Prevalence of Plasmid Mediated Quinolone Resistance Determinants among ESBL producing Enterobacteriaceae in Lima, Peru.

RINCÓN GIOVANNA; RADICE MARCELA; SEVILLA ANDRADE, CARLOS; PURAY CHAVEZ, MARITZA; GUTKIND GABRIEL; DI CONZA JOSÉ

Denver, Colorado

Conferencia; 53rd ICAAC- Annual Interscience Conference on Antimicrobial Agents and Chemotherapy; 2013

American Society of Microbiology

Abstract: Background: Both extended spectrum cephalosporins and quinolones constitute first line antibiotic options in infections caused by different enterobacteria, although the last decade highlighted the unexpected rise of plasmid mediated quinolone resistance determinants (PMQR). In this study we searched for the prevalence of PMQR genes within 27 ESBL producing enterobacteria collected in hospitals in metropolitan area in Lima, Peru, during January 2011. Methods: A total of 27 presumptive ESBL producing enterobacterial isolates (Escherichia coli 15, Klebsiella pneumoniae 9 and other species 3) were included. Antimicrobial susceptibility tests were performed according to CLSI recommendations. Screening for ESBL and AmpC beta-lactamases were conducted by double disk synergy tests. ESBL and PMQR determinants were investigated by PCR followed by sequencing and/or RFLP-PCR using BseGI. Results: The most prevalent PMQR determinant detected among ESBL producers was aac(6´)-Ib-cr (15/27), mainly associated to blaCTX-M group1 (12/15). Five isolates (18,5%) harbored qnr genes: qnrB1 (n=1), qnrB19 (n=3) and qnrS1 (n=1). OqxAB coding genes were found in three E. coli isolated; one of them also harbored aac(6´)-Ib-cr and blaCTX-M group1 and the remaining two also displayed bla CTX-M group 9. Finally, qepA1 gene was detected in one E. coli isolate as unique PMQR mechanism, additionally it was detected bla CTX-M group 9. Conclusion: High variability of PMQR determinants were found among ESBL-producing Enterobacteriaceae. As expected, the main PMQR mechanism, aac(6´)-Ib-cr, was more frequently associated to CTX M group 1 producers (80%).