Science et technologie vétérinaires

Outbreak of Dermatophilus congolensis in Grazing Beef Cattle in Northeastern Mexico: First Report

Abstract

Antonio Cantú Covarrubias, Carolina Segundo Zaragoza, Adrián Muñoz Bucio, Efrén Díaz-Aparicio, Roberto Arnulfo Cervantes Olivares

Dermatophilus congolensis is a bacterium that causes exudative dermatitis with scab formation in bovines. Humidity and ticks are predisposing factors. This study describes skin lesions in 27 bovines from a Simbrah herd of grazing livestock of 180 females (15%), aged 18 to 30 months old, in Aldama, Tamaulipas, Mexico. Lesions were distributed in the lower extremities, the belly and the neck and consisted of thick grayish to dark brown scabs with exudates and blood. Scabs were collected from four of the most severely affected animals, placed in sterile tubes and then transported in refrigeration to the laboratory. Samples were processed for isolate D. congolensis. The four samples revealed long branched filaments made up of coccoid cells arranged in parallel rows, one after the other, which is a characteristic of D. congolensis. In this outbreak, morbidity was 15% (27/180) and mortality was 22% (6/27). The PCR using ESP1 and ESP2 primers amplified a product between 400 and 500 bp, and the 16 s sequence was 100% identical to D. congolensis gene for 16S rRNA, strain: NBRC 105199 Sequence ID: dbj|AB550800.1|. The observation of lesions, clinical signs, identification and sequence led to this first report of bovine dermatophilosis in Mexico.