Molecular analysis of non-O1/non-O139 Vibrio choleraeisolated from hospitalised patients in China

Luo, Yun; Ye, Julian; Jin, Dazhi; Ding, Gang; Zhang, Zheng; Mei, Lingling; Octavia, Sophie; Lan, Ruiting

doi:10.1186/1471-2180-13-52

Cited by 53 publications

(46 citation statements)

References 48 publications

(51 reference statements)

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“…Toxigenic non-O1/non-O139 V. cholerae strains appear to be frequently isolated from both clinical and environmental samples worldwide and are reported to be highly diverse (39,40). Variability among the isolates of this study was observed, with 55 profiles comprising up to 12 virulence factors (Table 5).…”

Section: Discussionmentioning

confidence: 82%

Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland

Ceccarelli

Chen

Hasan

et al. 2015

Appl Environ Microbiol

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f Non-O1/non-O139 Vibrio cholerae inhabits estuarine and coastal waters globally, but its clinical significance has not been sufficiently investigated, despite the fact that it has been associated with septicemia and gastroenteritis. The emergence of virulent non-O1/non-O139 V. cholerae is consistent with the recognition of new pathogenic variants worldwide. Oyster, sediment, and water samples were collected during a vibrio surveillance program carried out from 2009 to 2012 in the Chesapeake Bay, Maryland. V. cholerae O1 was detected by a direct fluorescent-antibody (DFA) assay but was not successfully cultured, whereas 395 isolates of non-O1/non-O139 V. cholerae were confirmed by multiplex PCR and serology. Only a few of the non-O1/non-O139 V. cholerae isolates were resistant to ampicillin and/or penicillin. Most of the isolates were sensitive to all antibiotics tested, and 77 to 90% carried the El Tor variant hemolysin gene hlyA ET , the actin cross-linking repeats in toxin gene rtxA, the hemagglutinin protease gene hap, and the type 6 secretion system. About 19 to 21% of the isolates carried the neuraminidase-encoding gene nanH and/or the heat-stable toxin (NAG-ST), and only 5% contained a type 3 secretion system. None of the non-O1/non-O139 V. cholerae isolates contained Vibrio pathogenicity island-associated genes. However, ctxA, ace, or zot was present in nine isolates. Fifty-five different genotypes showed up to 12 virulence factors, independent of the source of isolation, and represent the first report of both antibiotic susceptibility and virulence associated with non-O1/non-O139 V. cholerae from the Chesapeake Bay. Since these results confirm the presence of potentially pathogenic non-O1/non-O139 V. cholerae, monitoring for total V. cholerae, regardless of serotype, should be done within the context of public health. Vibrio cholerae, a waterborne bacterial pathogen, is an autochthonous inhabitant of riverine and estuarine aquatic environments. There are Ͼ200 serogroups, based on O antigenic characters, but only serogroups O1 and O139 have been associated with epidemic cholera, and both are considered a major public health threat for developing countries (1).Developed countries today rarely witness cholera cases caused by epidemic strains of V. cholerae, and outbreaks are typically travel associated (2). However, infections other than cholera can be caused by nonepidemic V. cholerae serogroups that are collectively referred to as non-O1/non-O139 V. cholerae and are generally acquired through the consumption of raw or undercooked seafood. Non-O1/non-O139 V. cholerae infections are continuously reported worldwide (3, 4), emphasizing their clinical significance. Although non-O1/non-O139 V. cholerae strains generally do not produce cholera toxin, other virulence factors contribute to their pathogenicity, including the hemolysin gene hlyA (5), the protease gene hapA (6), the cytotoxic actin cross-linking repeats in toxin gene rtxA (7), the sialidase gene nanH (8), the heat-stable toxin (NAG-ST) (9), a type 6...

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Section: Discussionmentioning

confidence: 82%

Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland

Ceccarelli

Chen

Hasan

et al. 2015

Appl Environ Microbiol

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“…While most of these putative virulence factors are expressed in only a fraction of clinical NOVC isolates, RTX, HapA and VCC are expressed in almost all V. cholerae serogroups and are therefore more promising as potential toxigenic factors [2], [9], [11]. VCC is a particularly interesting candidate; in a study using a streptomycin-fed murine model of disease, VCC was shown to be the predominant cause of death [12].…”

