Detection of Metallo-Beta-Lactamase (MBL) producing pseudomonas aeruginosa and acinetobacter Spp. from a Tertiary Care Hospital

 Non-Fermenting Gram-Negative Bacilli [NFGNB] which are considered as environmental contaminants have emerged as multidrug-resistant bacteria and are of serious concern to the treating physician. The aim of this study was to determine the proportion of metallo-beta-lactamase producing Pseudomonas aeruginosa and Acinetobacter species in clinical samples received in the Microbiology Laboratory and to study the antibiotic sensitivity pattern of metallo-beta-lactamase (MBL) producing strains.

 Various samples (pus, sputum, urine, blood and body fluids, etc.) were processed according to standard protocols. P.aeruginosa and Acinetobacter spp were isolated and identified with the help of various culture media, staining methods and biochemical reactions. Antibiotic susceptibility test was done by using Kirby-bauer disc diffusion method. MBL producers were identified using CLSI guidelines.

 Out of 600 positive culture isolates from various samples, 65 (10.8%) were non-fermenting gram-negative bacilli, 40 (61.53%) were Pseudomonas aeruginosa, and 25 (38.47%) were Acinetobacter species. The overall incidence of MBL positive isolates in our study was 12.3% (8 of 65). All the isolates of Pseudomonas aeruginosa and Acinetobacterspecies were 100% sensitive to Colistin and Tigecycline.

 The study helps in understanding the antibiotic resistance pattern of isolates causing nosocomial infections, helping clinicians in making appropriate antibiotic choices as an empirical therapy and the policy-makers to bring out the measures in controlling the superbugs.