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Kim H, Jeon S, Kim J, Kim S, Lee DY. Genetic Characteristics and Relatedness of Imported Vibrio choleraeO1 Biotype El Tor in Korea. ANNALS OF CLINICAL MICROBIOLOGY 2013. [DOI: 10.5145/acm.2013.16.1.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- HyeonHee Kim
- Division of Enteric Diseases, Center for Infection Diseases, Korea National Institute of Health, KCDC, Cheongwon, Korea
| | - Semi Jeon
- Division of TB and Respiratory Diseases, Center for Infection Diseases, Korea National Institute of Health, KCDC, Cheongwon, Korea
| | - JunYoung Kim
- Division of Enteric Diseases, Center for Infection Diseases, Korea National Institute of Health, KCDC, Cheongwon, Korea
| | - SeongHan Kim
- Division of TB and Respiratory Diseases, Center for Infection Diseases, Korea National Institute of Health, KCDC, Cheongwon, Korea
| | - Deog-Yong Lee
- Division of Enteric Diseases, Center for Infection Diseases, Korea National Institute of Health, KCDC, Cheongwon, Korea
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Shakoor S, Zaidi AK, Hasan R. Tropical Bacterial Gastrointestinal Infections. Infect Dis Clin North Am 2012; 26:437-53. [DOI: 10.1016/j.idc.2012.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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53
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Shakya G, Kim DW, Clemens JD, Malla S, Upadhyaya BP, Dumre SP, Shrestha SD, Adhikari S, Sharma S, Rijal N, Shrestha SK, Mason C, Kansakar P. Phenotypic and genetic characterization of Vibrio cholerae O1 clinical isolates collected through national antimicrobial resistance surveillance network in Nepal. World J Microbiol Biotechnol 2012; 28:2671-8. [PMID: 22806193 DOI: 10.1007/s11274-012-1077-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 05/05/2012] [Indexed: 11/25/2022]
Abstract
Cholera occurs in sporadic cases and outbreaks in Nepal each year. Vibrio cholerae O1 (n = 522) isolated during 2007-2010 from diarrheal patients at 10 different hospital laboratories in Nepal were characterized. Biochemical and serologic identifications showed that all the isolates belonged to serogroup O1, El Tor biotype. Except 72 isolates of Inaba serotype isolated in the year 2007, all the remaining isolates were of Ogawa serotype. All isolates were resistant to nalidixic acid and furazolidone. Resistance to tetracycline, ciprofloxacin, erythromycin and co-trimoxazole were 21, 4, 16 and 90 % respectively. Seventy-seven of these isolates were selected for further characterization for ctxB gene and MLVA typing. Two different variants of classical type cholera toxin were observed. Ogawa strains from 2007 and 2010-Western Nepal outbreak harbored CTX-3 type cholera toxin, whereas Inaba serotypes in 2007 and the remaining Ogawa serotypes in 2008-2010 harbored CTX 3b-type toxin. MLVA analysis showed circulation of four different groups of altered V. cholerae O1 El Tor strains. Two different profiles were seen among 2007 Inaba (9, 3, 6, x, x) and Ogawa (10, 7, 6, x, x) isolates. The MLVA profile of 2008 and 2009 Ogawa isolates were similar to those of Inaba strains of 2007. Isolates from 2010 also showed three different MLVA profiles; profile 9, 3, 6, x, x in 3 isolates, 11, 7, 6, x, x among 2010 Western Nepal outbreak strains and profile 8, 3, 6, x, x among isolates from Butwal and Kathmandu.
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Affiliation(s)
- Geeta Shakya
- National Public Health Laboratory, Kathmandu, Nepal
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Aliabad NH, Bakhshi B, Pourshafie MR, Sharifnia A, Ghorbani M. Molecular diversity of CTX prophage in Vibrio cholerae. Lett Appl Microbiol 2012; 55:27-32. [PMID: 22502605 DOI: 10.1111/j.1472-765x.2012.03253.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The objective of this study was to investigate the molecular diversity of CTX genetic element within toxigenic Vibrio cholerae genomes and to determine the genetic diversity of V. cholerae population collected in a 6-year period (2004-2009) in Iran. METHODS AND RESULTS The results of mismatch amplification mutation assay (MAMA)-PCR and sequencing showed cytosine nucleotide in positions 203 and 115 in all 50 El Tor V. cholerae strains, which is the same as classical ctxB sequence. One strain yielded amplicons with both El Tor and classical biotype primers in MAMA-PCR indicative of presence of two copies of CTX phages with different genotypes (rstR(ET) ctxB(class) and rstR(ET) ctxB(ET)) integrated within the genome of this isolate, which suggested the integration of two different CTX phages at different occasions or point mutation in one copy of CTX. Sequencing and PCR analysis indicated the presence of hybrid CTX genotype (rstR(ET) ctx(class)) in 70.6% of the isolates; however, only El Tor RS1 phage has been integrated in flanking to the CTX phages with different genotypes. CONCLUSIONS Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and ribosomal gene spacer-PCR (RS-PCR) showed a relatively homogenous population in different years. Our findings indicate that sequence analysis of RS and ctxB regions has more discriminative power than restriction-based methods. SIGNIFICANCE AND IMPACT OF THE STUDY Investigating the molecular diversity of CTX prophage among V. cholerae strains helps to establish a new valuable database of genetic information about isolates, which is of great importance for epidemiologic studies in Iran and other countries encountering cholera epidemics.
