistance of Nontyphoidal Salmonella in Vegetable, Fruit, and Water Samples in Ho Chi Minh City, Vietnam. Foodborne Pathog Dis 2021; 18:354-363. [PMID: 33902318 DOI: 10.1089/fpd.2020.2891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we investigated the prevalence, serovar distribution, and antimicrobial resistance pattern of Salmonella isolates from vegetable, fruit, and water samples in Ho Chi Minh City, Vietnam. Salmonella was detected in 75% (30/40), 57.1% (12/21), 17.5% (28/160), and 2.5% (1/40) of river water, irrigation water, vegetable, and ice water samples, respectively. However, no Salmonella was isolated from 160 fruit and 40 tap water samples examined. A total of 102 isolates obtained from 71 samples belonged to 34 different serovars, of which Salmonella Rissen was the most prevalent, followed by Salmonella London, Salmonella Hvittingfoss, and Salmonella Weltevreden. Certain Salmonella serovars such as Newport, Rissen, and Weltevreden were isolated from both vegetable and water samples. Antimicrobial resistance was most commonly observed against tetracycline (35.3%), followed by chloramphenicol (34.3%), ampicillin (31.4%), trimethoprim/sulfamethoxazole (23.5%), and nalidixic acid (10.8%). Of 102 isolates analyzed, 52 (51%) showed resistance to at least 1 antimicrobial class whereas 27 (26.5%) showed multidrug resistant (MDR) phenotype, being resistant to at least three different classes of antimicrobials. Determination of the presence and type of β-lactamase genes showed the cooccurrence of blaTEM-1 and blaCMY-2 in one Salmonella Agona isolate from a river water sample. Taken together, these data indicated that both environmental water and vegetables were contaminated with Salmonella, including MDR strains, and that environmental water used in irrigation might have been the source of Salmonella contamination in the vegetables.
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Affiliation(s)
- Dao Thi Anh Nguyen
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,The Southern Regional Testing Center of Food Safety, Institute of Public Health Ho Chi Minh City, Ministry of Health, Ho Chi Minh City, Vietnam
| | - Sharda Prasad Awasthi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, Japan
| | - Phuong Hoai Hoang
- The Southern Regional Testing Center of Food Safety, Institute of Public Health Ho Chi Minh City, Ministry of Health, Ho Chi Minh City, Vietnam
| | - Phuc Do Nguyen
- The Southern Regional Testing Center of Food Safety, Institute of Public Health Ho Chi Minh City, Ministry of Health, Ho Chi Minh City, Vietnam
| | - Hassan Jayedul
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Noritoshi Hatanaka
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, Japan
| | - Atsushi Hinenoya
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, Japan
| | - Chinh Van Dang
- The Southern Regional Testing Center of Food Safety, Institute of Public Health Ho Chi Minh City, Ministry of Health, Ho Chi Minh City, Vietnam
| | - Shah M Faruque
- School of Environment and Life Sciences, Independent University Bangladesh (IUB), Dhaka, Bangladesh
| | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, Japan
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Naser IB, Hoque MM, Faruque SN, Kamruzzaman M, Yamasaki S, Faruque SM. Vibrio cholerae strains with inactivated cqsS gene overproduce autoinducer-2 which enhances resuscitation of dormant environmental V. cholerae. PLoS One 2019; 14:e0223226. [PMID: 31574121 PMCID: PMC6772001 DOI: 10.1371/journal.pone.0223226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/16/2019] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Toxigenic Vibrio cholerae resides in aquatic reservoirs of cholera-endemic areas mostly in a dormant form known as conditionally viable environmental cells (CVEC) in which the bacteria remain embedded in an exopolysaccharide matrix, and fail to grow in routine bacteriological culture. The CVEC can be resuscitated by supplementing culture media with either of two autoinducers CAI-1 and AI-2, which are signal molecules controlling quorum sensing, a regulatory network of bacterial gene expression dependent on cell density. This study investigated possible existence of variant strains that overproduce AIs, sufficient to resuscitate CVEC in environmental waters. METHODS Environmental V. cholerae isolates and Tn insertion mutants of a V. cholerae strain C6706 were screened for production of AIs using bioluminescent reporter strains. Relevant mutations in environmental strains which overproduced AI-2 were characterized by nucleotide sequencing and genetic complementation studies. Effect of AIs produced in culture supernatants of relevant strains on reactivation of CVEC in water was determined by resuscitation assays. RESULTS Two of 54 environmental V. cholerae isolates were found to overproduce AI-2. Screening of a Tn-insertion library of V. cholerae strain C6706, identified a mutant which overproduced AI-2, and carried Tn insertion in the cqsS gene. Nucleotide sequencing also revealed mutations inactivating the cqsS gene in environmental isolates which overproduced AI-2, and this property was reversed when complemented with a wild type cqsS gene. Culture of river water samples supplemented with spent medium of these mutants resuscitated dormant V. cholerae cells in water. SIGNIFICANCE V. cholerae strains with inactivated cqsS gene may offer a convenient source of AI-2 in enhanced assays for monitoring bacteriological quality of water. The results also suggest a potential role of naturally occurring cqsS mutants in the environmental biology of V. cholerae. Furthermore, similar phenomenon may have relevance in the ecology of other waterborne bacterial pathogens beyond V. cholerae.
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Affiliation(s)
- Iftekhar Bin Naser
- School of Life Sciences, Independent University Bangladesh, Dhaka, Bangladesh
- Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - M. Mozammel Hoque
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shah Nayeem Faruque
- Department of Biochemistry and Microbiology, North South University, Dhaka, Bangladesh
| | - M. Kamruzzaman
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shinji Yamasaki
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Shah M. Faruque
- School of Life Sciences, Independent University Bangladesh, Dhaka, Bangladesh
- Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- * E-mail: ,
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Rahman M, Nabi A, Asadulghani M, Faruque SM, Islam MA. Toxigenic properties and stx phage characterization of Escherichia coli O157 isolated from animal sources in a developing country setting. BMC Microbiol 2018; 18:98. [PMID: 30170562 PMCID: PMC6119239 DOI: 10.1186/s12866-018-1235-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/16/2018] [Indexed: 12/21/2022] Open
Abstract
Background In many Asian countries including Bangladesh E. coli O157 are prevalent in animal reservoirs and in the food chain, but the incidence of human infection due to E. coli O157 is rare. One of the reasons could be inability of the organism from animal origin to produce sufficient amount of Shiga toxin (Stx), which is the main virulence factor associated with the severe sequelae of infection. This study aimed to fill out this knowledge gap by investigating the toxigenic properties and characteristics of stx phage of E. coli O157 isolated from animal sources in Bangladesh. Results We analysed 47 stx2 positive E. coli O157 of food/animal origin for stx2 gene variants, Shiga toxin production, presence of other virulence genes, stx phage insertion sites, presence of genes associated with functionality of stx phages (Q933 and Q21) and stx2 upstream region. Of the 47 isolates, 46 were positive for both stx2a and stx2d while the remaining isolate was positive for stx2d only. Reverse Passive Latex Agglutination assay (RPLA) showed that 42/47 isolates produced little or no toxin, while 5 isolates produced a high titre of toxin (64 to 128). 39/47 isolates were positive for the Toxin Non-Producing (TNP) specific regions in the stx2 promoter. Additionally, all isolates were negative for antiterminator Q933while a majority of isolates were positive for Q21 gene suggesting the presence of defective stx phage. Of the yehV and wrbA phage insertion sites, yehV was found occupied in 11 isolates while wrbA site was intact in all the isolates. None of the isolates was positive for the virulence gene, cdt but all were positive for hlyA, katP, etpD and eae genes. Isolates that produced high titre Stx (n = 5) produced complete phage particles capable of infecting multiple bacterial hosts. One of these phages was shown to produce stable lysogens in host strains rendering the Stx2 producing ability. Conclusion Despite low frequency in the tested isolates, E. coli O157 isolates in Bangladesh carry inducible stx phages and have the capacity to produce Stx2, indicating a potential risk of E. coli O157 infection in humans.
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Affiliation(s)
- Mahdia Rahman
- Enteric and Food Microbiology Laboratory, Laboratory Sciences and Services Division (LSSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka, 1212, Bangladesh
| | - Ashikun Nabi
- Enteric and Food Microbiology Laboratory, Laboratory Sciences and Services Division (LSSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka, 1212, Bangladesh.,Present Address: Department of Biology, University of Vermont, Burlington, VT, 05405, USA
| | - Md Asadulghani
- Enteric and Food Microbiology Laboratory, Laboratory Sciences and Services Division (LSSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka, 1212, Bangladesh
| | - Shah M Faruque
- Enteric and Food Microbiology Laboratory, Laboratory Sciences and Services Division (LSSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka, 1212, Bangladesh.,Present Address: Department of Mathematics and Natural Sciences, BRAC University, Mohakhali, Dhaka, 1212, Bangladesh
| | - Mohammad Aminul Islam
- Enteric and Food Microbiology Laboratory, Laboratory Sciences and Services Division (LSSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka, 1212, Bangladesh.
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Islam MS, Mahmud ZH, Islam MS, Zaman RU, Islam MR, Gope PS, Islam K, Jahan H, Opel A, Shaha GC, Faruque SM, Clemens JD. Faecal contamination of commuters' hands in main vehicle stations in Dhaka city, Bangladesh. Trans R Soc Trop Med Hyg 2017; 110:367-72. [PMID: 27358288 DOI: 10.1093/trstmh/trw037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/25/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Faecal-oral carriage via hands is an important transmission pathway for diarrhoeal pathogens. The level of faecal contamination of commuters' hands in Dhaka, Bangladesh, was examined in this study. METHODS A total of 900 hand washing samples, including both left and right hands, were collected during one year to cover three different seasons in Bangladesh: winter, summer and rainy seasons. Standard membrane filtration technique was used to quantify total coliforms (TC), faecal coliforms (FC), faecal streptococci (FS), Escherichia coli (EC) and Clostridium perfringens (CP). RESULTS The hands of the commuters were contaminated with TC, FC, FS, CP and EC. The TC, FC, FS, CP and EC counts were 1.95, 1.65, 4.04, 1.54 and1.46 log10 colony forming units (cfu) in the left hand; and 2.13, 1.82, 4.11, 1.52 and 1.61 log10 cfu in the right hand, respectively. There were no statistically significant differences in counts of left and right hands. The highest counts were observed for FS in all seasons. CONCLUSIONS This evidence based study may be used to provide interventions to reduce the contamination of commuters' hands through washing with detergent and, thus, help to prevent the spread of infectious diseases.
