Bacteriology of surgical site infections and antibiotic susceptibility pattern of the isolates at a tertiary care hospital in Karachi.

Abstract

OBJECTIVE: To study post surgical infections and sensitivity of the Isolates so that recommendations can be made for their prevention and empirical antibiotic treatment. SETTING: Swabs/pus specimens from the patients developing surgical site infections at PNS Shifa, Karachi were processed in the Department of Pathology during January, 1998 to September, 1999. METHODS: One hundred and twenty-nine swabs/pus specimens from various types of surgical sites suspected to be infected on clinical grounds were processed, by standard methods and antibiotic susceptibility testing of all the isolates was done by using Modified Kirby Baur disc diffusion technique. RESULTS: Of the one hundred and fifty-three organisms isolated, the most common was Staphylococcus aureus (50.32%), followed by Pseudomonas aeruginosa (16.3%), Escherichia coli (14.37%), Klebsiella pneumoniae (11.76%), miscellaneous gram negative rods (5.88%) and Streptococcus pyogenes (1.30%). About 50% of the Staphylococcus aureus isolates were found to be methicillin resistant. In case of Pseudomonas aeruginosa and Escherichia coli more than 60% of the isolates were found resistant to Gentamicin. The resistance to third generation cephalosporins and the quinolone ciprofloxacin was also quite high. Other isolates also showed a very high level of antibiotic resistance. CONCLUSION: In addition to the economic burden for antibiotic treatment, such infections for multi-resistant organisms are a serious threat to our surgical patients. To prevent these happenings, there is an urgent need to adopt basic principles of asepsis and sterilisation and to make judicious use of prophylactic and therapeutic antibiotics.