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Affiliation(s)
- N H Aliabad
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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55
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Sithivong N, Morita-Ishihara T, Vongdouangchanh A, Phouthavane T, Chomlasak K, Sisavath L, Khamphaphongphane B, Sengkeopraseuth B, Vongprachanh P, Keosavanh O, Southalack K, Jiyoung L, Tsuyuoka R, Ohnishi M, Izumiya H. Molecular subtyping in cholera outbreak, Laos, 2010. Emerg Infect Dis 2012; 17:2060-2. [PMID: 22099098 PMCID: PMC3310560 DOI: 10.3201/eid1711.110280] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A cholera outbreak in Laos in July 2010 involved 237 cases, including 4 deaths. Molecular subtyping indicated relatedness between the Vibrio cholerae isolates in this and in a 2007 outbreak, uncovering a clonal group of V. cholerae circulating in the Mekong basin. Our finding suggests the subtyping methods will affect this relatedness.
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Reimer AR, Van Domselaar G, Stroika S, Walker M, Kent H, Tarr C, Talkington D, Rowe L, Olsen-Rasmussen M, Frace M, Sammons S, Dahourou GA, Boncy J, Smith AM, Mabon P, Petkau A, Graham M, Gilmour MW, Gerner-Smidt P. Comparative genomics of Vibrio cholerae from Haiti, Asia, and Africa. Emerg Infect Dis 2012; 17:2113-21. [PMID: 22099115 PMCID: PMC3310578 DOI: 10.3201/eid1711.110794] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
A strain from Haiti shares genetic ancestry with those from Asia and Africa. Cholera was absent from the island of Hispaniola at least a century before an outbreak that began in Haiti in the fall of 2010. Pulsed-field gel electrophoresis (PFGE) analysis of clinical isolates from the Haiti outbreak and recent global travelers returning to the United States showed indistinguishable PFGE fingerprints. To better explore the genetic ancestry of the Haiti outbreak strain, we acquired 23 whole-genome Vibriocholerae sequences: 9 isolates obtained in Haiti or the Dominican Republic, 12 PFGE pattern-matched isolates linked to Asia or Africa, and 2 nonmatched outliers from the Western Hemisphere. Phylogenies for whole-genome sequences and core genome single-nucleotide polymorphisms showed that the Haiti outbreak strain is genetically related to strains originating in India and Cameroon. However, because no identical genetic match was found among sequenced contemporary isolates, a definitive genetic origin for the outbreak in Haiti remains speculative.
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Development and evaluation of a PCR assay for tracking the emergence and dissemination of Haitian variant ctxB in Vibrio cholerae O1 strains isolated from Kolkata, India. J Clin Microbiol 2012; 50:1733-6. [PMID: 22357499 DOI: 10.1128/jcm.00387-12] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A PCR-based assay was developed to discriminate the classical, El Tor, and Haitian types of ctxB alleles. Our retrospective study using this newly developed PCR showed that Haitian ctxB first appeared in Kolkata during April 2006, and 93.3% of strains isolated during 2011 carried the new allele. Dendrogram analysis showed a pulsed-field gel electrophoresis (PFGE) pattern of the new variant strains isolated recently that was distinct from the PFGE pattern of the strains carrying classical ctxB that closely matched the 2006 to 2007 variant strains.
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58
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Okada K, Roobthaisong A, Nakagawa I, Hamada S, Chantaroj S. Genotypic and PFGE/MLVA analyses of Vibrio cholerae O1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in Thailand. PLoS One 2012; 7:e30863. [PMID: 22292065 PMCID: PMC3265523 DOI: 10.1371/journal.pone.0030863] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 12/22/2011] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Vibrio cholerae O1 El Tor dominated the seventh cholera pandemic which occurred in the 1960s. For two decades, variants of V. cholerae O1 El Tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic El Tor biotype. This study aims to characterize V. cholerae O1 isolates from outbreaks in Thailand with special reference to genotypic variations over time. METHODS/FINDINGS A total of 343 isolates of V. cholerae O1 from cholera outbreaks from 2007 to 2010 were investigated, and 99.4% were found to carry the classical cholera toxin B subunit (ctxB) and El Tor rstR genes. Pulsed-field gel electrophoresis (PFGE) differentiated the isolates into 10 distinct pulsotypes, clustered into two major groups, A and B, with an overall similarity of 88%. Ribotyping, multiple-locus variable-number tandem-repeat analysis (MLVA), and PCR to detect Vibrio seventh pandemic island II (VSP-II) related genes of randomly selected isolates from each pulsotype corresponded to the results obtained by PFGE. Epidemiological investigations revealed that MLVA type 2 was strongly associated with a cholera outbreak in northeastern Thailand in 2007, while MLVA type 7 dominated the outbreaks of the southern Gulf areas in 2009 and MLVA type 4 dominated the outbreaks of the central Gulf areas during 2009-2010. Only MLVA type 16 isolates were found in a Thai-Myanmar border area in 2010, whereas those of MLVA types 26, 39, and 41 predominated this border area in 2008. Type 39 then disappeared 1-2 years later as MLVA type 41 became prevalent. Type 41 was also found to infect an outbreak area. CONCLUSIONS MLVA provided a high-throughput genetic typing tool for understanding the in-depth epidemiology of cholera outbreaks. Our epidemiological surveys suggest that some clones of V. cholerae O1 with similar but distinctive genetic traits circulate in outbreak sites, while others disappear over time.
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Affiliation(s)
- Kazuhisa Okada
- Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections, Nonthaburi, Thailand.