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Affiliation(s)
- Mohammad S Islam
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Zahid H Mahmud
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Mohammad S Islam
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Rokon U Zaman
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Mohammad R Islam
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Partha S Gope
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - Khairul Islam
- WaterAid in Bangladesh, Banani, House 51, Road No. 5, Dhaka 1209, Bangladesh
| | - Hasin Jahan
- WaterAid in Bangladesh, Banani, House 51, Road No. 5, Dhaka 1209, Bangladesh
| | - Aftab Opel
- WaterAid in Bangladesh, Banani, House 51, Road No. 5, Dhaka 1209, Bangladesh
| | - Ganesh C Shaha
- Dhaka University of Engineering and Technology, Gazipur, Bangladesh
| | - Shah M Faruque
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
| | - John D Clemens
- International Center for Diarrhoeal Disease Research, Bangladesh (icddr,b), Mohakhali, Dhaka - 1212, Bangladesh
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Hoque MM, Naser IB, Bari SMN, Zhu J, Mekalanos JJ, Faruque SM. Quorum Regulated Resistance of Vibrio cholerae against Environmental Bacteriophages. Sci Rep 2016; 6:37956. [PMID: 27892495 PMCID: PMC5124996 DOI: 10.1038/srep37956] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/01/2016] [Indexed: 12/26/2022] Open
Abstract
Predation by bacteriophages can significantly influence the population structure of bacterial communities. Vibrio cholerae the causative agent of cholera epidemics interacts with numerous phages in the aquatic ecosystem, and in the intestine of cholera patients. Seasonal epidemics of cholera reportedly collapse due to predation of the pathogen by phages. However, it is not clear how sufficient number of the bacteria survive to seed the environment in the subsequent epidemic season. We found that bacterial cell density-dependent gene expression termed "quorum sensing" which is regulated by signal molecules called autoinducers (AIs) can protect V. cholerae against predatory phages. V. cholerae mutant strains carrying inactivated AI synthase genes were significantly more susceptible to multiple phages compared to the parent bacteria. Likewise when mixed cultures of phage and bacteria were supplemented with exogenous autoinducers CAI-1 or AI-2 produced by recombinant strains carrying cloned AI synthase genes, increased survival of V. cholerae and a decrease in phage titer was observed. Mutational analyses suggested that the observed effects of autoinducers are mediated in part through the quorum sensing-dependent production of haemaglutinin protease, and partly through downregulation of phage receptors. These results have implication in developing strategies for phage mediated control of cholera.
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Affiliation(s)
- M Mozammel Hoque
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
| | - Iftekhar Bin Naser
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
| | - S M Nayeemul Bari
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, 19104-6076 USA
| | - John J Mekalanos
- Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Shah M Faruque
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
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Islam MS, Mahmud ZH, Islam MS, Saha GC, Zahid A, Ali AZ, Hassan MQ, Islam K, Jahan H, Hossain Y, Hasan MM, Cairncross S, Carter R, Luby SP, Cravioto A, Endtz HP, Faruque SM, Clemens JD. Safe distances between groundwater-based water wells and pit latrines at different hydrogeological conditions in the Ganges Atrai floodplains of Bangladesh. J Health Popul Nutr 2016; 35:26. [PMID: 27542826 PMCID: PMC5025979 DOI: 10.1186/s41043-016-0063-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/09/2016] [Indexed: 05/04/2023]
Abstract
BACKGROUND Groundwater drawn from shallow tubewells in Bangladesh is often polluted by nearby pit latrines, which are commonly used toilets in rural and sub-urban areas of the country. METHODS To determine the minimum safe distance of a tubewell from a pit latrine in different hydrogeological conditions of Bangladesh, 20 monitoring wells were installed at three study sites (Manda, Mohanpur and Bagmara) with the vertical and horizontal distances ranging from 18-47 to 2-15 m, respectively. Water samples were collected three times in three seasons and tested for faecal coliforms (FC) and faecal streptococci (FS) as indicators of contamination. Soil samples were analysed for texture, bulk density and hydraulic conductivity following standard procedures. Sediment samples were collected to prepare lithological logs. RESULTS When the shallow aquifers at one of the three sites (Mohanpur) were overlained by 18-23-m-thick aquitards, the groundwater of the monitoring wells was found contaminated with a lateral and vertical distances of 2 and 31 m, respectively. However, where the aquitard was only 9 m thick, contamination was found up to lateral and vertical distances of 4.5 and 40.5 m, respectively. The soil textures of all the sites were mainly composed of loam and sandy loam. The hydraulic conductivities in the first aquifer at Manda, Mohanpur and Bagmara were 5.2-7.3, 8.2 and 1.4-15.7 m/h, respectively. CONCLUSIONS The results showed that the safe distance from the tubewell to the pit latrine varied from site to site depending on the horizontal and vertical distances of the tubewell as well as hydrogeological conditions of a particular area.
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Affiliation(s)
- M Sirajul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh.
- Environmental Microbiology Laboratory, Laboratory Sciences and Services Division, icddr,b, GPO Box-128, Dhaka, 1000, Bangladesh.
| | - Zahid Hayat Mahmud
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | - M Shafiqul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | | | - Anwar Zahid
- Hydrogeology and Environmental Geology Section, Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh
- Directorate of Groundwater Hydrology, Bangladesh Water Development Board, Dhaka, 1205, Bangladesh
| | - Ahm Zulfiquar Ali
- Department of Soil, Water and Environment, University of Dhaka, Dhaka, 1000, Bangladesh
| | - M Qumrul Hassan
- Hydrogeology and Environmental Geology Section, Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Khairul Islam
- WaterAid Bangladesh, Banani, Dhaka, 1213, Bangladesh
| | - Hasin Jahan
- WaterAid Bangladesh, Banani, Dhaka, 1213, Bangladesh
| | - Yakub Hossain
- Village Education Resource Center, Savar, Dhaka, 1340, Bangladesh
| | - M Masud Hasan
- Village Education Resource Center, Savar, Dhaka, 1340, Bangladesh
| | | | | | - Stephen P Luby
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | - Alejandro Cravioto
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | - Hubert Ph Endtz
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Shah M Faruque
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | - John D Clemens
- International Centre for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
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10
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Zahid MSH, Awasthi SP, Asakura M, Chatterjee S, Hinenoya A, Faruque SM, Yamasaki S. Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System. PLoS One 2015; 10:e0137529. [PMID: 26361388 PMCID: PMC4567338 DOI: 10.1371/journal.pone.0137529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/19/2015] [Indexed: 11/18/2022] Open
Abstract
Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT) and toxin coregulated pilus (TCP), the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP)-cAMP receptor protein (CRP) is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.
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Affiliation(s)
- M. Shamim Hasan Zahid
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Sharda Prasad Awasthi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Masahiro Asakura
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Shruti Chatterjee
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Atsushi Hinenoya
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
| | - Shah M. Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan
- * E-mail:
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11
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Connor TR, Barker CR, Baker KS, Weill FX, Talukder KA, Smith AM, Baker S, Gouali M, Pham Thanh D, Jahan Azmi I, Dias da Silveira W, Semmler T, Wieler LH, Jenkins C, Cravioto A, Faruque SM, Parkhill J, Wook Kim D, Keddy KH, Thomson NR. Species-wide whole genome sequencing reveals historical global spread and recent local persistence in Shigella flexneri. eLife 2015; 4:e07335. [PMID: 26238191 PMCID: PMC4522646 DOI: 10.7554/elife.07335] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 07/04/2015] [Indexed: 12/15/2022] Open
Abstract
Shigella flexneri is the most common cause of bacterial dysentery in low-income countries. Despite this, S. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on serotyping reactions developed over half-a-century ago. Here we combine whole genome sequencing with geographical and temporal data to examine the natural history of the species. Our analysis subdivides S. flexneri into seven phylogenetic groups (PGs); each containing two-or-more serotypes and characterised by distinct virulence gene complement and geographic range. Within the S. flexneri PGs we identify geographically restricted sub-lineages that appear to have persistently colonised regions for many decades to over 100 years. Although we found abundant evidence of antimicrobial resistance (AMR) determinant acquisition, our dataset shows no evidence of subsequent intercontinental spread of antimicrobial resistant strains. The pattern of colonisation and AMR gene acquisition suggest that S. flexneri has a distinct life-cycle involving local persistence.
