The virulence factors EAST1 and AIDA are often detected in ETEC/VTEC strains isolated from pigs and their role in diarrhoeal infections is discussed. In order to elucidate the pathogenesis of AIDA, the colonisation patterns of F4 positive and AIDA positive strains were investigated. Two wild-type Escherichia coli strains AIDA/EAST1 and F4/EAST1 isolated from diarrhoeal piglets were used for animal experiment to evaluate the ability of the EAST1 toxin to be involved in induction of diarrhoea. Gnotobiotic piglets were supplemented with normal porcine serum and orally inoculated with the strains. Faecal bacterial shedding of the challenge strains was observed during the experiment. Light microscopy and scanning electron microscopy were used to detect the colonisation pattern of both challenge strains. Although bacterial isolation demonstrated shedding of the challenge strains until the end of the experiment, diarrhoea did not develop in any piglet. Based on histological examination, piglets were more heavily colonised in the case of infection with E. coli O149/F4/EAST1 strain. Scanning electron microscopy showed bacterial cells of F4/EAST1 E. coli adhering to enterocytes, in contrast to AIDA/EAST1 which were poorly present on the intestinal surface. The EAST1 toxin alone was not able to induce diarrhoea in animals. Therefore our results demonstrate that the function/role of EAST1 and AIDA in colibacillosis of pigs remains to be elucidated.

• MeSH
• bakteriální adheziny imunologie   MeSH
• bakteriální toxiny imunologie   MeSH
• enterotoxiny imunologie   MeSH
• Escherichia coli imunologie   MeSH
• feces mikrobiologie   MeSH
• gnotobiologické modely imunologie   MeSH
• imunohistochemie veterinární   MeSH
• infekce vyvolané Escherichia coli imunologie   mikrobiologie   veterinární   MeSH
• mikroskopie elektronová rastrovací veterinární   MeSH
• náhodné rozdělení MeSH
• nemoci prasat imunologie   mikrobiologie   MeSH
• nemoci střev imunologie   mikrobiologie   veterinární   MeSH
• neparametrická statistika MeSH
• prasata MeSH
• proteiny z Escherichia coli imunologie   MeSH
• průjem imunologie   mikrobiologie   veterinární   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Between 2005 and 2009, a total of 800 Escherichia coli strains isolated from piglets with diarrhea were tested for the presence of enteroaggregative heat-stable enterotoxin EAST1, heat-labile (LT) and heat-stable enterotoxins (STa) and shigatoxin (Stx2e) by PCR with the purpose of investigating the present distribution of virulence factors on swine farms in the Czech Republic. The isolates were analyzed for their O-serogroup, fimbrial (K88, K99, 987P, F41, F18) and nonfimbrial adhesins (adhesin involved in diffuse adherence AIDA and porcine attaching and effacing-associated factor PAA). The detection rates of ETEC and STEC isolates were 36.5% and 7.75%, respectively, which implies that ETEC play the major role in E. coli infections in Czech herds. Generally, the most common serotype was O149:K88 which possessed genetic determinants for LT and EAST1. None of the tested E. coli isolates was positive for genes K99, 987P and F41. It was shown that out of 800 E. coli strains isolated from pigs, 277 were EAST1 positive and 74% from the latter were identified as ETEC. Of the fimbrial adhesins, K88 and F18 were commonly detected. Over 80% of K88/EAST1 positive strains possessed the gene for paa. We detected no EAE isolate positive for fimbrial adhesins or PAA and AIDA. The AIDA was more often associated with F18 than with K88. The gene astA was also identified among E. coli isolates of non-diarrheic piglets. We tested rectal swab samples collected from apparently healthy piglets on three farms. On all farms, E. coli astA positive strains (26.66%, 90.00% and 46.66% astA positive animals) were isolated. Our results showed a significantly higher prevalence of astA positive E. coli isolates among apparently healthy piglets in comparison with diarrheic piglets. The question remains as to what is the role of the astA gene in the pathogenesis of porcine colibacillosis and as a virulence factor.

• MeSH
• bakteriální adheze fyziologie   MeSH
• bakteriální adheziny genetika   metabolismus   MeSH
• bakteriální fimbrie genetika   metabolismus   MeSH
• enterotoxigenní Escherichia coli izolace a purifikace   MeSH
• enterotoxiny izolace a purifikace   metabolismus   MeSH
• Escherichia coli genetika   izolace a purifikace   metabolismus   patogenita   MeSH
• faktory virulence metabolismus   MeSH
• feces mikrobiologie   MeSH
• infekce vyvolané Escherichia coli patologie   veterinární   MeSH
• nemoci prasat epidemiologie   mikrobiologie   MeSH
• polymerázová řetězová reakce veterinární   MeSH
• prasata MeSH
• prevalence MeSH
• proteiny z Escherichia coli genetika   metabolismus   MeSH
• průjem mikrobiologie   patologie   veterinární   MeSH
• shiga toxin metabolismus   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH