Review on the effects of potential prebiotics on controlling intestinal enteropathogens Salmonella and Escherichia coli in pig production
With 25.8% (88 715 cases in 2013) of all recorded outbreaks, salmonellosis is the second most common zoonosis in humans after campylobacteriosis. Epidemiological studies in the EU in 2013 confirmed that after poultry, sweets and chocolate, pork, with 8.9%, is the third most important cause for outbreak‐associated salmonellosis in humans (EFSA, 2015a). The Salmonella prevalence in fresh pig meat ranges from 0.7% to 26% (Lin et al., 2014; Ashraf et al., 2015; EFSA, 2015a). While outbreaks caused by pathogenic E. coli strains are less frequent although significant (1.7% by verotoxigenic E. coli, VTEC) (EFSA, 2015b) with 0–74% of contaminated pig meat (Nørrung and Buncic, 2008; Ashraf et al., 2015; EFSA, 2015a). Nonetheless, post‐weaning diarrhoea (PWD) caused by enterotoxigenic E. coli (ETEC) is an important cause of economic losses in pigsties due to high morbidity, mortality and reduced growth rates (Luppi et al., 2016).
Control of these pathogens can be implemented at the pre‐harvest level (on farm), at harvest level (during transport and slaughter) and at post‐harvest level (processing and retailing). Control programmes at farm level are most essential to limit the risks of pathogenic infections into the food chain. Preventing pathogens from entering through the feed is of major significance for the reduction in pathogens in pigs. Different intervention strategies such as using pathogen‐free or vaccinated incoming pigs (Andres and Davies, 2015), preventing infection from environmental contamination (Barco et al., 2014; Petruzzelli et al., 2015), antimicrobial medication (Nesterenko et al., 2016) and nutritional supplements have been assessed to reduce pathogenic prevalence in pigsties. Among the latter, non‐digestible carbohydrates (NDCs), also known as prebiotics, can be effective by restoring or improving the resistance to colonization, reinforcing the intestinal barrier function against invading pathogens (Bindels et al., 2015).
This study reviews two major intestinal pathogens in swine: Salmonella and E. coli infections. After a description of the prevalence of these pathogens, their pathogenicity and the influence of characteristics of feed on contamination in pigs, the mechanisms and effects of some potential prebiotics against these pathogens in pigs are described and analysed.