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Affiliation(s)
- Thomas R Connor
- Cardiff School of Biosciences, Cardiff, United Kingdom
- Pathogen Genomics, Wellcome Trust Sanger Centre, Cambridge, United Kingdom
| | | | - Kate S Baker
- Pathogen Genomics, Wellcome Trust Sanger Centre, Cambridge, United Kingdom
| | | | - Kaisar Ali Talukder
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Anthony M Smith
- Centre for Enteric Diseases, National Institute for Communicable Diseases and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Malika Gouali
- Unité des Bactéries Pathogènes Entériques, Institut Pasteur, Paris, France
| | - Duy Pham Thanh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ishrat Jahan Azmi
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Wanderley Dias da Silveira
- Department of Genetics, Evolution, and Bioagents, Institute of Biology, University of Campinas, São Paulo, Brazil
| | - Torsten Semmler
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie University, Berlin, Germany
- Robert Koch Institute, Berlin, Germany
| | - Lothar H Wieler
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie University, Berlin, Germany
- Robert Koch Institute, Berlin, Germany
| | - Claire Jenkins
- Gastrointestinal Bacteria Reference Unit, Public Health England, London, United Kingdom
| | | | - Shah M Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Julian Parkhill
- Pathogen Genomics, Wellcome Trust Sanger Centre, Cambridge, United Kingdom
| | - Dong Wook Kim
- Department of Pharmacy, School of Pharmacy, Hanyang University, Ansan, Republic of Korea
| | - Karen H Keddy
- Centre for Enteric Diseases, National Institute for Communicable Diseases and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nicholas R Thomson
- Pathogen Genomics, Wellcome Trust Sanger Centre, Cambridge, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
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12
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Baker KS, Dallman TJ, Ashton PM, Day M, Hughes G, Crook PD, Gilbart VL, Zittermann S, Allen VG, Howden BP, Tomita T, Valcanis M, Harris SR, Connor TR, Sintchenko V, Howard P, Brown JD, Petty NK, Gouali M, Thanh DP, Keddy KH, Smith AM, Talukder KA, Faruque SM, Parkhill J, Baker S, Weill FX, Jenkins C, Thomson NR. Intercontinental dissemination of azithromycin-resistant shigellosis through sexual transmission: a cross-sectional study. The Lancet Infectious Diseases 2015; 15:913-21. [DOI: 10.1016/s1473-3099(15)00002-x] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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13
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Mahmud ZH, Islam S, Zaman RU, Akter M, Talukder KA, Bardhan PK, Khan AI, Rhodes FC, Kamara A, Wurie IM, Alemu W, Jambai A, Faruque SM, Clemens JD, Islam MS. Phenotypic and genotypic characteristics of Vibrio cholerae O1 isolated from the Sierra Leone cholera outbreak in 2012. Trans R Soc Trop Med Hyg 2014; 108:715-20. [PMID: 25233936 DOI: 10.1093/trstmh/tru137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND This study describes phenotypic, genotypic and antibiotic susceptibility patterns of the strains isolated from the 2012 Sierra Leone cholera outbreak. Rectal swabs were collected from patients and cultured for Vibrio cholerae O1. METHODS The isolates were subjected to multiplex PCR, mismatch amplification mutation assay (MAMA) PCR, pulsed field gel electrophoresis (PFGE), and antibiotic sensitivity tests using disk diffusion and minimum inhibitory concentration (MIC) E-test following standard procedures. RESULTS Out of 17 rectal swabs tested, 15 yielded V. cholerae O1 biotype El Tor, serotype Ogawa. All the strains belonged to 'altered' variants as MAMA PCR result showed the presence of classical cholera toxin B. PFGE result revealed four pulse types. Using antibiotic disk diffusion, all the isolates were resistant to erythromycin, chloramphenicol, furazolidone, and trimethoprim/sulfamethoxazole (SXT) except SL1 which was sensitive to chloramphenicol and SXT. All the isolates were sensitive to nalidixic acid, tetracycline, doxycycline, azithromycin, and ciprofloxacin except SL2 which was resistant to nalidixic acid. However, variable sensitivity patterns were observed for kanamycin. The ranges of MIC were 0.125-0.50 mg/l, 0.003-0.023 mg/l and 0.38-0.75 mg/l for azithromycin, ciprofloxacin and tetracycline, respectively. CONCLUSIONS This study demonstrates that altered variants of V. cholerae O1 of four clonal types were responsible for the 2012 outbreak of cholera in Sierra Leone.
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Affiliation(s)
- Zahid H Mahmud
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Shafiqul Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Rokon U Zaman
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Mahmuda Akter
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Kaisar A Talukder
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Pradip K Bardhan
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Azharul I Khan
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Faye C Rhodes
- Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone
| | - Abdul Kamara
- Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone
| | - Isatta M Wurie
- World Health Organization, 21A and B Riverside Drive, off King Harman Road, Freetown, Sierra Leone
| | - Wondimagegnehu Alemu
- World Health Organization, 21A and B Riverside Drive, off King Harman Road, Freetown, Sierra Leone
| | - Amara Jambai
- Central Public Health Reference Laboratory, Ministry of Health and Sanitation, Connaught Hospital, Free Town, Sierra Leone
| | - Shah M Faruque
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - John D Clemens
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
| | - Mohammad S Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh, 68 Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka 1212, Bangladesh
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14
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Azmi IJ, Khajanchi BK, Akter F, Hasan TN, Shahnaij M, Akter M, Banik A, Sultana H, Hossain MA, Ahmed MK, Faruque SM, Talukder KA. Fluoroquinolone resistance mechanisms of Shigella flexneri isolated in Bangladesh. PLoS One 2014; 9:e102533. [PMID: 25028972 PMCID: PMC4100904 DOI: 10.1371/journal.pone.0102533] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 06/19/2014] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To investigate the prevalence and mechanisms of fluoroquinolone resistance in Shigella species isolated in Bangladesh and to compare with similar strains isolated in China. METHODS A total of 3789 Shigella isolates collected from Clinical Microbiology Laboratory of icddr,b, during 2004-2010 were analyzed for antibiotic susceptibility. Analysis of plasmids, plasmid-mediated quinolone-resistance genes, PFGE, and sequencing of genes of the quinolone-resistance-determining regions (QRDR) were conducted in representative strains isolated in Bangladesh and compared with strains isolated in Zhengding, China. In addition, the role of efflux-pump was studied by using the efflux-pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP). RESULTS Resistance to ciprofloxacin in Shigella species increased from 0% in 2004 to 44% in 2010 and S. flexneri was the predominant species. Of Shigella spp, ciprofloxacin resistant (CipR) strains were mostly found among S. flexneri (8.3%), followed by S. sonnei (1.5%). Within S. flexneri (n = 2181), 14.5% were resistance to ciprofloxacin of which serotype 2a was predominant (96%). MIC of ciprofloxacin, norfloxacin, and ofloxacin were 6-32 mg/L, 8-32 mg/L, and 8-24 mg/L, respectively in S. flexneri 2a isolates. Sequencing of QRDR genes of resistant isolates showed double mutations in gyrA gene (Ser83Leu, Asp87Asn/Gly) and single mutation in parC gene (Ser80Ile). A difference in amino acid substitution at position 87 was found between strains isolated in Bangladesh (Asp87Asn) and China (Asp87Gly) except for one. A novel mutation at position 211 (His→Tyr) in gyrA gene was detected only in the Bangladeshi strains. Susceptibility to ciprofloxacin was increased by the presence of CCCP indicating the involvement of energy dependent active efflux pumps. A single PFGE type was found in isolates from Bangladesh and China suggesting their genetic relatedness. CONCLUSIONS Emergence of fluoroquinolone resistance in Shigella undermines a major challenge in current treatment strategies which needs to be followed up by using empirical therapeutic strategies.
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Affiliation(s)
- Ishrat J. Azmi
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Bijay K. Khajanchi
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Fatema Akter
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Trisheeta N. Hasan
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad Shahnaij
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mahmuda Akter
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Atanu Banik
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Halima Sultana
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad A. Hossain
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad K. Ahmed
- Drug Testing Laboratory, Institute of Public Health, Dhaka, Bangladesh
| | - Shah M. Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Kaisar A. Talukder
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- * E-mail:
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15
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Hinenoya A, Shima K, Asakura M, Nishimura K, Tsukamoto T, Ooka T, Hayashi T, Ramamurthy T, Faruque SM, Yamasaki S. Molecular characterization of cytolethal distending toxin gene-positive Escherichia coli from healthy cattle and swine in Nara, Japan. BMC Microbiol 2014; 14:97. [PMID: 24742173 PMCID: PMC4001111 DOI: 10.1186/1471-2180-14-97] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 04/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cytolethal distending toxin (CDT)-producing Escherichia coli (CTEC) has been isolated from patients with gastrointestinal or urinary tract infection, and sepsis. However, the source of human infection remains unknown. In this study, we attempted to detect and isolate CTEC strains from fecal specimens of healthy farm animals and characterized them phenotypically and genotypically. RESULTS By PCR analysis, the cdtB gene was detected in 90 and 14 out of 102 and 45 stool specimens of healthy cattle and swine, respectively, and none from 45 chicken samples. Subtypes of the cdtB genes (I to V) were further examined by restriction fragment length polymorphism analysis of the amplicons and by type-specific PCRs for the cdt-III and cdt-V genes. Of the 90 cdtB gene-positive cattle samples, 2 cdt-I, 25 cdt-III, 1 cdt-IV, 52 cdt-V and 1 both cdt-III and cdt-V gene-positive strains were isolated while 1 cdt-II and 6 cdt-V gene-positive were isolated from 14 cdtB positive swine samples. Serotypes of some isolates were identical to those of human isolates. Interestingly, a cdt-II gene-positive strain isolated from swine was for the first time identified as Escherichia albertii. Phylogenetic analysis grouped 87 E. coli strains into 77 phylogroup B1, 6 B2, and 4 D, respectively. Most of the B1 strains harbored both lpfAO113 and ehaA. Three and twenty-two cdt-V gene-positive strains harbored eaeA and stx genes, respectively, and seven possessed cdt-V, stx and subAB genes. The cnf2 gene, normally present in cdt-III gene-positive strains, was also detected in cdt-V gene-positive strains. CONCLUSIONS Our results suggest that healthy cattle and swine could be the reservoir of CTEC, and they could be a potential source of human infections.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku ourai-kita, Izumisano, Osaka 598-8531, Japan.
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Ud-Din AIMS, Wahid SUH, Latif HA, Shahnaij M, Akter M, Azmi IJ, Hasan TN, Ahmed D, Hossain MA, Faruque ASG, Faruque SM, Talukder KA. Changing trends in the prevalence of Shigella species: emergence of multi-drug resistant Shigella sonnei biotype g in Bangladesh. PLoS One 2013; 8:e82601. [PMID: 24367527 PMCID: PMC3867351 DOI: 10.1371/journal.pone.0082601] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 10/26/2013] [Indexed: 11/18/2022] Open
Abstract
Shigellosis, caused by Shigella species, is a major public health problem in Bangladesh. To determine the prevalence and distribution of different Shigella species, we analyzed 10,827 Shigella isolates from patients between 2001 and 2011. S. flexneri was the predominant species isolated throughout the period. However, the prevalence of S. flexneri decreased from 65.7% in 2001 to 47% in 2011, whereas the prevalence of S. sonnei increased from 7.2% in 2001 to 25% in 2011. S. boydii and S. dysenteriae accounted for 17.3% and 7.7% of the isolates respectively throughout the period. Of 200 randomly selected S. sonnei isolates for extensive characterization, biotype g strains were predominant (95%) followed by biotype a (5%). Resistance to commonly used antibiotics including trimethoprim-sulfamethoxazole, nalidixic acid, ciprofloxacin, mecillinam and ampicillin was 89.5%, 86.5%, 17%, 10.5%, and 9.5%, respectively. All isolates were susceptible to ceftriaxone, cefotaxime, ceftazidime and imipenem. Ninety-eight percent of the strains had integrons belonging to class 1, 2 or both. The class 1 integron contained only dfrA5 gene, whereas among class 2 integron, 16% contained dhfrAI-sat1-aadA1-orfX gene cassettes and 84% harbored dhfrA1-sat2 gene cassettes. Plasmids of ∼5, ∼1.8 and ∼1.4 MDa in size were found in 92% of the strains, whereas only 33% of the strains carried the 120 MDa plasmid. PFGE analysis showed that strains having different integron patterns belonged to different clusters. These results show a changing trend in the prevalence of Shigella species with the emergence of multidrug resistant S. sonnei. Although S. flexneri continues to be the predominant species albeit with reduced prevalence, S. sonnei has emerged as the second most prevalent species replacing the earlier dominance by S. boydii and S. dysenteriae in Bangladesh.
