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Monospecies and polymicrobial biofilms differentially regulate the phenotype of genotype-specific oral cancer cells

Arzmi MH, Cirillo N, Lenzo JC, Catmull DV, O'Brien-Simpson N, Reynolds EC, et al.

Carcinogenesis, 2019 03 12;40(1):184-193.
PMID: 30428016 DOI: 10.1093/carcin/bgy137

Microbial infection has been shown to involve in oral carcinogenesis; however, the underlying mechanisms remain poorly understood. The present study aimed to characterize the growth of oral microorganisms as both monospecies and polymicrobial biofilms and determine the effects of their products on oral keratinocytes. Candida albicans (ALC3), Actinomyces naeslundii (AN) and Streptococcus mutans (SM) biofilms or a combination of these (TRI) were grown in flow-cell system for 24 h. The biofilms were subjected to fluorescent in situ hybridization using species-specific probes and analysed using confocal laser scanning microscopy. The effluent derived from each biofilm was collected and incubated with malignant (H357) and normal (OKF6) oral keratinocytes to assess extracellular matrix adhesion, epithelial-mesenchymal transition (EMT) and cytokines expression. Incubation of OKF6 with ALC3 and TRI effluent significantly decreased adhesion of the oral keratinocyte to collagen I, whereas incubation of H357 with similar effluent increased adhesion of the oral keratinocyte to laminin I, significantly when compared with incubation with artificial saliva containing serum-free medium (NE; P < 0.05). In OKF6, changes in E-cadherin and vimentin expression were not consistent with EMT although there was evidence of a mesenchymal to epithelial transition in malignant oral keratinocytes incubated with AN and SM effluent. A significant increase of pro-inflammatory cytokines expression, particularly interleukin (IL)-6 and IL-8, was observed when H357 was incubated with all biofilm effluents after 2- and 24-h incubation when compared with NE (P < 0.05). In conclusion, C.albicans, A.naeslundii and S.mutans form polymicrobial biofilms which differentially modulate malignant phenotype of oral keratinocytes.

Matched MeSH terms: Mouth Neoplasms/pathology*
Newly formulated 5% 5-aminolevulinic acid photodynamic therapy on Candida albicans

Greco G, Di Piazza S, Chan J, Zotti M, Hanna R, Gheno E, et al.

Photodiagnosis Photodyn Ther, 2020 Mar;29:101575.
PMID: 31614222 DOI: 10.1016/j.pdpdt.2019.10.010

BACKGROUND: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them.
METHODS: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm.
RESULTS AND CONCLUSION: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.

Matched MeSH terms: Mouth Diseases/drug therapy
Fulltext Hypoxia and therapeutic treatment of EV-A71 with an immune modulator TLR7 agonist in a new immunocompetent mouse model

Liou AT, Liao CC, Chou SF, Chang YS, Chang CS, Shih C

J Biomed Sci, 2019 Nov 11;26(1):93.
PMID: 31711481 DOI: 10.1186/s12929-019-0585-y

BACKGROUND: Enterovirus 71 (EV71 or EV-A71) was first identified in California about half a century ago. In recent years, outbreaks of EV-A71 were prevalent worldwide, including Taiwan, Malaysia, Singapore, Japan, and China. Between 2008 and 2011, China alone reported 1894 deaths associated with EV-A71 infection. In mild cases, EV-A71 can cause herpangina and hand-foot-and-mouth disease (HFMD). However, in severe cases, it could cause neurological disorders, including meningitis and encephalitis. Cardiopulmonary failure is common among hospitalized children with EV-A71 infection. No effective FDA-approved therapeutics against EV-A71 are clinically available.
METHODS: We report the establishment of an immunocompetent wild type strain 129 (wt-129) mouse model, which can be cross-species infected with human EV-A71 clinical isolates via an intraperitoneal route.
RESULTS: One intriguing disease phenotype of this new model is the development of characteristic "White-Jade" patches in the muscle, which lost sporadically the normal pink color of uninfected muscle. Viral VP1 protein and massive leukocyte infiltration were detected in muscles with or without white-jades. We demonstrated further that hypoxia is a general phenomenon associated with white-jades in both immunocompetent and immunodeficient mouse models. Therefore, hypoxia appears to be a feature intrinsic to EV-A71 infection, irrespective of its host's immunogenetic background. To date, no effective treatment for EV-A71 is available. Here, using this new wt-129 mouse model, we showed that timely treatment with compound R837 (a TLR7 immune modulator) via oral or intraperitoneal routes, rescued the hypoxia, limb paralysis, and death at a high therapeutic efficacy.
CONCLUSIONS: In this new immunocompetent mouse 129 model, we observed an unexpected white-jade phenotype and its associated hypoxia. The successful treatment with TLR7 immune modulators via an oral route, provide us a new research direction for EV-A71 basic science and translational research. It remains an open issue whether R837 or its related compounds, will be a promising drug candidate in clinical trials in EV-A71 endemic or epidemic areas in the future.

