Herman L., Botteldoorn N., De Smet S..
2002. Relation between colibacillosis Escherichia coli F18 and a polymorphism in the alpha(1,2) fucosyltransferase gene.
In : Second international symposium on Candidate Genes for Animal Health (C.G.A.H), Montpellier, France, August 16-18th 2002 : abstracts. CIRAD, INRA
Note générale : Session 3 : Genetic resistance / susceptibility to infectious diseases (bacteria / virus)
Résumé : Oedema disease and post-weaning diarrhoea in swine is associated with the colonisation of the small intestine with enterotoxigenic Escherichia coli (ETEC). Colonisation depends on adherence of the pathogen to intestinal epithelial cells, which is generally mediated by bacterial F4 (K88) and F18 fimbriae. The F18 adhesion factor is present in 30 to 50% of the ETEC strains causing colibacillosis in young pigs. Close linkage has been shown in Large White pigs between a polymorphism in the [alpha](1,2) fucosyltransferase gene (Fut1) at bp. 307 and adhesionresistance to E. coli F18 (Meijerink et al., 1997, Mamm. Genome 8, 736-741). In the present study the relation between this polymorphism and the presence of E. coli F18 was investigated in young pigs died from colibacillosis. The pigs were collected from pig farms in Flanders and were of mixed genetic sources. ETEC strains were isolated from the small intestine or the faeces of these pigs on Colombia base agar with 5% fresh horse blood. The strains were further typed by an ETEC multiplex PCR, detecting the heat labile (LTI), the heat stable (STI, STII) enterotoxin genes and the verotoxin 2 gene (vt2). The adhesion factor (K88-F18) was determined by a multiplex PCR. For testing the polymorphism in the Fut1 gene, a PCR/RFLP was developed. From the 249 ETEC strains, 47.3% were K88, 21.6% F18 ab and 13.6% F18 ac. In 17% of the strains, PCR did not amplify the enterotoxin or verotoxin 2 genes. On the other hand, 2.4% of these strains contained virulence genes but no K88 or F18 adhesion factor. The heat labile enterotoxin genes were found predominantly in the K88 strains, whereas the heat stable enterotoxin genes and the verotoxin 2 gene were more present in the F18 strains. From the piglets that have died from colibacillosis after an E. coli (ETEC) F18 infection, 74 were tested for the adhesion-resistance marker in the Fut1 gene. The frequency of the resistant A allele was 0.20. One pig, infected with an E. coli F18 ac strain, had the resistant AA genotype (1.35%). The F18 coding sequence (fedA) of this strain will be determined to search for the possible cause of adhesion. The frequency of the resistant AA genotype in a group (n=194) of healthy adult pigs and in a group (n=86) of K88 infected piglets was 7.2% and 4.7% respectively. The corresponding frequency of the A allele was 0.27 and 0.30. These data suggest a relation between the resistant genotype AA and resistance to E. coli F18 in the mixed pig population that was investigated. In view of the relatively low frequency of the AA genotype in healthy pigs, more piglets died from colibacillosis will be investigated to confirm this association. (Texte intégral)
Mots-clés Agrovoc : colibacillose, polymorphisme génétique, porcin, analyse biologique
Mots-clés complémentaires : Gène de résistance
Classification Agris : L10 - Génétique et amélioration des animaux
Auteurs et affiliations
- Herman L., Centre for Agricultural Resarch Ghent (BEL)
- Botteldoorn N., Centre for Agricultural Resarch Ghent (BEL)
- De Smet S., Ghent University (BEL)
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/512048/)
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