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Affiliation(s)
- Abu I. M. S. Ud-Din
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Syeda U. H. Wahid
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Hasan A. Latif
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad Shahnaij
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mahmuda Akter
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Ishrat J. Azmi
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Trisheeta N. Hasan
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Dilruba Ahmed
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad A. Hossain
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Abu S. G. Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shah M. Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Kaisar A. Talukder
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- * E-mail:
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Alam M, Ahsan S, Pazhani GP, Tamura K, Ramamurthy T, Gomes DJ, Rahman SR, Islam A, Akhtar F, Shinoda S, Watanabe H, Faruque SM, Nair GB. Phenotypic and Molecular Characteristics ofEscherichia coliIsolated from Aquatic Environment of Bangladesh. Microbiol Immunol 2013; 50:359-70. [PMID: 16714843 DOI: 10.1111/j.1348-0421.2006.tb03802.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Pathogenic Escherichia coli remains important etiological agent of infantile diarrhea in Bangladesh. Previous studies have focused mostly on clinical strains, but very little is known about their presence in aquatic environments. The present study was designed to characterize potentially pathogenic E. coli isolated between November 2001 and December 2003 from aquatic environments of 13 districts of Bangladesh. Serotyping of 96 randomly selected strains revealed O161 to be the predominant serotype (19%), followed by O55 and O44 (12% each), and 11% untypable. Serotype-based pathotyping of the E. coli strains revealed 47%, 30%, and 6% to belong to EPEC, ETEC, and EHEC pathotypes, respectively. The majority of the 160 strains tested were resistant to commonly used antimicrobial agents. Plasmid pro-filing showed a total of 17 different bands ranging from 1.3 to 40 kb. However, 35% of the strains did not contain any detectable plasmid, implying no correlation between plasmid and drug resistance. Although virulence gene profiling revealed 97 (61%) of the strains to harbor the gene encoding heat-stable enterotoxin (ST), 2 for the gene encoding Shiga toxin (Stx), and none for the gene for heat-labile enterotoxin (LT), serotype-based pathotyping of E. coli was not fully supported by this gene profiling. A dendrogram derived from the PFGE patterns of 22 strains of three predominant serogroups indicated two major clusters, one containing mainly serogroup O55 and the other O8. Three strains of identical PFGE profiles belonging to serogroup O55 were isolated from three distinct areas, which may be of epidemiological significance. Finally, it may be concluded that serotype-based pathotyping may be useful for E. coli strains of clinical origin; however, it is not precise enough for reliably identifying environmental strains as diarrheagenic.
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Affiliation(s)
- Munirul Alam
- Laboratory of Enteric Microbiology, Laboratory Sciences Division, International Center for Diarrhoeal Disease Research, Bangladesh, Mohakhali, Dhaka 1212, Bangladesh.
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Bari SMN, Roky MK, Mohiuddin M, Kamruzzaman M, Mekalanos JJ, Faruque SM. Quorum-sensing autoinducers resuscitate dormant Vibrio cholerae in environmental water samples. Proc Natl Acad Sci U S A 2013; 110:9926-31. [PMID: 23716683 PMCID: PMC3683778 DOI: 10.1073/pnas.1307697110] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cholera epidemics have long been known to spread through water contaminated with human fecal material containing the toxigenic bacterium Vibrio cholerae. However, detection of V. cholerae in water is complicated by the existence of a dormant state in which the organism remains viable, but resists cultivation on routine bacteriological media. Growth in the mammalian intestine has been reported to trigger "resuscitation" of such dormant cells, and these studies have prompted the search for resuscitation factors. Although some positive reports have emerged from these investigations, the precise molecular signals that activate dormant V. cholerae have remained elusive. Quorum-sensing autoinducers are small molecules that ordinarily regulate bacterial gene expression in response to cell density or interspecies bacterial interactions. We have found that isolation of pathogenic clones of V. cholerae from surface waters in Bangladesh is dramatically improved by using enrichment media containing autoinducers either expressed from cloned synthase genes or prepared by chemical synthesis. These results may contribute to averting future disasters by providing a strategy for early detection of V. cholerae in surface waters that have been contaminated with the stools of cholera patients or asymptomatic infected human carriers.
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Affiliation(s)
- S. M. Nayeemul Bari
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - M. Kamruzzaman Roky
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - M. Mohiuddin
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - M. Kamruzzaman
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - John J. Mekalanos
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Shah M. Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
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Kamruzzaman M, Bari SN, Faruque SM. In vitro and in vivo bactericidal activity of Vitex negundo leaf extract against diverse multidrug resistant enteric bacterial pathogens. ASIAN PAC J TROP MED 2013; 6:352-9. [DOI: 10.1016/s1995-7645(13)60038-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 12/15/2012] [Accepted: 01/15/2013] [Indexed: 10/26/2022] Open
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Abstract
Understanding the genetic and ecological factors which support the periodic emergence of toxigenic Vibrio cholerae causing outbreaks of cholera in regions where the disease is endemic, is vital to develop preventive measures. Besides environmental factors which are not precisely defined, bacteriophages, and horizontally transmissible genetic elements are known to have a significant role in the epidemiology and evolution of the pathogen. Cholera epidemics are also known to be self-limiting, and hence identifying natural factors which contribute to the collapse of epidemics may have important implications in controlling the disease. Phages have been shown to play a crucial role in modulating cholera epidemics, and enhance V. cholerae evolution through a bactericidal selection process which favors the emergence of new clones.
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Affiliation(s)
- Shah M Faruque
- Centre for Food and Water Borne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, 68, Shaheed Tajuddin Ahmed Sharani, Mohakhali, 1212, Dhaka, Bangladesh,
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Abstract
Understanding the genetic and ecological factors which support the emergence of new clones of pathogenic bacteria is vital to develop preventive measures. Vibrio cholerae the causative agent of cholera epidemics represents a paradigm for this process in that this organism evolved from environmental non-pathogenic strains by acquisition of virulence genes. The major virulence factors of V. cholerae, cholera toxin (CT) and toxin coregulated pilus (TCP) are encoded by a lysogenic bacteriophage (CTXφ) and a pathogenicity island, respectively. Additional phages which cooperate with the CTXφ in horizontal transfer of genes in V. cholerae have been characterized, and the potential exists for discovering yet new phages or genetic elements which support the transfer of genes for environmental fitness and virulence leading to the emergence of new epidemic strains. Phages have also been shown to play a crucial role in modulating seasonal cholera epidemics. Thus, the complex array of natural phenomena driving the evolution of pathogenic V. cholerae includes, among other factors, phages that either participate in horizontal gene transfer or in a bactericidal selection process favoring the emergence of new clones of V. cholerae.
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Affiliation(s)
- Shah M Faruque
- Centre for Food and Waterborne Diseases, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
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Seed KD, Faruque SM, Mekalanos JJ, Calderwood SB, Qadri F, Camilli A. Phase variable O antigen biosynthetic genes control expression of the major protective antigen and bacteriophage receptor in Vibrio cholerae O1. PLoS Pathog 2012; 8:e1002917. [PMID: 23028317 PMCID: PMC3441752 DOI: 10.1371/journal.ppat.1002917] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 08/05/2012] [Indexed: 02/05/2023] Open
Abstract
The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage.
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Affiliation(s)
- Kimberley D. Seed
- Howard Hughes Medical Institute and Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Shah M. Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Stephen B. Calderwood
- Division of Infectious Diseases, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Firdausi Qadri
- Centre for Vaccine Sciences, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Andrew Camilli
- Howard Hughes Medical Institute and Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Zahid MSH, Waise Z, Kamruzzaman M, Ghosh A, Nair GB, Bashar SK, Mekalanos JJ, Faruque SM. An experimental study of phage mediated bactericidal selection & emergence of the El Tor Vibrio cholerae. Indian J Med Res 2011; 133:218-24. [PMID: 21415498 PMCID: PMC3089055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND & OBJECTIVES Factor causing the elimination of the classical biotype of Vibrio cholerae O1, and its replacement by the El Tor biotype causing the 7 th cholera pandemic are unclear. Possible ability of the El Tor strains to adapt better than the classical strains to undefined environmental forces have been largely implicated for the change. Here we describe an environmental bacteriophage designated JSF9 which might have contributed to the range of factors. METHODS Competition assays were conducted in the infant mice model and in microcosms between representative El Tor and classical biotype strains in the absence or in the presence of JSF9 phage. RESULTS The JSF9 phage was found to kill classical strains and favour enrichment of El Tor strains, when mixtures containing strains of the two biotypes and JSF9 phage were subjected to alternate passage in infant mice and in samples of environmental water. Spontaneous derivatives of the classical biotype strains, as well as transposon mutants which developed resistance to JSF9 phage were found to be defective in colonization in the infant mouse model. INTERPRETATION & CONCLUSIONS These results suggest that in addition to other factors, the inherent ability of El Tor biotype strains to evade predation by JSF9 or similar phages which kill classical biotype strains, might have enhanced the emergence of El Tor strains as the predominant pandemic biotype.