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59
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Mohapatra SS, Mantri CK, Turabe Fazil MHU, Singh DV. Vibrio cholerae O1 biotype El Tor strains isolated in 1992 from Varanasi, India harboured El Tor CTXΦ and classical ctxB on the chromosome-I and classical CTXΦ and classical ctxB on the chromosome-II. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:783-790. [PMID: 23761370 DOI: 10.1111/j.1758-2229.2011.00287.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this study, we report the presence of the El Tor CTXΦ and classical CTXΦ in Vibrio cholerae O1 strains isolated from Varanasi, India. Polymerase chain reaction, DNA sequencing and restriction fragment length polymorphism revealed that, although ctx-positive strains isolated after 1990 contain CTXΦ harbouring El Tor type of rstR and classical ctxB, strains isolated before 1990 contain El Tor type of rstR and El Tor ctxB. Two V. cholerae O1 strains (VC104 and VC106) represent an altered/hybrid strain containing the RS1 element followed by CTXΦ prophage harbouring El Tor type rstR and classical ctxB on the chromosome-I and RS2 element followed by second copy of CTXΦ prophage harbouring classical type rstR and classical ctxB on the chromosome-II. This is the first report of occurrence of El Tor CTXΦ harbouring classical ctxB and classical CTXΦ harbouring classical ctxB in chromosome-I and -II, respectively in diarrhoeal isolates of V. cholerae O1 El Tor strains from Varanasi, India, and that had been isolated in 1992.
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Affiliation(s)
- Saswat S Mohapatra
- Infectious Disease Biology, Institute of Life Sciences, Nalco Square, Bhubaneswar-751023, India
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60
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Tran HD, Alam M, Trung NV, Van Kinh N, Nguyen HH, Pham VC, Ansaruzzaman M, Rashed SM, Bhuiyan NA, Dao TT, Endtz HP, Wertheim HFL. Multi-drug resistant Vibrio cholerae O1 variant El Tor isolated in northern Vietnam between 2007 and 2010. J Med Microbiol 2011; 61:431-437. [PMID: 22016560 PMCID: PMC3347965 DOI: 10.1099/jmm.0.034744-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Since 2007, there has been a re-emergence of cholera outbreaks in northern Vietnam. To understand the molecular epidemiological relatedness and determine the antibiotic susceptibility profiles of responsible V. cholerae O1 outbreak strains, a representative collection of 100 V. cholerae O1 strains was characterized. V. cholerae O1 strains isolated from diarrhoeal patients in northern Vietnam between 2007 and 2010 were investigated for antibiotic susceptibility and characterized by using phenotypic and genotypic tests, including PFGE analysis. Ten clinical V. cholerae O1 isolates from Bangladesh and Zimbabwe were included for comparison. The results revealed that all isolates were resistant to co-trimoxazole and nalidixic acid, 29 % were resistant to tetracycline and 1 % were resistant to azithromycin. All strains were susceptible to ampicillin–sulbactam, doxycycline, chloramphenicol and ciprofloxacin and 95 % were susceptible to azithromycin. MIC values did show reduced susceptibility to fluoroquinolones and 63 % of the strains were intermediately resistant to tetracycline. The isolates expressed phenotypic traits of both serogroup O1 Ogawa and El Tor and harboured an rstR El Tor and ctxB classical biotype. Among the outbreak isolates, only a single PFGE pattern was observed throughout the study period. This study shows that multi-drug resistant V. cholerae altered El Tor producing classical CT strains are now predominant in northern Vietnam.
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Affiliation(s)
- Huu Dat Tran
- Department of Medical Microbiology, Hanoi Medical University, 1 Ton That Tung Street, Hanoi, Vietnam.,National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Munirul Alam
- Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
| | - Nguyen Vu Trung
- Department of Medical Microbiology, Hanoi Medical University, 1 Ton That Tung Street, Hanoi, Vietnam.,National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Nguyen Van Kinh
- Department of Infectious Diseases, Hanoi Medical University, 1 Ton That Tung Street, Hanoi, Vietnam.,National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Hong Ha Nguyen
- National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Van Ca Pham
- National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Mohammad Ansaruzzaman
- Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
| | - Shah Manzur Rashed
- Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
| | - Nurul A Bhuiyan
- Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
| | - Tuyet Trinh Dao
- National Hospital of Tropical Diseases, 78 Giai Phong Street, Hanoi, Vietnam
| | - Hubert P Endtz
- Department of Medical Microbiology & Infectious Diseases, Erasmus MC, University Medical Centre Rotterdam, The Netherlands.,Enteric & Food Microbiology Laboratory, ICDDR,B: International Centre for Diarrhoeal Disease Research, Bangladesh GPO Box 128, Dhaka 1000, Bangladesh
| | - Heiman F L Wertheim
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Churchill Hospital, Old Road, Oxford OX3 7LJ, UK.,Oxford University Clinical Research Unit Vietnam, Wellcome Trust Major Overseas Program, National Hospital of Tropical Diseases, 78 Giai Phong Road, Dong Da, Hanoi, Vietnam
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61
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Sur D, Kanungo S, Sah B, Manna B, Ali M, Paisley AM, Niyogi SK, Park JK, Sarkar B, Puri MK, Kim DR, Deen JL, Holmgren J, Carbis R, Rao R, Thu Van N, Han SH, Attridge S, Donner A, Ganguly NK, Bhattacharya SK, Nair GB, Clemens JD, Lopez AL. Efficacy of a low-cost, inactivated whole-cell oral cholera vaccine: results from 3 years of follow-up of a randomized, controlled trial. PLoS Negl Trop Dis 2011; 5:e1289. [PMID: 22028938 PMCID: PMC3196468 DOI: 10.1371/journal.pntd.0001289] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 07/09/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Killed oral cholera vaccines (OCVs) have been licensed for use in developing countries, but protection conferred by licensed OCVs beyond two years of follow-up has not been demonstrated in randomized, clinical trials. METHODS/PRINCIPAL FINDINGS We conducted a cluster-randomized, placebo-controlled trial of a two-dose regimen of a low-cost killed whole cell OCV in residents 1 year of age and older living in 3,933 clusters in Kolkata, India. The primary endpoint was culture-proven Vibrio cholerae O1 diarrhea episodes severe enough to require treatment in a health care facility. Of the 66,900 fully dosed individuals (31,932 vaccinees and 34,968 placebo recipients), 38 vaccinees and 128 placebo-recipients developed cholera during three years of follow-up (protective efficacy 66%; one-sided 95%CI lower bound = 53%, p<0.001). Vaccine protection during the third year of follow-up was 65% (one-sided 95%CI lower bound = 44%, p<0.001). Significant protection was evident in the second year of follow-up in children vaccinated at ages 1-4 years and in the third year in older age groups. CONCLUSIONS/SIGNIFICANCE The killed whole-cell OCV conferred significant protection that was evident in the second year of follow-up in young children and was sustained for at least three years in older age groups. Continued follow-up will be important to establish the vaccine's duration of protection. TRIAL REGISTRATION ClinicalTrials.gov NCT00289224.
