scholarly journals Design and Construction of Vibrio cholerae Strains That Harbor Various CTX Prophage Arrays

2018 ◽  
Vol 9 ◽  
Author(s):  
Hyun J. Yu ◽  
Da S. R. Cha ◽  
Dong-Hun Shin ◽  
Gopinath B. Nair ◽  
Eun J. Kim ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Ctx Prophage ◽  
Design And Construction

Classification of hybrid and altered Vibrio cholerae strains by CTX prophage and RS1 element structure

2009 ◽  
Vol 47 (6) ◽  
pp. 783-788 ◽  
Author(s):  
Je Hee Lee ◽  
Seon Young Choi ◽  
Yoon-Seong Jeon ◽  
Hye Ri Lee ◽  
Eun Jin Kim ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Ctx Prophage

scholarly journals Vibrio cholerae LexA Coordinates CTX Prophage Gene Expression

2009 ◽  
Vol 191 (22) ◽  
pp. 6788-6795 ◽  
Author(s):  
Harvey H. Kimsey ◽  
Matthew K. Waldor
Keyword(s):  
Gene Expression ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Single Site ◽  
Virion Production ◽  
Regulatory Circuit ◽  
Ctxφ Prophage ◽  
Gene Regulatory ◽  
Ctx Prophage ◽  
Operator Site

ABSTRACT The filamentous bacteriophage CTXΦ transmits the cholera toxin genes by infecting and lysogenizing its host, Vibrio cholerae. CTXΦ genes required for virion production initiate transcription from the strong P A promoter, which is dually repressed in lysogens by the phage-encoded repressor RstR and the host-encoded SOS repressor LexA. Here we identify the neighboring divergent rstR promoter, P R, and show that RstR both positively and negatively autoregulates its own expression from this promoter. LexA is absolutely required for RstR-mediated activation of P R transcription. RstR autoactivation occurs when RstR is bound to an operator site centered 60 bp upstream of the start of transcription, and the coactivator LexA is bound to a 16-bp SOS box centered at position −23.5, within the P R spacer region. Our results indicate that LexA, when bound to its single site in the CTXΦ prophage, both represses transcription from P A and coactivates transcription from the divergent P R. We propose that LexA coordinates P A and P R prophage transcription in a gene regulatory circuit. This circuit is predicted to display transient switch behavior upon induction of CTXΦ lysogens.

scholarly journals RS1 Satellite Phage Promotes Diversity of Toxigenic Vibrio cholerae by Driving CTX Prophage Loss and Elimination of Lysogenic Immunity

2014 ◽  
Vol 82 (9) ◽  
pp. 3636-3643 ◽  
Author(s):  
M. Kamruzzaman ◽  
William Paul Robins ◽  
S. M. Nayeemul Bari ◽  
Shamsun Nahar ◽  
John J. Mekalanos ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Sub Saharan Africa ◽  
Host Cells ◽  
Adult Rabbit ◽  
Content Type ◽  
Rabbit Intestine ◽  
Sub Saharan ◽  
Toxigenic Strains ◽  
Ctx Prophage ◽  
El Tor

ABSTRACTIn El Tor biotype strains of toxigenicVibrio cholerae, the CTXϕ prophage often resides adjacent to a chromosomally integrated satellite phage genome, RS1, which produces RS1ϕ particles by using CTX prophage-encoded morphogenesis proteins. RS1 encodes RstC, an antirepressor against the CTXϕ repressor RstR, which cooperates with the host-encoded LexA protein to maintain CTXϕ lysogeny. We found that superinfection of toxigenic El Tor strains with RS1ϕ, followed by inoculation of the transductants into the adult rabbit intestine, caused elimination of the resident CTX prophage-producing nontoxigenic derivatives at a high frequency. Further studies usingrecAdeletion mutants and a clonedrstCgene showed that the excision event wasrecAdependent and that introduction of additional copies of the clonedrstCgene instead of infection with RS1ϕ was sufficient to enhance CTXϕ elimination. Our data suggest that once it is excised from the chromosome, the elimination of CTX prophage from host cells is driven by the inability to reestablish CTXϕ lysogeny while RstC is overexpressed. However, with eventual loss of the additional copies ofrstC, the nontoxigenic derivatives can act as precursors of new toxigenic strains by acquiring the CTX prophage either through reinfection with CTXϕ or by chitin-induced transformation. These results provide new insights into the role of RS1ϕ inV. choleraeevolution and the emergence of highly pathogenic clones, such as the variant strains associated with recent devastating epidemics of cholera in Asia, sub-Saharan Africa, and Haiti.

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).

