Colonization of mutans streptococci in 8- to 15-month-old children

OBJECTIVE: The age at which a child becomes colonized with mutans streptococci (MS) is important for understanding early childhood caries. The aim of this study was to explore the relationship of age with MS colonization in infants. METHODS: Inner-city children (n = 149) between the ages of 8 months and 15 months, inclusive, who reportedly were still using a baby bottle, were sampled for MS. RESULTS: Evidence of MS colonization was seen as early at 10 months of age. For children 12 months old or younger (n = 80), 25 percent had detectable levels of MS; in the 15-month age group, 60 percent were colonized. CONCLUSION: This study suggests that prevention of MS colonization in some populations may need to be initiated prior to the child's first birthday.     

变形链球菌在牙齿表面定植与婴幼儿年龄变化关系的研究

目的了解变形链球菌在婴幼儿牙面上的定植时间。方法本研究调查了变形链球菌在婴幼儿牙面上定植的时间,选取8～30个月的婴幼儿116名,并对其中11名婴儿进行了跟踪检查。结果变形链球菌可在10个月婴儿的牙面定植,12个月以内的婴儿定植率为16.67%,16～18个月幼儿为56.5%,19～24个月的为63.6%,30个月时达70.0%。在牙面有MS定植的儿童中,50.8%儿童MS的检出时间是在13～24个月。对11名婴儿跟踪调查,发现在12个月后有7名儿童牙面MS检查由阴性转成阳性,占63.6%,感染时间平均为18.71±3.58个月。结论在本研究中婴幼儿感染MS的时间较早,预防龋病的发生和MS的定植应从婴儿牙齿萌出时开始。     

Transmission of mutans streptococci in adults within a Chinese population

The purpose of this study was to investigate whether there was transmission between adults in Chinese families using chromosomal DNA fingerprinting. Plaque samples were obtained from buccal and occlusal surfaces of 11 married couples. The colonization levels of mutans streptococci were estimated as colony-forming units per milliliter, and caries experience was scored by decayed, missing and filled teeth. Information about medical history, diet regimes and age at marriage was obtained. The isolates were serotyped by biochemical test and genotyped using the restriction endonuclease HaeIII. The procedure was repeated after 3 months. The results showed that 1 couple had the same genotype of mutans streptococcus at the first examination, but this could not be repeated for the husband who had lost his mutans streptococci at the second examination. On the contrary, another couple that did not have the same mutans streptococcal genotype at the beginning had the same genotype after 3 months. No matching of genotypes was observed within 8 couples. In 1 male, no mutans streptococci were detected, therefore that couple was not considered. These data indicate that spouses had a chance to be infected by strains of mutans streptococci from another person. The results suggest that there may be transmission between adults in Chinese families, but it may be difficult for mutans streptococci to colonize another mouth permanently.     

Prevalence of mutans streptococci in one-year-old children

Colonization with mutans streptococci was studied in 1095 1-year-old children living in suburban Stockholm. During a scheduled vaccination appointment at a child health centre, a bacterial sample was obtained from the child's tongue and a structured questionnaire was completed by the accompanying parent. Six percent of the subjects were colonized with mutans streptococci. The variables most strongly correlated with presence of mutans streptococci were: non-Swedish background, consumption of sugar-containing beverages at night and total consumption of sugar-containing beverages. The results indicate that, by the age of 1 year, maternally influenced behaviour patterns such as dietary habits that may predispose to early colonization of mutans streptococci are already established. Such early colonization with mutans streptococci may predict high caries risk in the primary dentition.     

Antibody responses to mutans streptococci in children.

Because mutans streptococci (Streptococcus mutans, S. sobrinus) are considered the main causative bacteria in human dental caries, immune responses to these bacteria have aroused much research interest over the last two decades. Studies in man have focused mainly on salivary and serum antibodies developing naturally in response to oral colonization by mutans streptococci, or in relation to the development of dental caries. Although both salivary (IgA) and serum-derived (IgG) antibodies have been shown in many studies to protect against the adherence of and to interfere with the metabolism of mutans streptococci, no conclusive evidence relating to their clinical significance is available. In young children, serum IgG antibodies to S. mutans seem more important than salivary IgA antibodies in relation to protection against dental caries. In studies in animals and, recently, in man, monoclonal IgG antibodies to S. mutans protein antigen I/II ("adhesin") have provided effective protection against mutans streptococci. Whether they could also prevent dental caries in man is not yet known.     