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Affiliation(s)
- Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Suman Kanungo
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Binod Sah
- International Vaccine Institute, Seoul, Republic of Korea
| | - Byomkesh Manna
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Mohammad Ali
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Swapan K. Niyogi
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Jin Kyung Park
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Mahesh K. Puri
- International Vaccine Institute, Seoul, Republic of Korea
| | - Deok Ryun Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | | | | | - Rodney Carbis
- International Vaccine Institute, Seoul, Republic of Korea
| | - Raman Rao
- Shantha Biotechnics, Hyderabad, India
| | | | - Seung Hyun Han
- International Vaccine Institute, Seoul, Republic of Korea
- Seoul National University, Seoul, Korea
| | | | - Allan Donner
- University of Western Ontario, London, Ontario, Canada
| | | | | | | | - John D. Clemens
- International Vaccine Institute, Seoul, Republic of Korea
- * E-mail:
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62
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Characterization of Vibrio cholerae O1 El Tor biotype variant clinical isolates from Bangladesh and Haiti, including a molecular genetic analysis of virulence genes. J Clin Microbiol 2011; 49:3739-49. [PMID: 21880975 DOI: 10.1128/jcm.01286-11] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains.
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63
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Mutreja A, Kim DW, Thomson NR, Connor TR, Lee JH, Kariuki S, Croucher NJ, Choi SY, Harris SR, Lebens M, Niyogi SK, Kim EJ, Ramamurthy T, Chun J, Wood JLN, Clemens JD, Czerkinsky C, Nair GB, Holmgren J, Parkhill J, Dougan G. Evidence for several waves of global transmission in the seventh cholera pandemic. Nature 2011; 477:462-5. [PMID: 21866102 DOI: 10.1038/nature10392] [Citation(s) in RCA: 469] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/26/2011] [Indexed: 11/09/2022]
Abstract
Vibrio cholerae is a globally important pathogen that is endemic in many areas of the world and causes 3-5 million reported cases of cholera every year. Historically, there have been seven acknowledged cholera pandemics; recent outbreaks in Zimbabwe and Haiti are included in the seventh and ongoing pandemic. Only isolates in serogroup O1 (consisting of two biotypes known as 'classical' and 'El Tor') and the derivative O139 can cause epidemic cholera. It is believed that the first six cholera pandemics were caused by the classical biotype, but El Tor has subsequently spread globally and replaced the classical biotype in the current pandemic. Detailed molecular epidemiological mapping of cholera has been compromised by a reliance on sub-genomic regions such as mobile elements to infer relationships, making El Tor isolates associated with the seventh pandemic seem superficially diverse. To understand the underlying phylogeny of the lineage responsible for the current pandemic, we identified high-resolution markers (single nucleotide polymorphisms; SNPs) in 154 whole-genome sequences of globally and temporally representative V. cholerae isolates. Using this phylogeny, we show here that the seventh pandemic has spread from the Bay of Bengal in at least three independent but overlapping waves with a common ancestor in the 1950s, and identify several transcontinental transmission events. Additionally, we show how the acquisition of the SXT family of antibiotic resistance elements has shaped pandemic spread, and show that this family was first acquired at least ten years before its discovery in V. cholerae.
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Affiliation(s)
- Ankur Mutreja
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
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64
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Son MS, Taylor RK. Genetic Screens and Biochemical Assays to Characterize Vibrio cholerae O1 Biotypes: Classical and El Tor. ACTA ACUST UNITED AC 2011; 22A:6A.2.1-6A.2.17. [PMID: 25419260 DOI: 10.1002/9780471729259.mc06a02s22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vibrio cholerae serogroup O1 has two biotypes, classical and El Tor, the latter of which has displaced the prior and has been the causative agent for the ongoing seventh pandemic. However, reports since 2001 have identified clinical isolates of El Tor that have classical O1 biotype genetic and phenotypic characteristics. These El Tor variants have been emerging in clinical settings with increased frequency, including the 2010 cholera outbreak in Haiti. The emergence of El Tor variants warrants the proper and timely identification of clinical (or environmental) isolates' biotype. This unit describes some quick and simple genetic screens and phenotypic assays (biochemical characterization), to be performed simultaneously, commonly used to distinguish biotype and initiate characterization of any clinical (or environmental) isolates of Vibrio cholerae O1.
