Isolamento e caracterização molecular de Dichelobacter nodosus isolados de ovinos no estado da Bahia, Brasil / Isolation and molecular characterization of Dichelobacter nodosus isolated from sheep in Bahia, Brazil

ABSTRACT

Background: Pododermatitis or footrot is an infectious disease that affects the hoof and interdigital tissue of sheep causing lameness. The disease is caused by the interaction of the agent Dichelobacter nodosus and symbiotic bacteria in the complex environment of the epidermal tissues of the hoof and host immune system. D. nodosus is not able to invadehealthy hooves, so the infection is preceded by colonization of the interdigital skin by Fuso bacterium necrophorum. The aim of this research was to perform the isolation andcharacterization of D. nodosus in sheep farms of different municipalities of Bahia, obtaining the serogroups present in each herd.Materials, Methods & Results: The study was carried out in nine sheep farms from eight municipalities in the state of Bahia. All farms presented history of foot diseases. A total of 620 animals were observed, 140 of which were examined for lameness. To collect the contents of the lesions, sterile swabs were introduced into tubes containing sterile Thorley transport medium under refrigeration at 8°C and sent for laboratory analysis. Subsequently, each swab collected was seeded in two Petri dishes containing 4% hoof agar medium and incubated in anaerobic at 37°C for 96 hours. The purified samples were seeded on 2% hoof agar and incubated under the same conditions as above. The colonies were identified by the morphological characteristic and Gram staining. The DNA was extracted and stored at -20°C until its use in PCR, for identification and classification of D. nodosus in serogroups (A-I). In the nine farms visited were found animals with clinical signs of infectious pododermatitis. After processing, there was success of isolation in 39 samples (41%), confirming the presence of D. nodosus in all municipalities evaluated.[...]