ToxR of Vibrio cholerae affects biofilm, rugosity and survival with Acanthamoeba castellanii

被引:18
作者
Valeru S.P. [1 ]
Wai S.N. [2 ]
Saeed A. [1 ]
Sandström G. [1 ]
Abd H. [1 ]
机构
[1] Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Huddinge, SE-141 86, Stockholm
[2] Department of Molecular Biology, Umeå University
关键词
Association with amoebae; Biofilm; Outer membrane proteins; Rugose colonies; V; cholerae;
D O I
10.1186/1756-0500-5-33
中图分类号
学科分类号
摘要
Background: Vibrio cholerae causes the diarrheal disease cholera and utilizes different survival strategies in aquatic environments. V. cholerae can survive as free-living or in association with zooplankton and can build biofilm and rugose colonies. The bacterium expresses cholera toxin (CT) and toxin-coregulated pilus (TCP) as the main virulence factors. These factors are co-regulated by a transcriptional regulator ToxR, which modulates expression of outer membrane proteins (OmpU) and (OmpT). The aims of this study were to disclose the role of ToxR in expression of OmpU and OmpT, biofilm and rugose colony formation as well as in association with the free-living amoeba Acanthamoeba castellanii at different temperatures. Results: The toxR mutant V. cholerae produced OmpT, significant biofilm and rugose colonies compared to the wild type that produced OmpU, decreased biofilm and did not form rugoes colonies at 30°C. Interestingly, neither the wild type nor toxR mutant strain could form rugose colonies in association with the amoebae. However, during the association with the amoebae it was observed that A. castellanii enhanced survival of V. cholerae wild type compared to toxR mutant strain at 37°C. Conclusions: ToxR does seem to play some regulatory role in the OmpT/OmpU expression shift, the changes in biofilm, rugosity and survival with A. castellanii, suggesting a new role for this regulatory protein in the environments. © 2012 Valeru et al; licensee BioMed Central Ltd.
引用
收藏
相关论文
共 21 条
[1]  
Tauxe R.V., Mintz E.D., Quick R.E., Epidemic cholera in the new world: Translating field epidemiology into new prevention strategies, Emerg Infect Dis, 1, 4, pp. 141-146, (1995)
[2]  
Wai S.N., Mizunoe Y., Takade A., Kawabata S.-I., Yoshida S.-I., Vibrio cholerae O1 strain TSI-4 produces the exopolysaccharide materials that determine colony morphology, stress resistance, and biofilm formation, Applied and Environmental Microbiology, 64, 10, pp. 3648-3655, (1998)
[3]  
Islam M.S., Jahid M.I.K., Rahman M.M., Rahman M.Z., Shafiqu M., Islam M.S.K., Sack D.A., Schoolnik G.K., Biofilm acts as a microenvironment for plankton-associated Vibrio cholerae in the aquatic environment of Bangladesh, Microbiology and Immunology, 51, 4, pp. 369-379, (2007)
[4]  
Johnson L.R., Microcolony and biofilm formation as a survival strategy for bacteria, J Theor Biol, 251, 1, pp. 24-34, (2008)
[5]  
Wrangstadh M., Conway P.L., Kjelleberg S., The production and release of an extracellular polysaccharide during starvation of a marine Pseudomonas sp. and the effect thereof on adhesion, Archives of Microbiology, 145, 3, pp. 220-227, (1986)
[6]  
Abd H., Saeed A., Weintraub A., Nair G.B., Sandstrom G., Vibrio cholerae O1 strains are facultative intracellular bacteria, able to survive and multiply symbiotically inside the aquatic free-living amoeba Acanthamoeba castellanii, FEMS Microbiology Ecology, 60, 1, pp. 33-39, (2007)
[7]  
Abd H., Saeed A., Weintraub A., Sandstrom G., Vibrio cholerae O139 requires neither capsule nor LPS O side chain to grow inside Acanthamoeba castellanii, J Med Microbiol, 58, PART 1, pp. 125-131, (2009)
[8]  
Abd H., Weintraub A., Sandstrom G., Intracellular survival and replication of Vibrio cholerae O139 in aquatic free-living amoebae, Environmental Microbiology, 7, 7, pp. 1003-1008, (2005)
[9]  
Saeed A., Abd H., Edvinsson B., Sandstrom G., Vibrio cholerae-Acanthamoeba castellanii interaction showing endosymbiont-host relation, Symbiosis, 44, 1-3, pp. 153-158, (2007)
[10]  
Sandstrom G., Saeed A., Abd H., Acanthamoeba polyphaga is a possible host for Vibrio cholerae in aquatic environments, Exp Parasitol, 126, 1, pp. 65-68, (2010)