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Affiliation(s)
- Mike S Son
- Dartmouth Medical School, Hanover, New Hampshire
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65
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Ali A, Chen Y, Johnson JA, Redden E, Mayette Y, Rashid MH, Stine OC, Morris JG. Recent clonal origin of cholera in Haiti. Emerg Infect Dis 2011; 17:699-701. [PMID: 21470464 PMCID: PMC3377427 DOI: 10.3201/eid1704.101973] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Altered El Tor Vibrio cholerae O1, with classical cholera toxin B gene, was isolated from 16 patients with severe diarrhea at St. Mark’s Hospital, Arbonite, Haiti, <3 weeks after onset of the current cholera epidemic. Variable-number tandem-repeat typing of 187 isolates showed minimal diversity, consistent with a point source for the epidemic.
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Affiliation(s)
- Afsar Ali
- University of Florida, Gainesville, Florida 32610, USA
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66
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Ceccarelli D, Spagnoletti M, Bacciu D, Cappuccinelli P, Colombo MM. New V. cholerae atypical El Tor variant emerged during the 2006 epidemic outbreak in Angola. BMC Microbiol 2011; 11:130. [PMID: 21668969 PMCID: PMC3131240 DOI: 10.1186/1471-2180-11-130] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 06/13/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND V. cholerae is the etiological agent of cholera, a major public health concern in most developing countries. Virulence of V. cholerae relies on the powerful cholera toxin, encoded by the CTX prophage. The emergence of new pathogenic variants in the recent years has been mostly associated with new CTX prophage rearrangements. RESULTS In this retrospective study, we show that the epidemic V. cholerae O1 El Tor strain responsible for the 2006 outbreak in Angola is clonally and genetically different from El Tor strains circulating in the 1990s in the same area. Strains from 2006 carry ICEVchAng3 of the SXT/R391 family. This ICE is associated with a narrower multidrug resistance profile compared to the one conferred by plasmid p3iANG to strains of the 1990s. The CTX prophage carried by 2006 El Tor strains is characterized by rstR(ET) and ctxB(Cla) alleles organized in a RS1-RS2-Core array on chromosome I. Interestingly, the newly emerging atypical strain belongs to a clade previously known to comprise only clinical isolates from the Indian subcontinent that also contain the same ICE of the SXT/R391 family. CONCLUSIONS Our findings remark the appearance of a novel V. cholerae epidemic variant in Africa with a new CTXΦ arrangement previously described only in the Indian Subcontinent.
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Affiliation(s)
- Daniela Ceccarelli
- Dipartimento di Biologia e Biotecnologie Charles Darwin, Sapienza Università di Roma, Rome 00185, Italy.
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Goel AK, Jain M, Kumar P, Sarguna P, Bai M, Ghosh N, Gopalan N. Molecular characterization reveals involvement of altered El Tor biotype Vibrio cholerae O1 strains in cholera outbreak at Hyderabad, India. J Microbiol 2011; 49:280-4. [PMID: 21538250 DOI: 10.1007/s12275-011-0317-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 11/22/2010] [Indexed: 11/28/2022]
Abstract
Thirty-four Vibrio cholerae isolates collected from a cholera outbreak in Hyderabad, South India were found to belong to serogroup Ol biotype El Tor serotype Ogawa. The genotype of all the isolates was confirmed by PCR assays. All the isolates were found PCR positive for ctxAB, ompW, rflOl, rtxC, and tcpA genes. All the isolates but one harboured rstR ( El Tor ) allele. However, one isolate carried both rstR ( EL Tor ) as well as rstR ( Classical ) alleles. Cholera toxin (ctxB) genotyping of the isolates confirmed the presence of altered cholera toxin B of classical biotype in all the isolates. All the isolates except VCH35 harboured an RS1-CTX prophage array on the large chromosome. The isolate VCH35 contained a tandem repeat of classical CTX prophage on the small chromosome. The clonal relationship among the V. cholerae isolates as carried out by enterobacterial repetitive intergenic consensus sequences PCR, BOX PCR and randomly amplified polymorphic DNA, uniformly showed a genetic relationship among the outbreak isolates. The results of this study suggest that altered El Tor biotype V. cholerae with the classical cholera toxin gene are involved in cholera outbreaks in India.
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Affiliation(s)
- Ajay Kumar Goel
- Biotechnology Division, Defence Research & Development Establishment, Jhansi Road, Gwalior 474002, India.
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68
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Shamini G, Ravichandran M, Sinnott JT, Somboonwit C, Sidhu HS, Shapshak P, Kangueane P. Structural inferences for Cholera toxin mutations in Vibrio cholerae. Bioinformation 2011; 6:1-9. [PMID: 21464837 PMCID: PMC3064844 DOI: 10.6026/97320630006001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 02/01/2011] [Indexed: 11/23/2022] Open
Abstract
Cholera is a global disease that has persisted for millennia. The cholera toxin (CT) from Vibrio cholerae is responsible for the clinical symptoms of cholera. This toxin is a hetero-hexamer (AB(5)) complex consisting of a subunit A (CTA) with a pentamer (B(5)) of subunit B (CTB). The importance of the AB(5) complex for pathogenesis is established for the wild type O1 serogroup using known structural and functional data. However, its role is not yet documented in other known serogroups harboring sequence level residue mutations. The sequences for the toxin from different serogroups are available in GenBank (release 177). Sequence analysis reveals mutations at several sequence positions in the toxin across serogroups. Therefore, it is of interest to locate the position of these mutations in the AB(5) structure to infer complex assembly for its functional role in different serogroups. We show that mutations in the CTA are at the solvent exposed regions of the AB(5) complex, whereas those in the CTB are at the CTB/CTB interface of the homo-pentamer complex. Thus, the role of mutations at the CTB/CTB interface for B(5) complex assembly is implied. It is observed that these mutations are often non-synonymous (e.g. polar to non-polar or vice versa). The formation of the AB(5) complex involves inter-subunit residue-residue interactions at the protein-protein interfaces. Hence, these mutations, at the structurally relevant positions, are of importance for the understanding of pathogenesis by several serogroups. This is also of significance in the improvement of recombinant CT protein complex analogs for vaccine design and their use against multiple serogroups.
