Identification and distribution of Brachyspira species in feces from finishing pigs in Argentina

Abstract

Background and Aim: Brachyspira are Gram-negative, aerotolerant spirochetes that colonize the large intestine of various species of domestic animals and humans. The aim of this study was to determine the presence and distribution of different species of Brachyspira presents in feces from finishing pigs in Argentina. Materials and Methods: Fecal samples (n=1550) were collected from finishing pigs in 53 farms of the most important swine production areas of Argentina, and Brachyspiras species were identified by bacteriological and molecular methods. Results: The regional prevalence of Brachyspira spp. was at the level of 75.5% (confidence interval 95%, 62.9-87.9), and it was lower among those farms with >1001 sows. One hundred and twenty-eight isolates of Brachyspira were properly identified and the species found were: Brachyspira hyodysenteriae, Brachyspira pilosicoli, Brachyspira innocens, and Brachyspira murdochii. B. hyodysenteriae and B. pilosicoli had low prevalence (1.9% and 7.5%, respectively), B. innocens was isolated from 34% of the farms and B. murdochii was found in 39.6%. Conclusion: The present study provides epidemiological data about herd prevalence of the different Brachyspira species in Argentina, showing that the prevalence figure seems to be higher than that reported in other countries.

Carriage of Brachyspira hyodysenteriae on common insect vectors

“…Insect frass was also collected daily from freshly-soiled filter papers at the base of each housing, daily for 10 days post-inoculation. The frass from each collection was inoculated onto Brachyspira selective medium (BSM) agar plates and incubated anaerobically at 42 o C for 5 days; BSM was prepared in 0.5 L batches as described previously (Carranza et al, 2021), consisting of Columbia Agar Base No. 2 (Oxoid, U.K.) supplemented with 5.0 % sheep blood and 10 ml of a stock antibiotics preparation consisting of spectinomycin dihydrochloride, vancomycin hydrochloride, colistin methane sulphonate at 2.0, 0.125 and 0.125 g respectively, in 100 ml distilled water.…”