Pioneer oral bacteria, including Streptococcus gordonii , initiate the formation of oral biofilms on tooth surfaces, which requires differential expression of genes that recognize unique environmental cues. An S. gordonii ::Tn 917-lac... more
Pioneer oral bacteria, including Streptococcus gordonii , initiate the formation of oral biofilms on tooth surfaces, which requires differential expression of genes that recognize unique environmental cues. An S. gordonii ::Tn 917-lac biofilm-defective mutant was isolated by using an in vitro biofilm formation assay. Subsequent inverse PCR and sequence analyses identified the transposon insertion to be near the 3′ end of an open reading frame (ORF) encoding a protein homologous to a Streptococcus pneumoniae repressor, AdcR. The S. gordonii adc operon, consisting of the four ORFs adcR , adcC , adcB , and adcA , is homologous to the adc operon of S. pneumoniae , which plays a role in zinc and/or manganese transport and genetic competence in S. pneumoniae . AdcR is a metal-dependent repressor protein containing a putative metal-binding site, AdcC contains a consensus-binding site for ATP, AdcB is a hydrophobic protein with seven hydrophobic membrane-spanning regions, and AdcA is a lipo...
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Veillonella spp. are found in high numbers in the mouth in dental plaque and on the mucosa. Veillonellae utilize lactic acid for their metabolic needs. A symbiotic relationship between Veillonellae and other oral bacteria, including a... more
Veillonella spp. are found in high numbers in the mouth in dental plaque and on the mucosa. Veillonellae utilize lactic acid for their metabolic needs. A symbiotic relationship between Veillonellae and other oral bacteria, including a nutritional relationship with some streptococci, has been demonstrated both in vitro and in vivo. Thus, Veillonellae may protect the host from dental caries. Adherence is the initial step in bacterial colonization of oral surfaces. Recent evidence suggests that certain oral bacteria express molecules (adhesins) on their cell surface, which recognize receptors on other oral bacteria and/or in salivary pellicle. It has been previously demonstrated that Veillonella spp. bind avidly to Streptococcus. spp. found in subgingival plaque. The present study investigated the ability of V. atypica PK1910 to bind to saliva-coated hydroxyapatite (SHA), a model for adherence to the salivary pellicle. The results show that there was statistically significant enhanced ...
The primary habitats of oral veillonellae are the tongue, dental plaque, and the buccal mucosa. Isolates were obtained from each habitat and tested for coaggregation with a battery of other oral bacterial strains. All 59 tongue isolates... more
The primary habitats of oral veillonellae are the tongue, dental plaque, and the buccal mucosa. Isolates were obtained from each habitat and tested for coaggregation with a battery of other oral bacterial strains. All 59 tongue isolates tested for coaggregation were Veillonella atypica or Veillonella dispar. All but one of them coaggregated with strains of Streptococcus salivarius, a predominant inhabitant of the tongue surface but not subgingival dental plaque. These tongue isolates were unable to coaggregate with most normal members of the subgingival flora such as Actinomyces viscosus, Actinomyces naeslundii, Actinomyces israelii, and Streptococcus sanguis. In contrast, 24 of 29 Veillonella isolates, of which 20 were Veillonella parvula from subgingival dental plaque samples, coaggregated strongly with the three species of Actinomyces, S. sanguis, and other bacteria usually present in subgingival plaque, but they did not coaggregate with S. salivarius. The majority of isolates fr...
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Pediatric obesity is a public health concern requiring an interprofessional approach to care. Weight screening in the dental office can promote healthy behaviors to improve weight and oral health status and reduce systemic and oral health... more
Pediatric obesity is a public health concern requiring an interprofessional approach to care. Weight screening in the dental office can promote healthy behaviors to improve weight and oral health status and reduce systemic and oral health risks. Oral health care professionals can perform weight screenings quickly. Routine weight screening of pediatric patients and early intervention through education and referral of patients to a registered dietitian nutritionist and a physician for more in-depth evaluation may help reduce disease risk. Oral health care professionals can measure a patient's height and weight and can easily calculate body mass index percentile according to a patient's age and sex to detect weight status that does not fall within the normal range. Oral health care professionals should refer patients who are underweight, overweight, or obese to a registered dietitian nutritionist and the patient's physician for follow-up.