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Affiliation(s)
- M. Shamim Hasan Zahid
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Zaved Waise
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - M. Kamruzzaman
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - A.N. Ghosh
- National Institute of Cholera & Enteric Diseases, Kolkata, India
| | | | - S.A.M. Khairul Bashar
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh,Department of Life Sciences, North South University, Dhaka, Bangladesh
| | - John J. Mekalanos
- Department of Microbiology & Molecular Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Shah M. Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh,Department of Life Sciences, North South University, Dhaka, Bangladesh,Reprint requests: Dr Shah M. Faruque, Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh e-mail:
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Hassan F, Kamruzzaman M, Mekalanos JJ, Faruque SM. Satellite phage TLCφ enables toxigenic conversion by CTX phage through dif site alteration. Nature 2010; 467:982-5. [PMID: 20944629 PMCID: PMC2967718 DOI: 10.1038/nature09469] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 08/27/2010] [Indexed: 12/23/2022]
Abstract
Bacterial chromosomes often carry integrated genetic elements (e.g., plasmids, transposons, prophages, and islands) whose precise function and contribution to the evolutionary fitness of the host bacterium are unknown. The CTXϕ prophage, which encodes cholera toxin in Vibrio cholerae1, is known to be adjacent to a chromosomally integrated element of unknown function termed the toxin-linked cryptic (TLC)2. Here we report characterization of a TLC-related element that corresponds to the genome of a satellite filamentous phage (TLC-Knϕ1) which uses the morphogenesis genes of another filamentous phage (fs2ϕ) to form infectious TLC-Knϕ1 phage particles. The TLC-Knϕ1 phage genome carries a sequence similar to the dif recombination sequence which functions in chromosome dimer resolution using XerC and XerD recombinases3. The dif sequence is also exploited by lysogenic filamentous phages (e.g., CTXϕ) for chromosomal integration of their genomes. Bacterial cells defective in the dimer resolution often show an aberrant filamentous cell morphology3,4. We found that acquisition and chromosomal integration of the TLC-Knϕ1 genome restored a perfect dif site and normal morphology to V. cholerae wild type and mutant strains that displayed dif- filamentation phenotypes. Furthermore, lysogeny of a dif- nontoxigenic V. cholerae with TLC-Knϕ1 promoted its subsequent toxigenic conversion through integration of CTXϕ into the restored dif site. These results reveal a remarkable level of cooperative interactions between multiple filamentous phages in the emergence of the bacterial pathogen that causes cholera.
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Affiliation(s)
- Faizule Hassan
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
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25
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Chowdhury N, Asakura M, Neogi SB, Hinenoya A, Haldar S, Ramamurthy T, Sarkar B, Faruque SM, Yamasaki S. Development of simple and rapid PCR-fingerprinting methods for Vibrio cholerae
on the basis of genetic diversity of the superintegron. J Appl Microbiol 2009. [DOI: 10.1111/j.1364-5072.2009.04658.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hinenoya A, Naigita A, Ninomiya K, Asakura M, Shima K, Seto K, Tsukamoto T, Ramamurthy T, Faruque SM, Yamasaki S. Prevalence and characteristics of cytolethal distending toxin-producing Escherichia coli from children with diarrhea in Japan. Microbiol Immunol 2009; 53:206-15. [DOI: 10.1111/j.1348-0421.2009.00116.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yamasaki S, Asakura M, Tsukamoto T, Faruque SM, Deb R, Ramamurthy T. CYTOLETHAL DISTENDING TOXIN (CDT): GENETIC DIVERSITY, STRUCTURE AND ROLE IN DIARRHEAL DISEASE. TOXIN REV 2008. [DOI: 10.1080/15569540500320938] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Rahman MH, Biswas K, Hossain MA, Sack RB, Mekalanos JJ, Faruque SM. Distribution of genes for virulence and ecological fitness among diverse Vibrio cholerae population in a cholera endemic area: tracking the evolution of pathogenic strains. DNA Cell Biol 2008; 27:347-55. [PMID: 18462070 DOI: 10.1089/dna.2008.0737] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The pathogenic strains of Vibrio cholerae that cause acute enteric infections in humans are derived from environmental nonpathogenic strains. To track the evolution of pathogenic V. cholerae and identify potential precursors of new pathogenic strains, we analyzed 324 environmental or clinical V. cholerae isolates for the presence of diverse genes involved in virulence or ecological fitness. Of 251 environmental non-O1, non-O139 strains tested, 10 (3.9%) carried the toxin coregulated pilus (TCP) pathogenicity island encoding TCPs, and the CTX prophage encoding cholera toxin, whereas another 10 isolates carried the TCP island alone, and were susceptible to transduction with CTX phage. Most V. cholerae O1 and O139 strains carried these two major virulence determinants, as well as the Vibrio seventh pandemic islands (VSP-1 and VSP-2), whereas 23 (9.1%) non-O1, non-O139 strains carried several VSP island genes, but none carried a complete VSP island. Conversely, 30 (11.9%) non-O1, non-O139 strains carried type III secretion system (TTSS) genes, but none of 63 V. cholerae O1 or O139 strains tested were positive for TTSS. Thus, the distribution of major virulence genes in the non-O1, non-O139 serogroups of V. cholerae is largely different from that of the O1 or O139 serogroups. However, the prevalence of putative accessory virulence genes (mshA, hlyA, and RTX) was similar in all strains, with the mshA being most prevalent (98.8%) followed by RTX genes (96.2%) and hlyA (94.6%), supporting more recent assumptions that these genes imparts increased environmental fitness. Since all pathogenic strains retain these genes, the epidemiological success of the strains presumably depends on their environmental persistence in addition to the ability to produce major virulence factors. Potential precursors of new pathogenic strains would thus require to assemble a combination of genes for both ecological fitness and virulence to attain epidemiological predominance.
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Affiliation(s)
- M Hasibur Rahman
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
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Shinoda S, Nakagawa T, Hirakawa N, Miyoshi SI, Arakawa E, Ramamurthy T, Dutta B, Faruque SM, Nair GB. Molecular epidemiological studies of Vibrio cholerae in Bengal region. Biocontrol Sci 2008; 13:1-8. [PMID: 18432110 DOI: 10.4265/bio.13.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Vibrio cholerae isolates from environmental and clinical origins in the Bengal region in which epidemics of cholera break out periodically were analyzed with particular emphasis on the molecular epidemiological features. The presence of the virulence genes (ctxA, tcpA and toxR) in the isolates was analyzed by the PCR (polymerase chain reaction) method. PFGE (pulsed-field gel electrophoresis) was performed to determine the clonal relationships between the clinical and environmental strains. Antibiograms and O serovars of the isolates were also examined. O1 and O139 strains from both clinical and environmental sources were all positive for the three virulence genes while non-O1/non-O139 strains from both sources were all negative for ctxA and tcpA but positive for toxR. PFGE patterns of recent isolates of O1 and O139 were similar in each serovar regardless of origin, suggesting a clonal relationship between the clinical and environmental strains, although comparison with past isolates or isolates from different geographical area showed some differences.
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Affiliation(s)
- Sumio Shinoda
- Faculty of Science, Okayama University of Science, Ridai-cho, Okayama 700-0005, Japan.
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Stine OC, Alam M, Tang L, Nair GB, Siddique AK, Faruque SM, Huq A, Colwell R, Sack RB, Morris JG. Seasonal cholera from multiple small outbreaks, rural Bangladesh. Emerg Infect Dis 2008; 14:831-3. [PMID: 18439375 PMCID: PMC2600222 DOI: 10.3201/eid1405.071116] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Clinical and environmental Vibrio cholerae organisms collected from February 2004 through April 2005 were systematically isolated from 2 rural Bangladeshi locales. Their genetic relatedness was evaluated at 5 loci that contained a variable number of tandem repeats (VNTR). The observed minimal overlap in VNTR patterns between the 2 communities was consistent with sequential, small outbreaks from local sources.
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Affiliation(s)
- O Colin Stine
- University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Asakura M, Hinenoya A, Alam MS, Shima K, Zahid SH, Shi L, Sugimoto N, Ghosh AN, Ramamurthy T, Faruque SM, Nair GB, Yamasaki S. An inducible lambdoid prophage encoding cytolethal distending toxin (Cdt-I) and a type III effector protein in enteropathogenic Escherichia coli. Proc Natl Acad Sci U S A 2007; 104:14483-8. [PMID: 17726095 PMCID: PMC1964815 DOI: 10.1073/pnas.0706695104] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Indexed: 01/01/2023] Open
Abstract
Cytolethal distending toxins (CDTs) are inhibitory cyclomodulins, which block eukaryotic cell proliferation and are produced by a diverse group of Gram-negative bacteria, including Escherichia coli strains associated with intestinal and extraintestinal infections. However, the mode of transmission of the toxin gene clusters among diverse bacterial pathogens is unclear. We found that Cdt-I produced by enteropathogenic E. coli strains associated with diarrhea is encoded by a lambdoid prophage, which is inducible and infectious. The genome of Cdt-I converting phage (CDT-1Phi) comprises 47,021 nucleotides with 60 predicted ORFs organized into six genomic regions encoding the head and tail, virulence, integrase, unknown functions, regulation, and lysis. The genomic organization of CDT-1Phi is similar to those of SfV, a serotype-converting phage of Shigella flexneri, and UTI89, a prophage identified in uropathogenic E. coli. Besides the cdtI gene cluster, the virulence region of CDT-1Phi genome contains sequences homologous to a truncated cycle inhibiting factor and a type 3 effector protein. Mutation analysis of susceptible E. coli strain C600 suggested that the outer membrane protein OmpC is a putative receptor for CDT-1Phi. CDT-1Phi genome was also found to integrate into the host bacterial chromosome forming lysogens, which produced biologically active Cdt-I. Furthermore, phage induction appeared to cause enhanced toxigenicity of the E. coli strains carrying lysogenic CDT-1Phi. Our results suggest that CDT-1Phi is the latest member of a growing family of lambdoid phages encoding bacterial cyclomodulins and that the phage may have a role in horizontal transfer of these virulence genes.
