Mutans

Mutans is a Latin epithet used in biology, most commonly encountered in the name Streptococcus mutans. Streptococcus mutans is aGram-positive, facultative anaerobic coccus that colonizes the human oral cavity and is a major contributor to dental caries. The term mutans is part of a broader group known as mutans streptococci, which also includes related species such as Streptococcus sobrinus.

It thrives in dental biofilms, metabolizing dietary carbohydrates to lactic acid, which lowers pH and promotes enamel demineralization. It is both acidogenic and aciduric, tolerating and thriving in low-pH environments. A key virulence mechanism is adhesion and persistence in plaque via extracellular polysaccharides synthesized by glucosyltransferases (gtfB, gtfC, gtfD) from sucrose, forming sticky glucans that facilitate biofilm formation on tooth surfaces.

Clinical significance: Streptococcus mutans is frequently implicated in the development of dental caries; colonization commonly occurs in early childhood and persists in the oral cavity. Detection of mutans streptococci in saliva or plaque is sometimes used as a caries risk indicator. Prevention and control rely on good oral hygiene, fluoride exposure, dietary sugar reduction, and, in high-risk cases, targeted antimicrobial regimens or professional care.

Taxonomy and research: The mutans streptococci constitute a subset of viridans streptococci. Research covers biofilm formation, acid tolerance, and regulatory circuits such as quorum sensing that influence cariogenicity. The epithet mutans derives from Latin mutans, meaning changing or mutable.