Genetic organization of an M protein trans-acting positive regulator (Mga) orthologue and its adjacent M-like protein (SCM) alleles in Streptococcus canis

Using the 39 SCM allele isolates and polymerase chain reaction-based amplification and sequencing, we obtained the deduced Mga amino acid (AA) sequences. The 22 Mga sequences in whole-genome sequences were obtained by searching the National Collection of Type Cultures 12191(T) Mga sequence into the database. The percentage identity to the type-strain Mga sequence was examined along with its size. The presence of the Mga-specific motifs was confirmed. Of the 62 strains, we identified 59 Mga sequences with an AA size of 509 (except for four different sizes). Percentage identity ranged from 96.66–100% with the confirmed Mga-specific motifs and diverse SCM allele populations. Our findings support the presence of an Mga orthologue and diverse SCM allele populations.