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Affiliation(s)
- Masahiro Asakura
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Atsushi Hinenoya
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Mohammad S. Alam
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kensuke Shima
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Shamim Hasan Zahid
- Molecular Genetics Laboratory, International Center for Diarrhoeal Disease Research, Dhaka-1212, Bangladesh
| | - Lei Shi
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
- College of Light Industry and Food Technology, South China University of Technology, Guangzou 510640, Peoples Republic of China
| | - Norihiko Sugimoto
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - A. N. Ghosh
- National Institute of Cholera and Enteric Diseases, Kolkata 700010, India; and
| | - T. Ramamurthy
- National Institute of Cholera and Enteric Diseases, Kolkata 700010, India; and
| | - Shah M. Faruque
- Molecular Genetics Laboratory, International Center for Diarrhoeal Disease Research, Dhaka-1212, Bangladesh
| | - G. Balakrish Nair
- Molecular Genetics Laboratory, International Center for Diarrhoeal Disease Research, Dhaka-1212, Bangladesh
| | - Shinji Yamasaki
- *Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
- College of Light Industry and Food Technology, South China University of Technology, Guangzou 510640, Peoples Republic of China
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Faruque SM, Tam VC, Chowdhury N, Diraphat P, Dziejman M, Heidelberg JF, Clemens JD, Mekalanos JJ, Nair GB. Genomic analysis of the Mozambique strain of Vibrio cholerae O1 reveals the origin of El Tor strains carrying classical CTX prophage. Proc Natl Acad Sci U S A 2007; 104:5151-6. [PMID: 17360342 PMCID: PMC1829278 DOI: 10.1073/pnas.0700365104] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cholera outbreaks in subSaharan African countries are caused by strains of the El Tor biotype of toxigenic Vibrio cholerae O1. The El Tor biotype is the causative agent of the current seventh cholera pandemic, whereas the classical biotype, which was associated with the sixth pandemic, is now extinct. Besides other genetic differences the CTX prophages encoding cholera toxin in the two biotypes of V. cholerae O1 have distinct repressor (rstR) genes. However, recent incidences of cholera in Mozambique were caused by an El Tor biotype V. cholerae O1 strain that, unusually, carries a classical type (CTX(class)) prophage. We conducted genomic analysis of the Mozambique strain and its CTX prophage together with chromosomal phage integration sites to understand the origin of this atypical strain and its evolutionary relationship with the true seventh pandemic strain. These analyses showed that the Mozambique strain carries two copies of CTX(class) prophage located on the small chromosome in a tandem array that allows excision of the prophage, but the excised phage genome was deficient in replication and did not produce CTX(class) virion. Comparative genomic microarray analysis revealed that the strain shares most of its genes with the typical El Tor strain N16961 but did not carry the TLC gene cluster, and RS1 sequence, adjacent to the CTX prophage. Our data are consistent with the Mozambique strain's having evolved from a progenitor similar to the seventh pandemic strain, involving multiple recombination events and suggest a model for origination of El Tor strains carrying the classical CTX prophage.
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Affiliation(s)
- Shah M. Faruque
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
- To whom correspondence may be addressed. E-mail: or
| | - Vincent C. Tam
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
| | - Nityananda Chowdhury
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
| | - Pornphan Diraphat
- Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok 73170, Thailand
| | - Michelle Dziejman
- School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box 672, Rochester, NY 14642
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
| | - John F. Heidelberg
- The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850
| | - John D. Clemens
- **International Vaccine Institute, Kwanak, P.O. Box 14, Seoul 151-600, Korea; and
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
| | - G. Balakrish Nair
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
- To whom correspondence may be addressed. E-mail: or
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Qadri F, Chowdhury MI, Faruque SM, Salam MA, Ahmed T, Begum YA, Saha A, Al Tarique A, Seidlein LV, Park E, Killeen KP, Mekalanos JJ, Clemens JD, Sack DA. Peru-15, a live attenuated oral cholera vaccine, is safe and immunogenic in Bangladeshi toddlers and infants. Vaccine 2007; 25:231-8. [PMID: 16996172 DOI: 10.1016/j.vaccine.2006.08.031] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 08/13/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022]
Abstract
A live oral Vibrio cholerae O1 El Tor vaccine, Peru-15 was tested in a double-blind, randomized placebo controlled study for safety and immunogenicity in Phase I and Phase II studies in 240 Bangladeshi children aged 9 months-5 years of age. Two different doses (2x10(7) and 2x10(8)cfu) were tested. Vaccination did not elicit adverse events and the strain was genetically stable. Vibriocidal antibody responses developed in 42/50 (84%) toddlers (2-5 years) and 35/50 (70%) of younger children (9-23 months) and overall 77/100 (77%) who received the high dose. LPS-IgA-antibody responses were seen in 60% of toddlers and 34% of infants; 40% responded with IgA antibodies to cholera toxin. The responses to the reduced dose was lower. These studies demonstrate that Peru-15 at a dose of 2x10(8)cfu is safe and immunogenic in children in Bangladesh.
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Affiliation(s)
- Firdausi Qadri
- ICDDR,B: Centre for Health and Population Research, Bangladesh.
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Nair GB, Qadri F, Holmgren J, Svennerholm AM, Safa A, Bhuiyan NA, Ahmad QS, Faruque SM, Faruque ASG, Takeda Y, Sack DA. Cholera due to altered El Tor strains of Vibrio cholerae O1 in Bangladesh. J Clin Microbiol 2006; 44:4211-3. [PMID: 16957040 PMCID: PMC1698305 DOI: 10.1128/jcm.01304-06] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 08/01/2006] [Accepted: 08/14/2006] [Indexed: 11/20/2022] Open
Abstract
We determined the types of cholera toxin (CT) produced by a collection of 185 Vibrio cholerae O1 strains isolated in Bangladesh over the past 45 years. All of the El Tor strains of V. cholerae O1 isolated since 2001 produced CT of the classical biotype, while those isolated before 2001 produced CT of the El Tor biotype.
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Affiliation(s)
- G Balakrish Nair
- Laboratory Sciences Division, ICDDR,B: Centre for Health and Population Research, Mohakhali, Dhaka 1212, Bangladesh.
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35
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Abstract
Factors that enhance the transmission of pathogens are poorly understood. We show that Vibrio cholerae shed in human 'rice-water' stools have a 10-fold lower oral infectious dose in an animal model than in vitro grown V. cholerae, which may aid in transmission during outbreaks. Furthermore, we identify a bacterial factor contributing to this enhanced infectivity: The achievement of a transient motile but chemotaxis-defective state upon shedding from humans. Rice-water stool V. cholerae have reduced levels of CheW-1, which is essential for chemotaxis, and were consequently shown to have a chemotaxis defect when tested in capillary assays. Through mutational analyses, such a state is known to enhance the infectivity of V. cholerae. This is the first report of a pathogen altering its chemotactic state in response to human infection in order to enhance its transmission.
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Affiliation(s)
- Susan M. Butler
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Eric J. Nelson
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Nityananda Chowdhury
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka 1212, Bangladesh
| | - Shah M. Faruque
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka 1212, Bangladesh
| | - Stephen B. Calderwood
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, and Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
- Howard Hughes Medical Institute, 136 Harrison Avenue, Boston, MA 02111, USA
- For correspondence. E-mail ; Tel. (+1) 617 636 2144; Fax (+1) 617 636 2175
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36
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Faruque SM, Biswas K, Udden SMN, Ahmad QS, Sack DA, Nair GB, Mekalanos JJ. Transmissibility of cholera: in vivo-formed biofilms and their relationship to infectivity and persistence in the environment. Proc Natl Acad Sci U S A 2006; 103:6350-5. [PMID: 16601099 PMCID: PMC1458881 DOI: 10.1073/pnas.0601277103] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The factors that enhance the waterborne spread of bacterial epidemics and sustain the epidemic strain in nature are unclear. Although the epidemic diarrheal disease cholera is known to be transmitted by water contaminated with pathogenic Vibrio cholerae, routine isolation of pathogenic strains from aquatic environments is challenging. Here, we show that conditionally viable environmental cells (CVEC) of pathogenic V. cholerae that resist cultivation by conventional techniques exist in surface water as aggregates (biofilms) of partially dormant cells. Such CVEC can be recovered as fully virulent bacteria by inoculating the water into rabbit intestines. Furthermore, when V. cholerae shed in stools of cholera patients are inoculated in environmental water samples in the laboratory, the cells exhibit characteristics similar to CVEC, suggesting that CVEC are the infectious form of V. cholerae in water and that CVEC in nature may have been derived from human cholera stools. We also observed that stools from cholera patients contain a heterogeneous mixture of biofilm-like aggregates and free-swimming planktonic cells of V. cholerae. Estimation of the relative infectivity of these different forms of V. cholerae cells suggested that the enhanced infectivity of V. cholerae shed in human stools is largely due to the presence of clumps of cells that disperse in vivo, providing a high dose of the pathogen. The results of this study support a model of cholera transmission in which in vivo-formed biofilms contribute to enhanced infectivity and environmental persistence of pathogenic V. cholerae.
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Affiliation(s)
- Shah M. Faruque
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
- To whom correspondence may be addressed. E-mail:
, , or
| | - Kuntal Biswas
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - S. M. Nashir Udden
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - Qazi Shafi Ahmad
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - David A. Sack
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - G. Balakrish Nair
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
- To whom correspondence may be addressed. E-mail:
, , or
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
- To whom correspondence may be addressed. E-mail:
, , or
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37
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Faruque SM, Islam MJ, Ahmad QS, Biswas K, Faruque ASG, Nair GB, Sack RB, Sack DA, Mekalanos JJ. An Improved Technique for Isolation of EnvironmentalVibrio choleraewith Epidemic Potential: Monitoring the Emergence of a Multiple‐Antibiotic–Resistant Epidemic Strain in Bangladesh. J Infect Dis 2006; 193:1029-36. [PMID: 16518766 DOI: 10.1086/500953] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Accepted: 10/19/2005] [Indexed: 11/04/2022] Open
Abstract
Predicting cholera epidemics through monitoring the environment for the presence of pathogenic Vibrio cholerae is complicated by the presence in water of a large number of mostly nonpathogenic V. cholerae strains. V. cholerae strains causing recent cholera epidemics in Bangladesh carry the sulfamethoxazole-trimethoprim (SXT) element, which encodes resistance to several antibiotics. Here, we show that the use of a culture medium containing streptomycin, sulfamethoxazole, and trimethoprim (the antibiotic selection technique [AST]) can significantly enhance the isolation of environmental V. cholerae O1 with epidemic potential (P<.001). The AST was also used to monitor the recent emergence and spread of a new multiple-antibiotic-resistant strain of V. cholerae in Bangladesh. The results of this study support the hypothesis that pre-epidemic amplification of pathogenic V. cholerae occurs in the human host and leads to the start of an epidemic cycle dominated by a single clone of V. cholerae that spreads rapidly through environmental waters.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, Laboratory Sciences Division, International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh.
