Peeters J E, Geeroms R, Orskov F
National Institute of Veterinary Research, Brussels, Belgium.
Infect Immun. 1988 Jun;56(6):1442-8. doi: 10.1128/iai.56.6.1442-1448.1988.
A total of 568 strains of Escherichia coli isolated from healthy and diarrheic rabbits were separated into 11 different biotypes according to the fermentation patterns of four carbohydrates. Strains belonging to biotypes 1 to 3, 6, and 8 induced lesions characteristic for attaching and effacing E. coli (AEEC). They attached to the intestinal epithelium of the terminal small intestine and the large intestine of 5-week-old rabbits after experimental infection and caused effacement of the microvillous brush border. However, pathogenicity for weaned rabbits, as judged by diarrhea score, anorexia, and reduced weight gain, varied according to the biotypes of the strains. Strains belonging to biotypes 1 and 6 produced only discrete clinical signs, strains belonging to biotypes 2 and 3+ (motile) induced diarrhea and growth depression, whereas strains belonging to biotypes 3- (immotile) and 8 caused severe clinical signs and high mortality. This confirms evidence from the field. Biotypes 3- and 8, accounting for 35.5 and 7.1% of AEEC strains in weaned diarrheic rabbits, respectively, were not detected in weaned healthy rabbits, while biotype 2 was the predominant strain in weaned healthy rabbits (62.3%). Finally, serotyping showed a close relationship between biotype and serotype of the AEEC examined. Most strains of biotypes 1+ and 2+ tested were O109:K-:H2 and O132:K-:H2, respectively, whereas all strains tested of biotype 3- were O15:K-:H- and those of biotype 8 were O103:K-:H2. These data indicate that specific clones of AEEC might be involved in juvenile rabbit enteritis. It was concluded that determination of biotypes allows the screening of highly pathogenic AEEC in weaned rabbits (biotypes 3- and 8).
从健康和腹泻兔中分离出的568株大肠杆菌，根据四种碳水化合物的发酵模式被分为11种不同的生物型。属于生物型1至3、6和8的菌株引发了典型的肠集聚性大肠杆菌（AEEC）损伤。实验感染后，它们附着于5周龄兔的回肠末端和大肠的肠上皮，并导致微绒毛刷状缘消失。然而，根据腹泻评分、厌食和体重增加减少来判断，这些菌株对断奶兔的致病性因生物型而异。属于生物型1和6的菌株仅产生轻微的临床症状，属于生物型2和3 +（运动型）的菌株导致腹泻和生长抑制，而属于生物型3 -（不运动型）和8的菌株引起严重的临床症状和高死亡率。这证实了来自现场的证据。生物型3 -和8分别占断奶腹泻兔中AEEC菌株的35.5%和7.1%，在断奶健康兔中未检测到，而生物型2是断奶健康兔中的主要菌株（62.3%）。最后，血清分型显示所检测的AEEC的生物型和血清型之间存在密切关系。测试的大多数生物型1 +和2 +菌株分别为O109:K - :H2和O132:K - :H2，而测试的所有生物型3 -菌株均为O15:K - :H - ，生物型8的菌株均为O103:K - :H2。这些数据表明特定的AEEC克隆可能与幼兔肠炎有关。得出的结论是，确定生物型有助于筛选断奶兔中高致病性的AEEC（生物型3 -和8）。
