Comparative sequence analysis of recA gene among Vibrio cholerae isolates from Iran with globally reported sequences

Aims: To study the genetic relatedness between V. cholerae isolates from Iran and other countries based on housekeeping gene recA sequence analysis.

Methods and results: A 995-bp region of the recA gene from 24 V. cholerae isolates obtained from human and surface water origins in Iran over a 5-year period was sequenced and compared with the sequence data from the isolates belonging to other places. Cluster analysis of the constructed dendrogram based on recA sequence divergence for our clinical isolates showed one sequence type (ST), whereas environmental isolates revealed eight STs. Interestingly, one of our environmental isolates was intermixed with clinical isolates in the largest cluster containing the epidemic strains. Our 24 isolates plus 198 global isolates available in the GenBank showed 77 sequence types (STs) with at least one nucleotide difference.

Conclusions: Our result suggested that recA sequencing is a reliable analysis method for understanding the relatedness of the local isolates with the isolates obtained elsewhere.

Significance and impact of the study: Understanding the genetic relatedness between V. cholerae isolates could give insights into the health care system for better control and prevention of the cholera.