Characterization of Streptococcus equi subsp. ruminatorum isolated from spotted hyenas (Crocuta crocuta) and plains zebras (Equus burchelli), and identification of a M-like protein (SrM) encoding gene

Thirteen strains of Streptococcus equi subsp. ruminatorum from free-ranging spotted hyenas (Crocuta crocuta) and plains zebras (Equus burchelli) in Tanzania were characterized by biochemical and molecular-biological methods. Although the colony appearance of the S.e. ruminatorum wildlife strains differed from that of the S.e. ruminatorum type strain CECT 5772T, all biochemical reactions of the wildlife strains were similar to those of the type strain. In addition, all wildlife strains produced hyaluronidase and were capable of hydrolysing arginine, three strains (23%) synthesized acetoin, but only eight strains (62%) produced acid from ribose. rep-PCR indicated that different clones of S.e. ruminatorum were distributed among the hyena and zebra populations in the study area. Identical rep-PCR patterns in hyena and zebra strains suggest that a direct transmission of S.e. ruminatorum between these species may occur. The presence of a M-like protein (SrM) gene was demonstrated in all S.e. ruminatorum strains including the type strain. Sequencing of the M-like protein gene revealed a hypervariable region within the deduced amino acid sequence. Most of the strains clustered with previously described strains based on the hypervariable region of the S.e. zooepidemicus SzP protein. Sequencing also demonstrated that identical SrM protein sequences were shared among S.e. ruminatorum strains from different host species.