Molecular characterization of Vibrio cholerae isolates from Iran 2012 and 2013 outbreaks

Abstract

The aim of this study was to assess the genetic diversity of Vibrio cholerae isolated from 2012 and 2013 outbreaks in Iran, with regard to their virulence properties. A total of 20V.cholerae strains were collected from Sistan-Baluchestan province of Iran during 2012 and 2013 outbreaks. Hybridization assays showed the presence of ctx, zot, ace and rstC genes related to CTX and RS1 phages in all of the isolates. PCR assay indicated the concomitant presence of ORFs within RTX (1448, 1451) and TLC (1465, 1469) elements within the genome of the isolates. ERIC-PCR analysis showed four homogeneous profiles among which strains from 2013 outbreak and 72·7% of 2012 outbreak uniformly showed a common ERIC-PCR fingerprint. Ribotyping assay showed a single dominant profile (ribotype A) among 77·7 and 72·7% of isolates recovered from 2013 and 2012 outbreaks respectively. In conclusion, this study reports high degree of homogeneity among isolates from 2012 and 2013 outbreaks in Iran and emphasizes on the primary application of ERIC-PCR to generate fingerprints and differentiate between V.cholerae isolates of clinical origin in a timely manner for epidemiological investigations and source tracking purposes, although ribotyping method was proved to be more discriminatory. The clonality of Vibrio cholerae isolates recovered from patients with Afghan nationality during 2012 and 2013 outbreaks in Iran emphasizes on the need for monitoring Iran boundaries. This highlights the demand for a simple, reproducible and time-saving typing method for rapid and reliable assessment of clonal correlation of isolates in outbreaks. In this regard, ERIC-PCR produced results comparable with those obtained by PFGE and ribotyping which is of great significance in public health and source tracking purposes.