ESCHERICHIA-COLI ISOLATED FROM FARM-ANIMALS IN ENGLAND AND WALES BETWEEN 1986 AND 1991

Escherichia coli isolated from farm animals in England and Wales betwe en 1986 and 1991 were examined for their serogroup, fimbrial adhesin a nd toxin production, and resistance to antimicrobial drugs. Among the 3595 porcine isolates the more common serogroups were O149, O8, O138, O147 and O157. The F4(K88) adhesin was detected in 21 per cent of the cultures, whereas the other adhesins were never present in more than 3 per cent during any year, although there was an upward trend in the p revalence of the F6(987P) antigen. The heat labile enterotoxin was pro duced by more than 17 per cent of the cultures usually in association with the F4 antigen. The other toxins, heat stable (STa), verocytotoxi n (VT) and cytotoxic necrotising factor (CNF) were produced by 5.3, 4. 7 and 6.8 per cent of the cultures, respectively. Among the 1383 bovin e cultures the more common serogroups were O8, O101 and O17. The F5(K9 9) adhesin was detected in 9.1 per cent of the cultures, usually in as sociation with STa production. The toxins STa, VT and CNF were produce d by 4.4, 2.8 and 83 per cent of the cultures, respectively. Among the 407 ovine isolates the more common serogroups were O8, O101 and O78, and 11 per cent of the cultures produced the F5(K99) antigen. The toxi ns STa, VT and CNF were produced by 1.5, 6.1 and 9.1 per cent of the c ultures, respectively. In the case of the 402 poultry isolates the mor e common serogroups were O78, O2 and O8, which are usually associated with colisepticaemia. Resistance to antibiotics was common, particular ly among the bovine isolates.