Occurrence of bovine dermatophilosis in Huambo province, Angola

Abstract

Dermatophilosis is an exudative pustular dermatitis that affects cattle, sheep, horses, goats, dogs, cats, reptiles, and occasionally humans. This disease is caused by Dermatophilus congolensis, a pleomorphic Gram-positive actinomycete. According to the Veterinary Services, the highest incidence of the disease in Angola was identified in the provinces Huambo, Kwanza Sul and Malang during May 2013 and April 2015, but only supported on clinical sings.  In the present work ninety crust samples were taken from animals with lesions on the skin in Huambo province, in the period May 2013-April 2015. The bacteria were isolated following Haalstra´s method. Presumptive colonies of the Dermathophilus genus were subjected to Gram stain, biochemical identification, and molecular detection by PCR. Eight Dermathophilus congolensis isolates were tested for their sensitivity to eleven different antibiotics. A total of 30 samples showed typical colonies of the Dermatophilus genus. The amplicon of 817 bp corresponding to the 16S rRNA region was obtained in the 30 isolates suspecting of being D. congolensis. Drug sensitivity test revealed that Amoxicillin/clavulanate, Clindamycin, Erythromycin, Lincomycin, Azithromycin, Rifampicin, and Enrofloxacin were highly effective against the eight D. congolensis isolates. Observation of lesions and microbiologic diagnosis using biochemical and molecular techniques allowed confirming bovine dermatophilosis in the region of Huambo, Angola.

Key words: Dermatophilus congolensis, bovine, diagnosis, antimicrobial resistance.