Electron-microscopic observation of adherence of serotype c Streptococcus mutans to the enamel surface due to glucan synthesis.
Cellular adherence of three strains with water-insoluble glucan (IG)-synthesizing ability and a strain lacking the ability of serotype c Streptococcus mutans to the saliva-coated human enamel surface was examined by scanning (SEM) and transmission (TEM) electron-microscopy. SEM revealed that organisms of all strains used adhered directly to the enamel surface in the absence of sucrose. Cell-to-cell attachment was scarcely observed in the absence of sucrose. Cell-to-cell attachment via amorphous substance on the cell surface was observed by SEM when the strains with IG-synthesizing ability were incubated with the saliva-coated enamel in the presence of sucrose. TEM revealed that cell-associated enzymes of these strains synthesized filamentous and double-stranded fibrillar structures from sucrose. The strain lacking IG-synthesizing ability was unable to induce cell-to-cell attachment in the presence of sucrose, nor was it able to synthesize the amorphous substance. These results indicate that production of IG by cell-associated glucosyltransferase participates in cellular accumulation of serotype c S. mutans.
Koga
T
T
Department of Dental Research, National Institute of Health, Tokyo, Japan.
Toda
Y
Y
Moro
I
I
Hamada
S
S
D001422:Bacterial Adhesion; D003743:Dental Enamel / Q000382:microbiology* / Q000648:ultrastructure; D005936:Glucans / Q000096:biosynthesis*; D006801:Humans; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D012463:Saliva / Q000378:metabolism / Q000382:microbiology; D013295:Streptococcus mutans / Q000378:metabolism* / Q000648:ultrastructure; D013395:Sucrose / Q000378:metabolism
D005936:Glucans; D013395:Sucrose