Colicin resistance in relation to pathogenicity factors in strains of Escherichia coli isolated from the intestinal tract of piglets
Djønne, B.K.
Acta Veterinaria Scandinavica 27(1): 115-123
1986
ISSN/ISBN: 0044-605X PMID: 3529891 Document Number: 276625
315 E. coli strains isolated from 43 piglets (1-14 days old) were examined for K88 and K99 antigens, enterotoxin production and colicin resistance. 308 of the strains were classified into Group 1: O149, K88, producing heat labile (LT) and heat stable (ST) enterotoxins (127 strains); Group 2: O64, K99 producing ST (71), or Group 3: variable O-antigens, no K antigen or enterotoxin production (112). Almost all of the E. coli strains were resistant to colicins E1, E3, Ia, H and D+X. Resistance to colicins E2, B+M, V and K+X were found in 91.7%, 43.8%, 49.8% and 62.2%, respectively. E. coli strains in group 1 were resistant to colicin E2, while about 87% of the other strains were resistant to this colicin. E. coli strains in group 2 were more often resistant to colicin B+M, V and K+X (65%, 94%, 83%) than strains in group 1 (37%, 24%, 64%) and strains in group 3 (37%, 52%, 46%). E. coli strains in group 2 showed a high degree of multiresistance, 45.1% of the strains being resistant to all of the 9 colicins. About 10% of the other strains were resistant to all of the 9 colicins. E. coli strains, which harboured the enteropathogenicity factors K99 antigen and ST production, showed a higher degree of colicin resistance than both the E. coli strains with K88 antigen and ST and LT production, and the E. coli strains lacking enteropathogenicity factors.