Characterization of the Vibrio cholerae vexAB and vexCD efflux systems

Bina, James E.; Provenzano, Daniele; Wang, Chunmei; Bina, Xiaowen R.; Mekalanos, John J.

doi:10.1007/s00203-006-0133-5

Cited by 81 publications

(104 citation statements)

References 53 publications

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“…The major substrates for the VexCD were cholates. These properties are essentially consistent with those of VexAB and VexCD in V. cholerae O1 (5). By comparing the deduced amino acid sequences, we found that the sequence identities of VexAB and VexCD between V. cholerae NCTC4716 (non-O1) and V. cholerae N16961 (O1) were 98% and 97%, respectively.…”

Section: Discussionsupporting

confidence: 74%

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Molecular Cloning and Characterization of All RND‐Type Efflux Transporters in Vibrio cholerae Non‐O1

Rahman

Matsuo

Ogawa

et al. 2007

Microbiology and Immunology

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Resistance Nodulation cell Division (RND) efflux transporters are thought to be involved in mediating multidrug resistance in Gram‐negative bacteria, including Vibrio cholerae non‐O1. There are six operons for putative RND‐type efflux transporters present in the chromosome of V. cholerae O1 including two operons, vexAB and vexCD, which had already been identified. All of the six operons were cloned from V. cholerae non‐O1, NCTC4716 by the PCR method, introduced, and expressed in cells of drug hypersusceptible Escherichia coli KAM33 (AacrAB, AydhE). Only vexEF conferred elevated minimum inhibitory concentrations (MICs) of some antimicrobial agents in the E. coli cells. However, VexEF did not confer increased MIC of any drug tested in tolC‐deficient E. coli KAM43 cells. On the other hand, when E. coli KAM43 was transformed with vexAB, vexCD or vexEF together with tolCVc of V. cholerae NCTC4716, we observed elevated MICs of various antimicrobial agents. Among them, E. coli KAM43 expressing both VexEF and TolCVc showed much higher MICs and much broader substrate specificity than the other two. We also observed ethidium efflux activity via VexEF‐TolCVc, and the activity required Na+. Thus, VexEF‐TolCVc is either a Na+‐activated or a Na+‐coupled transporter. To our knowledge, this is the first report on the requirement of Na+ for an RND‐type efflux transporter.

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Section: Discussionsupporting

confidence: 74%

“…We have so far characterized all of the six efflux transporters categorized in the MATE family from V. cholerae non-O1, NCTC4716 (2,18,19). Several drug efflux transporters belonging to other families have been reported in V. cholerae (O1, non-O1, and non-O139) (5,9,20).…”

mentioning

confidence: 99%

Molecular Cloning and Characterization of All RND‐Type Efflux Transporters in Vibrio cholerae Non‐O1

Rahman

Matsuo

Ogawa

et al. 2007

Microbiology and Immunology

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“…Namely, VmeAB could be involved in the escape from the instantaneous bactericidal effect of deoxycholate, and efflux transporters other than VmeAB might be involved in the growth in the presence of deoxycholate. In fact, expression of vexAB and vexCD, which encode RND-type efflux transporters in V. cholerae, has been shown to be induced by bile salts (Bina et al, 2006). Our results suggest that other multidrug transporter(s) which is (are) able to extrude deoxycholate is (are) present in V. parahaemolyticus.…”

Section: Discussionmentioning

confidence: 65%

“…In fact, two RND-type efflux transporters (VexAB and VexCD) in V. cholerae have been characterized (Bina et al, 2006). VmeAB shared high sequence similarity with AcrAB and MexAB, but to a lesser extent with VexAB and VexCD.…”

