Investigation of OqxAB and Qep A the quinolone resistance determinants in Carbapenem resistant Enterobactericeae isolates

Yeliz Tanrıverdi Cayci¹, Ferhan Korkmaz², Ilknur Biyik¹, Kemal Bilgin¹, Asuman Birinci¹ 

¹Department of Medical Microbiology, Medical Faculty of Ondokuz Mayis University, Samsun, Turkey - ²Microbiology Laboratory, Rize State Hospital, Rize, Turkey

Aim: Quinolone resistance is very important among Enterobactericeae isolates. Recently, new plasmid-mediated quinolone resistance were defined.  In this study we aimed to investigate the presence of plasmid-mediated efflux pump genes oqxAB and qepA in carbapenem resistant clinical isolates of Enterobactericeae. 

Materials and method: Total of 204 Enterobacterceae isolates were tested in the study. Identification of the isolates were performed in Vitek MS (Biomeriux, France) and antimicrobial susceptibility was tested in Vitek2 Compakt system (Biomeriux, France). DNA preperation was performed by a boiling technique. The oqxA, oqxB and qepA genes were investigated in polymesrase chain reaction, by using specific primers. The oqxA positive isolates were screened for oqxB.

Results: Of the 204 isolates, 102 were carbapenem resistant Enterobactericeae. oqxAB was detected  in 20.1% of carbapenem resistant isolates and 11.7% of carbapenem susceptible isolates. Both oqxA and oqxB positivity were determined in carbapenem resistant K. pneumoniae isolates. QepA was detected in any of the isolates.

Conclusion: In this study it was found that positivity of oqxAB was higher in carbapenem resistant isolates. This finding may suggest the presence of resistance genes in same plasmid and carried from one bacterium to another.