Metagenomic analysis reveals ecological and functional signatures of oral phageome associated with severe early childhood caries.

OBJECTIVES: Severe early childhood caries (S-ECC) is highly prevalent, affecting children's oral health. S-ECC development is closely associated with the complex oral microbial microbiome and its microorganism interactions, such as the imbalance of bacteriophages and bacteria. Till now, little is known about oral phageome on S-ECC. Therefore, this study aimed to investigate the potential role of the oral phageome in the pathogenesis of S-ECC. METHODS: Unstimulated saliva (2 mL) was collected from 20 children with and without S-ECC for metagenomics analysis. Metagenomics sequencing and bioinformatic analysis were performed to determine the two groups' phageome diversity, taxonomic and functional annotations. Statistical analysis and visualization were performed with R and SPSS Statistics software. RESULTS: 85.7 % of the extracted viral sequences were predicted from phages, in which most phages were classified into Myoviridae, Siphoviridae, and Podoviridae. Alpha diversity decreased, and Beta diversity increased in the S-ECC phageome compared to the healthy group. The abundance of Podoviridae phages increased, and the abundance of Inoviridae, Herelleviridae, and Streptococcus phages decreased in the S-ECC group. Functional annotation revealed increased annotation on glycoside hydrolases and nucleotide metabolism, decreased glycosyl transferases, carbohydrate-binding modules, and biogenic metabolism in the S-ECC phageome. CONCLUSIONS: Metagenomic analysis revealed reduced Streptococcus phages and significant changes in functional annotations within the S-ECC phageome. These findings suggest a potential weakening of the regulatory influence of oral bacteria, which may indicate the development of innovative prevention and treatment strategies for S-ECC. These implications deserve further investigation and hold promise for advancing our understanding and management of S-ECC. CLINICAL SIGNIFICANCE: The findings of this study indicate that oral phageomes are associated with bacterial genomes and metabolic processes, affecting the development of S-ECC. The reduced modulatory effect of the oral phageome in counteracting S-ECC's cariogenic activity suggests a new avenue for the prevention and treatment of S-ECC.

Isolation and Characterization of Streptococcus mutans Phage as a Possible Treatment Agent for Caries.

Streptococcus mutans is a key bacterium in dental caries, one of the most prevalent chronic infectious diseases. Conventional treatment fails to specifically target the pathogenic bacteria, while tending to eradicate commensal bacteria. Thus, caries remains one of the most common and challenging diseases. Phage therapy, which involves the use of bacterial viruses as anti-bacterial agents, has been gaining interest worldwide. Nevertheless, to date, only a few phages have been isolated against S. mutans. In this study, we describe the isolation and characterization of a new S. mutans phage, termed SMHBZ8, from hundreds of human saliva samples that were collected, filtered, and screened. The SMHBZ8 genome was sequenced and analyzed, visualized by TEM, and its antibacterial properties were evaluated in various states. In addition, we tested the lytic efficacy of SMHBZ8 against S. mutans in a human cariogenic dentin model. The isolation and characterization of SMHBZ8 may be the first step towards developing a potential phage therapy for dental caries.

Caries experience and oral health related quality of life in a cohort of Ugandan HIV-1 exposed uninfected children compared with a matched cohort of HIV unexposed uninfected children.

BACKGROUND: Very few studies consider the oral health status and quality of life in HIV-1 exposed uninfected (HEU) children. The aim of this study was to estimate the prevalence of caries in primary teeth and its oral health related quality of life impacts in HEU children compared to HIV-unexposed-uninfected (HUU) children, whilst adjusting for confounding covariates. METHODS: This study uses data from the Ugandan site of the ANRS 121741 PROMISE- PEP trial (ClinicalTrials.gov, number NCT00640263) conducted in 2009-2013 that recruited mothers with HIV-1 and their uninfected children. Of 244 HEU-children-caretaker pairs available at the end of the one-year trial, 166 were re-enrolled in the ANRS 12341 PROMISE-PEP M&S study at 5-7 years and 164 were included in this study. These were age and sex-matched with 181 HUU children-caretaker comparators. Caries experience was recorded using World Health Organization's Decayed, Missed and Filled teeth (dmft/DMFT) indices. The Early Childhood Oral health Impact Scale (ECOHIS) was used for assessment of oral health related quality of life. Mixed effects logistic regression was conducted with dmft and ECOHIS scores as outcomes and HIV-1 exposure status as the main exposure. RESULTS: Forty-eight percent of HEU children and 60% of HUU had dmft> 0. Corresponding figures for ECOHIS> 0 were 12% of HEU and 22% of HUU. The crude analysis showed differences related to HIV-1 exposure in caries experience and oral health related quality of life. Mixed effect logistic regression analyses were not significant when adjusted for use of dental care and toothache. If caregivers' DMFT> 0, the adjusted odds ratio for caries experience (dmft> 0) was 1.6 (95% CI: 1.0-2.8) while if dmft> 0 the adjusted odds ratio for quality of life impacts (ECOHIS> 0) was 4.6 (95% CI: 2.0-10.6). CONCLUSION: The prevalence of untreated caries in primary teeth and quality of life impacts was high in this study population. HIV-1 exposed uninfected children were not more likely than HUU children to experience dental caries or have impaired oral health related quality of life. Given the global expansion of the HEU child population, the present findings indicating no adverse effect of pre- and post-natal HIV-1 exposure on caries in deciduous teeth are reassuring.

