Characterization of CTX-M-type-extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae isolated from Indonesian undergraduate medical students of a university in Surabaya, Indonesia

Abstract

Enterobacteriaceae isolates producing CTX-M-type extended-spectrum β-lactamase (ESBL) has been found in hospitalized patients and healthy individuals in communities of the Southeast Asian countries. Medical students might have more risk of ESBL-producing Enterobacteriaceae contagion, because medical students who belong to communities have direct and indirect contacts with workers and patients in healthcare facilities. The aim of this study was to collect information for evaluation of the potential risk of ESBL-producing Enterobacteriaceae contagion in Indonesian undergraduate medical students by characterizing genotypic properties of Escherichia coli isolates-producing CTX-M-type ESBL. A total 141 fecal samples collected from 207 medical students of a university in Surabaya, Indonesia were subjected to PCR, XbaI and S1 nuclease-pulsed-field gel electrophoresis (PFGE), Southern blotting, and sequencing analysis. Eighty-two ESBL-producing Enterobacteriaceae, including 75 E. coli and 7 Klebsiella pneumoniae were isolated from 79 (56.0%) students. Among 75 ESBL-producing E. coli, blaCTX-M-15 was the most prevalent type (44.0%). Although XbaI-PFGE results showed genetic background of the E. coli isolates producing CTX-M-type ESBL were diverse, five clonal spread cases of certain E. coli producing CTX-M-type ESBL isolates were observed among the medical students. Our results suggested that ESBL-producing Enterobacteriaceae might be circulating among the medical students through contaminated environment such as in a university or communities they belonged.