Abstract :
Background: The reducing susceptibility of broad-spectrum betalactam antibiotics, mediated by AmpC betalactamase, extended-spectrum betalactamases (ESBL), and metallo betalactamase (MBL) enzymes, is a rapidly growing problem globally.
Aim of the study: This study was conducted to phenotypically detect the predominance and incidence of AmpC beta-lactamase, ESBL, and MBL-producing Pseudomonas aeruginosa from different clinical specimens.
Materials and Methods: Over the course of a year, a prospective cross-sectional observational investigation had been performed in a tertiary hospital in Nalgonda. AmpC betalactamase, ESBL, and MBL enzymes were detected phenotypically in 46 nonrepetitive isolates of Pseudomonas aeruginosa. An antagonistic disc test was used to identify the enzyme AmpC betalactamase phenotypically. Based on CLSI guidelines, the double disk synergistic test and combined disk diffusion approach were employed to phenotypically detect ESBL. The Imipenem and Imipenem plus EDTA disk synergistic/potentiation test identified MBL.
Results: Twenty segregates (43.4%) in total tested positive for AmpC beta-lactamase. Six strains (13%) of them produced inducible AmpC. Co-production of AmpC with MBL and ESBL was described in 15% and 40% of the details, respectively.
Conclusion: The research highlights the significant incidence of multidrug-resistant (MDR) Pseudomonas aeruginosa producing beta-lactamases with different constituents. Therefore, appropriate antimicrobial strategies and actions to restrict the erratic application of cephalosporins and carbapenems are necessary to prevent the spread of these various pathogens that produce beta-lactamases.

Keyword : AmpC beta-lactamase, Extended spectrum beta-lactamase, Metallo beta-lactamase, Pseudomonas aeruginosa.