奶瓶龋儿童口腔变链菌的研究

目的：研究儿童口腔内的变链菌基因型与奶瓶龋易感性的关系。方法：取20名奶瓶龋及20名无龋儿童牙菌斑及唾液接种于TYCSB培养基计数并筛选MS,采用AP－PCR法鉴定变链菌基因型。结果：奶瓶龋组儿童唾液及菌斑变链菌计数高于无龋组;并且有两种以上基因型变链菌的比例也高于对照组（14／20vs 5/20)。结论：患有奶瓶龋的儿童不仅变链菌计数高,而且多数被两个以上基因型的MS感染。     

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus, are generally considered to be the principal microbial pathogen of dental caries. The objective of the study was to isolate S. mutans and S. sobrinus, identify them by PCR, and to compare their presence with the caries status and caries risk in Mongolian preschool and school children. Forty one preschool children aged 3–5 years and 40 school children aged 12–15 years were enrolled in this study. As assessed using Cariostat test, 75.6% of preschool children had high caries risk and 37.5% of school children had high caries risk. In preschool children, the prevalence of S. mutans and S. sobrinus were 100% and 36.6%, respectively; 63.4% were positive for S. mutans alone and 36.6% were positive for both S. mutans and S. sobrinus. In school children, the prevalence of S. mutans and S. sobrinus were 100% and 25.0%, respectively; 75.0% carried S. mutans alone and 25.0% had both S. mutans and S. sobrinus. The percentage of children positive for both S. mutans and S. sobrinus in the high caries risk group were significantly higher than those in the low risk group of either preschool (42.0% vs. 10.0%, P< 0.001) or school children (46.6% vs. 12.0%, P<0.001). Moreover, the caries status of children positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone (P< 0.01 for preschool children, and P< 0.05 for school children).     

Colonization of rat molar teeth by mutans streptococci with different salivary agglutination characteristics

The oral implantation of salivary agglutination-positive and -negative mutans streptococci was studied using streptomycin resistant (StrR) organisms. StrR Streptococcus mutans strains Ingbritt and NCTC 10449 are agglutinated by rat saliva and the StrR strains Streptococcus sobrinus 6715-13 and Strep. mutans GS5 are not. Four groups of Sprague-Dawley rats were inoculated orally with each organism (one per group) and fed a sucrose diet. A further two groups of animals were similarly inoculated with either the agglutination-positive Strep. mutans Ingbritt or the agglutination-negative Strep. sobrinus 6715-13 and fed a glucose diet. StrR streptococci were recovered from smooth-surface dental plaque of all animals on the sucrose diet with no significant difference in the recovery of agglutination-positive Strep. mutans strains Ingbritt and NCTC 10449 and agglutination-negative Strep. mutans GS5. However, the recovery of agglutination-negative Strep. sobrinus 6715-13 from smooth-surface plaque of animals on either the sucrose or the glucose diets was significantly lower than that of the other strains. Agglutination-positive Strep. mutans Ingbritt colonized smooth enamel surfaces of animals on the sucrose and the glucose diets in numbers that were not significantly different. However, the colonization of such surfaces by agglutination-negative Strep. sobrinus 6715-13 was significantly enhanced by the sucrose diet. Agglutination-positive and -negative StrR mutans streptococci were recovered from fissure plaque of all inoculated sucrose-fed animals in numbers that were not significantly different. Successful colonization of smooth enamel surfaces by the StrR streptococci resulted in increased smooth-surface caries.(ABSTRACT TRUNCATED AT 250 WORDS)     

猛性龋儿童变链菌分离株耐酸性实验研究

目的 :确定猛性龋儿童变链菌和远缘链球菌临床株的耐酸性。方法 :采用紫外分光光度计比较猛性龋、非猛性龋、无龋儿童变链菌 (各 6株 )和远缘链球菌 (猛性龋儿童 6株 ,非猛性龋和无龋儿童各 3株 )临床株在体外不同初始 pH条件下的生长情况。 结果 :初始 pH 4.5～ 5 .5条件下 ,各组变链菌生长抑制程度均明显大于远缘链球菌(P <0 .0 5 )。初始pH 4.5条件下 ,猛性龋儿童远缘链球菌分离株耐酸性明显强于非猛性龋和无龋儿童分离菌株(P <0 .0 5 )。结论 :远缘链球菌的耐酸性强于变链菌 ;猛性龋儿童远缘链球菌分离株耐酸性强     

Colonization by mutans streptococci in the mouths of 3- and 4-year-old Chinese children with or without enamel hypoplasia

