Iranian clonal population of Salmonella enterica serovar Enteritidis, characterized by multi-locus sequence typing (MLST) method

Background and Objectives: Some 2 million tons of chicken meat is produced by Iran per annum, positioning Iran among the top producers in the region. This study aimed to evaluate the molecular epidemiology and genetic characteristics of Salmonella enterica Enteritidis in Iran. Materials and Methods: A representative selection of isolates (n=76), initially genotyped by a 7-locus MLVA typing system, was examined by the standard MLST genotyping. Results and Conclusion: All the MLVA typed isolates, classified into six types, were gathered under a single ST11 MLST type. This is an intriguing observation as much more genome heterogeneity was expected considering the extent of diversity in the host and geography origin of the examined isolates. ST11, on the other hand is not exclusively found in Iran as it is reported also from Brazil, Denmark, Japan and the United States. In explanation of these observations, ST11 might stand for a single probably ancestral clone of Salmonella enterica Enteritidis successfully scattered in all these geographically diverse countries. Further global investigation covering more isolates and methods like whole genome sequencing would be advisable.