Colonization of 8-week-old conventionally reared goats by Escherichia coli O157 : H7 after oral inoculation
| Autor: | Linda K. Johnson, N. M. Y. Ahmed, Angus I. Best, Martin J. Woodward, R. M. La Ragione, Geoffrey R. Pearson, Ute Weyer, Derek Clifford, W. A. Cooley |
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| Rok vydání: | 2005 |
| Předmět: |
Microbiology (medical)
Time Factors Ileum Biology Escherichia coli O157 medicine.disease_cause Microbiology medicine Animals Large intestine Colonization Intestinal Mucosa Adhesins Bacterial Escherichia coli Escherichia coli Infections Feces Intimin Microscopy Inoculation Escherichia coli Proteins Goats Immunochemistry General Medicine biology.organism_classification Enterobacteriaceae Animals Suckling Disease Models Animal medicine.anatomical_structure Flagella Mutation |
| Zdroj: | Journal of Medical Microbiology. 54:485-492 |
| ISSN: | 1473-5644 0022-2615 |
| Popis: | Enterohaemorrhagic Escherichia coli O157 : H7 infections of man have been associated with consumption of unpasteurized goat's milk and direct contact with kid goats on petting farms, yet little is known about colonization of goats with this organism. To assess the contribution of flagella and intimin of E. coli O157 : H7 in colonization of the goat, 8-week-old conventionally reared goats were inoculated orally in separate experiments with 1×1010 c.f.u. of a non-verotoxigenic strain of E. coli O157 : H7 (strain NCTC 12900 Nalr), an aflagellate derivative (DMB1) and an intimin-deficient derivative (DMB2). At 24 h after inoculation, the three E. coli O157 : H7 strains were shed at approximately 5×104 c.f.u. (g faeces)−1 from all animals. Significantly fewer intimin-deficient bacteria were shed only on days 2 (P = 0.003) and 4 (P = 0.014), whereas from day 7 to 29 there were no differences. Tissues from three animals inoculated with wild-type E. coli O157 : H7 strain NCTC 12900 Nalr were sampled at 24, 48 and 96 h after inoculation and the organism was cultured from the large intestine of all three animals and from the duodenum and ileum of the animal examined at 96 h. Tissues were examined histologically but attaching-effacing (AE) lesions were not observed at any intestinal site of the animals examined at 24 or 48 h. However, the animal examined at 96 h, which had uniquely shed approximately 1×107 E. coli O157 : H7 (g faeces)−1 for the preceding 3 days, showed a heavy, diffuse infection with cryptosporidia and abundant, multifocal AE lesions in the distal colon, rectum and at the recto-anal junction. These AE lesions were confirmed by immunohistochemistry to be associated with E. coli O157 : H7. |
| Databáze: | OpenAIRE |
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