ANTIBIOTIC-RESISTANCE OF ENTEROBACTERIACEAE ISOLATED FROM THE FECAL FLORA OF FATTENING PIGS

From June 1991 to April 1992 407 faecal samples were collected from th ree groups of pigs (I n = 248, II n = 87, III n = 72) at a pig fatteni ng farm to determine the prevalence and the degree of antibiotic resis tance of Enterobacteriaceae as well as the antibiotic susceptibility o f the strains isolated. Despite the absence of mass medication during the observation period, the prevalence of resistance to the most commo nly used antimicrobial agents in veterinary medicine was high (range a moxicillin 70%-97%, oxytetracycline 89%-100%, sulfamethoxazole 88%-100 %, trimethoprim 78%-100%). The high degree of resistance to oxytetracy cline and sulfamethoxazole ranged from 8%-67% and 4%46%, respectivily. The percentage of the isolated Escherichia coli strains resistant to oxytetracycline, streptomycin and sulfamethoxazole ranged from 49% to 68%; the other agents tested showed lower percentages (0-13%). Resista nce to three or more antibiotics was observed in 43% of the isolates. Of the 52 resistance patterns that could be distinguished, 51% was acc ounted by only four patterns: oxytetracycline+streptomycin+sulfamethox azole 20%, sulfamethoxazole 12%, streptomycin+sulfamethoxazole 11% and streptomycin+oxytetracycline 8%.