RESUMEN
OBJECTIVES: Our aim was to investigate the effect of short-term xylitol consumption on the microbial composition of plaque and saliva. METHODS: Twelve volunteers (22-38 yrs) harboring mutans streptococci (MS) participated in the randomized, double-blind, cross-over study. The experimental chewing gum contained 65% xylitol while the control gum contained 63% sorbitol and 2% maltitol w/w. The polyol dose was approximately 6 g/day. Stimulated saliva and plaque samples were collected before and after the two four-week test periods. The samples were cultured for MS, total streptococci, lactobacilli, and total facultatives. A part of the samples were subjected to DNA-DNA hybridizations of 14 microbial plaque species: Actinomyces naeslundii, A. viscosus, Fusobacterium nucleatum, Lactobacillus acidophilus, L. fermentum, L. paracasei, L. rhamnose, L. plantarum, Streptococcus gordonii, S. oralis, S. parasanguis, S. salivarius, S. sanguinis, Veillonella parvula. RESULTS: The MS counts of the plaque samples collected from "caries-prone" tooth sites decreased significantly (P<.01) in the xylitol gum group but not in the sorbitol gum group. Also the plaque MS percentage decreased significantly in the xylitol gum group (P<.01). The salivary MS counts did not decrease either in the xylitol or in the sorbitol gum groups. Nor were changes detected in the salivary levels of total streptococci or lactobacilli. The DNA-DNA hybridization assay revealed no study-induced changes in the microbial composition of the dental plaque. CONCLUSIONS: Within the limitations of this pilot study, xylitol consumption reduced MS counts in plaque but appeared not to affect the microbial composition of plaque or saliva in general.
RESUMEN
PURPOSE: The purpose of this study was to examine the effects of xylitol gum (XG) on the acquisition pattern of 39 bacterial species, including mutans streptococci (MS), in infants. METHODS: Ninety-seven mothers (MS counts > 10(5) CFU/ml) were randomly divided into 4 groups and received: (1) XG (4.2 gm/day); (2) XG (6 months after baseline exams); (3) sorbitol gum (4.2 gm/day); or (4) no gum. Groups 1 and 3 chewed gum 3 times a day for 9 months. Microbiota of plaque and saliva samples from the mother-child pairs were analyzed by culturing and via checkerboard DNA-DNA hybridization. RESULTS: MS was isolated from 33% of the predentate infant (< or =5 months old) baseline saliva samples and from 41% of the saliva and 65% of the plaque samples at the final visit. At baseline, positive responses to "mother's checking of baby's food temperature using baby's spoon" and "starting a bottle after stopping breast-feeding" were significant predictors (P = .009 and P < .001, respectively) of infant's total streptococci counts. At the final visit (9 months later), there were no significant differences between treatment groups for infants' 39 microbial plaque species, including MS. CONCLUSIONS: Maternal use of xylitol gum did not result in statistically significant differences in the microbial plaque composition of 9- to 14-month-old infants.
Asunto(s)
Cariostáticos/uso terapéutico , Goma de Mascar , Caries Dental/microbiología , Edulcorantes/uso terapéutico , Adulto , Bacterias/clasificación , Alimentación con Biberón , Recuento de Colonia Microbiana , Utensilios de Comida y Culinaria , Índice CPO , ADN Bacteriano/análisis , Placa Dental/microbiología , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Hibridación de Ácido Nucleico , Placebos , Saliva/microbiología , Método Simple Ciego , Sorbitol/uso terapéutico , Streptococcus mutans/aislamiento & purificación , Streptococcus sobrinus/aislamiento & purificación , Xilitol/uso terapéuticoRESUMEN
Allelic replacement of the C terminus of a Streptococcus mutans surface protein affects murein hydrolase activity. The targeted open reading frame encodes a 67-kDa protein (SmaA) with an N-terminal signal sequence and cleavage site, three 46-amino-acid (aa) direct repeats, and two 88-aa direct repeats. The identical autolytic profile was obtained using a sortase mutant (SrtA(-)).
Asunto(s)
N-Acetil Muramoil-L-Alanina Amidasa/genética , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Streptococcus mutans/enzimología , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Datos de Secuencia Molecular , Peso Molecular , Mutagénesis Insercional , Sistemas de Lectura Abierta/genética , Peptidoglicano/metabolismo , Señales de Clasificación de Proteína/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Eliminación de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis identified enolase as a cell surface component of Streptococcus mutans, which was confirmed by enzyme-linked immunosorbent assay, Western blotting, and transmission electron microscopy. Surface enolase was demonstrated to bind to human plasminogen and salivary mucin MG2. The results suggested a role for enolase in S. mutans attachment, clearance, or breach of the bloodstream barrier.