Susceptibility of clinically important gram-negative bacilli to 15 antibiotics. Comparison of patterns in Poland and Federal Republic of Germany.

Three hundred and sixty strains of Gram-negative bacilli (Escherichia coli, Salmonella enteritidis, Enterobacter cloacae, Providencia, indole-positive and indole-negative Proteus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens), were isolated by random in Poland and Germany, and tested by agar dilution method for susceptibility to 15 antimicrobial agents, including six cephalosporin derivatives, colistin, gentamycin and tobramycin, three newer tetracyclines, ampicillin and carbenicillin, and a combination of trimethoprim and sulfamethoxazole. This investigation revealed existence of growing antibiotic-resistance of Gram-negative bacilli to all antimicrobial agents. A detailed analysis of this problem is described and a list of agents effective in vitro is presented. Some evidence has been found concerning possible existence of geographical differences in antibiotic-susceptibility patterns of strains of Gram-negative bacilli, isolated in Poland and Federal Republic of Germany.