A survey on the occurrence of Brachyspira pilosicoli and Brachyspira hyodysenteriae in growing-finishing pigs

Abstract

Background: The major pathogenic intestinal spirochetes affecting pigs during the growing- finishing stage of production include Brachyspira hyodysenteriae and Brachyspira pilosicoli. Infections by these pathogens, which affect the economics of pig production, can result in mortality, growth rate losses and substantial antibiotic costs. The aim of this study was to assess the current occurrence of B. hyodysenteriae and B. pilosicoli in Polish pig herds. Moreover, associations between the presence of diarrhea or other intestinal pathogens and occurrence of B. hyodysenteriae and B. pilosicoli in pigs were investigated. Methods: Between January 2017 and August 2019, a total of 401 samples of pig feces from 95 different herds were submitted to the National Veterinary Research Institute of Poland. These samples were obtained from pigs older than 7 weeks. All the received fecal samples were examined for the presence of B. hyodysenteriae, B. pilosicoli and Lawsonia intracellularis by real-time PCR. Results: For B. pilosicoli, 4.5% (95% CI, 2.5–7.0%) of samples and 13.7% (95% CI, 7.5–22.3%) of herds were positive. Out of 12 samples, B. pilosicoli was detected simultaneously with L. intracellularis, B. hyodysenteriae and B. pilosicoli were detected alone in two samples each. In terms of B. hyodysenteriae, 7.0% of samples (95% CI, 4.7–9.9%) from 18.9% of herds (95% CI, 11.6–28.3%) were positive in real time PCR. The presence of B. hyodysenteriae in fecal samples was associated with the presence of diarrhea in pigs. Conclusions: This study confirmed that B. pilosicoli infections occur in Polish pig herds, but the prevalence is at a low level and the presence of B. pilosicoli is not associated with the development of diarrhea in pigs. B. hyodysenteriae is still a common cause of diarrhea among pigs from Polish herds.