scholarly journals Identification of Vibrio cholerae pathogenicity island (ctxA, OmpW and tcpA) in non - O139 and non - O1 V. cholerae strains isolated from Karun River in Ahvaz, Iran

2012 ◽  
Vol 6 (6) ◽  
pp. 1185-1189 ◽  
Author(s):  
Farajzadeh Sheikh Ahmad ◽  
Goodarzi Hamed ◽  
Aslani Sajad
Keyword(s):  
Vibrio Cholerae ◽  
Pathogenicity Island ◽  
Karun River

scholarly journals Pathogenic Potential of Environmental Vibrio cholerae Strains Carrying Genetic Variants of the Toxin-Coregulated Pilus Pathogenicity Island

2003 ◽  
Vol 71 (2) ◽  
pp. 1020-1025 ◽  
Author(s):  
Shah M. Faruque ◽  
M. Kamruzzaman ◽  
Ismail M. Meraj ◽  
Nityananda Chowdhury ◽  
G. Balakrish Nair ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Genetic Variants ◽  
Pathogenicity Island ◽  
Biologically Active ◽  
Pathogenic Potential ◽  
Origin And Evolution ◽  
Colonization Factor ◽  
Evolution Of Virulence ◽  
Toxin Coregulated Pilus ◽  
El Tor

ABSTRACT The major virulence factors of toxigenic Vibrio cholerae are cholera toxin (CT), which is encoded by a lysogenic bacteriophage (CTXΦ), and toxin-coregulated pilus (TCP), an essential colonization factor which is also the receptor for CTXΦ. The genes for the biosynthesis of TCP are part of a larger genetic element known as the TCP pathogenicity island. To assess their pathogenic potential, we analyzed environmental strains of V. cholerae carrying genetic variants of the TCP pathogenicity island for colonization of infant mice, susceptibility to CTXΦ, and diarrheagenicity in adult rabbits. Analysis of 14 environmental strains, including 3 strains carrying a new allele of the tcpA gene, 9 strains carrying a new allele of the toxT gene, and 2 strains carrying conventional tcpA and toxT genes, showed that all strains colonized infant mice with various efficiencies in competition with a control El Tor biotype strain of V. cholerae O1. Five of the 14 strains were susceptible to CTXΦ, and these transductants produced CT and caused diarrhea in adult rabbits. These results suggested that the new alleles of the tcpA and toxT genes found in environmental strains of V. cholerae encode biologically active gene products. Detection of functional homologs of the TCP island genes in environmental strains may have implications for understanding the origin and evolution of virulence genes of V. cholerae.

scholarly journals Examination of Diverse Toxin-Coregulated Pilus-Positive Vibrio cholerae Strains Fails To Demonstrate Evidence for Vibrio Pathogenicity Island Phage

2003 ◽  
Vol 71 (6) ◽  
pp. 2993-2999 ◽  
Author(s):  
Shah M. Faruque ◽  
Jun Zhu ◽  
Asadulghani ◽  
M. Kamruzzaman ◽  
John J. Mekalanos
Keyword(s):  
Vibrio Cholerae ◽  
Virulence Factors ◽  
Genetic Variants ◽  
Horizontal Transfer ◽  
Pathogenicity Island ◽  
Culture Conditions ◽  
Filamentous Phage ◽  
Colonization Factor ◽  
Toxin Coregulated Pilus ◽  
El Tor

ABSTRACT The major virulence factors of toxigenic Vibrio cholerae are cholera toxin, which is encoded by a lysogenic filamentous bacteriophage (CTXΦ), and toxin-coregulated pilus (TCP), an essential colonization factor that is also the receptor for CTXΦ. The genes involved in the biosynthesis of TCP reside in a pathogenicity island, which has been reported to correspond to the genome of another filamentous phage (designated VPIΦ) and to encode functions necessary for the production of infectious VPIΦ particles. We examined 46 V. cholerae strains having diverse origins and carrying different genetic variants of the TCP island for the production of the VPIΦ and CTXΦ in different culture conditions, including induction of prophages with mitomycin C and UV irradiation. Although 9 of 10 V. cholerae O139 strains and 12 of 15 toxigenic El Tor strains tested produced extracellular CTXΦ, none of the 46 TCP-positive strains produced detectable VPIΦ in repeated assays, which detected as few as 10 particles of a control CTX phage per ml. These results contradict the previous report regarding VPIΦ-mediated horizontal transfer of the TCP genes and suggest that the TCP island is unable to support the production of phage particles. Further studies are necessary to understand the mechanism of horizontal transfer of the TCP island.

scholarly journals Comparative Genomic Analyses of the Vibrio Pathogenicity Island and Cholera Toxin Prophage Regions in Nonepidemic Serogroup Strains of Vibrio cholerae

2003 ◽  
Vol 69 (3) ◽  
pp. 1728-1738 ◽  
Author(s):  
Manrong Li ◽  
Mamuka Kotetishvili ◽  
Yuansha Chen ◽  
Shanmuga Sozhamannan
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Fragment Length Polymorphism ◽  
Pathogenicity Island ◽  
Filamentous Phage ◽  
Comparative Genomic ◽  
Genomic Analyses ◽  
Ctxφ Prophage ◽  
Horizontal Acquisition ◽  
Restriction Fragment Length