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Affiliation(s)
- Gunasagaran Shamini
- Department of Biotechnology, AIMST University, Semeling 08100, Kedah, Malaysia
- Biomedical Informatics, Pondicherry, India 607402
| | | | - John T Sinnott
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, University of South Florida, College of Medicine, Tampa, Florida 33606, USA
- Clinical Research Unit, Hillsborough Health Department,Tampa, Florida 33602, USA
| | - Charurut Somboonwit
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, University of South Florida, College of Medicine, Tampa, Florida 33606, USA
- Clinical Research Unit, Hillsborough Health Department,Tampa, Florida 33602, USA
| | - Harcharan S Sidhu
- Department of Biotechnology, AIMST University, Semeling 08100, Kedah, Malaysia
| | - Paul Shapshak
- Division of Infectious Disease, Department of Internal Medicine, Tampa General Hospital, University of South Florida, College of Medicine, Tampa, Florida 33606, USA
- Department of Psychiatry and Behavioral Medicine, University of South Florida, College of Medicine, Tampa, Florida 33613, USA
| | - Pandjassarame Kangueane
- Department of Biotechnology, AIMST University, Semeling 08100, Kedah, Malaysia
- Biomedical Informatics, Pondicherry, India 607402
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69
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Use of oral cholera vaccines in an outbreak in Vietnam: a case control study. PLoS Negl Trop Dis 2011; 5:e1006. [PMID: 21283616 PMCID: PMC3026769 DOI: 10.1371/journal.pntd.0001006] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 12/22/2010] [Indexed: 11/19/2022] Open
Abstract
Background Killed oral cholera vaccines (OCVs) are available but not used routinely for cholera control except in Vietnam, which produces its own vaccine. In 2007–2008, unprecedented cholera outbreaks occurred in the capital, Hanoi, prompting immunization in two districts. In an outbreak investigation, we assessed the effectiveness of killed OCV use after a cholera outbreak began. Methodology/Principal Findings From 16 to 28 January 2008, vaccination campaigns with the Vietnamese killed OCV were held in two districts of Hanoi. No cholera cases were detected from 5 February to 4 March 2008, after which cases were again identified. Beginning 8 April 2008, residents of four districts of Hanoi admitted to one of five hospitals for acute diarrhea with onset after 5 March 2008 were recruited for a matched, hospital-based, case-control outbreak investigation. Cases were matched by hospital, admission date, district, gender, and age to controls admitted for non-diarrheal conditions. Subjects from the two vaccinated districts were evaluated to determine vaccine effectiveness. 54 case-control pairs from the vaccinated districts were included in the analysis. There were 8 (15%) and 16 (30%) vaccine recipients among cases and controls, respectively. The vaccine was 76% protective against cholera in this setting (95% CI 5% to 94%, P = 0.042) after adjusting for intake of dog meat or raw vegetables and not drinking boiled or bottled water most of the time. Conclusions/Significance This is the first study to explore the effectiveness of the reactive use of killed OCVs during a cholera outbreak. Our findings suggest that killed OCVs may have a role in controlling cholera outbreaks. Simple measures such as adequate sanitation and clean water stops the spread of cholera; however, in areas where these are not available, cholera spreads quickly and may lead to death in a few hours if treatment is not initiated immediately. The use of life-saving rehydration therapy is the mainstay in cholera control, however, the rapidity of the disease and the limited access to appropriate healthcare units in far-flung areas together result in an unacceptable number of deaths. The WHO has recommended the use of oral cholera vaccines as a preventive measure against cholera outbreaks since 2001, but this was recently updated so that vaccine use may also be considered once a cholera outbreak has begun. The findings from this study suggest that reactive use of killed oral cholera vaccines provides protection against the disease and may be a potential tool in times of outbreaks. Further studies must be conducted to confirm these findings.
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Takeda Y. Vibrio parahaemolyticus, enterotoxigenic Escherichia coli, enterohemorrhagic Escherichia coli and Vibrio cholerae. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2011; 87:1-12. [PMID: 21233598 PMCID: PMC3035056 DOI: 10.2183/pjab.87.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 12/07/2010] [Indexed: 05/30/2023]
Abstract
This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure-activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) produced by enterohemorrhagic Escherichia coli O157:H7, (iv) discovery of Vibrio cholerae O139, (v) isolation of new variant of Vibrio cholerae O1 El Tor that carries classical ctxB, and production of high concentration of cholera toxin by these strains, and (vi) conversion of viable but nonculturable (VBNC) Vibrio cholerae to culturable state by co-culture with eukaryotic cells.
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Affiliation(s)
- Yoshifumi Takeda
- Collaborative Research Center of Okayama University for Infectious Diseases in India.
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71
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Cholera toxin production by the El Tor variant of Vibrio cholerae O1 compared to prototype El Tor and classical biotypes. J Clin Microbiol 2010; 48:4283-6. [PMID: 20810767 DOI: 10.1128/jcm.00799-10] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Vibrio cholerae O1 El Tor variant strains produced much more cholera toxin than did prototype El Tor strains. The amount of cholera toxin produced by El Tor variant strains both in vitro and in vivo was more or less equivalent to that produced by classical strains.
