A Genetic Analysis of Mutants Separated Simultaneously with an Inoculated Organism from the Same Lesion in Mice Inoculated with Group A Streptococcus

Abstract

Mutants separated simultaneously with an inoculated organism from the same lesion in mice inoculated with group A streptococcus were genetically analyzed. Mutants of group A streptococcus include uridine diphosphate-N-acetylglucosamine-4-epimerase, which is not reported to be among group A reference strains. The base sequence of the genes of this enzyme remains unknown. However, it is demonstrated that 4-epimerase has both substrates of UDP-glucose and UDP-N-acetylglucosamine. And it is found that Enterococcus faecalis V583 has 2 kinds of UDP-glucose 4-epimerase genes (galE-1, galE-2). Therefore, we attempted to amplify galE-1 and galE-2 genes using the heat treated products (genomic DNA) of the specimens as the template, and analyze them by PCR Primer. Amplification was successful using the mutants, whereas it failed using the reference strains. Therefore, we regarded the sequences of galE-1 and galE-2 obtained from NCBI as the reference sequence. The result of sequencing revealed that the mutants had the sequences of galE-1 and galE-2. The types of mutant strains included frame shift, missense mutation, and silent mutation. However, the biological strain producing these mutants was not determined. These mutants were identified as Enterococcus faecalis based on the biochemical properties described in Bergey’s Manual, serologic test findings, and DNA homologous sequence test, which was previously reported. Thus, in this study, they were identified as Enterococcus excluding Enterococcus faecalis.