Background: P. aeruginosa continues to be a major cause of nosocomial infection. The emergence of resistance to β-lactam antibiotics is by production of different classes of β-lactamases.
Objective: To investigate the prevalence of extended‑spectrum β-lactamase (ESBL), AmpC β-lactamase, and metallo‑β-lactamase (MBL) enzymes in clinical isolates of P.aeruginosa.
Material & methods: A total of 180 clinical isolates of P. aeruginosa were tested for the presence of ESBL, AmpC and MBL enzymes. Detection of ESBL was done by double disk synergy test (MDDST) & phenotypic confirmatory disc diffusion test (PCDDT). Amp C was tested by AmpC disc test and cefoxitin hodge test. MBL production was confirmed by disc potentiation test. Antibiotic susceptibility was done by disc diffusion test as per the Clinical and Laboratory Standards Institute guidelines 2016.
Results: Maximum isolates were obtained from pus 43(23.88%) followed by urine 34(18.88%).Beta-lactamase production was observed in 85 strains. Eighty three isolates were potential ESBL producers, 27.71% (23/83) were confirmed positive. AmpC production was detected in 21.66% (26/120) while MBL in 59.01% (36/61) isolates. The co-production of the ESBL/AmpC / MBL β-lactamases was observed in 12 (14.11%) strains. Out of 180 isolates 34 (18.89%) were multi-drug resistant (MDR) and 3 (1.66%) were possible extensively drug resistant XDR.
Conclusions: The study emphasizes the high prevalence of multidrug resistant P. aeruginosa producing β-lactamase enzymes. Thus, continuous surveillance to detect the resistant strains, strict guidelines for the antibiotic therapy and implementation of infection control measures is necessary to reduce the increasing burden of antibiotic resistance.