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Abstract
Cholera is a waterborne diarrheal disease that continues to plague the developing world. Individuals become infected by consuming water from reservoirs contaminated by virulent strains of the bacterium Vibrio cholerae. Epidemiological and environmental observations of a cholera outbreak in Dhaka, Bangladesh, suggest that lytic bacteriophage specific for V. cholerae may limit the severity of cholera outbreaks by killing bacteria present in the reservoir and in infected individuals. To quantify this idea and generate testable hypotheses, we analyzed a mathematical model that combines the epidemiology of cholera with the population dynamics of the bacteria and phage. Under biologically reasonable conditions, we found that vibriophage can ameliorate cholera outbreaks. If phage predation limits bacterial density before an outbreak, a transient reduction in phage density can disrupt that limitation, and subsequent bacterial growth can initiate a cholera outbreak. The severity of the outbreak depends on the density of phage remaining in the reservoir. If the outbreak is initiated instead by a rise in bacterial density, the introduction of phage can reduce the severity of the outbreak and promote its decline. In both situations, the magnitude of the phage effect depends mainly on vibrio growth and phage mortality rates; the lower the rates, the greater the effect. Our analysis also suggests that either bacteria in the environmental reservoir are hyperinfectious or most victims ingest bacteria amplified in food or drinking water contaminated by environmental water carrying few viable V. cholerae. Our theoretical results make a number of empirically testable predictions.
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Affiliation(s)
- Mark A. Jensen
- *Department of Biology, Emory University, Atlanta, GA 30332
| | - Shah M. Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka-1212, Bangladesh; and
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115
- To whom correspondence should be addressed. E-mail:
| | - Bruce R. Levin
- *Department of Biology, Emory University, Atlanta, GA 30332
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Hasan KZ, Pathela P, Alam K, Podder G, Faruque SM, Roy E, Haque AKMF, Haque R, Albert MJ, Siddique AK, Sack RB. Aetiology of diarrhoea in a birth cohort of children aged 0-2 year(s) in rural Mirzapur, Bangladesh. J Health Popul Nutr 2006; 24:25-35. [PMID: 16796147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The incidence of aetiology-specific diarrhoea and the pathogenicity of infectious agents in a birth cohort (n=252) in rural Bangladesh were determined. Stool specimens or rectal swabs were collected from diarrhoeal cases over two years and routinely on a monthly basis. Stool samples from children with diarrhoea were compared with stool samples from children without diarrhoea to calculate rates of isolation and pathogenicity of agents. In total, 1750 stool specimens from diarrhoea patients and 5679 stool specimens from children without diarrhoea were tested. An infectious agent was identified in 58% of the stool specimens from diarrhoea patients and 21.6% of the stool specimens from children without diarrhoea. The most commonly-isolated pathogens from all specimens were enterotoxigenic Escherichia coli (ETEC), enteroadherent E. coli, Shigella, Campylobacter jejuni, Giardia, and rotavirus. ETEC (ST and LT-ST toxin), enterotoxigenic Bacteroides fragilis, Shigella, and rotavirus were associated more with disease than with asymptomatic infections. Aetiology-specific infections were associated with acute episodes. The isolated enteropathogens were essentially the same as those found in other tropical rural settings. Enterotoxigenic B. fragilis was also identified as a pathogen. Ongoing vaccine efforts focusing on Shigella, rotavirus, and ETEC would be useful.
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Affiliation(s)
- Khundkar Z Hasan
- Public Health Sciences Division, ICDDR,B: Centre for Health and Population Research, GPO Box 128, Dhaka 1000, Bangladesh.
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40
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Qadri F, Svennerholm AM, Shamsuzzaman S, Bhuiyan TR, Harris JB, Ghosh AN, Nair GB, Weintraub A, Faruque SM, Ryan ET, Sack DA, Calderwood SB. Reduction in capsular content and enhanced bacterial susceptibility to serum killing of Vibrio cholerae O139 associated with the 2002 cholera epidemic in Bangladesh. Infect Immun 2005; 73:6577-83. [PMID: 16177333 PMCID: PMC1230989 DOI: 10.1128/iai.73.10.6577-6583.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae O139 emerged in 1992 as a major cause of epidemic cholera. However, the incidence of disease due to this new serogroup subsequently decreased for almost a decade. In April 2002, there was a dramatic resurgence of V. cholerae O139 in Bangladesh. We compared the phenotypic properties of the bacterial isolates and the immunological responses in patients with disease due to V. cholerae O139 during the 2002 epidemic with those dating to the emergence of this disease in 1993 to 1995. Strains isolated from patients in the two time periods were compared with respect to capsular polysaccharide, their resistance to the bactericidal effect of serum, and their capacity to be used as target strains in complement-mediated vibriocidal assays. Phase-contrast microscopy showed that strains isolated in 2002 had less capsular material than those isolated from 1993 to 1995 (P = <0.001), a finding confirmed by electron microscopic studies. Strains isolated in 2002 were more susceptible to the bactericidal activity of serum compared to strains from 1993 to 1995 (P = 0.013). Compared to results using a standard O139 strain, a modified vibriocidal assay utilizing a 2002 strain, CIRS 134, as the target organism detected higher vibriocidal responses in both O139-infected cholera patients as well as O139 vaccine recipients. The vibriocidal assay utilizing the less encapsulated 2002 strain, CIRS 134, is a more sensitive indicator of adaptive immune responses to recent infection with V. cholerae O139. Consequently, this assay may be useful in studies of both O139-infected patients and recipients of O139 vaccines.
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Affiliation(s)
- Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka.
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41
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Larocque RC, Harris JB, Dziejman M, Li X, Khan AI, Faruque ASG, Faruque SM, Nair GB, Ryan ET, Qadri F, Mekalanos JJ, Calderwood SB. Transcriptional profiling of Vibrio cholerae recovered directly from patient specimens during early and late stages of human infection. Infect Immun 2005; 73:4488-93. [PMID: 16040959 PMCID: PMC1201252 DOI: 10.1128/iai.73.8.4488-4493.2005] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Understanding gene expression by bacteria during the actual course of human infection may provide important insights into microbial pathogenesis. In this study, we evaluated the transcriptional profile of Vibrio cholerae, the causative agent of cholera, in clinical specimens from cholera patients. We collected samples of human stool and vomitus that were positive by dark-field microscopy for abundant vibrios and used a microarray to compare gene expression in organisms recovered directly from specimens collected during the early and late stages of human infection. Our results reveal that V. cholerae gene expression within the human host environment differs from patterns defined in in vitro models of pathogenesis. tcpA, the major subunit of the essential V. cholerae colonization factor, was significantly more highly expressed in early than in late stages of infection; however, the genes encoding cholera toxin were not highly expressed in either phase of human infection. Furthermore, expression of the virulence regulators toxRS and tcpPH was uncoupled. Interestingly, the pattern of gene expression indicates that the human upper intestine may be a uniquely suitable environment for the transfer of genetic elements that are important in the evolution of pathogenic strains of V. cholerae. These findings provide a more detailed assessment of the transcriptome of V. cholerae in the human host than previous studies of organisms in stool alone and have implications for cholera control and the design of improved vaccines.
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Affiliation(s)
- Regina C Larocque
- Division of Infectious Diseases, Gray-Jackson 504, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
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42
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Qadri F, Chowdhury MI, Faruque SM, Salam MA, Ahmed T, Begum YA, Saha A, Alam MS, Zaman K, Seidlein LV, Park E, Killeen KP, Mekalanos JJ, Clemens JD, Sack DA. Randomized, controlled study of the safety and immunogenicity of Peru-15, a live attenuated oral vaccine candidate for cholera, in adult volunteers in Bangladesh. J Infect Dis 2005; 192:573-9. [PMID: 16028125 DOI: 10.1086/432074] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2005] [Accepted: 03/23/2005] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND A live oral Vibrio cholerae O1 El Tor vaccine candidate, Peru-15, was studied for safety, immunogenicity, and excretion in phase 1 (inpatient) and phase 2 (outpatient) studies of Bangladeshi adults.METHODs. The study was conducted among adults, by use of a double-blind, randomized, placebo-controlled design. A single dose of Peru-15 (approximately 2 x 108 cfu) or placebo (buffer only) was given in standard bicarbonate and ascorbic acid buffer.RESULTS. Study treatment did not elicit any major adverse events in the volunteers, during either the inpatient or the outpatient phases, and there were no reports of diarrhea. V. cholerae was isolated from the stool of only 1 volunteer and was found to be genetically identical to the vaccine strain. Vibriocidal antibody responses were seen in 30 (75%) of 40 vaccine recipients and in 3 (10%) of 30 placebo recipients. Peripheral blood immunoglobulin (Ig) A and IgM antibody-secreting cell responses to lipopolysaccharide were seen in the majority of vaccine recipients (response rate, 78%--88%). Seroconversion for lipopolysaccharide-specific IgA antibodies was seen in 88% of vaccine recipients. The response in vaccine recipients was significantly higher than that in placebo recipients, in all of the immunological assays (P=.036 to <.001). A lower immunological response against cholera toxin B subunit was detected.CONCLUSIONS. The safety and immunogenicity of this Peru-15 vaccine candidate indicates the usefulness of future studies in Bangladesh, where cholera is endemic.
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Affiliation(s)
- Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B): Centre for Health and Population Research, Dhaka, Bangladesh.
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43
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Faruque SM, Bin Naser I, Fujihara K, Diraphat P, Chowdhury N, Kamruzzaman M, Qadri F, Yamasaki S, Ghosh AN, Mekalanos JJ. Genomic sequence and receptor for the Vibrio cholerae phage KSF-1phi: evolutionary divergence among filamentous vibriophages mediating lateral gene transfer. J Bacteriol 2005; 187:4095-103. [PMID: 15937172 PMCID: PMC1151723 DOI: 10.1128/jb.187.12.4095-4103.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
KSF-1phi, a novel filamentous phage of Vibrio cholerae, supports morphogenesis of the RS1 satellite phage by heterologous DNA packaging and facilitates horizontal gene transfer. We analyzed the genomic sequence, morphology, and receptor for KSF-1phi infection, as well as its phylogenetic relationships with other filamentous vibriophages. While strains carrying the mshA gene encoding mannose-sensitive hemagglutinin (MSHA) type IV pilus were susceptible to KSF-1phi infection, naturally occurring MSHA-negative strains and an mshA deletion mutant were resistant. Furthermore, d-mannose as well as a monoclonal antibody against MSHA inhibited infection of MSHA-positive strains by the phage, suggesting that MSHA is the receptor for KSF-1phi. The phage genome comprises 7,107 nucleotides, containing 14 open reading frames, 4 of which have predicted protein products homologous to those of other filamentous phages. Although the overall genetic organization of filamentous phages appears to be preserved in KSF-1phi, the genomic sequence of the phage does not have a high level of identity with that of other filamentous phages and reveals a highly mosaic structure. Separate phylogenetic analysis of genomic sequences encoding putative replication proteins, receptor-binding proteins, and Zot-like proteins of 10 different filamentous vibriophages showed different results, suggesting that the evolution of these phages involved extensive horizontal exchange of genetic material. Filamentous phages which use type IV pili as receptors were found to belong to different branches. While one of these branches is represented by CTXphi, which uses the toxin-coregulated pilus as its receptor, at least four evolutionarily diverged phages share a common receptor MSHA, and most of these phages mediate horizontal gene transfer. Since MSHA is present in a wide variety of V. cholerae strains and is presumed to express in the environment, diverse filamentous phages using this receptor are likely to contribute significantly to V. cholerae evolution.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, International Centre for Diarrheal Disease Research, Bangladesh, Dhaka.