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The objective of this study was to evaluate reported bruxism among children affected by attention deficit hyperactivity disorder (ADHD).Thirty children diagnosed with ADHD and 30 healthy age and gender matched controls participated in the... more
The objective of this study was to evaluate reported bruxism among children affected by attention deficit hyperactivity disorder (ADHD).Thirty children diagnosed with ADHD and 30 healthy age and gender matched controls participated in the study. All subjects were examined for dental attrition, and the parents were asked for signs and symptoms of bruxism in their children using a questionnaire. Prevalence of oral parafunction was evaluated comparing ADHD children taking medications, ADHD children not taking medications, and controls. Subjects affected by ADHD and pharmacologically treated showed higher occurrence of bruxism compared to subjects affected by ADHD not taking medicines and controls; and within the ADHD group taking medications, CNS-stimulants have been associated with such side effect more frequently than the other drugs.
Research Interests: Dentistry, Adolescent, Medicine, Humans, Child, and 15 moreFemale, Male, Regression Analysis, Attrition, Questionnaires, Analysis of Variance, Bruxism, Pilot Projects, Serotonin Uptake Inhibitors, Case Control Studies, Dopamine antagonists, Child preschool, Attention deficit disorder with hyperactivity, Attention deficit hyperactivity disorder, and Central nervous system stimulants
The recent availability of genome sequences for Veillonella species provides an exceptional opportunity to probe their biology and role in the microbial ecology of the mouth. The recent genome-scale stoichiometric model of Porphyromonas... more
The recent availability of genome sequences for Veillonella species provides an exceptional opportunity to probe their biology and role in the microbial ecology of the mouth. The recent genome-scale stoichiometric model of Porphyromonas gingivalis metabolic networks is an exceptional example of such an approach and illustrates the potential of advancements in genome sequencing and bioinformatic tools in studies of bacterial metabolism and ecology. Fifteen complete genomes, three metagenomes of TM7, and 38 genome surveys of oral isolates are available at the human oral microbiome database (HOMD). Seven Veillonella genomes are currently available as genome surveys at the HOMD. Almost 10% of the total cultivable biota from the tongue consists of Veillonellae. Veillonellae lack hexokinase activity but have other glycolytic enzymes. Veillonellae are also unable to incorporate radiolabeled glucose into bacterial cell compounds and seem to lack a glucose phosphotransferase system. The observations on the Veillonella physiology can now be confirmed and visualized in the carbohydrate metabolism glycolysis-gluconeogenesis pathway constructed with Veillonella parvula ATCC 10790 genome data. This chapter presents the genomic evidence for the presence of both nitrate reduction enzymes and membrane-bound proton-translocating ATPases. Interactions between Streptococcus spp. and Veillonella spp. naturally occur in vivo and emphasize the natural relationship of species in the development of biofilms. The availability of complete Veillonella genome sequences provides a unique opportunity for developing genetic systems for Veillonellae.
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The purpose of this study was to investigate the principal reason for primary tooth extraction and the tooth type most frequently extracted in children aged 3-13 years. The patients selected for this retrospective study were identified by... more
The purpose of this study was to investigate the principal reason for primary tooth extraction and the tooth type most frequently extracted in children aged 3-13 years. The patients selected for this retrospective study were identified by analyzing dental records of children receiving treatment at Franciscan Children's Hospital & Rehabilitation Center, Boston, MA (FCH & RC). In total, 2,000 records were reviewed, and 567 extracted primary teeth were analyzed from 277 patients who had at least one primary tooth extracted under local anesthesia. The criteria for inclusion in this study included children between the ages of 3 and 13 years. First primary molars were the most common tooth type extracted and comprised 30% of teeth removed. Central incisors were the next common tooth type extracted and accounted for 25% of the extractions. There was no difference, by gender, in the extraction of tooth type but there were striking differences according to age. Almost half of the primary...
