[Resistance of gram-negative bacteria against cefaclor and other antibiotics (author's transl)].

Five hundred and eighty-six strains of eight species of Enterobacteriaceae were tested for their resistance against cefaclor, cefamandole, cephalothin, ampicillin, mezocillin, tetracycline and co-trimoxazole. Cefaclor showed a low rate of resistance against Escherichia coli (1.2%), Klebsiella (2%) and Proteus mirabilis (3.1%), but a high rate of resistance against indole-positive Proteus species (60%) and Serratia (80%). Cefamandole was also effective against cefaclor and ampicillin resistant strains. Multiresistant strains were predominant especially amongst Enterobacter, Serratia and indole-positive Proteus species. Of 266 ampicillin resistant strains, 198 strains (74.4%) proved to be sensitive to cefaclor. Among the orally administered antibiotics cefaclor exhibited the best result with 12.1% resistant strains compared to 14.8% strains resistant to co-trimoxazole and 45.4% resistant to ampicillin.