This case-control study compared the prevalence and concentration of mutans streptococci (MS) in saliva between children with and without enamel hypoplasia (EHP). A total of 486 3- or 4-year-old Chinese children were initially screened for EHP, then distributed into two groups: 234 children diagnosed as having EHP were assigned to the case group; 252 who were free of EHP were included in the control group. The concentration of MS in saliva was assayed for each child. Nutritional status was deduced from body height and weight. Birth weight, prematurity, and nursing history were also determined. MS were found in 94.7% of the study population. The differences in MS concentrations were not associated with low birth weight, prematurity, length of breast feeding, or body height and weight. A statistically significant association existed between the presence of EHP and high counts of MS (p < 0.001). High MS counts were correlated with severity of enamel defects (p < 0.001). When the caries status of the children was controlled as the confounding factor in statistical analyses, the association between EHP and MS decreased but still remained significant (p = 0.025). This study shows that high MS counts are correlated with EHP, suggesting that irregularities in enamel surfaces could be a contributing factor that fosters the increased colonization of MS in the mouths of children.     

Association of mutans streptococci between caregivers and their children

The purposes of this literature review were to: (1) review the sources of mutans streptococci (MS) colonization in children and the effect of MS levels of primary caregivers on children's MS colonization; and (2) evaluate studies examining interventions to reduce transmission of MS from caregivers to their children. Forty-six studies were reviewed. Strong evidence demonstrated that mothers are a primary source of MS colonization of their children. A few investigations showed other potential sources of children's MS colonization, notably fathers. The role of other factors influencing transmission, such as socioeconomic status (SES) and specific cultural or behavioral practices, are unclear. There were at least 12 reports of microbiological interventions to reduce transmission of MS from caregivers to their children. Even though most studies found a reduction of MS in the children and 2 showed significant caries reduction, these studies generally lock consistent findings regarding caries reduction, hove a small sample size and inadequate control groups, and lock blindness of investigators and subjects. The efficacy of microbiological approaches on the caregivers to reduce caries risk in children still needs to be established through more rigorously designed clinical trials.     

Factors influencing oral colonization of mutans streptococci in young children

This paper aims to critically review current knowledge about the key factors involved in oral colonization of the cariogenic group of bacteria, mutans streptococci (MS) in young children. MS, consisting mainly of the species Streptococcus mutans and Streptococcus sobrinus, are commonly cultured from the mouths of infants, with prevalence of infection ranging from around 30 per cent in 3 month old predentate children to over 80 per cent in 24 month old children with primary teeth. MS is usually transmitted to children through their mothers, and the risk of transmission increases with high maternal salivary levels of MS and frequent inoculation. Factors that affect the colonization of MS may be divided into bacterial virulence, host-related and environmental factors. Complex interaction among these factors determine the success and timing of MS colonization in the child. As clinical studies have shown that caries risk is correlated with age at which initial MS colonization occurred, strategies for the prevention of dental caries should include timely control of colonization of the cariogenic bacteria in the mouths of young children.     

Characterization of maternal mutans streptococci transmission in an African American population

In the current literature database, information on microbiological attributes to caries outcomes in African American populations is limited and scattered. Few reports have discussed MS infection and transmission from African American mothers to their children. During the past few years, the research group at the University of Alabama at Birmingham and the Jefferson County Pubic Health Department have done a series of extensive studies to systematically investigate the prevalence of MS colonization, the time of initial MS infection as defined as "the window of infectivity," the source of MS transmission as defined as "the fidelity of transmission, and the chemotherapeutic management of MS transmission and caries prevention. The objective of this report was to summarize the main significant findings generated during a period of 15 years of study. One limitation of the studies outlined in this article is that the research populations were predominately African American families. The inclusion of white and other minorities would make the conclusions more generalizable to the US population as a whole. Nevertheless, the information presented in this report can serve as baseline knowledge for future studies of caries etiology in African American and other ethnic populations.     

Salivary mutans streptococci and dental caries patterns in pre-school children

Abstract Recent studies have suggested that the identification of caries as discrete patterns may be valuable in describing and predicting caries experience on an individual basis. The purpose of this study was to assess the association between levels of salivary mutans streptococci and the prevalence, incidence and distribution of caries patterns in the primary dentition. A cohort of pre-school children (n=146, mean age 3.8 yr) were examined for dental caries and sampled for salivary mutans streptococci (SMS) at baseline and once annually for 2 yr. Children's tooth surfaces were categorized into four patterns: pit/fissure, maxillary anterior, posterior proximal, and buccal/lingual smooth surface. Salivary mutans streptococci were enumerated using a tongue blade technique, and were categorized as low (0 CPU), moderate (1–50 CPU) and high (>50 CPU). At year 2, children with high baseline SMS had the 1) highest prevalence of caries (87%) and the highest dmfs (9.15); 2) highest prevalence of each pattern, and 3) greatest number of patterns. Among children with the pit/fissure pattern, those with high baseline SMS had the greatest pit/fissure dmfs after 2 yr. Results show that baseline SMS levels were associated with both cross-sectional and longitudinal caries experience, numbers of caries patterns, and the prevalence and severity of those patterns.     

