Frequency and resistance patterns of bacterial isolates from surgical patients in a teaching hospital in Addis Ababa.

Specimens from surgical patients in a teaching hospital in Addis Ababa were processed for aerobic culture; 2654 isolates were tested for their sensitivities to 11 antibiotics using the Kirby-Bauer technique. Proteus, E. coli, S. aureus, Klebsiella and Pseudomonas comprised over 80% of the isolates. Only gentamicin, polymyxin B, kanamycin and trimethoprim-sulphamethoxazole were effective against the majority (over 70%) of the Gram-negative isolates. Over 85% of the S. aureus strains were susceptible to gentamicin, kanamycin, trimethoprim-sulphamethoxazole, cephalothin and lincomycin. All B-haemolytic streptococci were susceptible to penicillin and 77% to tetracycline. Between 70% and 90% of the Gram-negatives were multiple resistant, with greatly varied resistance patterns. A few types occurred more frequently. The findings of high rates of resistance to the many antibiotics underscore the need for a policy that should promote a more rational use of antibiotics.