抄録
Mutans streptococci has been implicated as a primary causative agent of dental caries in animal. Two kinds of mutans streptococci, Streptococcus orisuis serovar strains were identified previously. New gram-positive streptococcal mutans-like strains from the oral flora of pigs were characterized. The distribution of three kinds of the mutans streptococci was studied. A third strain was newly identified as Streptococcus ferus based on 16S rRNA gene sequencing, G+C content, DNA-DNA homology, and extensive biochemical testing, and serologically grouped into serotype c of mutans streptococci. The distribution of three strains revealed that S. ferus was the predominant species. S. orisuis serovar strains made up 4∼13% of all the streptococci in young pigs. These results suggest that the detection rate of these mutans streptococci corelates with feed containing sucrose and S. ferus is the outlived strain among the three mutans streptococci in pig oral cavity.
