Antibiogram of bacteria isolated from wound exudates

Authors:Arjun Ojha Kshetry*, Binod Lekhak , Bijendra Raj Raghubanshi
Int J Biol Med Res. 2015; 6(2): 4997-5002  |  PDF File

Abstract

ABSTRACT Objective: The objective of this study was to isolate, identify and determine the antibiotic susceptibility pattern of aerobic causative infectious agents of wound infection from pus specimen. Determination of prevalence of methicillin-resistance among S. aureus (MRSA) and their Minimum Inhibitory Concentration (MIC) to vancomycin was the other objective. Methods: The study was carried out in KIST Medical College and Teaching Hospital, Lalitpur, Nepal form November 2012 to June 2013. Pus sample collected aseptically were processed in the microbiology laboratory. The culture of the specimen, identification of the isolates and their antibiotic susceptibility testing were done as per the standard guidelines. Results: In a total of 149 culture positive specimens, 83(55.7%) were S. aureus, a leading cause of wound infection followed by (23.4%) belonging to the members of Enterobacteriaceae family. Coagulase Negative Staphylococci accounts for 14(9.4%), 8(5.4%); Acinetobacter spp., 5(3.4%); Pseudomonas aeruginosa and 4(2.7%); Enterococcus spp. In vitro susceptibility testing of all of these isolates showed that Imipenem was the most efficient drug for the Gram-negative isolates. Vancomycin was reported to be the most sensitive drug for Gram-positive isolates with 100% susceptibility rate. Among 83 S. aureus, the prevalence of MRSA was 27(32.5%). Detection of inducible clindamycin resistance in S. aureus showed that 10(12%) were iMLSB phenotypes. Similarly, β-lactamase production in S. aureus was detected in 53(62%) isolates. All of the MRSA strains were sensitive to vancomycin while subjected to determine Minimum Inhibitory Concentrations. Conclusion: S. aureus is one of the major pathogen that causes wound infections. Prevalence of drug resistant superbugs like MRSA is increasing which is a major concern and thus, antibiotic susceptibility testing is crucial in empirical drug therapy. MIC determination is more sensitive than disc diffusion.