Identification and Detection of Biofilm Producing Staphylococcus Aureus and Its Antibiogram Activities

Abstract

Objectives: The main aim of this work is to determine the antibiogram profile of biofilm-producing Staphylococcus aureus from various clinical specimens of the patients.
 Methods: Various bacterial cultures of non-repeated clinical specimens from a total of 3388 patients were determined using standard microbiological and biochemical methods.
 Results: Out of 3388 only 604 (17.02%) displayed growth positive. A total of 65 (51.58%) S. aureus isolates were recovered, 25 (38.46%) were identified as methicillin-resistant S. aureus (MRSA) by Cefoxitin (30 μg) disk diffusion technique, of which majority were from pus/wound swab 22 (37.29%). The antibiogram of the isolates was analyzed by Kirby-Bauer disk diffusion technique analyzing Linezolid to be the most effective drug with susceptibility of 100% to both MRSA and methicillin-sensitive S. aureus, followed by vancomycin, tigecycline, and tetracycline. In vitro biofilm production by tissue culture plate (TCP) and Congo red agar method detected 52 (80%) and 25 (38.46%) as biofilm producers, respectively. TCP identified 2 (3.07%), 7 (10.76%), and 44 (67.69%) as strongly, moderately, and weakly adherent. About 30.7% of MRSA obtained were positive biofilm producers. The minimum inhibitory concentration value of Oxacillin for S. aureus by agar dilution method ranged from 0.025 μg/mL to 128 μg/mL.
 Conclusion: This study shows that biofilm production was more in methicillin-resistant strains and displayed a high degree of resistance to almost all groups of antibiotics.