Rapid Screening of toxigenic and non-toxigenic V. cholera from clinical and environmental samples in Iraq by PCR

Abstract

Zonnla occludens toxin (zot) is one of the major virulence factors of Vibrio cholera. The detection of zot producing V. cholerae using conventional culture, biochemical and immunological based assays is time-consuming laborious, and requiring more than three days to perform. In this work aspecific primers for zot gene were used for detection of V. cholerae that isolated from clinical and environmental samples. The results revealed that 12 of 15 clinical isolates were Ol serogroup, 6 isolates belonged to each of serotypes ogawa and lnaba and 3 isolates belonged to the serotype Non/ Ol, and all environmental isolates (5 isolates) were belonged to the serotype Non/ O1. Few colonies of V. cholerae were suspended in nutrient broth and used as few plates in PCR reaction for the detection of zot gene, The 947 bp sequence of a gene that codes for the zonula occludens toxin was amplified by PCR. Direct use of V. cholerae pure culture for PCR replaces the need for DNA extraction or boiling. PCR results showed that all clinical (Ol) isolates of V. cholerae contain gene namely zot, while the Non/ O1 isolates that had been isolated from clinical sources, as well as, that isolated from environment showed no existence for zot gene. The results of Molecular epidemiology study indicated that the source of outbreaks of 2007, 2008 and 2009 is the same all over Iraq, according to the PCR profile.

Keywords

• toxigenic, non-toxigenic, pcr, V. cholera