Molecular characterization of beta-lactam resistance of Salmonella isolates from pediatric patients in Romania.

The molecular characterization of 16 clinical isolates of Salmonella enterica (14 serotype Typhimurium and 2 serotype Kingston) obtained between January and June 1999 from feces of children hospitalized in Iasi, Romania were genotypically compared by pulse field gel electrophoresis of XbaI restricted bacterial DNA. The majority of the clinical isolates (12/16) belonged to cluster A and (4/16) to unrelated strains, correlating to the OMP profile. Two major different patterns of beta-lactamases were identified: the first with pI of 5.4, 8.2 in 6/16 strains and the second with pI of 5.4 in 5/16. The blaTEM beta-lactamase was identified in 14/16 of the clinical isolates and the blaSHV-5 gene in one strain. We concluded that extended spectrum beta-lactamase (ESBL) with pIs of 8.2 was the most frequent enzyme produced by serotype Typhimurium isolates which were related.