Fairbrother J M, Broes A, Jacques M, Larivière S
Faculty of Veterinary Medicine, Groupe de Recherche sur les Maladies Infectieuses du Porc, University of Montreal, Saint Hyacinthe, Quebec, Canada.
Am J Vet Res. 1989 Jul;50(7):1029-36.
Eighteen strains of Escherichia coli serogroup O115:K"V165" isolated from 1- to 8-week-old pigs with diarrhea were tested for toxigenicity, pathogenicity in pigs and mice, serum resistance, mannose-resistant hemagglutination (MRHA), F165 and other surface antigens, colicin V (Col V), aerobactin, and biotype. Twelve strains were positive for heat-stable enterotoxin (STb), MRHA-negative, and F165-negative; 5 strains were enterotoxin-negative, MRHA-positive, and F165-positive; and 1 strain was MRHA-positive, but F165- and enterotoxin-negative. Six of the 12 STb-positive strains moderately colonized the ileum of newborn colostrum-deprived pigs within 24 hours after inoculation. Two of the colonizing strains were able to induce watery diarrhea. All 12 STb-positive strains were nonpathogenic for adult mice and were serum-sensitive; 11 of 12 were Col V-negative, 9 of 12 did not produce aerobactin, and 10 of 12 belonged to biotypes other than 1 or 2. All 6 enterotoxin-negative strains colonized the small and large intestines, associated with peritoneal serosal surfaces, and induced septicemia and polyserositis in newborn colostrum-deprived pigs 1 to 2 days after inoculation. In contrast, 3 STb-positive strains poorly colonized the intestines and did not induce septicemia in pigs at 3 days after inoculation. All 6 enterotoxin-negative strains were Col V-positive, produced aerobactin, and belonged to biotype 1 or 2. Of the 5 enterotoxin-negative, F165-positive strains, only 4 were pathogenic for intraperitoneally inoculated adult mice and were serum-resistant. The enterotoxin-negative, F165-negative strain was neither serum-resistant nor mouse-pathogenic.(ABSTRACT TRUNCATED AT 250 WORDS)
对从1至8周龄腹泻仔猪分离出的18株大肠杆菌O115:K“V165”血清型菌株进行了产毒性、对猪和小鼠的致病性、血清抗性、甘露糖抗性血凝（MRHA）、F165及其他表面抗原、大肠菌素V（Col V）、气杆菌素和生物型检测。12株菌株热稳定肠毒素（STb）呈阳性、MRHA阴性且F165阴性；5株菌株肠毒素阴性、MRHA阳性且F165阳性；1株菌株MRHA阳性，但F165和肠毒素阴性。12株STb阳性菌株中的6株在接种后24小时内中度定殖于新生无初乳仔猪的回肠。其中2株定殖菌株能够诱发水样腹泻。所有12株STb阳性菌株对成年小鼠无致病性且对血清敏感；12株中有11株Col V阴性，12株中有9株不产气杆菌素，12株中有10株属于生物型1或2以外的生物型。所有6株肠毒素阴性菌株定殖于小肠和大肠，与腹膜浆膜表面相关，并在接种后1至2天在新生无初乳仔猪中诱发败血症和多浆膜炎。相比之下，3株STb阳性菌株在接种后3天内在猪肠道中定殖不佳且未诱发败血症。所有6株肠毒素阴性菌株Col V阳性、产气杆菌素且属于生物型1或2。在5株肠毒素阴性、F165阳性菌株中，只有4株对腹腔接种的成年小鼠有致病性且对血清有抗性。肠毒素阴性、F165阴性菌株既无血清抗性也无小鼠致病性。（摘要截短至250字）
