Showing posts with label e coli. Show all posts
Showing posts with label e coli. Show all posts

Friday, 19 August 2011

Pubmed - Diarrhea: the nemesis of the artificially reared, early weaned piglet and a strategy for defense


Abstract

Rearing early weaned piglets artificially for the purpose of increasing the efficiency of the sow is an attractive management concept. However, high death losses resulting from diarrhea in artificially reared piglets have dampered enthusiasm for early weaning. Enterotoxigenic Escherichia coli, transmissible gastroenteritis virus and rotavirus are the three main enteropathogens responsible for causing the diarrhea. The enteropathogens infect the small intestine, which produces a secretory or malabsorptive diarrhea. In nature, the nursing piglet is protected from the enteropathogens by antibody bathing his gut. The source of the antibody is the dam's colostrum and milk. It should be possible to protect artificially reared, early weaned piglets from enteropathogens by feeding them diets that contain antibodies to putative enteropathogens.

Bovine colostrum contains immunoglobulin G antibodies against intimin, EspA, and EspB and inhibits hemolytic activity mediated by the type three secretion system of attaching and effacing Escherichia coli.


Instituto de Patobiología, Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina.

Abstract

Enterohemorrhagic Escherichia coli (EHEC) is the main cause of hemolytic-uremic syndrome, an endemic disease in Argentina which had an incidence in 2005 of 13.9 cases per 100,000 children younger than 5 years old. Cattle appear to be a major reservoir of EHEC, and a serological response to EHEC antigens has been demonstrated in natural and experimental infections. In the current study, antibodies against proteins implicated in EHEC's ability to form attaching and effacing lesions, some of which are exported to the host cell via a type three secretion system (TTSS), were identified in bovine colostrum by Western blot analysis. Twenty-seven (77.0%) of the 35 samples examined contained immunoglobulin G (IgG) antibodies against the three proteins assayed in this study: EspA, EspB, and the carboxy-terminal 280 amino acids of gamma-intimin, an intimin subtype associated mainly with O157:H7 and O145:H- serotypes. Every colostrum sample was able to inhibit, in a range between 45.9 and 96.7%, the TTSS-mediated hemolytic activity of attaching and effacing E. coli. The inhibitory effect was partially mediated by IgG and lactoferrin. In conclusion, we found that early colostrum from cows contains antibodies, lactoferrin, and other unidentified substances that impair TTSS function in attaching and effacing E. coli strains. Bovinecolostrum might act by reducing EHEC colonization in newborn calves and could be used as a prophylactic measure to protect non-breast-fed children against EHEC infection in an area of endemicity.

PMID:
 
18562563