ABSTRACT Two major virulence factors are associated with epidemic strains (O1 and O139 serogroups) of Vibrio cholerae: cholera toxin encoded by the ctxAB genes and toxin-coregulated pilus encoded by the tcpA gene. The ctx genes reside in the genome of a filamentous phage (CTXφ), and the tcpA gene resides in a vibrio pathogenicity island (VPI) which has also been proposed to be a filamentous phage designated VPIφ. In order to determine the prevalence of horizontal transfer of VPI and CTXφ among nonepidemic (non-O1 and non-O139 serogroups) V. cholerae, 300 strains of both clinical and environmental origin were screened for the presence of tcpA and ctxAB. In this paper, we present the comparative genetic analyses of 11 nonepidemic serogroup strains which carry the VPI cluster. Seven of the 11 VPI+ strains have also acquired the CTXφ. Multilocus sequence typing and restriction fragment length polymorphism analyses of the VPI and CTXφ prophage regions revealed that the non-O1 and non-O139 strains were genetically diverse and clustered in lineages distinct from that of the epidemic strains. The left end of the VPI in the non-O1 and non-O139 strains exhibited extensive DNA rearrangements. In addition, several CTXφ prophage types characterized by novel repressor (rstR) and ctxAB genes and VPIs with novel tcpA genes were found in these strains. These data suggest that the potentially pathogenic, nonepidemic, non-O1 and non-O139 strains identified in our study most likely evolved by sequential horizontal acquisition of the VPI and CTXφ independently rather than by exchange of O-antigen biosynthesis regions in an existing epidemic strain.

scholarly journals Crystal structure of VC1805, a conserved hypothetical protein from a Vibrio cholerae pathogenicity island, reveals homology to human p32

2008 ◽  
Vol 71 (3) ◽  
pp. 1563-1571 ◽  
Author(s):  
Md. Arif Sheikh ◽  
Jane A. Potter ◽  
Kenneth A. Johnson ◽  
Robert B. Sim ◽  
E. Fidelma Boyd ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Vibrio Cholerae ◽  
Pathogenicity Island ◽  
Hypothetical Protein

Molecular evolution of Vibrio pathogenicity island-2 (VPI-2): mosaic structure among Vibrio cholerae and Vibrio mimicus natural isolates

Microbiology ◽  
2005 ◽  
Vol 151 (1) ◽  
pp. 311-322 ◽  
Author(s):  
William S. Jermyn ◽  
E. Fidelma Boyd
Keyword(s):  
Vibrio Cholerae ◽  
Gene Cluster ◽  
Gene Tree ◽  
Pathogenicity Island ◽  
Housekeeping Gene ◽  
Gene Trees ◽  
Modification System ◽  
Restriction Modification System ◽  
Vibrio Mimicus ◽  
Natural Isolates

Vibrio cholerae is a Gram-negative rod that inhabits the aquatic environment and is the aetiological agent of cholera, a disease that is endemic in much of Southern Asia. The 57·3 kb Vibrio pathogenicity island-2 (VPI-2) is confined predominantly to toxigenic V. cholerae O1 and O139 serogroup isolates and encodes 52 ORFs (VC1758 to VC1809), which include homologues of an integrase (VC1758), a restriction modification system, a sialic acid metabolism gene cluster (VC1773–VC1783), a neuraminidase (VC1784) and a gene cluster that shows homology to Mu phage. In this study, a 14·1 kb region of VPI-2 comprising ORFs VC1773 to VC1787 was identified by PCR and Southern blot analyses in all 17 Vibrio mimicus isolates examined. The VPI-2 region in V. mimicus was inserted adjacent to a serine tRNA similar to VPI-2 in V. cholerae. In 11 of the 17 V. mimicus isolates examined, an additional 5·3 kb region encoding VC1758 and VC1804 to VC1809 was present adjacent to VC1787. The evolutionary history of VPI-2 was reconstructed by comparative analysis of the nanH (VC1784) gene tree with the species gene tree, deduced from the housekeeping gene malate dehydrogenase (mdh), among V. cholerae and V. mimicus isolates. Both gene trees showed an overall congruence; on both gene trees V. cholerae O1 and O139 serogroup isolates clustered together, whereas non-O1/non-O139 serogroup isolates formed separate divergent branches with similar clustering of strains within the branches. One exception was noted: on the mdh gene tree, V. mimicus sequences formed a distinct divergent lineage from V. cholerae sequences; however, on the nanH gene tree, V. mimicus clustered with V. cholerae non-O1/non-O139 isolates, suggesting horizontal transfer of this region between these species.

scholarly journals Characterization of pathogenicity island prophage in clinical and environmental strains of Vibrio cholerae

2011 ◽  
Vol 60 (12) ◽  
pp. 1742-1749 ◽  
Author(s):  
H. Mohammadi-Barzelighi ◽  
B. Bakhshi ◽  
A. Rastegar Lari ◽  
M. R. Pourshafie
Keyword(s):  
Vibrio Cholerae ◽  
Pathogenicity Island

scholarly journals Analysis of Clinical and Environmental Strains of Nontoxigenic Vibrio cholerae for Susceptibility to CTXΦ: Molecular Basis for Origination of New Strains with Epidemic Potential

