Transfer of drug resistance and enterotoxin production in porcine Escherichia coli strains and relationship between K88 antigen and raffinose (melitose) fermentation.
To obtain an indication of the frequency of drug resistance together with enterotoxin production in a select group of porcine E coli strains, those enterotoxigenic strains that were resistant to specific antimicrobial agents were mated as donors with nonenterotoxigenic E coli strains that were sensitive to these drugs as recipients. Seven of the 17 strains tested transferred drug resistance by direct mating. These 7 strains also transferred drug resistance following mobilization. The frequency of recipient conversion was increased following mobilization, as compared with the frequency of conversion resulting from direct mating. In 2 of these strains, enterotoxin production was transferred together with drug resistance. Eight strains transferred drug resistance only after mobilization, and in 2 of these, enterotoxin production was transferred simultaneously with resistance to the antimicrobial agents. In 2 of the 17 strains tested, neither transfer of drug resistance nor transfer of enterotoxin production could be achieved by direct mating or after mobilization. Thirty-nine porcine E coli strains were tested for K88 antigen production and raffinose (melitose) fermentation with a view toward determining whether raffinose fermentation could be used as a diagnostic tool for the detection of the K88 antigen. In 11 of the K88-positive strains tested, only 7 fermented raffinose. In the remaining 28 K88-negative strains, 17 fermented raffinose. Consequently no meaningful correlation existed between these 2 properties of porcine enterotoxigenic E coli strains.
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis*; D004352:Drug Resistance, Microbial; D004768:Enterotoxins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D029968:Escherichia coli Proteins; D005285:Fermentation; D036781:Fimbriae Proteins; D011887:Raffinose / Q000378:metabolism; D013552:Swine / Q000382:microbiology*
D000942:Antigens, Bacterial; D000954:Antigens, Surface; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C026888:K88 antigen, E coli; D036781:Fimbriae Proteins; D011887:Raffinose