Role of SMU.2055 gene in cariogenic capacity of Streptococcus mutans

• Published in: Nan fang yi ke da xue xue bao = Journal of Southern Medical University 2017-06, Vol.37 (6), p.786
• Main Authors: Chen, Xuan, Xu, Xiao-Hu, Wu, Xin-Yu, Li, Zhuan-Ling, Zhao, Wang-Hong
• Format: Article
• Language: Chinese
• Subjects: Acids - metabolism; Bacterial Proteins - genetics; Dental Caries - microbiology; Genes, Bacterial; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Streptococcus mutans - genetics; Streptococcus mutans - pathogenicity; Streptococcus mutans - ultrastructure
• ISSN: 1673-4254

To construct a SMU.2055-dificient mutant strain of Streptococcus mutans (S. mutans) and evaluate its cariogenic capacity in comparison with wild-type S. mutans. The SMU.2055-dificient mutant strain of S. mutans was constructed using homologous recombination technique and observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorbance at 600 nm and pH values of the wild-type and mutant strains were monitored to evaluate their growth and acid production. After acid adaption, the two strains were challenged with acid shock and their survival rates were determined. PCR and sequence analyses verified the successful construction of the SMU.2055-dificient mutant strain. Observation with SEM revealed obvious changes in the morphology of the mutant strain, which showed reduced irregular substances between the individual bacteria as compared with the wild-type strain. TEM revealed major alterations in the cellular architecture of the mutant strain with blurry cell membrane an