Occurrence of extended-spectrum β-lactamase, AmpC, and carbapenemase-producing genes in gram-negative bacterial isolates from human immunodeficiency virus infected patients.

BACKGROUND

Progressive decline of immune response in HIV patients makes them susceptible to frequent bacterial infections. High usage of antibiotics influences the emergence of multidrug-resistant bacteria and worsens the clinical outcomes. In this study, the occurrence of drug-resistant genes in Gram-negative bacterial isolates from HIV patients in South India was analyzed.

METHODS

A total of 173 Gram-negative bacterial (GNB) isolates from HIV patients were screened for antibiotic susceptibility profile using the Kirby-Bauer diskdiffusion method. Positivity of drug-resistant genes was analyzed using polymerase chain reaction method.

RESULTS

In this study, 72.8% of bacterial isolates were obtained from urine specimens, and Escherichia coli (47.4%) was the predominantly isolated bacterium. Overall, 87.3% and 83.2% of GNB were resistant to 3rd generation cephalosporin antibiotics such as cefotaxime and ceftazidime, respectively, 56.6% were resistant to cephamycin (cefoxitin) and 43% to carbapenem (imipenem) antibiotics. Extended-spectrum β-lactamases (ESBL) production was noted among 79.5% of GNB isolates, followed by AmpC (57.1%) and Metallo β-lactamases (37.3%). Molecular analysis revealed that ESBL genes such as blaTEM (94.1%), blaCTX-M (89.2%), and blaSHV (24.2%) were detected at higher levels among GNB isolates. Carbapenemase-producing genes such as blaOXA-48 (20%), blaOXA-23 (2.6%), and both blaOXA-23 and blaOXA-51 like genes (2.6%) and AmpC producing genes such as blaCIT (26.7%), blaDHA (3.6%), and blaACC (1.8%) were detected at low-level.

CONCLUSIONS

This study concludes that ESBL producing genes are detected at high level among gram-negative bacterial isolates from HIV patients in South India.