[Characteristics of the E. coli strains isolated from calves]

A study was carried out on E. coli strains eliminated in the Pleven District. It was proved that 19.4% of the strains were enteropathogenic. The enteropathogenic E. coli provoked dilatation of the ligated intestinal segments. All enteropathogenic E. coli proved positive for K 99 antigen. For the non-enteropathogenic E. coli K 99 antigen was not proved. The enteropathogenic E. coli strains referred to the serotypes O 101, O 8, O 9 and O 11, whereas the non-enteropathogenic ones referred to the serotypes O 78, O 35, O 117, O 26, O 111 and O 86. The strains under consideration were not haemolytic. The prevailing part were sensitive to kanamycin, ampicillin, spectam, medium sensitive to streptomycin and slightly sensitive to furazolin and erythran. No differences were proved with regard to sensitivity both of enteropathogenic and nonenteropathogenic E. coli strains to antibiotics.