Streptococcus dentapri sp. nov., isolated from the wild boar oral cavity

Abstract

Four Gram-stain-positive, catalase-negative, coccoid-shaped isolates were obtained from the oral cavities of wild boars and characterized by phenotypic and phylogenetic studies. On the results of biochemical tests, the organisms were tentatively identified as a streptococcal species. Comparative 16S rRNA gene sequencing studies confirmed that the organisms are members of the genus Streptococcus, with Streptococcus equi subsp. equi ATCC 33398 T as their closest phylogenetic relative (94.7 % similarity). DNA-DNA hybridization analysis showed that the isolates displayed less than 10 % relatedness to Streptococcus equi subsp. equi DSM 20561 T . From the phylogenetic and phenotypic evidence, the four isolates represent a novel species of the genus Streptococcus, for which the name Streptococcus dentapri sp. nov. (type strain NUM 1529 T 5JCM 15752 T 5DSM 21999 T ) is proposed.Oral streptococci make up a proportion of the normal flora of the oral cavity in humans and animals. Among oral streptococci, the mutans group is one of the groups of micro-organisms responsible for dental caries (Hamada & Slade, 1980;Loesche, 1986). This group was proposed because its members share similar phenotypic characteristics. One of the causes of caries is an enzyme, glucosyltransferase (GTase), which is produced by this group of bacteria. GTase catalyses the formation of sticky water-insoluble glucans from sucrose. The glucans adhere oral bacteria to teeth and so lead to the formation of dental plaque. The bacteria continue to produce acid on the tooth surfaces and cause dental caries (Hamada & Slade, 1980;Loesche, 1986). Previously, we reported a novel mutans streptococci, Streptococcus orisuis, isolated from the oral cavity of a pig (Takada & Hirasawa, 2007). GTase gene (gtf) studies and rat caries experiments involving S. orisuis have been performed (ShinozakiKuwahara et al., 2008;Yamaguchi, 2008). Streptococcus dentirousetti , isolated from the bat oral cavity, showed a gtf gene sequence similar to that of S. orisuis (unpublished GenBank accession no. AB355819). The colonization of the oral cavity by mutans streptococci is assumed to result from sucrose intake. As wild boars are omnivorous animals, they will probably have the opportunity to ingest sucrose. We investigated the microflora of the oral cavities of wild boars, focusing on mutans streptococci.To investigate the oral microflora of wild boars, mitis salivarius agar (MS agar; Difco) and MS agar supplemented with 0.2 U bacitracin ml 21 (MSB agar) are widely used to isolate Streptococcus mutans as well as other oral streptococcal species. The four mutans streptococcus-like strains on MSB agar selected for this study were chosen randomly from 38 isolates of streptococci obtained from the oral cavities of eight generally healthy wild boars (three from Aomori and five from Tokushima prefectures in Japan). The strains were grown on brain heart infusion (BHI; Difco) agar supplemented with 5 % horse blood at 37 u C in an atmosphere of 95 % N 2 and 5 % CO 2 . Biochemical analysis was...

Streptococcus troglodytae sp. nov., from the chimpanzee oral cavity

“…Additional novel species, such as Streptococcus devriesei from horses, Streptococcus orisuis from pigs, Streptococcus dentirousetti from bats, Streptococcus dentapri from wild boars 3These authors contributed equally to this work. and Streptococcus ursoris from bears have been reported (Collins et al, 2004;Takada & Hirasawa, 2007Takada et al, 2010;Shinozaki-Kuwahara et al, 2011). Recently, housekeeping gene sequences, as well as the 16S rRNA gene sequences, have been identified as being important for the evaluation of the taxonomic position of the micro-organisms (Christensen et al, 2004;Hung et al, 2005;Okamoto et al, 2008;Glazunova et al, 2009).…”

Streptococcus porcorum sp. nov., isolated from domestic and wild pigs

“…Phenotypic data were obtained in this study. Takada & Hirasawa, 2007;Takada et al, 2010). Streptococcus thoraltensis, Streptococcus hyovaginalis and Streptococcus hyointestinalis are also a-haemolytic and do not react with Lancefield group A, B, C, D, F or G streptococcal antisera.…”

Streptococcus oricebi sp. nov., isolated from the oral cavity of tufted capuchin

“…Novel streptococci from the oral cavity of various animals have previously been reported (Takada & Hirasawa, 2007, 2008Takada et al, 2010Takada et al, , 2013Shinozaki-Kuwahara et al, 2011Okamoto et al, 2013;Saito et al, 2014). Some oral streptococci are known to form characteristic colonies on Mitis Salivarius (MS) agar, demonstrating the synthesis of exopolysaccharides from sucrose (Hamada et al, 1979;Coykendall & Gustafson, 1985;Kilian et al, 1989).…”