A study of 245 infected surgical wounds in Singapore

The aims of the study were to correlate the laboratory detection rate of wound infections with the actual wound infection rate, and to analyse the bacteriology of these wounds to provide a rationale for antibiotic usage in prophylaxis and treatment of surgical wound infections. The wound infection rate in a general surgical unit was determined using the most comprehensive surveillance available to us and was correlated with the laboratory detection rate. A correlation coefficient of 0.8 was obtained, allowing a reasonable estimation of the actual wound infection rate from laboratory data. Review of the bacteriology of consecutive infected surgical wounds over a 4 year period in a university hospital, revealed that the commonest organisms cultured were Staphylococcus aureus, Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, enterococci and beta-haemolytic streptococci. Methicillin-resistant S. aureus (MRSA) caused 50% of all staphylococcal wound infections. All MRSA isolates were sensitive to fusidic acid and vancomycin. All the non-MRSA isolates of S. aureus were sensitive to cephalexin. Some 89% of E. coli were sensitive to gentamicin, with 93% and 100% sensitive to cefuroxime and ceftriaxone respectively. Klebsiella isolates have shown an increased resistance to aminoglycosides, with a new strain from one patient, isolated in 1990, resistant to penicillins, aminoglycosides and third generation cephalosporins. Pseudomonas spp., enterococci and beta-haemolytic streptococci did not show a change in resistance patterns over the same time period.