Objective: To investigate the prevalence of aac(6')-Ib-cr gene in Enterobacter cloacae isolates.
Methods: PCR and sequencing were performed on 81 strains of Enterobacter cloacae isolated clinically in Anhui province to identify aac (6')-IB-cr gene. Disk diffusion method was used to test the susceptibility of the Enterobacter cloacae isolates with aac (6')-Ib-cr gene to fluoroquinolones, aminoglycosides, and other antimicrobial agents. AmpC and extended-spectrum beta-lactamases (ESBLs) were detected by modified three-dimensional extract test, and the molecular typing was analyzed by ERIC-PCR.
Results: Aac (6')-Ib-cr gene was identified in 3 (3.7%) of the 81 Enterobacter cloacae isolates with different ERIC-PCR patterns. The isolates with aac (6')-Ib-cr gene were resistant to fluoroquinolones, aminoglycosides, chloramphenicol, ampicillin, cefoxitin, and second and third generation cephalosporins. Two of the 3 isolates produced AmpC and ESBLs, and 1 isolate produced only ESBLs.
Conclusion: Aac (6')-Ib-cr gene is prevalent in Enterobacter cloacae isolates with resistance to most of antimicrobial agents and no clone spread in found in them.