Comparative analysis of factors promoting virulence in Vibrio cholerae O139 and Vibrio cholerae classical

Abstract

The genus Vibrio is most extensively characterized and medically important group within the family vibrionaceae and it is the most important member of the genus is Vibrio cholerae, the causative agent of cholera. Depending on the presence of O1 antigen they are devided in to two serogroups or serovars: O1 and non-O1. Further O1 is devided in to two biotypes: classical and El Tor. These two biotypes are divided into three serotypes that are inaba, ogawa and hikojima. The virulence properties vary from strain to strain (serogroups). The current study was undertaken aiming at exploring the factors involved with virulence in V. cholerae classical in comparison to V. cholerae O139 by various studies like bacterial antibiotic susceptibility test, haemolytic activity, In silico approach to find potential virulence factors and gene expression pattern study for OMPU & OMPT (Semi quantitative study). MIC of V. cholerae O139 was found to be 12.5, 50 and 25 µg/ml and MIC of V. cholerae classical was found to be 6.25, 25, 12.5 µg/ml for amphicillin, chloramphenicol and amphotericin respectively. So V. cholerae O139 showed more resistance to all the three antibiotics when compared to V. cholerae classical. Similarly, V. cholerae O139 showed higher haemolytic activity than V. cholerae classical. Gene expression pattern confirmed that OMP U gene expression was significantly higher in V. cholerae O 139 as compared V. cholerae classical biotype. But OMP T gene expression is significantly higher in V. cholerae classical as compared to V. cholerae O 139. As OMP U plays a measure role in virulence (as reported previously), V. cholerae O139 is more virulent than V. cholerae classical.