A simple method for monitoring mutans streptococci in young children

The study assessed the practicability of the Dentocult-SM® STRIP MUTANS test in children, using dental floss to transfer the denial plaque to the strip. The subjects were children of 2–3 yr ( n = 365) and 5–6 yr ( n = 398). The rnutans streptocci count on the strip was found to be a good Indicator of infection and was surprisingly accurate in the prediction of the 3-yr caries increment.     

Salivary antimicrobial proteins and mutans streptococci in tonsillectomized children.

Whole saliva from 53 children who had been tonsillectomized when they were younger than 4 years old was analyzed for selected antimicrobial proteins and oral mutans streptococci 3-4 years after the operation. The results were compared with those from age- and gender-matched control children with no history of tonsillectomy. The salivary analyses comprised both immune (total IgA, IgG and IgM) and selected nonimmune (lactoferrin, myeloperoxidase, salivary peroxidase) antimicrobial proteins. Specific IgA and IgG antibodies against viral antigens (adeno-, cytomegalo-, respiratory syncytial- and Epstein-Barr-viruses) and against Streptococcus mutans cells were quantitated in both groups. The tonsillectomized children had statistically significantly higher concentrations of all immunoglobulin isotypes (P 0.001) as well as of lactoferrin (P less than 0.005), and myeloperoxidase (P less than 0.001) in saliva. However, no differences were found in the numbers of cariogenic mutans streptococci or in the total oral aerobic flora. In line with the streptococcal counts, no differences existed in anti-S. mutans IgA or IgG titers between the groups. Most antibodies against viruses, especially of IgG isotype, were significantly (P less than 0.001) higher in saliva of tonsillectomized children than in that of the controls. The results suggest that, within a long run, the humoral immune status of human saliva is not weakened by tonsillectomy. Also, mainly serum-derived antimicrobial proteins (myeloperoxidase, lactoferrin, IgG) exist in high concentrations in whole saliva after tonsillectomy.     

High prevalence of mutans streptococci in a population with extremely low prevalence of dental caries

The quantitative distribution of the mutans streptococci was investigated in populations with very low caries prevalence. Three hundred and seven school children from rural Sudan with an estimated age of 12 years were examined for dental status and salivary mutans streptococci. Forty-two isolates from the salivary cultures were determined to species level by studying the serogroup and biotype. Denial caries in permanent teeth was diagnosed in 12% of the children and the mean DMFT was 0.17 (range 0-6 DMFT). Caries was confined to fissures. Mutans streptococci were found in 96% of the children and high counts were obtained in 45%. Of 42 isolated strains, 37 belonged to Streptococcus mutans , 5 to Streptococcus sobrinus and none to Streptococcus rattus. The observations show that the mutans streptococci can be widespread in human populations with extremely low prevalence of dental caries and consequently that these bacteria may be readily propagated in human populations without association to a caries-promoting life style.     

Hydrophobicity test in mutans streptococci

Kinetic hydrophobic measurements were performed by confronting 40 mutans streptococci from thirty 10- to 20-year-old patients with 200 ml hexadecane (Sigma). Fourteen patients had high dental caries risk (Group A), dmft + DMFT > 5 with 3 or more active caries, and 16 had low dental caries risk (Group B), dmft + DMFT < 3 without active caries. Twenty bacteria from Group A and 20 bacteria from Group B were typed using De La Higuera's procedure and confirmed by API strip (bio-Merieux). From the 14 patients in Group A we obtained 12 S. mutans (8 hydrophobic/4 non-hydrophobic), 5 S. sobrinus (4 hydrophobic/1 non-hydrophobic) and 3 S. rattus (hydrophobic). From the 16 patients in Group B we obtained 11 Streptococcus mutans (10 non-hydrophobic/1 hydrophobic), 7 Streptococcus sobrinus (6 non-hydrophobic/ 1 hydrophobic) and 2 Streptococcus rattus (hydrophobic). Patients with high dental caries risk have a higher prevalence of hydrophobic bacteria than patients with low dental caries risk (p = 0.0003). All typed S. rattus were hydrophobic.