Section: Discussionmentioning

confidence: 99%

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

et al. 2007

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Genes vmeA and vmeB, encoding a multidrug efflux transporter in the halophilic bacterium Vibrio parahaemolyticus, have been cloned using a drug-hypersusceptible Escherichia coli strain as the host. Cells of E. coli KAM33 (DacrAB DydhE) carrying the vmeAB region from V. parahaemolyticus conferred much higher MICs for a variety of antimicrobial agents than did control cells. Cells possessing VmeAB under energized conditions maintained very low intracellular concentrations of ethidium. This was as expected for an energy-dependent efflux system, and supports the notion -based on sequence homology -that VmeAB belongs to the resistance nodulation cell division (RND) family of multidrug efflux transporters. It is likely that VmeAB forms functional complexes with the outer-membrane protein TolC in E. coli, because introduction of vmeAB into cells of E. coli KAM43, which lacks the tolC gene, failed to elevate the MICs for any of the antimicrobial agents tested. Therefore, a V. parahaemolyticus homologue of tolC was also cloned, designated vpoC, and was introduced together with vmeAB into cells of E. coli KAM43. The MICs of all agents tested were raised and were comparable to the values observed in E. coli KAM33 harbouring a plasmid carrying vmeAB. Finally, a vmeAB-deficient mutant of V. parahaemolyticus was constructed (designated TM3). TM3 showed slightly higher susceptibility than the parental V. parahaemolyticus to some antimicrobial agents. Survival rate of the TM3 when exposed to deoxycholate decreased compared with that of the parent. INTRODUCTIONVibrio parahaemolyticus, a slightly halophilic marine bacterium, is a major cause of food poisoning in Japan (Obata et al., 2001; WHO, 1999;Yamazaki et al., 2003) and many other countries (Cabanillas-Beltran et al., 2006; CDC, 2006;Lozano-Leon et al., 2003;McLaughlin et al., 2005; Sen et al., 2007;Su et al., 2005a). The organism has some peculiar physiological characteristics, such as a very fast growth rate, a Na + requirement for growth (Baumann & Schubert, 1984) and an ability to live in diverse environments including brackish water (Kumazawa & Kato, 1985), on estuarine algae (Kumazawa et al., 1991), and in mammalian hosts, including humans (Yamamoto & Yokota, 1989).In achieving human infection, V. parahaemolyticus survives in the intestine and especially in the duodenum, where bile acids and their conjugates are abundant. Bile acids are anionic detergents and support the digestion of fats in the intestine. In addition, bile has bactericidal effects due to its membrane-solvent property (Provenzano et al., 2000). Thus, bile resistance of enteropathogenic bacteria is thought to be important for their survival in the intestine. Some enteropathogenic bacteria have been shown to possess systems to protect from the actions of bile. In the case of Vibrio cholerae, the outer-membrane component TolC Vc , which had already been identified as a component of some multidrug efflux transporters (sometimes called multidrug efflux pumps), was found to contribute to resistance to bile,...

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“…Oligonucleotide PCR primers used for cloning are listed in Table 1. Deletion of vpsR (VC0665) in strain JB58 was constructed by homologous recombination using the allelic exchange plasmid pWM91 as previously described (Bina et al, 2006(Bina et al, , 2008. Briefly, 1 kb regions flanking vpsR were amplified by PCR using vpsR-F1/R2 and vpsR-F2/R1 primer pairs.…”

Section: Methodsmentioning

confidence: 99%

Cyclo(valine–valine) inhibits Vibrio cholerae virulence gene expression

et al. 2014

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Vibrio cholerae has been shown to produce a cyclic dipeptide, cyclo(phenylalanine-proline) (cFP), that functions to repress virulence factor production. The objective of this study was to determine if heterologous cyclic dipeptides could repress V. cholerae virulence factor production. To that end, three synthetic cyclic dipeptides that differed in their side chains from cFP were assayed for virulence inhibitory activity in V. cholerae. The results revealed that cyclo(valinevaline) (cVV) inhibited virulence factor production by a ToxR-dependent process that resulted in the repression of the virulence regulator aphA. cVV-dependent repression of aphA was found to be independent of known aphA regulatory genes. The results demonstrated that V. cholerae was able to respond to exogenous cyclic dipeptides and implicated the hydrophobic amino acid side chains on both arms of the cyclo dipeptide scaffold as structural requirements for inhibitory activity. The results further suggest that cyclic dipeptides have potential as therapeutics for cholera treatment.

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Characterization of the Vibrio cholerae vexAB and vexCD efflux systems

Cited by 81 publications

References 53 publications

Molecular Cloning and Characterization of All RND‐Type Efflux Transporters in Vibrio cholerae Non‐O1

Molecular Cloning and Characterization of All RND‐Type Efflux Transporters in Vibrio cholerae Non‐O1

VmeAB, an RND-type multidrug efflux transporter in Vibrio parahaemolyticus

Cyclo(valine–valine) inhibits Vibrio cholerae virulence gene expression

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