Replication and integration of a Vibrio cholerae cryptic plasmid linked to the CTX prophage

1998 ◽  
Vol 28 (6) ◽  
pp. 1247-1254 ◽  
Author(s):  
Eric J. Rubin ◽  
Wei Lin ◽  
John J. Mekalanos ◽  
Matthew K. Waldor
Keyword(s):  
Vibrio Cholerae ◽  
Cryptic Plasmid ◽  
Ctx Prophage

scholarly journals Activation of the Vibrio cholerae SOS Response Is Not Required for Intestinal Cholera Toxin Production or Colonization

2006 ◽  
Vol 74 (2) ◽  
pp. 927-930 ◽  
Author(s):  
Mariam Quinones ◽  
Brigid M. Davis ◽  
Matthew K. Waldor
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Sos Response ◽  
Toxin Production ◽  
Mrna Levels ◽  
Suckling Mouse ◽  
Potent Inducer ◽  
Genes Encoding ◽  
Mouse Intestine ◽  
Ctx Prophage

ABSTRACT Cholera toxin, one of the main virulence factors of Vibrio cholerae, is encoded in the genome of CTXφ, a V. cholerae-specific lysogenic filamentous bacteriophage. Although the genes encoding cholera toxin, ctxAB, are known to have their own promoter, the toxin genes can also be transcribed from an upstream CTXφ promoter, PrstA . The V. cholerae SOS response to DNA damage induces the CTX prophage by stimulating gene expression initiating from PrstA . Here, we investigated whether ctxA mRNA levels increase along with the levels of the transcripts for the other CTXφ genes following stimulation of the V. cholerae SOS response. Treatment of V. cholerae with the SOS-inducing agent mitomycin C increased the level of ctxA mRNA approximately sevenfold, apparently by augmenting the activity of PrstA . However, using suckling mice as a model host, we found that intraintestinal ctxA transcription does not depend on PrstA . In fact, the suckling mouse intestine does not appear to be a potent inducer of the V. cholerae SOS response. Furthermore, alleviation of LexA-mediated repression of the V. cholerae SOS regulon was not required for V. cholerae growth in the suckling mouse intestine. Our observations suggest that pathogenicity of V. cholerae does not depend on its SOS response.

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 RS1 Element of Vibrio cholerae Can Propagate Horizontally as a Filamentous Phage Exploiting the Morphogenesis Genes of CTXΦ

2002 ◽  
Vol 70 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Shah M. Faruque ◽  
Asadulghani ◽  
M. Kamruzzaman ◽  
Ranjan K. Nandi ◽  
A. N. Ghosh ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Kanamycin Resistance ◽  
Open Reading Frames ◽  
Filamentous Phage ◽  
Pcr Analysis ◽  
Recombination System ◽  
Genes Encoding ◽  
Ctx Prophage ◽  
A Site ◽  
El Tor

ABSTRACT In toxigenic Vibrio cholerae, cholera toxin is encoded by the CTX prophage, which consists of a core region carrying ctxAB genes and genes required for CTXΦ morphogenesis, and an RS2 region encoding regulation, replication, and integration functions. Integrated CTXΦ is often flanked by another genetic element known as RS1 which carries all open reading frames (ORFs) found in RS2 and an additional ORF designated rstC. We identified a single-stranded circularized form of the RS1 element, in addition to the CTXΦ genome, in nucleic acids extracted from phage preparations of 32 out of 83 (38.5%) RS1-positive toxigenic V. cholerae strains analyzed. Subsequently, the corresponding double-stranded replicative form (RF) of the RS1 element was isolated from a representative strain and marked with a kanamycin resistance (Kmr) marker in an intergenic site to construct pRS1-Km. Restriction and PCR analysis of pRS1-Km and sequencing of a 300-bp region confirmed that this RF DNA was the excised RS1 element which formed a novel junction between ig1 and rstC. Introduction of pRS1-Km into a V. cholerae O1 classical biotype strain, O395, led to the production of extracellular Kmr transducing particles, which carried a single-stranded form of pRS1-Km, thus resembling the genome of a filamentous phage (RS1-KmΦ). Analysis of V. cholerae strains for susceptibility to RS1-KmΦ showed that classical biotype strains were more susceptible to the phage compared to El Tor and O139 strains. Nontoxigenic (CTX−) O1 and O139 strains which carried genes encoding the CTXΦ receptor toxin-coregulated pilus (TCP) were also more susceptible (>1,000-fold) to the phage compared to toxigenic El Tor or O139 strains. Like CTXΦ, the RS1Φ genome also integrated into the host chromosomes by using the attRS sequence. However, only transductants of RS1-KmΦ which also harbored the CTXΦ genome produced a detectable level of extracellular RS1-KmΦ. This suggested that the core genes of CTXΦ are also required for the morphogenesis of RS1Φ. The results of this study showed for the first time that RS1 element, which encodes a site-specific recombination system in V. cholerae, can propagate horizontally as a filamentous phage, exploiting the morphogenesis genes of CTXΦ.

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.

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