Antibiotic Sensitivity Pattern of Aerobic Bacterial Isolates in Wound Infections in Navi Mumbai, India

Background: Wound infection is a breach in the integrity and protective function of the skin. Mostly bacteria (e.g. Staphylococcus aureus), certain viruses (e. g. Herpes virus) and fungi (e.g. Candida albicans) are responsible for wound infection. This study was conducted for isolation, identification and antibiotic sensitivity testing of aerobic bacterial strains from wound infection.

Methods: Total 216 pus samples were collected and immediately inoculated on Blood agar and MacConkey agar plates. Then the culture plates were placed in incubator at 37°C for 24 hours. After incubation, all isolates were identified by using Gram staining and different biochemical tests. Antibiotic sensitivity test was performed on Mueller Hinton agar plate by Kirby Bauer Disc Diffusion method as per CLSI guidelines.

Results: Among 216 samples, 166 (76.8%) showed positive growth. Fifteen different bacterial species were isolated. The most commonly isolated organism was Staphylococcus aureus (26.7%) followed by Pseudomonas sp. (16.4%), Escherichia coli (11.9%), Klebsiella sp. (7.8%). Antibiotic sensitivity test showed that the most effective antibiotics for Gram positive bacteria were Linezolid (87.2%) and Ampicillin + Sulbactam (82.3%) whereas Cefotaxime (48%) was the least effective antibiotic. The most effective antibiotic for Gram negative isolates was Amikacin (72.3%) followed by Netilline (67.3%). Cefuroxime (21.9%) was the least effective antibiotic for Gram negative bacteria.

Conclusion: Staphylococcus aureus was the most frequently isolated bacteria in wound infection. Linezolid and Amikacin were the most effective antibiotics for Gram positive and Gram negative bacteria, respectively.