ABSTRACT
To determine the wound etiology, antibiotic resistance pattern of pathogens and incidence of bacteremia in patients with surgical site infections [SSI]. Experimental study. Department of Microbiology University of Karachi, from September, 2008 to October, 2012. Pus swab [n=250] and blood samples [n=56] were collected from patients having SSIs. Swabs were inoculated on 5% sheep blood agar, MacConkey's agar and Sabrouad dextrose agar and identified by standard microbiological and quick test strip methods. Blood samples were dispensed into blood culture bottles and incubated at 35[degree]C for 5-7 days. Resistance pattern of isolates were determined by Kirby Bauer disc diffusion technique and results were interpreted as outlined by Clinical Laboratory Standards Institute [CLSI] specifications. E. coli ATCC 25922 and S. aureus ATCC 25923 were used as control strains. Data was analyzed by SPSS 13. In Pus swabs positive growth was obtained in 224 [90%] specimens. Escherichia coli was the commonest pathogen isolated [n=109, 26%] followed by Candida spp. [n=77, 18%], S. aureus [n=73, 17%], Klebsiella spp. [n=66, 16%], Pseudomonas spp. [n=32, 8%], Proteus spp. [n=29, 7%], Morganella spp. [n=17, 4%] and Providencia spp. [n=15, 4%] whereas in blood samples bacteremia was found in 15 [27%] specimens of which E. coli [47%] and S. aureus [33%] were the most common isolates. Gram negative bacteria demonstrated high resistance against commonly prescribed drugs while Polymyxin B showed reasonable activity against these organisms. S. aureus showed high rates of Methicillin resistance with cross-resistance to most antimicrobial agents. Frequency of bacteremia and resistance to antibiotics was high in patients with SSIs