title: Transfer of drug resistance and enterotoxin production in porcine Escherichia coli strains and relationship between K88 antigen and raffinose (melitose) fermentation.
abstract: 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.
mesh_terms: 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*
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C026888:K88 antigen, E coli; D036781:Fimbriae Proteins; D011887:Raffinose