Multiple drug resistance in Escherichia coli - an analysis of all-nation computer-processed data.

In a computer-assisted surveillance program, a one-year yield of nationally collected strains of E. coli, and separately of their enteropathogenic serotypes, were analysed for their biresistance to 10 frequently used antibacterials, and also their typical three-, four-, and five-resistance which occur most frequently. It was shown that, like in staphylococci (1), classical drugs: ampicillin, streptomycin, chloramphenicol, tetracycline, and kanamycin all show a significant degree of mutual selectivity. This was confirmed by analyses of comparatively large numbers of strains with higher complexity of multiple resistance. It is important and significant, for the regulation of further antibiotic policy, that the computer analysis showed a mutual devaluation of gentamicin and colistin antibiotics. Colistin-resistant strains of E. coli showed a high degree of resistance to gentamicin - far higher than strains resistant to any other drugs, even strains resistant to four or five classical drugs, vice versa, gentamicin-resistant strains were in more than 50% resistant to colistin - a value which is much higher than that of the very good effectiveness of gentamicin toward strains resistant to other antibiotics, even to five of them at once. This is another important observation, similar to one-way selectivity of oxacillin-resistant staphylococci by lincomycin resistance. Such findings urge for a special surveillance program for these crucially important antibiotics in the all-nation computer-assisted surveillance of the resistance to antibiotics in problem bacteria. Enteropathogenic strains of E. coli showed far higher resistance values not only for classical antibiotics, but also for kanamycin, nalidixin and septrin resistance.