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We tested culture supernatants from a battery of oral bacterial strains for their ability to influence the expression of CD11b and CD45 on the neutrophil plasma membrane. Several bacterial extracts stimulated the up-regulation of both... more
We tested culture supernatants from a battery of oral bacterial strains for their ability to influence the expression of CD11b and CD45 on the neutrophil plasma membrane. Several bacterial extracts stimulated the up-regulation of both CD11b and CD45 simultaneously. Two supernatants in particular (a clinical isolate of A. actinomycetemcomitans and F. nucleatum ATCC25586) potently stimulated the deployment of CD11b and CD45 from their intracellular storage site to the plasma membrane. Both supernatants inhibited superoxide release stimulated by exposure of neutrophils to formyl methionyl leucyl phenylalanine (FMLP) but had variable effects on superoxide release stimulated by phorbol myristate acetate (PMA). The ability of products of oral bacteria to modulate neutrophil plasma membrane antigen composition may regulate functional reactivity and thus be an important factor in the pathogenesis of periodontal infection and inflammation.
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The acronym CHARGE refers to a non-random clustering of congenital malformations whose cause remains unknown. To date, the dental features of CHARGE association are not well known. A brief review of the literature and a case in a 10-year... more
The acronym CHARGE refers to a non-random clustering of congenital malformations whose cause remains unknown. To date, the dental features of CHARGE association are not well known. A brief review of the literature and a case in a 10-year old boy with the CHARGE association are presented. The patient had multiple dental anomalies including congenital absence of teeth, ectopic eruption, submergence of primary molars and an odontogenic fibroma associated with an impacted permanent molar.
Research Interests: Dentistry, Intellectual Disability, Medicine, Congenital Heart Defects, Humans, and 14 moreChild, Pubmed, Male, Dental anomalies, Pediatric dentistry, Odontogenic, Pediatric Dentistry, Syndrome, Choanal atresia, Congenital Malformations, Tooth abnormalities, Molar, Paediatrics and reproductive medicine, and Mandibular neoplasms
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The placement of orthodontic appliances creates a favorable environment for the accumulation of a microbiota and food residues, which, in time, may cause caries or exacerbate any pre-existing periodontal disease. The purpose of the... more
The placement of orthodontic appliances creates a favorable environment for the accumulation of a microbiota and food residues, which, in time, may cause caries or exacerbate any pre-existing periodontal disease. The purpose of the present study was to compare the total bacterial counts present on metallic and ceramic orthodontic brackets in order to clarify which bracket type has a higher plaque retaining capacity and to determine the levels of Streptococcus mutans and Lactobacillus spp on both types of brackets. Thirty-two metallic brackets and 24 ceramic brackets were collected from orthodontic patients at the day of debonding. Two brackets were collected from each patient; one from a maxillary central incisor and another from a maxillary second premolar. Sixteen patients who used metallic brackets and 12 patients who used ceramic brackets were sampled. Bacterial populations were studied using "checkerboard" DNA-DNA hybridization, which uses DNA probes to identify speci...
Research Interests: Dentistry, Medicine, Ceramics, Humans, Campylobacter, and 15 morePubmed, Lactobacillus, Bacteria, Orthodontic Brackets, Incisor, Surface Properties, Dental Plaque, Streptococcus, Eikenella corrodens, Streptococcus mutans, Dental Alloys, Bracket, DNA probes, Aggregatibacter actinomycetemcomitans, and Bicuspid
The purpose of this study was to examine factors associated with early childhood caries (ECC) and to develop a profile of risk factors for Hispanic families affected by this condition. Sixty Hispanic families with at least 1 child... more
The purpose of this study was to examine factors associated with early childhood caries (ECC) and to develop a profile of risk factors for Hispanic families affected by this condition. Sixty Hispanic families with at least 1 child affected by ECC and 60 Hispanic families without any affected children were included in the study. Data was collected using a parent-completed questionnaire which gathered information about family demographics, dental care and hygiene practices, and feeding practices of the children. Parents in families without ECC were significantly more likely to have visited the dentist recently and the children were less likely to sleep while feeding compared to families with an ECC-affected child. Within families affected by ECC, siblings with ECC were significantly more likely to use the bottle and to sleep while feeding compared with their siblings without ECC. Fifty-five percent of the subject families had more than 1 child affected by ECC. However, odds ratios did...
