TY - JOUR
T1 - Variation of expression defects in cell surface 190-kDa protein antigen of Streptococcus mutans
AU - Lapirattanakul, Jinthana
AU - Nomura, Ryota
AU - Matsumoto-Nakano, Michiyo
AU - Srisatjaluk, Ratchapin
AU - Ooshima, Takashi
AU - Nakano, Kazuhiko
N1 - Funding Information:
This study was supported by Thailand Research Fund, Office of the Higher Education Commission, and Mahidol University ( MRG5580025 ), and a Grant-in-Aid for Scientific Research (B) 23390472 and 24390461 from the Japan Society for Promotion of Science .
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Streptococcus mutans, which consists of four serotypes, c, e, f, and k, possesses a 190-kDa cell surface protein antigen (PA) for initial tooth adhesion. We used Western blot analysis to determine PA expression in 750 S. mutans isolates from 150 subjects and found a significantly higher prevalence of the isolates with PA expression defects in serotypes f and k compared to serotypes c and e. Moreover, the defect patterns could be classified into three types; no PA expression on whole bacterial cells and in their supernatant samples (Type N1), PA expression mainly seen in supernatant samples (Type N2), and only low expression of PA in the samples of whole bacterial cells (Type W). The underlying reasons for the defects were mutations in the gene encoding PA as well as in the transcriptional processing of this gene for Type N1, defects in the sortase gene for Type N2, and low mRNA expression of PA for Type W. Since cellular hydrophobicity and phagocytosis susceptibility of the PA-defective isolates were significantly lower than those of the normal expression isolates, the potential implication of such defective isolates in systemic diseases involving bacteremia other than dental caries was suggested. Additionally, multilocus sequence typing was utilized to characterize S. mutans clones that represented a proportion of isolates with PA defects of 65-100%. Therefore, we described the molecular basis for variation defects in PA expression of S. mutans. Furthermore, we also emphasized the strong association between PA expression defects and serotypes f and k as well as the clonal relationships among these isolates.
AB - Streptococcus mutans, which consists of four serotypes, c, e, f, and k, possesses a 190-kDa cell surface protein antigen (PA) for initial tooth adhesion. We used Western blot analysis to determine PA expression in 750 S. mutans isolates from 150 subjects and found a significantly higher prevalence of the isolates with PA expression defects in serotypes f and k compared to serotypes c and e. Moreover, the defect patterns could be classified into three types; no PA expression on whole bacterial cells and in their supernatant samples (Type N1), PA expression mainly seen in supernatant samples (Type N2), and only low expression of PA in the samples of whole bacterial cells (Type W). The underlying reasons for the defects were mutations in the gene encoding PA as well as in the transcriptional processing of this gene for Type N1, defects in the sortase gene for Type N2, and low mRNA expression of PA for Type W. Since cellular hydrophobicity and phagocytosis susceptibility of the PA-defective isolates were significantly lower than those of the normal expression isolates, the potential implication of such defective isolates in systemic diseases involving bacteremia other than dental caries was suggested. Additionally, multilocus sequence typing was utilized to characterize S. mutans clones that represented a proportion of isolates with PA defects of 65-100%. Therefore, we described the molecular basis for variation defects in PA expression of S. mutans. Furthermore, we also emphasized the strong association between PA expression defects and serotypes f and k as well as the clonal relationships among these isolates.
KW - Cell surface protein antigen
KW - Expression defect
KW - MLST
KW - S. mutans
KW - Serotype
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U2 - 10.1016/j.ijmm.2015.03.001
DO - 10.1016/j.ijmm.2015.03.001
M3 - Article
C2 - 25792295
AN - SCOPUS:84955710378
VL - 305
SP - 383
EP - 391
JO - International Journal of Medical Microbiology
JF - International Journal of Medical Microbiology
SN - 1438-4221
IS - 3
ER -