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44
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Faruque SM, Islam MJ, Ahmad QS, Faruque ASG, Sack DA, Nair GB, Mekalanos JJ. Self-limiting nature of seasonal cholera epidemics: Role of host-mediated amplification of phage. Proc Natl Acad Sci U S A 2005; 102:6119-24. [PMID: 15829587 PMCID: PMC1087956 DOI: 10.1073/pnas.0502069102] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phage predation of Vibrio cholerae has recently been reported to be a factor that influences seasonal epidemics of cholera in Bangladesh. To understand more about this phenomenon, we studied the dynamics of the V. cholerae-phage interaction during a recent epidemic in Dhaka. Because the outbreak strain causing this epidemic was resistant to multiple antibiotics, including streptomycin, we used a selective medium containing streptomycin to monitor accurately the abundance of this strain in the environment. The changing prevalence in the environment of the epidemic V. cholerae O1 strain and a particular lytic cholera phage (JSF4) to which it was sensitive was measured every 48-72 h for 17 weeks. We also monitored the incidence of phage excretion in stools of 387 cholera patients during the epidemic. The peak of the epidemic was preceded by high V. cholerae prevalence in the environment and was followed by high JSF4 phage levels as the epidemic ended. The buildup to the phage peak in the environment coincided with increasing excretion of the same phage in the stools of cholera patients. These results suggest that patients toward the end of the epidemic ingested both JSF4 phage and the outbreak V. cholerae strain. Host-mediated phage amplification during the cholera epidemic likely contributed to increased environmental phage abundance, decreased load of environmental V. cholerae and, hence, the collapse of the epidemic. Thus, in vivo phage amplification in patients and subsequent phage predation in the environment may explain the self-limiting nature of seasonal cholera epidemics in Bangladesh.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka-1212, Bangladesh.
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45
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Abstract
Vibrio cholerae, a Gram-negative bacterium belonging to the gamma-subdivision of the family Proteobacteriaceae is the etiologic agent of cholera, a devastating diarrheal disease which occurs frequently as epidemics. Any bacterial species encountering a broad spectrum of environments during the course of its life cycle is likely to develop complex regulatory systems and stress adaptation mechanisms to best survive in each environment encountered. Toxigenic V. cholerae, which has evolved from environmental nonpathogenic V. cholerae by acquisition of virulence genes, represents a paradigm for this process in that this organism naturally exists in an aquatic environment but infects human beings and cause cholera. The V. cholerae genome, which is comprised of two independent circular mega-replicons, carries the genetic determinants for the bacterium to survive both in an aquatic environment as well as in the human intestinal environment. Pathogenesis of V. cholerae involves coordinated expression of different sets of virulence associated genes, and the synergistic action of their gene products. Although the acquisition of major virulence genes and association between V. cholerae and its human host appears to be recent, and reflects a simple pathogenic strategy, the establishment of a productive infection involves the expression of many more genes that are crucial for survival and adaptation of the bacterium in the host, as well as for its onward transmission and epidemic spread. While a few of the virulence gene clusters involved directly with cholera pathogenesis have been characterized, the potential exists for identification of yet new genes which may influence the stress adaptation, pathogenesis, and epidemiological characteristics of V. cholerae. Coevolution of bacteria and mobile genetic elements (plasmids, transposons, pathogenicity islands, and phages) can determine environmental survival and pathogenic interactions between bacteria and their hosts. Besides horizontal gene transfer mediated by genetic elements and phages, the evolution of pathogenic V. cholerae involves a combination of selection mechanisms both in the host and in the environment. The occurrence of periodic epidemics of cholera in endemic areas appear to enhance this process.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh.
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Dziejman M, Serruto D, Tam VC, Sturtevant D, Diraphat P, Faruque SM, Rahman MH, Heidelberg JF, Decker J, Li L, Montgomery KT, Grills G, Kucherlapati R, Mekalanos JJ. Genomic characterization of non-O1, non-O139 Vibrio cholerae reveals genes for a type III secretion system. Proc Natl Acad Sci U S A 2005; 102:3465-70. [PMID: 15728357 PMCID: PMC552950 DOI: 10.1073/pnas.0409918102] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Non-O1, non-O139 Vibrio cholerae can cause gastroenteritis and extraintestinal infections, but, unlike O1 and O139 strains of V. cholerae, little is known about the virulence gene content of non-O1, non-O139 strains and their phylogenetic relationship to other pathogenic V. cholerae. Comparative genomic microarray analysis of four pathogenic non-O1, non-O139 strains indicates that these strains are quite divergent from O1 and O139 strains. Genomic sequence analysis of a non-O1, non-O139 strain (AM-19226) that appeared particularly pathogenic in experimental animals suggests that this strain carries a type III secretion system (TTSS) that is related to the TTSS2 gene cluster found in a pandemic clone of Vibrio parahaemolyticus. The genes for this V. cholerae TTSS system appear to be present in many clinical and environmental non-O1, non-O139 strains, including at least one clone that is globally distributed. We hypothesize that the TTSS present in some pathogenic strains of non-O1, non-O139 V. cholerae may be involved in the virulence and environmental fitness of these strains.
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Affiliation(s)
- Michelle Dziejman
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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Nusrin S, Khan GY, Bhuiyan NA, Ansaruzzaman M, Hossain MA, Safa A, Khan R, Faruque SM, Sack DA, Hamabata T, Takeda Y, Nair GB. Diverse CTX phages among toxigenic Vibrio cholerae O1 and O139 strains isolated between 1994 and 2002 in an area where cholera is endemic in Bangladesh. J Clin Microbiol 2005; 42:5854-6. [PMID: 15583324 PMCID: PMC535256 DOI: 10.1128/jcm.42.12.5854-5856.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PCR surveillance of the rstR genes of CTX phages in Vibrio cholerae O1 and O139 showed no relationship between the incidence of disease and changes in the rstR but showed variations in their presence in O1 and O139 strains and the occurrence of multiple types in a few strains.
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Affiliation(s)
- Suraia Nusrin
- Laboratory Sciences Division, ICDDR,B Centre for Health and Population Research, Mohakhali, Dhaka-1212, Bangladesh.
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Faruque SM, Naser IB, Islam MJ, Faruque ASG, Ghosh AN, Nair GB, Sack DA, Mekalanos JJ. Seasonal epidemics of cholera inversely correlate with the prevalence of environmental cholera phages. Proc Natl Acad Sci U S A 2005; 102:1702-7. [PMID: 15653771 PMCID: PMC547864 DOI: 10.1073/pnas.0408992102] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The relationship among (i) the local incidence of cholera, (ii) the prevalence in the aquatic environment of Vibrio cholerae, and (iii) bacterial viruses that attack potentially virulent O1 and O139 serogroup strains of this organism (cholera phages) was studied in Dhaka, Bangladesh. Over nearly a 3-year period, we found that significantly more environmental water samples contained either a phage or a phage-susceptible V. cholerae strain than both (P < 0.00001). The number of cholera patients varied seasonally during this period and frequently coincided with the presence of pathogenic V. cholerae strains in water samples that otherwise lacked detectable cholera phages. Interepidemic periods were characterized by water samples containing cholera phages but no viable bacteria. Our data support the conclusion that cholera phages can influence cholera seasonality and may also play a role in emergence of new V. cholerae pandemic serogroups or clones.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh
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Faruque SM, Chowdhury N, Khan R, Hasan MR, Nahar J, Islam MJ, Yamasaki S, Ghosh AN, Nair GB, Sack DA. Shigella dysenteriae type 1-specific bacteriophage from environmental waters in Bangladesh. Appl Environ Microbiol 2004; 69:7028-31. [PMID: 14660345 PMCID: PMC310026 DOI: 10.1128/aem.69.12.7028-7031.2003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigella dysenteriae type 1 is the causative agent of the most severe form of bacillary dysentery, which occurs as epidemics in many developing countries. We isolated a bacteriophage from surface water samples from Bangladesh that specifically lyses strains of S. dysenteriae type 1. This phage, designated SF-9, belongs to the Podoviridae family and has a 41-kb double-stranded DNA genome. Further screening of water samples for the prevalence of the phage revealed 9 of 71 (12.6%) water samples which were positive for the phage. These water samples were also positive in PCR assays for one or more S. dysenteriae type 1-specific genes, including ipaBCD and stx1, and live S. dysenteriae type 1 was isolated from three phage-positive samples. The results of this study suggest that phage SF-9 may have epidemiological applications in tracing the presence of S. dysenteriae type 1 in environmental waters.
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Affiliation(s)
- Shah M Faruque
- Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka 1212, Bangladesh.
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De K, Ramamurthy T, Faruque SM, Yamasaki S, Takeda Y, Nair GB, Nandy RK. Molecular characterisation of rough strains ofVibrio choleraeisolated from diarrhoeal cases in India and their comparison to smooth strains. FEMS Microbiol Lett 2004; 232:23-30. [PMID: 15019730 DOI: 10.1016/s0378-1097(04)00013-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Revised: 10/23/2003] [Accepted: 01/04/2004] [Indexed: 11/17/2022] Open
Abstract
Sixteen of the 18 Vibrio cholerae rough strains isolated from hospitalised diarrhoea patients were found to contain O1 serotype-specific (wbe) genes and all currently known virulence genes. Expression of the regulatory element ToxR was evident in these strains. Cholera toxin production ability of the rough strains was found to be higher (c. three- to five-fold) as compared to the smooth counterparts and this was transcriptionally regulated. Strains exhibiting the rough phenotype were more amenable to the uptake of CTXphi, which led us to consider that the rough phenotype could play a role in the generation of genetic diversity among V. cholerae strains.
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Affiliation(s)
- Keya De
- Division of Microbiology, National Institute of Cholera and Enteric Diseases, P33 CIT Road, Scheme XM, Kolkata 700 010, India
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