Isolation and Identification of Black-Pigmented Bacteria from Donkey Oral Cavity

Objective: Black-pigmented Gram-negative anaerobic rods are an important pathogen in progress and development of gingivitis and periodontitis. To investigate the phylogenetic affinities of periodontopathic bacteria, a group of Gram-negative anaerobic rods from donkey oral cavity was focused and identified.

Methods: The bacteria were analyzed biochemical using the Rapid ID 32 A and API-ZYM Microsystems and serologically using anti-sera of genera Prevotella and Porphyromonas, were subjected to DNA analysis and had their 16S rRNA gene analyzed.

Results: Two kinds of black-pigmented colonies from 3 donkeys were isolated on Brucella- blood agar plates from oral cavities. These characteristics of the isolates were identified as genus Prevotella biochemically. GC content of the isolates was 43-48%, was similar to those of P. intermedia. To determine the phylogenetic affinities of the species, its almost complete 16S rRNA gene was sequenced and subjected to a comparative analysis. Highest sequence relatedness was shown with one is P. intermedia and the other was Prevotella multiformis. These results indicated that two clinical isolates from donkey oral cavity were one is P. intermedia. Based on phylogenetic, phenotypic evidence and pigmentation, the new species was proposed Prevotella asinus.

Conclusion:: This study shows that there are at least 2 black-pigmented anaerobic rods in the oral cavity of donkey. One is P. intermedia and the other is new species proposed Prevotella asinus.