Open AccessStreptococcus caledonicus sp. nov., isolated from sheep
Author(s) -
Geoffrey Foster,
Miranda Kirchner,
Jakub Muchowski,
Nicholas Duggett,
Luke Randall,
H. I. Knight,
Adrian M. Whatmore
Publication year - 2020
Publication title -
international journal of systematic and evolutionary microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 173
eISSN - 1466-5034
pISSN - 1466-5026
DOI - 10.1099/ijsem.0.004081
Subject(s) - biology , streptococcus , microbiology and biotechnology , bacteria , genetics
Five strains of an unidentified Gram-positive, catalase-negative, chain-forming coccus-shaped organism recovered from sheep in Scotland were characterized using phenotypic and molecular taxonomic methods. Based on morphological and biochemical criteria, the strains were tentatively identified as streptococci but they did not appear to correspond to any recognised species of the genus. Comparative 16S rRNA gene sequencing showed the strains were highly related to each other and confirmed their placement in the genus Streptococcus , with a maximum nucleotide identity of around 97 % to extant species. Best matches were with Streptococcus hillyeri followed by Streptococcus porci . Average nucleotide identity and in silico DNA–DNA hybridization values determined from whole-genome sequence were also consistent with the group representing a novel species. Best matches, again seen to S. hillyeri , followed by S. porci and S. plurextorum , were below accepted cut-off values for species delineation. Based on biochemical criteria and molecular genetic evidence, it is proposed that the unknown isolates from sheep be assigned to a new species of the genus Streptococcus as Streptococcus caledonicus sp. nov. The type strain of Streptococcus caledonicus is S784/96/1 T =CCUG 73951 T =NCTC 14363 T .