Colonization of the Human Oral Cavity by a Streptococcus mutans Mutant Producing Increased Bacteriocin

Abstract

Streptococcus mutans strain JH1005 is a mutant that produces levels of bacteriocin activity three-fold-elevated than those produced by its parent, JH1001. A single infection regimen with JH1005 was found to result in persistent colonization of the teeth of all three adult subjects tested. This is a significant improvement over JH1001, which required multiple exposures in order to colonize the teeth of humans reliably. The levels of total cultivable bacteria and indigenous S. sanguis were not affected by JH1005 colonization. In two of the three subjects, total (indigenous plus JH1005) S. mutans levels were significantly decreased. The results provide additional support for the role of bacteriocin production as an ecological determinant in colonization by S. mutans. They also indicate that a practical regimen for infection by an effector strain might be achieved for use in the replacement therapy of dental caries.

Frequency of four different mutacin genes in Streptococcus mutans genotypes isolated from caries-free and caries-active individuals

“…Mutacins have been implicated as virulence factors in dental caries (Hillman et al, 1987;Novak et al, 1994). In this study, we investigated the detection frequency of mutacin genes in S. mutans strains isolated from caries-free and caries-active individuals.…”

“…Clinically, mutacins have been considered important for the establishment and equilibrium of bacteria in dental biofilms: the mutacin-producing strains might colonize more easily and suppress non-producing or susceptible strains (Hillman et al, 1987). Longo et al (2003) analysed 19 strains isolated from children and found only one strain that showed an amplicon homologous to the gene for mutacin II.…”

“…Mutacins are peptide or protein antibiotics that are mainly bactericidal for other bacteria of the same or closely related species, as well as for other Gram-positive micro-organisms, and are likely to confer an ecological advantage in diverse bacterial communities such as the dental biofilm (Parrot et al, 1990;Balakrishnan et al, 2002). Some studies have demonstrated that the mutacin activity of S. mutans could be related to the prevalence of this species in the dental biofilm, saliva and dental caries (Berkowitz and Jordan, 1975;Hillman et al, 1987).…”

“…Mutacins are peptide or protein antibiotics that are mainly bactericidal for other bacteria of the same or closely related species, as well as for other Gram-positive micro-organisms, and are likely to confer an ecological advantage in diverse bacterial communities such as the dental biofilm (Parrot et al, 1990; Balakrishnan et al, 2002). Some studies have demonstrated that the mutacin activity of S. mutans could be related to the prevalence of this species in the dental biofilm, saliva and dental caries (Berkowitz and Jordan, 1975;Hillman et al, 1987).Classification of mutacin-producer strains based on their bactericidal activity divides mutacins into four types, I, II, III and IV. The antimicrobial spectrum of mutacin IV is specifically against members of the mitis group of oral streptococci, while that of mutacins I, II and III is broader (Qi et al, 1999a(Qi et al, , b, 2001.…”

Plausible Drug Targets in the Streptococcus mutans Quorum Sensing Pathways to Combat Dental Biofilms and Associated Risks

“…Streptococcus mutans mediated dental caries is a multifactorial disease are being ignored due to its non-life threatening nature [62,63]. An unknown fact exists as the inflammation process takes its pace slowly and gradually, it would act as a 'silent killer' for the patients suffering from dental caries.…”