Role of Candida species from HIV infected children in enamel caries lesions: an in vitro study.

OBJECTIVES: This study analyzed the capacity of Candida spp. from dental biofilm of HIV infected (HIV+) children to demineralize primary molar enamel in vitro by Transversal Microhardness (TMH), Polarized Light Microscopy (PLM) and the quantity of calcium ions (Ca2+) released from the enamel. MATERIAL AND METHODS: Candida spp. samples were isolated from the supragingival biofilm of HIV+ children. A hundred and forty (140) enamel blocks were randomly assigned to six groups: biofilm formed by C. albicans (Group 1); mixed biofilm formed by C. albicans and C. tropicalis (Group 2); mixed biofilm formed by C. albicans and C. parapsilosis (Group 3); mixed biofilm formed by C. albicans, C. parapsilosis and C. glabrata (Group 4); biofilm formed by C. albicans ATCC (Group 5) and medium without Candida (Group 6). Enamel blocks from each group were removed on days 3, 5, 8 and 15 after biofilm formation to evaluate the TMH and images of enamel were analyzed by PLM. The quantity of Ca2+ released, from Groups 1 and 6, was determined using an Atomic Absorption Spectrophotometer. The SPSS program was used for statistical analysis and the significance level was 5%. RESULTS: TMH showed a gradual reduction in enamel hardness (p<0.05) from the 1st to 15th day, but mainly five days after biofilm formation in all groups. The PLM showed superficial lesions indicating an increase in porosity. C. albicans caused the release of Ca2+ into suspension during biofilm formation. CONCLUSION: Candida species from dental biofilm of HIV+ children can cause demineralization of primary enamel in vitro.

Role of Candida species from HIV infected children in enamel caries lesions: an in vitro study

Abstract Objectives This study analyzed the capacity of Candida spp. from dental biofilm of HIV infected (HIV+) children to demineralize primary molar enamel in vitro by Transversal Microhardness (TMH), Polarized Light Microscopy (PLM) and the quantity of calcium ions (Ca2+) released from the enamel. Material and Methods Candida spp. samples were isolated from the supragingival biofilm of HIV+ children. A hundred and forty (140) enamel blocks were randomly assigned to six groups: biofilm formed by C. albicans (Group 1); mixed biofilm formed by C. albicans and C. tropicalis (Group 2); mixed biofilm formed by C. albicans and C. parapsilosis (Group 3); mixed biofilm formed by C. albicans, C. parapsilosis and C. glabrata (Group 4); biofilm formed by C. albicans ATCC (Group 5) and medium without Candida (Group 6). Enamel blocks from each group were removed on days 3, 5, 8 and 15 after biofilm formation to evaluate the TMH and images of enamel were analyzed by PLM. The quantity of Ca2+ released, from Groups 1 and 6, was determined using an Atomic Absorption Spectrophotometer. The SPSS program was used for statistical analysis and the significance level was 5%. Results TMH showed a gradual reduction in enamel hardness (p<0.05) from the 1st to 15th day, but mainly five days after biofilm formation in all groups. The PLM showed superficial lesions indicating an increase in porosity. C. albicans caused the release of Ca2+ into suspension during biofilm formation. Conclusion Candida species from dental biofilm of HIV+ children can cause demineralization of primary enamel in vitro.

Salivary IgA and dental caries in HIV patients: A pilot study.

