Classical RS1 and environmental RS1 elements in Vibrio cholerae O1 El Tor strains harbouring a tandem repeat of CTX prophage: revisiting Mozambique in 2005

2010 ◽  
Vol 59 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Seon Young Choi ◽  
Je Hee Lee ◽  
Eun Jin Kim ◽  
Hye Ri Lee ◽  
Yoon-Seong Jeon ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Tandem Repeat ◽  
Small Chromosome ◽  
Classical Type ◽  
Large Chromosome ◽  
New Type ◽  
Vibrio Cholerae O1 ◽  
Ctx Prophage ◽  
El Tor

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 RS1cla and RS1env, and a CTXenv with rstR env and the classical ctxB were identified on the large chromosome of the Mozambican isolates collected in 2005.

scholarly journals Genetic organization of pre-CTX and CTX prophages in the genome of an environmental Vibrio cholerae non-O1, non-O139 strain

Microbiology ◽  
2006 ◽  
Vol 152 (12) ◽  
pp. 3633-3641 ◽  
Author(s):  
Diganta Maiti ◽  
Bhabatosh Das ◽  
Arjun Saha ◽  
Ranjan K. Nandy ◽  
G. Balakrish Nair ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Genetic Locus ◽  
Single Copy ◽  
Small Chromosome ◽  
Large Chromosome ◽  
Critical Determinant ◽  
Multiple Copies ◽  
New Type ◽  
Ctx Prophage ◽  
El Tor

The cholera toxin (CT) is a critical determinant of the virulence of epidemic Vibrio cholerae strains. The ctxAB operon encoding CT is part of the genome of a filamentous bacteriophage CTXΦ, which may integrate as a single copy or as multiple copies in the genome of V. cholerae. The CTXΦ genome is composed of RS2 (2.4 kb) and core (4.5 kb) regions. In the present study extensive genetic mapping analyses indicated that two copies of tandemly arrayed CTX prophages are integrated in the small chromosome of an environmental V. cholerae strain, VCE232, belonging to serogroup O4. Further mapping revealed that the integration of prophages has occurred in the same genetic locus of the small chromosome of VCE232 as that of V. cholerae O1 biotype El Tor strains. Interestingly, a new type of RS2-like element 3.5 kb in size was found in the CTX prophage genome in the small chromosome of VCE232. Cloning followed by sequencing of the new RS2-like element of VCE232 revealed the presence of three ORFs, which probably encode highly divergent types of phage regulatory proteins. Furthermore, the strain VCE232 also harbours two copies of a tandemly arranged CTX prophage devoid of the ctxAB genes, called pre-CTX prophage, in its large chromosome. The presence of multiple copies of diverse CTX prophages in both the chromosomes of VCE232 suggests that toxigenic environmental V. cholerae non-O1, non-O139 strains could play a role in the emergence of new epidemic clones.

scholarly journals Multilocus variable-number tandem repeat analysis of Vibrio cholerae O1 El Tor strains harbouring classical toxin B

2010 ◽  
Vol 59 (7) ◽  
pp. 763-769 ◽  
Author(s):  
Seon Young Choi ◽  
Je Hee Lee ◽  
Yoon-Seong Jeon ◽  
Hye Ri Lee ◽  
Eun Jin Kim ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Tandem Repeat ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Group Iii ◽  
Repeat Analysis ◽  
Group I ◽  
Ctx Prophage ◽  
El Tor

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).

scholarly journals Multilocus sequence typing (MLST) analysis of Vibrio cholerae O1 El Tor isolates from Mozambique that harbour the classical CTX prophage

2006 ◽  
Vol 55 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Je Hee Lee ◽  
Kyung Ho Han ◽  
Seon Young Choi ◽  
Marcelino E. S. Lucas ◽  
C. Mondlane ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Tandem Repeat ◽  
Multilocus Sequence Typing ◽  
Sequence Type ◽  
Genetic Loci ◽  
Mlst Analysis ◽  
Vibrio Cholerae O1 ◽  
Ctx Prophage ◽  
El Tor

