Antimicrobial susceptibility pattern of bacterial isolates from surgical wound infections in Tertiary Care Hospital in Allahabad, India

Abstract

The aim of present study to analyze the occurrence and in-vitro antimicrobial susceptibility of bacterial pathogens isolated from surgical wound infections. Specimens from a total of 129 patients undergoing either emergency or elective surgery were collected from infected sites or stitch lines and inoculated onto appropriate media. The bacterial cultures were identified utilizing standard microbiological and biochemical methods. Isolates were tested for susceptibility to antimicrobials using the Kirby Bauer disk diffusion method. Statistical analysis was performed using the chi-square test. Of 129 patients investigated (62 emergency and 67 elective surgery cases), bacterial isolates were isolated with almost equal frequency both from emergency and elective surgery cases. Of 108 (83.72%) culture positive samples, 62 (57.41%) were Gram negative, 39 (36.11%) Gram positive, and 7 (6.48%) showed multiple organisms. Of total 115 bacteria isolated (101 single and 7 double organisms culture positive), 33 (28.69%) were Escherichia coli and were also the commonest; followed by Staphylococcus aureus, 30 (26.09%) cases. S. aureus and Streptococcus spp. showed maximum susceptibility (100%) to linezolid and vancomycin. Maximum susceptibility of E. coli was observed to ciprofloxacin (75.7%), followed by gentamicin (54.5%); of Klebsiella spp. to ceftriaxone and gentamicin (66.6% each), of Proteus spp. to gentamicin (70%) followed by ciprofloxacin (60%), and of Pseudomonas aeruginosa to piperacillin (100%) and tobramycin (71.4%). E. coli and S. aureus were the most common and Salmonella spp. and Acinetobacter spp. were the least common organism causing surgical site infections. The definitive therapy included ciprofloxacin and gentamicin for E. coli; linezolid and vancomycin for S. aureus and Streptococcus spp; ceftriaxone and ciprofloxacin for Klebsiella spp., Citrobacter spp., acinetobacter spp and Salmonella spp.

KEYWORDS: Antimicrobial susceptibility pattern; Bacterial isolates; Gram negative; Gram positive organisms

Internet Journal of Medical Update 2012 January;7(1):27-34