Molecular epidemiology and antibiotic resistance patterns of Salmonella enterica from southwestern Greece

Background: A study was conducted at the University Hospital of Patras between January 2002 and December 2003 to investigate antibiotic resistance patterns and clonality of Salmonella enterica in southwestern Greece. Methods: Ninety-five isolates recovered from different outpatients were characterized by specific antisera and were tested for their susceptibility to various antimicrobial agents. Clones were identified by pulsed-field gel electrophoresis ( PFGE) of Xbal chromosomal DNA digests. Results: Five serotypes were characterized among 95 isolates, recovered mainly from children, with the predominance of Salmonella enteritidis followed by Salmonella typhimurium. The strains were further distinguished by PFGE to 16 clones. The majority of S. enteritidis ( 61 strains) belonged to clone A, already characterized in Greece, while S. typhimurium ( 18 isolates) belonged to 3 clones, exhibiting multiresistant phenotypes. Conclusions: One clone S. enteritidis, type A, circulates in southwestern Greece, mainly during summer, while clonality was also observed among S. typhimurium.