Chlorhexidine resistance in Escherichia coli isolated from clinical lesions.

Clinical isolates of Escherichia coli (148 strains) were studied for their resistance to chlorhexidine, six antibiotics and three metals. The distribution pattern of their susceptibility to chlorhexidine clearly revealed two peaks, and the resistance was differentiated by 5 micrograms/ml of chlorhexidine. Resistance to chlorhexidine was found in 12.8% of the isolates. The frequencies of resistance to SM, TC, CP, KM, CER, GM, Hg, Cd and As were 43.2, 36.4, 18.9, 25.0, 16.2, 4.1, 35.1, 91.2 and 47.2%, respectively. The frequency of chlorhexidine resistance was lower than that of drug and metal resistance except in the case of GM resistance. Furthermore, all of these chlorhexidine-resistant strains were multiple-drug-resistant also multiple-metal-resistant.