Research Interests: Dentistry, Fathers, Medicine, Humans, Dental Caries, and 15 moreInfant, Bottle Feeding, Medicaid, Boston, Oral Hygiene, Odds ratio, Breast feeding, Dental Care, Educational Status, Early Childhood Caries, Chi Square Distribution, Logistic Models, Case Control Studies, Child preschool, and Paediatrics and reproductive medicine
Severe early childhood caries (ECC) results from bacterial acid production in an acidic environment. The purpose of this study was to determine Streptococcus mutans, Streptococcus sobrinus, and acid-tolerant counts in severe early... more
Severe early childhood caries (ECC) results from bacterial acid production in an acidic environment. The purpose of this study was to determine Streptococcus mutans, Streptococcus sobrinus, and acid-tolerant counts in severe early childhood caries. Two- to 6-year-olds with severe-ECC (N=77) or who were caries-free (N=40) were examined. Plaque samples from teeth and the tongue were cultured anaerobically on blood, acid, and S. mutans selective agars. Severe-ECC children were monitored post-treatment for recurrent caries. Severe-ECC and caries-free children were balanced by household income and education level. Carious lesions were observed in 75% maxillary incisors and >80% molars in severe-ECC. At baseline, S. mutans, and S. sobrinus counts and proportions of S mutans were higher in severe-ECC than caries-free children. Acid and blood counts were elevated only in anterior samples of severe-ECC children. Baseline counts of S. sobrinus, but not S. mutans, were higher in children wi...
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Background. Autism spectrum disorder (ASD) is a neurodevelopmental disorder categorized into autism, pervasive developmental disorder – not otherwise specified (PDD‐NOS) and Asperger syndrome.Aims. To identify factors associated with... more
Background. Autism spectrum disorder (ASD) is a neurodevelopmental disorder categorized into autism, pervasive developmental disorder – not otherwise specified (PDD‐NOS) and Asperger syndrome.Aims. To identify factors associated with the behaviour of patients with ASD in a dental setting, use of general anaesthesia (GA), and protective stabilization.Design. The dental charts of 395 patients with ASD patients and 386 unaffected patients were reviewed. The following data were analysed: ASD diagnosis, age, gender, residence, seizure disorder, additional diagnosis (mental retardation, cerebral palsy, self‐injurious behaviour or pica), medications, caries prevalence and severity, dental treatment history, behaviour, and behaviour guidance technique(s) used.Results. Within both groups, younger patients were more uncooperative. ASD patients with autism were more uncooperative than patients with PDD‐NOS; patients with an additional diagnosis were also more uncooperative. ASD patients wi...
Research Interests: Dentistry, Autism, Adolescent, Medicine, Humans, and 15 moreChild, Female, Dental Caries, Male, Dental Local Anesthesia, Autism Spectrum Disorder, General Anesthesia, Adult, Logistic Models, Behavior Control, Conscious Sedation, Case Control Studies, Child preschool, Child behavior disorders, and DMF index
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Screening a genomic library of Tannerella forsythensis (Bacteroides forsythus), using synthetic substrates conjugated to a fluorogen, 4‐methylumbelliferone identified two glycosidase genes, which encode α‐d‐glucosidase and... more
Screening a genomic library of Tannerella forsythensis (Bacteroides forsythus), using synthetic substrates conjugated to a fluorogen, 4‐methylumbelliferone identified two glycosidase genes, which encode α‐d‐glucosidase and N‐acetyl‐β‐d‐glucosaminidase, respectively. The α‐d‐glucosidase has a Mr of 81,141 and is homologous to an α‐d‐glucosidase from Bacteroidesthetaiotaomicron. The N‐acetyl‐β‐d‐glucosaminidase has a Mr of 87,787 and is homologous to an N‐acetyl‐β‐d‐glucosaminidase in Porphyromonasgingivalis W83.
