Antimicrobial susceptibility pattern of aerobic microbial isolates in a clinical laboratory in Karachi - Pakistan

Backgroun and Objective: Resistance to multiple antimicrobials is the major cause of debility and death due to infectious diseases around the world. Our objective was to determine the frequency and antimicrobial susceptibility pattern of aerobic microbial isolates in a clinical laboratory.

All culture specimens of tissue, pus, urine, bone, blood, fluid, stool, sputum, and high vaginal swab received in the Microbiology Department of Clinical & Research Laboratory, Baqai Institute of Diabetology and Endocrinology from May 2010 to January 2011 were included in the present study. Bacterial isolates were identified and their antimicrobial susceptibility pattern was determined.

Out of 312 cultured specimens, 272 (87.17%) were found infected with 437 microbial organisms (412 bacteria and 25 Candida isolates). A total of 90 (20.59%) multi-drug resistant (MDR) isolates were found. MDR Escherichia coli was isolated in 40 (34.19%) out of 117 culture specimens which showed the growth of Escherichia coli, Pseudomonas aeruginosa in 17 (22.08%), Methicillin-resistant Staphylococcus aureus in 13 (11.50%), Klebsiella pneumoniae in 7 (22.58%), Proteus species in 6 (31.58%), Acinetobacter species in 3 (33.33%), Enterobacter species in 2 (28.57%), Coliform (Escherichia coli) in 1 (16.67%) and Enterococcus species were isolated in 1 (50%) culture specimen.

High prevalence of multi-drug resistant bacteria was found in the present study. Emergence of antimicrobial resistance has become a major challenge in infectious disease medicine. Antimicrobial resistance may be due to misuse of antimicrobials by physicians and self medication in Pakistan. Further large scale studies are needed to validate our findings.