F Engelen1, D Thiry2, B Devleesschauwer3,4, M Heyndrickx5, J Mainil2, L De Zutter4, E Cox1. 1. Laboratory of Immunology, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University (UGent), Merelbeke, Belgium. 2. Bacteriology, Department of Infectious Diseases, Institute for Fundamental and Applied Research in Animals and Health (FARAH) and Faculty of Veterinary Medicine, University of Liège (ULiège), Liège, Belgium. 3. Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium. 4. Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. 5. Unit Technology and Food, Institute for Agricultural and Fisheries Research (ILVO), Melle, Belgium.
Abstract
AIMS: The purpose of this study was to investigate the occurrence of Escherichia coli O157 and O26 on Belgian dairy cattle farms, the presence of virulence genes in the confirmed isolates and the association of E. coli O26 presence with calf diarrhoea. METHODS AND RESULTS: In total, 233 recto-anal mucosal swabs (RAMS) were obtained from healthy and diarrheic dairy calves on three farms, each alternately visited three consecutive times. RAMS were analysed for presence of E. coli O157 and O26, and stx1, stx2 and eae virulence genes. Overall, 19% of RAMS tested positive for E. coli O157, while 31% tested positive for E. coli O26. The majority of isolates possessed both stx and eae, denoting a high pathogenic potential to humans. While both serogroups persisted at farm level, persistence within the same animal over time appeared to be relatively rare. Interestingly, E. coli O26 was already abundantly present at a younger age compared to E. coli O157. Calf diarrhoea could not be associated with presence of E. coli O26. CONCLUSIONS: Young dairy calves are important on-farm reservoirs of potentially pathogenic E. coli O157 and O26. A role of E. coli O26 in calf diarrhoea could not be confirmed. SIGNIFICANCE AND IMPACT OF THE STUDY: O157 and O26 are responsible for the majority of human STEC infections. Gaining more epidemiological information regarding their occurrence and persistence on cattle farms will contribute to a better understanding of STEC ecology and risk of human transmission.
AIMS: The purpose of this study was to investigate the occurrence of Escherichia coli O157 and O26 on Belgian dairy cattle farms, the presence of virulence genes in the confirmed isolates and the association of E. coli O26 presence with calf diarrhoea. METHODS AND RESULTS: In total, 233 recto-anal mucosal swabs (RAMS) were obtained from healthy and diarrheic dairy calves on three farms, each alternately visited three consecutive times. RAMS were analysed for presence of E. coli O157 and O26, and stx1, stx2 and eae virulence genes. Overall, 19% of RAMS tested positive for E. coli O157, while 31% tested positive for E. coli O26. The majority of isolates possessed both stx and eae, denoting a high pathogenic potential to humans. While both serogroups persisted at farm level, persistence within the same animal over time appeared to be relatively rare. Interestingly, E. coli O26 was already abundantly present at a younger age compared to E. coli O157. Calf diarrhoea could not be associated with presence of E. coli O26. CONCLUSIONS: Young dairy calves are important on-farm reservoirs of potentially pathogenic E. coli O157 and O26. A role of E. coli O26 in calf diarrhoea could not be confirmed. SIGNIFICANCE AND IMPACT OF THE STUDY: O157 and O26 are responsible for the majority of human STEC infections. Gaining more epidemiological information regarding their occurrence and persistence on cattle farms will contribute to a better understanding of STEC ecology and risk of human transmission.
Authors: Deborah V Hoyle; Marianne Keith; Helen Williamson; Kareen Macleod; Heather Mathie; Ian Handel; Carol Currie; Anne Holmes; Lesley Allison; Rebecca McLean; Rebecca Callaby; Thibaud Porphyre; Sue C Tongue; Madeleine K Henry; Judith Evans; George J Gunn; David L Gally; Nuno Silva; Margo E Chase-Topping Journal: Appl Environ Microbiol Date: 2021-04-27 Impact factor: 4.792
Authors: Audrey Habets; Frederik Engelen; Jean-Noël Duprez; Brecht Devleesschauwer; Marc Heyndrickx; Lieven De Zutter; Damien Thiry; Eric Cox; Jacques Mainil Journal: Vet Sci Date: 2020-10-31