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72
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Genetic determinants of virulence, antibiogram and altered biotype among the Vibrio cholerae O1 isolates from different cholera outbreaks in India. INFECTION GENETICS AND EVOLUTION 2010; 10:815-9. [DOI: 10.1016/j.meegid.2009.06.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 06/22/2009] [Accepted: 06/26/2009] [Indexed: 11/19/2022]
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73
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Sithivong N, Izumiya H, Munnalath K, Phouthavane T, Chomlasak K, Sisavath L, Vongdouangchanh A, Vongprachanh P, Watanabe H, Ohinishi M. Cholera outbreak, Laos, 2007. Emerg Infect Dis 2010; 16:745-6. [PMID: 20350415 PMCID: PMC3321958 DOI: 10.3201/eid1604.091493] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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74
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Morita M, Ohnishi M, Arakawa E, Yamamoto S, Nair GB, Matsushita S, Yokoyama K, Kai A, Seto K, Watanabe H, Izumiya H. Emergence and genetic diversity of El Tor Vibrio cholerae O1 that possess classical biotype ctxB among travel-associated cases of cholera in Japan. J Med Microbiol 2010; 59:708-712. [DOI: 10.1099/jmm.0.017624-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vibrio cholerae O1 are classified into two biotypes, classical and El Tor, each encoding a biotype-specific cholera toxin. However, El Tor strains have recently emerged with a classical cholera-toxin genotype (El Tor variant). We characterized El Tor strains of V. cholerae O1 from travel-associated cases of cholera in Japan isolated from 1991 to 2006 by cholera toxin B subunit gene (ctxB) typing and by molecular epidemiological methods. ctxB in the biotype El Tor shifted from the El Tor-specific type to the classical-specific type around 1993, and this type fully dominated the later half of the 1990s. Based on the results of PFGE and multilocus variable-number tandem repeat analysis, strains of the classical biotype remained diverse from those of El Tor biotype. The El Tor biotype strains formed multiple minor clusters and intermingled with each other irrespective of their origins and toxin types. El Tor variant strains are widespread in Asian countries and show significant genetic diversity, indicating that their spread is a result of multiclonal expansion rather than spread from a single clone.
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Affiliation(s)
- Masatomo Morita
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Makoto Ohnishi
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Eiji Arakawa
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Shouji Yamamoto
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | | | | | - Keiko Yokoyama
- Tokyo Metropolitan Institute of Public Health, Tokyo, Japan
| | - Akemi Kai
- Tokyo Metropolitan Institute of Public Health, Tokyo, Japan
| | - Kazuko Seto
- Osaka Prefectural Institute of Public Health, Osaka, Japan
| | - Haruo Watanabe
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Hidemasa Izumiya
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
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Okada K, Chantaroj S, Roobthaisong A, Hamada S, Sawanpanyalert P. A cholera outbreak of the Vibrio cholerae O1 El Tor variant carrying classical CtxB in northeastern Thailand in 2007. Am J Trop Med Hyg 2010; 82:875-8. [PMID: 20439970 DOI: 10.4269/ajtmh.2010.09-0537] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Cholera outbreaks occurred in Thailand in 2007. Isolates from the northeastern regions were analyzed. Interestingly, the outbreak strain was identified as biotype El Tor; serotype Ogawa with cholera toxin B subunit gene (ctxB) of the classical type and CTX prophage repressor gene of the El Tor type. The clone was genetically closely related to pulsotype H, which is predominantly found in India. It was probably introduced into Thailand recently.
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Affiliation(s)
- Kazuhisa Okada
- Thailand-Japan Research Collaboration Center on Emerging and Re-emerging Infections (RCC-ERI), Nonthaburi, Thailand.
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76
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Choi SY, Lee JH, Jeon YS, Lee HR, Kim EJ, Ansaruzzaman M, Bhuiyan NA, Endtz HP, Niyogi SK, Sarkar BL, Nair GB, Nguyen BM, Hien NT, Czerkinsky C, Clemens JD, Chun J, Kim DW. Multilocus variable-number tandem repeat analysis of Vibrio cholerae O1 El Tor strains harbouring classical toxin B. J Med Microbiol 2010; 59:763-769. [PMID: 20299504 DOI: 10.1099/jmm.0.017939-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Atypical Vibrio cholerae O1 strains - hybrid strains (strains that cannot be classified either as El Tor or classical biotype) and altered strains (El Tor biotype strains that produce classical cholera toxin) - are currently prevalent in Asia and Africa. A total of 74 hybrid and altered strains that harboured classical cholera toxin were investigated by multilocus variable-number tandem repeat analysis (MLVA). The results showed that the hybrid/altered strains could be categorized into three groups and that they were distant from the El Tor strain responsible for the seventh cholera pandemic. Hybrid/altered strains with a tandem repeat of the classical CTX prophage on the small chromosome were divided into two MLVA groups (group I: Mozambique/Bangladesh group; group III: Vietnam group), and altered strains with the RS1-CTX prophage containing the El Tor type rstR and classical ctxB on the large chromosome were placed in two MLVA groups (group II: India/Bangladesh group; group III: India/Vietnam group).