INTRODUCTION: The interrelationship of human immunodeficiency virus (HIV) infection and dental caries, as well as Salivary IgA (S-IgA) level, appear to remain underexplored while a manual and electronic search of the literature was made. Hence, this study was undertaken to assess the relationship of S-IgA and dental caries status in HIV +ve children. AIM: The aim of this study was to find out the relationship of S-IgA antibody with dental caries by measuring the concentration of IgA in saliva of HIV +ve and HIV -ve children and to determine the dental caries status in HIV +ve and HIV -ve children, which may help in treatment planning and prevention of the same. MATERIALS AND METHODS: Twenty-eight HIV +ve children aged between 6 and 14 years and 28 age matched HIV -ve children were included in this study, and both samples were randomly selected from the same nongovernmental organization (NGO). The HIV status of both these samples was confirmed from their medical records provided by the NGO. 2 cc of unstimulated saliva was collected from both groups in special tubes coded numerically using the method described by Collins and Dawes, and the samples were analyzed to measure the concentration of IgA using commercially available ELISA kit (DRG Diagnostics, Germany). Examination of dental caries was carried out according to the WHO criteria (1997) using a flat mouth mirror and Community periodontal index (CPI) probe. RESULTS: In HIV +ve group, mean salivary IgA level was calculated as 81.61 ± 6.20 µg/ml, mean decayed, missing, filled teeth (DMFT) was 3.86 ± 3.37, mean decayed, extracted and filled teeth (deft) was 4.75 ± 2.86. In HIV -ve group, the mean salivary IgA level was calculated as 145.57 ±17.83 µg/ml, mean DMFT was 2.54 ± 0.69, mean deft was 2.43 ± 2.01. Strong -ve correlation between S-IgA and DMFT (r = -0.781, t = 6.38, P < 0.001) and negative, but not significant correlation (r = -0.19, t = 0.99, P > 0.05) between S-IgA and deft was found in HIV +ve group. Strong -ve correlation between S-IgA and DMFT (r = -0.655, t = 4.42, P < 0.001), S-IgA and deft (r = -0.942, t = 14.32, P < 0.001) was found in HIV -ve group. CONCLUSION: This study suggests that the individuals, who are suffering from IgA deficiency in general, are more susceptible to dental caries than normal individuals.

Oral manifestations in human immunodeficiency virus infected children in highly active antiretroviral therapy era.

OBJECTIVE: Conducted a literature review to identify studies that reported on the oral manifestations in human immunodeficiency virus (HIV) infected children in highly active antiretrovial therapy (HAART) era. METHODS: A search electronic data base were used and the terms used were 'oral lesions' and 'oral manifestations'. The studies of prevalence of oral manifestation in children with HIV worldwide, descriptive studies, case reports, studies on the association of oral lesions and levels of immune suppression, use of HAART and transmission of HIV were included. RESULTS: There have been substantial changes in the management of HIV disease, especially in the past decade because of the use of HAART. However, children are still being infected and present some peculiarities when compared with adults. Molecular epidemiology, transmission and therapy of the common opportunistic oral infections of HIV disease need to be better understood as a consequence of improved anti-HIV strategies. Treatment with HAART improves the immune function and decreases mortality, morbidity, and opportunistic infections in HIV-infected persons. CONCLUSION: The frequency and severity of oral disease associated with HIV infection have reduced considerably, although the use of HAART may be associated with an increased appearance of oral lesions associated with human papillomavirus and potentially increase the risk of later oral squamous cell carcinoma.

An investigation of the role of oral epithelial cells and Langerhans cells as possible HIV viral reservoirs.

BACKGROUND: The role of the oral mucosa as a target of human immunodeficiency virus (HIV-1) infection and persistence is unclear. HIV-1 has been reported in oral epithelial cells, but this has not been confirmed. Cellular reservoirs may impede antiretroviral therapies and should be identified. This study was performed to determine the presence of HIV-1 in oral epithelial and Langerhans cells (LCs) of HIV-1-positive antiretroviral naïve patients. Non-invasive brush biopsy technique for future in vivo HIV research was also evaluated. METHODS: Oral mucosal cells were harvested from the buccal mucosae, dorsal tongue and the gingiva of the mandibular teeth of 35 HIV-1-positive patients using a Cytobrush Plus cell collector. Epithelial cells were purified from the samples by flow cytometric cell sorting using cytokeratin stains after which the epithelial cell samples were further purified and divided into superficial and deep epithelial cells by laser microdissection on Pap stained cytospin smears. LCs were picked up individually by laser microdissection from CD1a stained cytospin smears. Purified epithelial and LC samples were tested for the presence of HIV-1 DNA by polymerase chain reaction analysis. RESULTS: Ten of the patients had HIV-1 DNA in one or more of the sampled anatomical locations. No HIV-1 DNA could be demonstrated in any of the purified superficial or deep epithelial or LC samples. CONCLUSIONS: HIV-DNA can be found using non-invasive oral brush biopsies and should be investigated further as an experimental model for in vivo oral HIV research. Better ways to purify the different cell types should be investigated.

