COMPARATIVE STUDY OF GELATINASE ACTIVITY AND PELLICLE FORMATION AMONG EXTENDED-SPECTRUM BETA-LACTAMASE AND NON-EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING ACINETOBACTER BAUMANNII FROM DIABETIC FOOT ULCER INFECTIONS

Abstract

Objective: The aim of the study was to assess and compare the gelatinase activity and pellicle formation in extended-spectrum beta-lactamase (ESBL) and non-ESBL producing Acinetobacter baumannii isolates from diabetic foot ulcer infection (DFI).Methods: A total of 42 isolates of A. baumannii recovered from patients of DFI from September 2016 to February 2018. Isolates were identified by the standard microbiological method and confirmed by the BD Phoenix 100 system. The antimicrobial susceptibility test was performed by the Kirby–Bauer disk diffusion method and ESBL was detected by double disk diffusion synergy test method. Gelatinase production was determined by the Luria Bertani agar supplemented with 30 g/L gelatin, and pellicle formation was determined by the Mueller-Hinton broth which is incubated at two different temperatures.Results: A total of 42 A. baumannii isolates were multidrug resistant. Among 21 isolates, each was ESBL and non-ESBL producers. Pellicle formation at 25°C in ESBL and non-ESBL producer isolates was 47.61% (10/21) and 28.57% (06/21). Pellicle formation at 37°C in ESBL and non-ESBL producer isolates was 57.14% (12/21) and 42.85% (09/21), respectively. Gelatinase production was present in 38.09% ESBL and 28.57% in non-ESBL producers. ESBL strains were more virulent compared to non-ESBL producers among patients of DFIs.Conclusion: This study showed that pellicle formation at 37°C was highly virulent due to ESBL producers. Gelatinase production was elevated in ESBL compared to non-ESBL producer isolates. This attribute of the isolates could render ESBL positive more pathogenic. Colistin and polymyxin B are the only choices of treatment for multidrug-resistant Acinetobacter baumannii infections.