Influence of colostrum deprivation and concurrent Cryptosporidium parvum infection on the colonization and persistence of Escherichia coli O157 : H7 in young lambs
| Autor: | R. N. Marshall, Angus I. Best, Martin J. Woodward, Ute Weyer, Derek Clifford, W. A. Cooley, R. M. La Ragione, S. Farrelly, J. Marshall, Linda K. Johnson, Geoffrey R. Pearson |
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| Rok vydání: | 2006 |
| Předmět: |
Microbiology (medical)
Gastrointestinal Diseases animal diseases Colony Count Microbial Cryptosporidiosis Sheep Diseases Escherichia coli O157 medicine.disease_cause Microbiology Caecum Feces Microscopy Electron Transmission Pregnancy medicine Animals Escherichia coli Escherichia coli Infections Cryptosporidium parvum Gastrointestinal tract Microscopy Confocal Sheep biology Inoculation Colostrum General Medicine biology.organism_classification Immunohistochemistry Enterobacteriaceae Intestines Animals Newborn Female |
| Zdroj: | Journal of Medical Microbiology. 55:819-828 |
| ISSN: | 1473-5644 0022-2615 |
| Popis: | Escherichia coliO157 : H7 andCryptosporidium parvuminfections of man have been associated with direct contact with small ruminants. Colostrum protects neonates against gastrointestinal pathogens, and orphan lambs, which are common on petting farms, may be deprived of this protection. In a recent study, it was demonstrated that high shedding ofE. coliO157 : H7 by an 8-week-old goat kid was associated with coincidentalC. parvuminfection. Furthermore, both pathogens were co-located in the distal gastrointestinal tract. It was hypothesized that colostrum deprivation and pre-infection withC. parvumpredisposed young ruminants to colonization and increased shedding ofE. coliO157 : H7. To test this, 21 lambs 5 weeks of age were divided into four groups as follows: (A) colostrum-deprived and inoculated withE. coliO157 : H7, (B) colostrum-deprived and inoculated withC. parvumand thenE. coliO157 : H7, (C) conventionally reared and inoculated withE. coliO157 : H7, (D) conventionally reared and inoculated withC. parvumand thenE. coliO157 : H7.C. parvumwas detected between 8 and 12 days post-inoculation in most of the infected lambs. At 24 h post-inoculation withE. coliO157 : H7, all lambs were shedding between 5×104and 5×107 c.f.u.E. coliO157 : H7 per gram of faeces.E. coliO157 : H7 was shed in higher numbers in the groups pre-inoculated withC. parvum, whether conventionally reared or colostrum-deprived. Interestingly, for the colostrum-deprived lambs on day 3, a significant difference in shedding ofE. coliO157 : H7 was observed (P=0.038), with the lambs inoculated withE. colialone yielding higher counts than those pre-inoculated withC. parvum. From day 15 onwards, shedding ofE. coliO157 : H7 was highest from the colostrum-deprivedC. parvum-infected lambs, then (in descending order of shedding) the colostrum-deprived lambs, the conventionally reared lambs infected withC. parvum, and the conventionally reared animals. In total, four animals were euthanized, two at 24 h and two at 96 h post inoculation withE. coliO157 : H7 (two conventionally reared and two colostrum-deprived). All animals euthanized were from groups pre-inoculated withC. parvumprior to challenge withE. coliO157 : H7. On examination of tissues, in three of the four animals examined, multifocal attaching and effacing lesions were observed in the caecum, colon, rectum and at the recto-anal junction, and were confirmed by immunohistochemistry to be associated withE. coliO157 : H7. |
| Databáze: | OpenAIRE |
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