Diversity and antibiotic resistance patterns of enterobacteria isolated from seafood in Thailand

Abstract

Contamination with enterobacteria was detectable in 89% of seafood samples from three central seafood markets in Thailand. The average numbers obtained from the same type of seafood were between 1.3 ± 0.9 and 4.5 ± 1.3 log CFU/g per sample. Eighty-one strains and 16 species were distinguished based on ERIC-PCR patterns and TP-RAPD patterns, respectively. The highest prevalence (90% of strains) was resistant to penicillin G whereas none was resistant to gentamycin. In addition, 63% exhibited multidrug resistance. The 16S rDNA sequences of a representative strain from each species exhibited 99% identity to either one of six genera including Citrobacter, Enterobacter, Klebsiella, Providencia, Serratia, and Yersinia. Three β-lactamase genes including blaTEM, ampC, and shv were detected at the frequencies of 43%, 27%, and 24%, respectively. The representative strains possessing β-lactamase genes exhibited β-lactamase activity ranging from 1.96 ± 0.88 to 11.3 ± 0.37 μmol of hydrolyzed nitrocefin/min/mg protein.