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Affiliation(s)
- Seon Young Choi
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Je Hee Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Yoon-Seong Jeon
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Hye Ri Lee
- International Vaccine Institute, Seoul, Republic of Korea
| | - Eun Jin Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - M Ansaruzzaman
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh
| | - Nurul A Bhuiyan
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh
| | - Hubert P Endtz
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh
| | - S K Niyogi
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - B L Sarkar
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - G Balakrish Nair
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | | | | | - John D Clemens
- International Vaccine Institute, Seoul, Republic of Korea
| | - Jongsik Chun
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Dong Wook Kim
- International Vaccine Institute, Seoul, Republic of Korea
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77
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Lee JH, Choi SY, Jeon YS, Lee HR, Kim EJ, Nguyen BM, Hien NT, Ansaruzzaman M, Islam MS, Bhuiyan NA, Niyogi SK, Sarkar BL, Nair GB, Kim DS, Lopez AL, Czerkinsky C, Clemens JD, Chun J, Kim DW. Classification of hybrid and altered Vibrio cholerae strains by CTX prophage and RS1 element structure. J Microbiol 2010; 47:783-8. [PMID: 20127474 DOI: 10.1007/s12275-009-0292-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 10/05/2009] [Indexed: 01/08/2023]
Abstract
Analysis of the CTX prophage and RS1 element in hybrid and altered Vibrio cholera O1 strains showed two classifiable groups. Group I strains contain a tandem repeat of classical CTX prophage on the small chromosome. Strains in this group either contain no element(s) or an additional CTX prophage or RS1 element(s) on the large chromosome. Group II strains harbor RS1 and CTX prophage, which has an E1 Tor type rstR and classical ctxB on the large chromosome.
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Affiliation(s)
- Je Hee Lee
- International Vaccine Institute, Seoul 151-919, Republic of Korea
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78
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Molecular keys of the tropism of integration of the cholera toxin phage. Proc Natl Acad Sci U S A 2010; 107:4377-82. [PMID: 20133778 DOI: 10.1073/pnas.0910212107] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cholera toxin is encoded in the genome of CTXvarphi, a lysogenic filamentous phage of Vibrio cholerae. CTXvarphi variants contribute to the genetic diversity of cholera epidemic strains. It has been shown that the El Tor variant of CTXvarphi hijacks XerC and XerD, two host-encoded tyrosine recombinases that normally function to resolve chromosome dimers, to integrate at dif1, the dimer resolution site of the larger of the two V. cholerae chromosomes. However, the exact mechanism of integration of CTXvarphi and the rules governing its integration remained puzzling, with phage variants integrated at either or both dimer resolution sites of the two V. cholerae chromosomes. We designed a genetic system to determine experimentally the tropism of integration of CTXvarphi and thus define rules of compatibility between phage variants and dimer resolution sites. We then showed in vitro how these rules are explained by the direct integration of the single-stranded phage genome into the double-stranded bacterial genome. Finally, we showed how the evolution of phage attachment and chromosome dimer resolution sites contributes to the generation of genetic diversity among cholera epidemic strains.
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79
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Choi SY, Lee JH, Kim EJ, Lee HR, Jeon YS, von Seidlein L, Deen J, Ansaruzzaman M, Lucas GMES, Barreto A, Songane FF, Mondlane C, Nair GB, Czerkinsky C, Clemens JD, Chun J, Kim DW. Classical RS1 and environmental RS1 elements in Vibrio cholerae O1 El Tor strains harbouring a tandem repeat of CTX prophage: revisiting Mozambique in 2005. J Med Microbiol 2009; 59:302-308. [PMID: 20007761 DOI: 10.1099/jmm.0.017053-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Currently, Vibrio cholerae O1 serogroup biotype El Tor strains producing classical type cholera toxin (altered strains or El Tor variants) are prevalent in Asia and in Mozambique. Mozambican strains collected in 2004 contained a tandem repeat of CTX prophage on the small chromosome and each CTX prophage harboured the classical rstR and classical ctxB. We found that the majority of the strains collected in 2005 in Mozambique contained extra elements on the large chromosome in addition to the tandem repeat of CTX prophage on the small chromosome. New type RS1 elements RS1(cla) and RS1(env), and a CTX(env) with rstR(env) and the classical ctxB were identified on the large chromosome of the Mozambican isolates collected in 2005.
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Affiliation(s)
- Seon Young Choi
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Je Hee Lee
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Eun Jin Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | - Hye Ri Lee
- International Vaccine Institute, Seoul, Republic of Korea
| | - Yoon-Seong Jeon
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | | | - Jaqueline Deen
- International Vaccine Institute, Seoul, Republic of Korea
| | - M Ansaruzzaman
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka, Bangladesh
| | | | | | | | | | - G Balakrish Nair
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - John D Clemens
- International Vaccine Institute, Seoul, Republic of Korea
| | - Jongsik Chun
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.,International Vaccine Institute, Seoul, Republic of Korea
| | - Dong Wook Kim
- International Vaccine Institute, Seoul, Republic of Korea
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80
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Safa A, Nair GB, Kong RYC. Evolution of new variants of Vibrio cholerae O1. Trends Microbiol 2009; 18:46-54. [PMID: 19942436 DOI: 10.1016/j.tim.2009.10.003] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2009] [Revised: 10/27/2009] [Accepted: 10/28/2009] [Indexed: 12/17/2022]
Abstract
Vibrio cholerae typically contains a prophage that carries the genes encoding the cholera toxin, which is responsible for the major clinical symptoms of the disease. In recent years, new pathogenic variants of V. cholerae have emerged and spread throughout many Asian and African countries. These variants display a mixture of phenotypic and genotypic traits from the two main biotypes (known as 'classical' and 'El Tor'), suggesting that they are genetic hybrids. Classical and El Tor biotypes have been the most epidemiologically successful cholera strains during the past century, and it is believed that the new variants (which we call here 'atypical El Tor') are likely to develop successfully in a manner similar to these biotypes. Here, we describe recent advances in our understanding of the epidemiology and evolution of the atypical El Tor strains.
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Affiliation(s)
- Ashrafus Safa
- Department of Biology and Chemistry and MERIT, City University of Hong Kong, 83, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong SAR
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