DO ESCHERICHIA-COLI SUSCEPTIBILITIES TO VARIOUS ANTIBIOTICS DECREASE IN THE PRESENCE OF POLYUNSATURATED FATTY-ACIDS - A PRELIMINARY-REPORT

Polyunsaturated fatty acids (PUFAs) constitute an ingredient of the da ily diet and therefore they might be in dose contact with the polymicr obial gastrointestinal flora. In order to study the interaction of bac teria and PUFAs, eight Escherichia coli strains were cultured in the p resence of docosahexaenoic acid (DHA) at a concentration of 100 mu g/m l, and six of the latter eight at 75 mu g/ml whereas nine other E. col i strains were cultured in the presence of 50 mu g/ml gamma-linolenic acid (GLA). DHA provoked greater than or equal to 4-fold increases in the minimum inhibitory and bactericidal concentrations of various anti biotics in six strains at 100 mu g/ml and in three strains at 75 mu g/ ml, which were not antibiotic-specific and involved mainly aminoglycos ides. GLA provoked in four strains greater than or equal to 4-fold inc reases in MICs-MBCs of ampicillin. The clinical relevance of these obs ervations require further study.