Plasmid Profile and ERIC–PCR Characterization of Salmonella Infantis Isolates Recovered from Poultry Sources

Abstract

Backgrounds: Salmonella is known as one of the most important bacterial agents infecting both humans and animals. Salmonella Infantis has been reported as one of the 15 most prevalent serovars all over the world. Despite, its clinical importance, there is a paucity of information on the molecular characteristics of Salmonella Infantis in Iran. Objectives: This study was conducted to characterize Salmonella Infantis isolates collected from poultry sources in last decade by plasmid profile and enterobacterial repetitive intergenic consensus (ERIC–PCR). Methods: Forty Salmonella Infantis isolates from poultry sources were subjected to plasmid profile and ERIC–PCR characterization. A commercial plasmid extraction kit was used to extract and purify plasmid DNA which then were separated by gel electrophoresis and viewed under an UV transilluminator. For ERIC–PCR, a commercial bacterial chromosomal DNA extraction kit was used. ERIC2 primer was chosen for ERIC-PCR test in this study. Results: Plasmid profile showed that 35% of isolates did not contain any plasmids but the rest of isolates (65%) carried variable number of plasmids with different molecular weight. Six plasmid profiles were found among 40 Salmonella Infantis isolates. Using ERIC2 primer, seven profiles were found among 40 Salmonella Infantis isolates in ERIC-PCR. Bands with molecular weights ranging from 400 to 3000 bp were observed.Conclusions: This study provided some genetic data on Salmonella Infantis isolates recovered from poultry sources and these data can be used for a broader epidemiological study nationwide. These findings showed that both plasmid- and ERIC profiles are valuable in epidemiological studies but also have some limitations.