Molecular identification of virulence gene agFA in different serovars of Salmonella isolated from human in Iran

BACKGROUND AND OBJECTIVESSalmonella is zoonotic bacteria and one of the most frequently isolated foodborne pathogens. Recently, there is no cost effective vaccine available, so it is a major worldwide public health concern. The agfA gene encodes AgfA protein that mediates the binding of salmonella to fibronectin, which was predicted to be ۸۶% similar in primary sequence to the Escherichia coli curli structural protein (CsgA). The aim of this study was to analysis of the presence of agfA virulence gene in different serovars of Salmonella isolated from human in Iran, so that it can be used for diagnosis.MATERIALS AND METHODSA total ۴۸ isolate of ۱۱ different Salmonella serovars from the microbial collection of the Razi Vaccine and Serum Research Institute were used. Biochemical tests and serotyping were used to confirm the serovars. DNA extraction was performed by boiling method. Detection agfA gene (۲۶۱bp) in different Salmonella serovars was performed by PCR then amplified products were analyzed by agarose gel electrophoresis.RESULTS AND DISCUSSION A total ۳۶ out of ۴۸ Salmonella isolates were positive (۷۵%) for agfA gene. The results showed the presence of agfA gene was the most common in S.paratyphiA (۹۰%), while low prevalence of this gene was observed in S.paratyphiB (۴۲.۸%).CONCLUSIONThe results indicated the presence of the agfA gene in different Salmonella serovars. The detection of this gene helps to understand the pathogenesis of salmonella. Moreover, presence of agfA gene in S.paratyphiA shows that they are specific target for molecular identification.