Section: Introductionmentioning

confidence: 99%

Outer Membrane Vesicles Mediate Transport of Biologically Active Vibrio cholerae Cytolysin (VCC) from V. cholerae Strains

et al. 2014

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BackgroundOuter membrane vesicles (OMVs) released from Gram-negative bacteria can serve as vehicles for the translocation of virulence factors. Vibrio cholerae produce OMVs but their putative role in translocation of effectors involved in pathogenesis has not been well elucidated. The V. cholerae cytolysin (VCC), is a pore-forming toxin that lyses target eukaryotic cells by forming transmembrane oligomeric β-barrel channels. It is considered a potent toxin that contributes to V. cholerae pathogenesis. The mechanisms involved in the secretion and delivery of the VCC have not been extensively studied.Methodology/Principal FindingsOMVs from V. cholerae strains were isolated and purified using a differential centrifugation procedure and Optiprep centrifugation. The ultrastructure and the contents of OMVs were examined under the electron microscope and by immunoblot analyses respectively. We demonstrated that VCC from V. cholerae strain V:5/04 was secreted in association with OMVs and the release of VCC via OMVs is a common feature among V. cholerae strains. The biological activity of OMV-associated VCC was investigated using contact hemolytic assay and epithelial cell cytotoxicity test. It showed toxic activity on both red blood cells and epithelial cells. Our results indicate that the OMVs architecture might play a role in stability of VCC and thereby can enhance its biological activities in comparison with the free secreted VCC. Furthermore, we tested the role of OMV-associated VCC in host cell autophagy signalling using confocal microscopy and immunoblot analysis. We observed that OMV-associated VCC triggered an autophagy response in the target cell and our findings demonstrated for the first time that autophagy may operate as a cellular defence mechanism against an OMV-associated bacterial virulence factor.Conclusion/SignificanceBiological assays of OMVs from the V. cholerae strain V:5/04 demonstrated that OMV-associated VCC is indeed biologically active and induces toxicity on mammalian cells and furthermore can induce autophagy.

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“…The isolates were selected based on their different gene characters (types of ctxB, rstR, and VSP-I/II), different years, and different provinces/regions; all 76 isolates represented the different characters of O139 isolates in China, from both clinical and environmental sources (see Table S2 in the supplemental material). Seven housekeeping genes (adk, gyrB, metE, mdh, pntA, purM, and pyrC) were targeted for MLST analysis, based on a previous study (22); primers are listed in Table S1 in the supplemental material. The PCR products were visualized on an agarose gel, and direct sequencing was performed in both directions.…”

Section: Bacterial Isolates and Serological Identificationmentioning

confidence: 99%

A Molecular Surveillance Reveals the Prevalence of Vibrio cholerae O139 Isolates in China from 1993 to 2012

et al. 2014

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bVibrio cholerae serogroup O139 was first identified in 1992 in India and Bangladesh, in association with major epidemics of cholera in both countries; cases were noted shortly thereafter in China. We characterized 211 V. cholerae O139 isolates that were isolated at multiple sites in China between 1993 and 2012 from patients (n ‫؍‬ 92) and the environment (n ‫؍‬ 119). Among clinical isolates, 88 (95.7%) of 92 were toxigenic, compared with 47 (39.5%) of 119 environmental isolates. Toxigenic isolates carried the El Tor CTX prophage and toxin-coregulated pilus A gene (tcpA), as well as the Vibrio seventh pandemic island I (VSP-I) and VSP-II. Among a subset of 42 toxigenic isolates screened by multilocus sequence typing (MLST), all were in the same sequence type as a clinical isolate (MO45) from the original Indian outbreak. Nontoxigenic isolates, in contrast, generally lacked VSP-I and -II, and fell within13 additional sequence types in two clonal complexes distinct from the toxigenic isolates. In further pulsed-field gel electrophoresis (PFGE) (with NotI digestion) studies, toxigenic isolates formed 60 pulsotypes clustered in one group, while the nontoxigenic isolates formed 43 pulsotypes which clustered into 3 different groups. Our data suggest that toxigenic O139 isolates from widely divergent geographic locations, while showing some diversity, have maintained a relatively tight clonal structure across a 20-year time span. Nontoxigenic isolates, in contrast, exhibited greater diversity, with multiple clonal lineages, than did their toxigenic counterparts.

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Molecular analysis of non-O1/non-O139 Vibrio choleraeisolated from hospitalised patients in China

Cited by 53 publications

References 48 publications

Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland

Non-O1/Non-O139 Vibrio cholerae Carrying Multiple Virulence Factors and V. cholerae O1 in the Chesapeake Bay, Maryland

Outer Membrane Vesicles Mediate Transport of Biologically Active Vibrio cholerae Cytolysin (VCC) from V. cholerae Strains

A Molecular Surveillance Reveals the Prevalence of Vibrio cholerae O139 Isolates in China from 1993 to 2012

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