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Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder. The authors conducted a study to evaluate the demographics, caries experience and behavior of patients with ASD and compare these characteristics with those of... more
Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder. The authors conducted a study to evaluate the demographics, caries experience and behavior of patients with ASD and compare these characteristics with those of patients without ASD (unaffected patients). The authors reviewed patients' charts and identified a group of 395 patients with ASD and a group of 386 unaffected patients. They obtained the following patient data for analysis: primary diagnosis, age, sex, residence (home versus institution or group home), presence of seizure disorder, additional diagnosis (mental retardation, cerebral palsy, self-injurious behavior or pica), medications, caries prevalence, caries severity and behavior. The ASD group had a male:female ratio of 4:1, and patients had a diagnosis of autism, pervasive developmental disorder-not otherwise specified or Asperger syndrome. Sex distribution was equal in the unaffected group, which was younger and had a higher decayed, missing and filled teeth (DMFT) score than did the ASD group. When the authors controlled for age and sex, they noted a statistically significant association between ASD and dental caries prevalence. A significantly higher percentage of patients with ASD than unaffected patients were uncooperative and required dental treatment to take place under general anesthesia. Caries prevalence and severity in patients with ASD were not associated with institutionalization, presence of seizure disorder or additional diagnosis. People with ASD were more likely to be caries-free and had lower DMFT scores than did their unaffected peers. Significantly more patients with ASD than unaffected patients were uncooperative and required general anesthesia to undergo dental treatment.
Research Interests: Dentistry, Nonparametric Statistics, Cerebral Palsy, Adolescent, Medicine, and 15 moreChild Behavior, Humans, Child, Oral health, Female, Dental Caries, Male, Dental Local Anesthesia, Autism Spectrum Disorder, Asperger Syndrome, Cross Sectional Studies, Case Control Studies, Autistic disorder, Child preschool, and DMF index
The presence of Chlamydia trachomatis has been previously shown in the temporomandibular joint (TMJ). This study investigated whether the presence of other bacteria associated with reactive arthritis (ReA) can be identified in the TMJ.... more
The presence of Chlamydia trachomatis has been previously shown in the temporomandibular joint (TMJ). This study investigated whether the presence of other bacteria associated with reactive arthritis (ReA) can be identified in the TMJ. Posterior bilaminar tissue removed during TMJ surgery from 26 patients (24 F, 2 M) was evaluated for the presence of C. trachomatis, Mycoplasma fermentans, Mycoplasma genitalium, Campylobacter jejuni, Yersinia enterocolitica, Salmonella spp, and Shigella spp by highly specific polymerase chain reaction (PCR) assays. Bacterial DNA was identified in the TMJ as follows: C. trachomatis, 11 of 26 (42%); M. fermentans/orale, 6 of 26 (23%); M. genitalium, 9 of 26 (35%). Nine of 26 TMJs (35%) had the presence of a single bacterial species. Eight of 26 TMJs (31%) had more than 1 species, as follows: C. trachomatis with either M. genitalium or M. fermentans/orale in 5 of 26 (19%), M. fermentans/orale with M. genitalium 2 of 26 (8%), and C. trachomatis/M. fermentans/orale/M. genitalium, 1 of 26 (4%). A total of 17 of 26 (65%) of TMJs had the presence of bacteria identified in the TMJ. Campylobacter jejuni, Y. enterocolitica, Salmonella spp, and Shigella spp were not identified in any samples. The presence of M. genitalium in the human TMJ has not been previously reported. The presence of bacteria in the TMJ, either singly or concurrently with other bacteria, may serve as the pathogenetic mechanism of TMJ inflammation. The presence of 2 bacteria from the urogenital tract in the TMJ suggests that internal derangement of the TMJ may occur as a result of a sexually acquired infection.
