@article{2321,
  author = {L Wieler and G Sobjinski and T Schlapp and K Failing and R Weiss and C Menge and G Baljer},
  title = {Longitudinal prevalence study of diarrheagenic Escherichio coli in dairy calves},
  abstract = {A longitudinal study (cohort study) elaborating 1,224 rectal swabs from 221 calves aging between 1 and 12 weeks was conducted on 11 dairy farms (i) to ascer-tain associations between diarrhea and shedding of diarrheagenic E coli and (ii) to facilitate the zoonotic potential assessment of E.coli strains shed byyoung calves.Calves were screened weekly by PCR of swab cultures for shedding of enterotoxigenic E coli [ETEC; by detection of heat stable (est) and heat labile enterotoxin genes (e/fj],diffusely adhering E.coli [DAEC;diffuse adhesion (daa)], typical enteropathogenic E.coli [EPEC; bundle-forming pili (bfpA) and intimin (eaej\ as well as enterohemorrhagic E.coli [EHEC, intimin (eae) and Shiga toxin (stx)]. In addition, EHEC-hemolysin- (HlyEHEC) and alpha-hemolysin- (a-Hly) produ-cing E.coli were detected by inoculation of blood agar plates. Within the 221 calves, prevalences were 69.7 % (25.2 % of the 1,224 samples) for HlyEHEC-producing E coli, 55.3 % (19.3 %) for eae,and 18.2 % (4.5 %) for stx. E coli strains exhibiting an a-Hly phenotype were detected in 66.5 % of the calves and 21.9 % of fecal samples.The esf gene was detectable in 31.7 %of the calves from only 9 of 11 herds and in 7.8 % of the samples. Calves shedding DAEC or typica EPEC were not identified.The detection freguency of virulence traits significantly depended on the calves' age and shedding dynamics differed between the traits. A significant correlation between calf diarrhea and shedding of EHEC virulence traits was determined for several postnatal periods (1st week:HlyEHEC; 1st amp; 10* week: eae; 4th weeksfx).Shedding of ETEC (est) was associated with diarrhea in newborn calves (1st week) only HlyEHEC- and a-Hly-producing E.coli were shed significantly more freguently by diarrheic calves in 1st and 8th week of life, respectively. The knowledge gained in this study highlights the high prevalence of zoonotic E.coli already in calves. The age-dependent shedding dynamic of the various E.coli pathovars has to be considered regarding prophylaxis as well as planning Intervention studies, both for calves and humans.Im Rahmen einer longitudinalen epidemiologischen Untersuchung (Kohorten-Studie) wurden auf 11 Mi Ichvieh betrieben insgesamt 1.224 Rektaltupfer von 221 Kälbern in einem Alter von 1-12 Wochen entnommen. Die Ziele der Untersuchung lagen in (i) der Feststellung von Assoziationen zwischen dem Auftreten von Durchfall und dem Vorkommen bestimmter darmpathogener E coli, und (ii) der Einschätzung des Zoonosepotentials der von den Kälbern ausgeschiedenen E co//-lsolate. Hierzu wurden die wöchentlich von den Kälbern entnommenen Proben über Nacht bebrütet und in der Bouillonkultur anschließend mittels PCR das Vorkommen von enterotoxischen E.coli [ETEC; Nachweis der Gene für hitze-stabiles},
  year = {2007},
  journal = {Berliner und Münchener Tierärztliche Wochenschrift},
  volume = {120},
  pages = {296-306},
  month = {07/2007},
  publisher = {Schlütersche Verlagsgesellschaft mbH & Co. KG},
  address = {Hannover},
  issn = {0005-9366},
  doi = {10.2376/0005-9366-120-296},
  language = {English},
}