Vibrio cholerae O1 isolates belonging to the Ogawa serotype, El Tor biotype, harbouring the classical CTX prophage were first isolated in Mozambique in 2004. Multilocus sequence typing (MLST) analysis using nine genetic loci showed that the Mozambique isolates have the same sequence type (ST) as O1 El Tor N16961, a representative of the current seventh cholera pandemic. Analysis of the CTX prophage in the Mozambique isolates indicated that there is one type of rstR in these isolates: the classical CTX prophage. It was also found that the ctxB-rstR-rstA-rstB-phs-cep fragment was PCR-amplified from these isolates, which indicates the presence of a tandem repeat of the classical CTX prophage in the genome of the Mozambique isolates. The possible origin of these isolates and the presence of the tandem repeat of the classical prophage in them implicate the presence of the classical CTX phage.

scholarly journals Vibrio cholerae O1 clinical strains isolated in 1992 in Kolkata with progenitor traits of the 2004 Mozambique variant

2009 ◽  
Vol 58 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Souvik Chatterjee ◽  
Tapas Patra ◽  
Kausik Ghosh ◽  
Amit Raychoudhuri ◽  
Gururaja P. Pazhani ◽  
...  
Keyword(s):  
Retrospective Analysis ◽  
Vibrio Cholerae ◽  
Polymyxin B ◽  
Small Chromosome ◽  
Phenotypic Traits ◽  
Clinical Strains ◽  
Vibrio Cholerae O1 ◽  
Ctx Prophage ◽  
El Tor ◽  
Clinical Cases

Retrospective analysis led to the detection of two Vibrio cholerae variant O1 strains (VC51 and VC53), which were isolated in 1992 in Kolkata from clinical cases, with identical traits to 2004 Mozambique variant O1 strains. The Mozambique O1 strains that caused a huge outbreak in 2004 have been shown to have phenotypic traits of both classical and El Tor biotypes, and thereby have been reported as variant. Our study demonstrated that two O1 strains isolated in Kolkata during 1992 were of the El Tor background as evidenced by polymyxin B (50 U ml−1) resistance, positivity in Voges–Proskauer reactions and sensitivity to biotype-specific vibrio phages. With the features of classical CTX prophage, localization in the small chromosome, and an absence of RS1 and pTLC, both Mozambique and Kolkata strains appeared to be identical. Furthermore, two Kolkata strains exhibited an identical ribotype to that of the Mozambique variant, displaying ribotype pattern RI that had been assigned to Kolkata V. cholerae O1 strains isolated on or before 1992. NotI pulsotype analysis indicated that these 1992 Kolkata strains along with the Mozambique variant O1 belonged to very closely related clones. Considering the chronological events, and the typical identity at the phenotypic and the genotypic level between the two O1 strains isolated during 1992 from Kolkata and during 2004 from Mozambique, we propose that some of the 1992 Kolkata O1 strains might have acted as progenitors for Mozambique variant O1 strains.

scholarly journals CTX Prophages in Classical Biotype Vibrio cholerae: Functional Phage Genes but Dysfunctional Phage Genomes

2000 ◽  
Vol 182 (24) ◽  
pp. 6992-6998 ◽  
Author(s):  
Brigid M. Davis ◽  
Kathryn E. Moyer ◽  
E. Fidelma Boyd ◽  
Matthew K. Waldor
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Virulence Factor ◽  
Experimental Results ◽  
Single Locus ◽  
Large Chromosome ◽  
Genetic Element ◽  
Functional Forms ◽  
Ctx Prophage ◽  
El Tor

ABSTRACT CTXφ is a filamentous, lysogenic bacteriophage whose genome encodes cholera toxin, the primary virulence factor produced byVibrio cholerae. CTX prophages in O1 El Tor and O139 strains of V. cholerae are found within arrays of genetically related elements integrated at a single locus within theV. cholerae large chromosome. The prophages of O1 El Tor and O139 strains generally yield infectious CTXφ. In contrast, O1 classical strains of V. cholerae do not produce CTXφ, although they produce cholera toxin and they contain CTX prophages integrated at two sites. We have identified the second site of CTX prophage integration in O1 classical strains and characterized the classical prophage arrays genetically and functionally. The genes of classical prophages encode functional forms of all of the proteins needed for production of CTXφ. Classical CTX prophages are present either as solitary prophages or as arrays of two truncated, fused prophages. RS1, a genetic element that is closely related to CTXφ and is often interspersed with CTX prophages in El Tor strains, was not detected in classical V. cholerae. Our model for CTXφ production predicts that the CTX prophage arrangements in classical strains will not yield extrachromosomal CTX DNA and thus will not yield virions, and our experimental results confirm this prediction. Thus, failure of O1 classical strains ofV. cholerae to produce CTXφ is due to overall deficiencies in the structures of the arrays of classical prophages, rather than to mutations affecting individual CTX prophage genes.

scholarly journals Variation in Epitopes of the B Subunit of El Tor and Classical Biotype Vibrio cholerae O1 Cholera Toxin

Microbiology ◽  
1989 ◽  
Vol 135 (5) ◽  
pp. 1195-1200 ◽  
Author(s):  
M. L. Tamplin ◽  
M. K. Ahmed ◽  
R. Jalali ◽  
R. R. Colwell
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
B Subunit ◽  
Vibrio Cholerae O1 ◽  
El Tor

scholarly journals Genetic Diversity of Toxigenic and Nontoxigenic Vibrio cholerae Serogroups O1 and O139 Revealed by Array-Based Comparative Genomic Hybridization

2007 ◽  
Vol 189 (13) ◽  
pp. 4837-4849 ◽  
Author(s):  
Bo Pang ◽  
Meiying Yan ◽  
Zhigang Cui ◽  
Xiaofen Ye ◽  
Baowei Diao ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Clonal Selection ◽  
Gene Clusters ◽  
Small Chromosome ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Pathogenic Potential ◽  
Genomic Microarray ◽  
Ctx Prophage ◽  
El Tor

ABSTRACT Toxigenic serogroups O1 and O139 of Vibrio cholerae may cause cholera epidemics or pandemics. Nontoxigenic strains within these serogroups also exist in the environment, and also some may cause sporadic cases of disease. Herein, we investigate the genomic diversity among toxigenic and nontoxigenic O1 and O139 strains by comparative genomic microarray hybridization with the genome of El Tor strain N16961 as a base. Conservation of the toxigenic O1 El Tor and O139 strains is found as previously reported, whereas accumulation of genome changes was documented in toxigenic El Tor strains isolated within the 40 years of the seventh pandemic. High phylogenetic diversity in nontoxigenic O1 and O139 strains is observed, and most of the genes absent from nontoxigenic strains are clustered together in the N16961 genome. By comparing these toxigenic and nontoxigenic strains, we observed that the small chromosome of V. cholerae is quite conservative and stable, outside of the superintegron region. In contrast to the general stability of the genome, the superintegron demonstrates pronounced divergence among toxigenic and nontoxigenic strains. Additionally, sequence variation in virulence-related genes is found in nontoxigenic El Tor strains, and we speculate that these intermediate strains may have pathogenic potential should they acquire CTX prophage alleles and other gene clusters. This genome-wide comparison of toxigenic and nontoxigenic V. cholerae strains may promote understanding of clonal differentiation of V. cholerae and contribute to an understanding of the origins and clonal selection of epidemic strains.

scholarly journals Cholera Toxin Production by the El Tor Variant of Vibrio cholerae O1 Compared to Prototype El Tor and Classical Biotypes

2010 ◽  
Vol 48 (11) ◽  
pp. 4283-4286 ◽  
Author(s):  
J. Ghosh-Banerjee ◽  
M. Senoh ◽  
T. Takahashi ◽  
T. Hamabata ◽  
S. Barman ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Toxin Production ◽  
Vibrio Cholerae O1 ◽  
El Tor
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