Research Interests: Microbiology, Dentistry, Adolescent, Medicine, Chlamydia trachomatis, and 15 moreOral and Maxillofacial Surgery, Humans, Mycobacterium, Female, Male, Bacteria, Polymerase Chain Reaction, Enterobacteriaceae, Middle Aged, Mycoplasma Genitalium, Adult, Arthritis Reactive, Campylobacter jejuni, Salmonella spp, and Reactive Arthritis
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Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity,... more
Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity, would differentiate severe ECC (S-ECC) from caries-free children. Children’s diets were obtained by survey and plaque bacteria detected by PCR from 72 S-ECC and 38 caries-free children. S-ECC children had higher scores for between-meal juice (p < 0.01), solid-retentive foods (p < 0.001), eating frequency (p < 0.005), and estimated food cariogenicity (p < 0.0001) than caries-free children. S-ECC children with lesion recurrence ate fewer putative caries-protective foods than children without new lesions. Streptococcus mutans (p < 0.005), Streptococcus sobrinus (p < 0.005), and Bifidobacteria (p < 0.0001) were associated with S-ECC, and S. mutans with S. sobrinus was associated with lesion recurrence (p < 0.05). S. mutans-positive ...
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Severe early childhood caries (ECC) is difficult to treat successfully. This study aimed to characterize the microbiota of severe ECC and evaluate whether baseline or follow-up microbiotas are associated with new lesions post-treatment.... more
Severe early childhood caries (ECC) is difficult to treat successfully. This study aimed to characterize the microbiota of severe ECC and evaluate whether baseline or follow-up microbiotas are associated with new lesions post-treatment. Plaque samples from 2- to 6-year-old children were analyzed by a 16S rRNA-based microarray and by PCR for selected taxa. Severe-ECC children were monitored for 12 months post-therapy. By microarray, species associated with severe-ECC (n = 53) compared with caries-free (n = 32) children included Slackia exigua (p = 0.002), Streptococcus parasanguinis (p = 0.013), and Prevotella species (p < 0.02). By PCR, severe-ECC-associated taxa included Bifidobacteriaceae (p < 0.001), Scardovia wiggsiae (p = 0.003), Streptococcus mutans with bifidobacteria (p < 0.001), and S. mutans with S. wiggsiae (p = 0.001). In follow-up, children without new lesions (n = 36) showed lower detection of taxa including S. mutans, changes not observed in children with fol...
Research Interests: Dentistry, Microbial Ecology, Biology, Medicine, Humans, and 15 moreChild, Dental Caries, Polymerase Chain Reaction, Dental, Recurrence, Gram Positive Bacteria, Pediatric dentistry, Dental Plaque, Early Childhood Caries, Pediatric Dentistry, Streptococcus mutans, Bifidobacterium, Partial Least Square, Case Control Studies, and Child preschool
Severe early childhood caries (ECC), while strongly associated with Streptococcus mutans using selective detection (culture, PCR), has also been associated with a widely diverse microbiota using molecular cloning approaches. The aim of... more
Severe early childhood caries (ECC), while strongly associated with Streptococcus mutans using selective detection (culture, PCR), has also been associated with a widely diverse microbiota using molecular cloning approaches. The aim of this study was to evaluate the microbiota of severe ECC using anaerobic culture. The microbial composition of dental plaque from 42 severe ECC children was compared with that of 40 caries-free children. Bacterial samples were cultured anaerobically on blood and acid (pH 5) agars. Isolates were purified, and partial sequences for the 16S rRNA gene were obtained from 5,608 isolates. Sequence-based analysis of the 16S rRNA isolate libraries from blood and acid agars of severe ECC and caries-free children had >90% population coverage, with greater diversity occurring in the blood isolate library. Isolate sequences were compared with taxon sequences in the Human Oral Microbiome Database (HOMD), and 198 HOMD taxa were identified, including 45 previously ...