Transmisión de la infección por streptococcus mutans / Transmission of the streptococcus mutans infection

La caries dental es una enfermedad infecciosa y como tal, el estudio de las vías de transmisión que utilizan los microorganismos causantes, reviste gran importancia para el mejor entendimiento de la enfermedad y de las formas como esta puede ser prevenida. Ésta transmisión ha sido estudiada con mayor interés en los microorganismos pertenecientes al grupo de los estreptococos mutans, puesto que son los agentes infecciosos más relacionados con el inicio de la lesión de caries.

Prevalence of cytomegalovirus, human herpesvirus-6, and Epstein-Barr virus in periodontitis patients and healthy subjects in the Thai population.

Fifty periodontitis patients and 30 healthy patients with oral cavities were selected from the Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from March 2001 to November 2002. Their ages varied between 15 and 70 years. Among the periodontitis patients, specimens were collected from both disease and healthy sites. All samples were evaluated for the presence of CMV, HHV-6, and EBV-1 by nested PCR. Among the periodontitis patients, CMV was found in 34%, of which 8% were at the disease sites, 10% were at the healthy sites, and 16% were from both sites. EBV was not found in this group of the patients, while HHV-6 was found in 4%, at the disease sites only. CMV was found in one (3.3%) healthy control while HHV-6 and EBV-1 were not found. The depth of sample sites, various demographic and baseline characteristics eg sex, age, occupation and root planning were not associated with the presence of these viruses.

Association of HIV viral load with oral diseases.

OBJECTIVE: The measurement of HIV viral load as a predictor of disease progression has revolutionized the medical management of HIV patients. In this study, oral diseases as measured by DMFT (decayed, missing and filled teeth), periodontal assessment and oral Candidacolonization, were related to HIV viral load. Also correlated was HIV status assessments, including CD4+ count, a history of intravenous drug abuse (IVDA) and the use of protease inhibitor drugs. MATERIALS AND METHODS: Oral and periodontal examination, dental radiographs, and tongue swab for fungal culture was accomplished over a 2-month period on 39 HIV positive patients attending the University of Maryland Dental School. Twenty-eight (71. 8%) of these patients had a history of IVDA. Viral load was measured by a quantitative RT-PCR. RESULTS: Among the patients with high viral load (>10 000 copies ml-1), 92.3% were found to have a history of IVDA. Also, patients with high viral load demonstrated average CD4+ counts of 136 mm-3 while moderate viral load (400-10 000 copies ml-1) corresponded to average counts of 271 mm-3. Periodontal pocket depths (PPD) of >5 mm at a minimum of two oral sites were found in 76.9% of the patients with high viral load. Among the high viral load patients, 69.2% had DMFT >20, 69.2% were culture positive for Candida and 81.5% of patients on protease inhibitors demonstrated moderate or low viral loads. CONCLUSION: These data demonstrated that elevated viral load levels correlate well with oral disease prevalence in this predominantly IVDA population of HIV-infected dental patients.

High prevalence of hepatitis C virus antibody and RNA in patients with oral cancer.

We have investigated the correlation between the prevalence of hepatitis C virus (HCV), which is detectable in saliva, and oral cancer and other digestive tract cancers in the Northern Kyushu region of Japan. Anti-HCV antibodies were detected in sera from 24 of the 100 patients with oral cancer (24%, p < 0.05 vs the control group, p < 0.01 vs the stomach cancer group), in 11 of 104 patients with non-malignant diseases receiving dental treatment (the control group, 10.6%), and in 12 of 113 patients with stomach cancer (10.6%). HCV-RNA was detected in sera from 17 of 100 oral cancer patients (17%, p < 0.05 vs the control group) and 4 of 104 patients of the control group (3.9%). These results indicate a high prevalence of HCV infection in oral cancer patients, which warrants a systematic study of etiological associations between oral cancer and HCV.