ANTIBIOTIC-RESISTANCE OF ESCHERICHIA-COLI AND SALMONELLA FROM APPARENTLY HEALTHY SLAUGHTERED CATTLE AND PIGS, AND DISEASED ANIMALS IN ZAMBIA

Escherichia (E.) coli and Salmonella (S.) choleraesuis (subsp. cholera esuis and subsp. salamae) from apparently healthy slaughtered cattle a nd pigs in 1989 in Zambia, were examined for antibiotic resistance and the presence of conjugative R plasmid. Salmonella strains from diseas ed animals (cattle, chickens, leopards, lions and warthogs) were simil arly tested. The majority of the cattle had been nomadically kept in s o-called ''traditional farms'' while all the pigs were from commercial farms. More pigs (39% ; 41/105) harboured drug-resistant E. coli than cattle (6.7% ; 7/105). Moreover, the number of drug-resistant E. coli was higher among strains from pigs (31.2% ; 49/157) than cattle (4.2% ; 7/167). For both cattle and pigs, drug resistance was more frequent ly observed against tetracycline, streptomycin, sulfadimethoxine and a mpicillin than other antibiotics and the single resistance pattern occ urred most frequency, especially among pig E. coli strains. Drug-resis tant Salmonella was recorded in 3.6% (1/28) of strains from slaughtere d cattle and 31,3% (10/32) of those from diseased animals. Drug-resist ant E. coli from pigs and cattle carried R plasmid at high frequency.