Research Interests: Microbiology, Biology, Medicine, Clinical Microbiology, Biological Sciences, and 15 morePhylogeny, Humans, Child, Female, Clinical, Dental Caries, Male, Cluster Analysis, Microbiome, Actinomyces, Early Childhood Caries, Streptococcus mutans, Ribosomal DNA, Child preschool, and Medical and Health Sciences
Oral streptococci such as Streptococcus gordonii are facultative anaerobes that initiate biofilm formation on tooth surfaces. An isolated S. gordonii ::Tn 917-lac biofilm-defective mutant contained a transposon insertion in an open... more
Oral streptococci such as Streptococcus gordonii are facultative anaerobes that initiate biofilm formation on tooth surfaces. An isolated S. gordonii ::Tn 917-lac biofilm-defective mutant contained a transposon insertion in an open reading frame (ORF) encoding a homolog of NosX of Ralstonia eutropha , a putative maturation factor of nitrous oxide reductase. Located downstream are two genes, qor1 and qor2 , predicted to encode two putative NADPH quinone oxidoreductases. These three genes are cotranscribed, forming a putative oxidative stress response ( osr ) operon in S. gordonii . Inactivation of nosX , qor1 , or qor2 resulted in biofilm-defective phenotypes. Expression of nosX , measured by the β-galactosidase activity of the nosX ::Tn 917-lac mutant, was growth-phase dependent and enhanced when grown under aerobic conditions or in the presence of paraquat. Real-time reverse transcription-PCR revealed that nosX -specific mRNA levels were increased approximately 8.4 and 3.5 fold in ...
Research Interests: Microbiology, Biofilms, Bacteriology, Biology, Oxidative Stress, and 15 moreMedicine, Biological Sciences, Humans, Biofilm, Mutation, Oxidoreductases, Real Time, Antioxidant enzyme, Oxygen, Nitrous Oxide, Amino Acid Sequence, Open Reading Frame, Molecular Sequence Data, Streptococci, and Medical and Health Sciences
Background/Aims: Severe early childhood caries is a microbial infection that severely compromises the dentition of young children. The aim of this study was to characterize the microbiota of severe early childhood caries. Methods: Dental... more
Background/Aims: Severe early childhood caries is a microbial infection that severely compromises the dentition of young children. The aim of this study was to characterize the microbiota of severe early childhood caries. Methods: Dental plaque samples from 2- to 6-year-old children were analyzed using 16S rRNA gene cloning and sequencing, and by specific PCR amplification for Streptococcus mutans and Bifidobacteriaceae species. Results: Children with severe caries (n = 39) had more dental plaque and gingival inflammation than caries-free children (n = 41). Analysis of phylotypes from operational taxonomic unit analysis of 16S rRNA clonal metalibraries from severe caries and caries-free children indicated that while libraries differed significantly (p < 0.0001), there was increased diversity than detected in this clonal analysis. Using the Human Oral Microbiome Database, 139 different taxa were identified. Within the limits of this study, caries-associated taxa included Granulica...
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Previous studies have shown a positive correlation between salivary IgA antibody levels to Streptococcus mutans and caries resistance in adults. In this study, enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody... more
Previous studies have shown a positive correlation between salivary IgA antibody levels to Streptococcus mutans and caries resistance in adults. In this study, enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody levels with S. mutans in whole and parotid saliva from 20 caries-susceptible (CS; DMFS > 5) and 20 caries-resistant (CR; DMFS < or = 1) children (aged 7-11 years). Whole salivary S. mutans numbers were significantly greater (P < or = 0.05) in the CS group (mean of 31.2% of total oral streptococci) than in the CR group (mean of 1.6% of total oral streptococci). Whole saliva, but not parotid saliva, from CR children had significantly higher (P < or = 0.05) levels of IgA antibodies to S. mutans than saliva from CS children. These results suggest that salivary IgA antibodies to S. mutans may play a role in natural protection from dental caries in children and that the source of increased salivary IgA antibody in CR children may be either the mi...