1998 ◽  
Vol 66 (12) ◽  
pp. 5819-5825 ◽  
Author(s):  
Shah M. Faruque ◽  
Asadulghani ◽  
Manujendra N. Saha ◽  
A. R. M. Abdul Alim ◽  
M. John Albert ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Surface Waters ◽  
Molecular Basis ◽  
Regulatory Gene ◽  
Pathogenicity Island ◽  
Rrna Gene ◽  
Naturally Occurring ◽  
Multiple Copies ◽  
Gene Restriction

ABSTRACT Toxigenic Vibrio cholerae strains are lysogens of CTXΦ, a filamentous phage which encodes cholera toxin. The receptor for CTXΦ for invading V. cholerae cells is the toxin-coregulated pilus (TCP), the genes for which reside in a larger genetic element, the TCP pathogenicity island. We analyzed 146 CTX-negative strains of V. cholerae O1 or non-O1 isolated from patients or surface waters in five different countries for the presence of the TCP pathogenicity island, the regulatory genetoxR, and the CTXΦ attachment sequence attRS, as well as for susceptibility of the strains to CTXΦ, to investigate the molecular basis for the emergence of new clones of toxigenicV. cholerae. DNA probe or PCR assays for tcpA,tcpI, acfB, toxR, andattRS revealed that 6.85% of the strains, all of which belonged to the O1 serogroup, carried the TCP pathogenicity island,toxR, and multiple copies of attRS, whereas the remaining 93.15% of the strains were negative for TCP but positive for either one or both or neither of toxR andattRS. An analysis of the strains for susceptibility to CTXΦ, using a genetically marked derivative of the phage CTX-KmΦ, showed that all TCP-positive CTX-negative strains and 1 of 136 TCP-negative strains were infected by the phage either in vitro or in the intestines of infant mice. The phage genome integrated into the chromosome of infected V. cholerae O1 cells forming stable lysogens. Comparative analysis of rRNA gene restriction patterns revealed that the lysogens derived from nontoxigenic progenitors were either closely related to or distinctly different from previously described clones of toxigenic V. cholerae. To our knowledge, this is the first demonstration of lysogenic conversion of naturally occurring nontoxigenic V. cholerae strains by CTXΦ. The results of this study further indicated that strains belonging to the O1 serogroup of V. cholerae are more likely to possess the TCP pathogenicity island and hence to be infected by CTXΦ, leading to the origination of potential new epidemic clones.

scholarly journals The Vibrio Pathogenicity Island of Epidemic Vibrio cholerae Forms Precise Extrachromosomal Circular Excision Products

2003 ◽  
Vol 185 (23) ◽  
pp. 6893-6901 ◽  
Author(s):  
C. Rajanna ◽  
J. Wang ◽  
D. Zhang ◽  
Zheng Xu ◽  
A. Ali ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Virulence Gene ◽  
Pathogenicity Island ◽  
Pcr Analysis ◽  
Integrase Gene ◽  
Site Specific ◽  
The Core ◽  
Left And Right ◽  
The Right ◽  
Insight Into

ABSTRACT The Vibrio pathogenicity island (VPI) in epidemic Vibrio cholerae is an essential virulence gene cluster. Like many pathogenicity islands, the VPI has at its termini a phage-like integrase gene (int), a transposase-like gene (vpiT), and phage-like attachment (att) sites, and is inserted at a tRNA-like locus (ssrA). We report that the VPI precisely excises from the chromosome and that its left and right ends join to form an extrachromosomal circular excision product (pVPI). Two-stage nested PCR analysis and DNA sequencing confirmed the int-att-vpiT junction and that the core attP of pVPI is identical to the chromosomal VPI attR site. Excision was independent of toxR and toxT. Excision was independent of recA, suggesting that it is mediated by site-specific recombination. Interestingly, while excision was detected in int and vpiT mutants, excision was abolished in a double (int vpiT) mutant and was restored by plasmids containing genes for either recombinase. Excision results in deletion of A361 in the ssrA locus, which flanks the right junction of the VPI. Since A361 encodes U70 in the critical G · U base pair in the acceptor stem of the ssrA RNA that is the determinant for aminoacylation with alanine, this deletion might have deleterious effects on ssrA function. Also, vpiT may have undergone interchromosomal translocation or may represent an independent integration event, as it was found downstream of hutA in some isolates. Our results provide new insight into the molecular biology of the VPI, and we propose that the process of excision and circularization is important in the emergence, pathogenesis, and persistence of epidemic V. cholerae.

scholarly journals A Vibrio cholerae pathogenicity island associated with epidemic and pandemic strains

1998 ◽  
Vol 95 (6) ◽  
pp. 3134-3139 ◽  
Author(s):  
D. K. R. Karaolis ◽  
J. A. Johnson ◽  
C. C. Bailey ◽  
E. C. Boedeker ◽  
J. B. Kaper ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Pathogenicity Island ◽  
Pandemic Strains
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