Matched MeSH terms: Foot-and-Mouth Disease; Hand, Foot and Mouth Disease
Comparison of the transmission potential of two genetically distinct Sindbis viruses after oral infection of Aedes aegypti (Diptera: Culicidae)

Myles KM, Pierro DJ, Olson KE

J Med Entomol, 2004 Jan;41(1):95-106.
PMID: 14989352

Within mosquitoes, arboviruses encounter barriers to infection and dissemination that are critical determinants of vector competence. The molecular mechanisms responsible for these barriers have yet to be elucidated. The prototype Sindbis (SIN) strain, AR339, and viruses derived from this strain, such as TR339 virus, have limited infection and transmission potential in the medically important arthropod vector, Aedes aegypti (L.). However, the Malaysian SIN virus strain, MRE16, disseminates in nearly 100% of Ae. aegypti 14 d after oral infection. Here, we compare the spatial and temporal infection patterns of MRE16 and TR339 viruses in Ae. aegypti. The results indicate that a midgut escape barrier is primarily responsible for the significantly lower dissemination and transmission potentials observed after oral infection with TR339 virus. MRE16 and TR339 viruses now represent a well-characterized model system for the further study of virus determinants of vector infection, particularly determinants affecting the midgut escape barrier in Ae. aegypti.

Matched MeSH terms: Mouth/virology
Fulltext Mechanisms of Oral Bacterial Virulence Factors in Pancreatic Cancer

Sun Z, Xiong C, Teh SW, Lim JCW, Kumar S, Thilakavathy K

Front Cell Infect Microbiol, 2019;9:412.
PMID: 31867287 DOI: 10.3389/fcimb.2019.00412

Pancreatic cancer is a highly lethal disease, and most patients remain asymptomatic until the disease enters advanced stages. There is lack of knowledge in the pathogenesis, effective prevention and early diagnosis of pancreatic cancer. Recently, bacteria were found in pancreatic tissue that has been considered sterile before. The distribution of flora in pancreatic cancer tissue was reported to be different from normal pancreatic tissue. These abnormally distributed bacteria may be the risk factors for inducing pancreatic cancer. Therefore, studies on combined effect of multi-bacterial and multi-virulence factors may add to the knowledge of pancreatic cancer pathogenesis and aid in designing new preventive and therapeutic strategies. In this review, we outlined three oral bacteria associated with pancreatic cancer and their virulence factors linked with cancer.

Matched MeSH terms: Mouth/microbiology*
Fulltext Development and virtual validation of a novel digital workflow to rehabilitate palatal defects by using smartphone-integrated stereophotogrammetry (SPINS)

Farook TH, Jamayet NB, Asif JA, Din AS, Mahyuddin MN, Alam MK

Sci Rep, 2021 04 19;11(1):8469.
PMID: 33875672 DOI: 10.1038/s41598-021-87240-9

Palatal defects are rehabilitated by fabricating maxillofacial prostheses called obturators. The treatment incorporates taking deviously unpredictable impressions to facsimile the palatal defects into plaster casts for obturator fabrication in the dental laboratory. The casts are then digitally stored using expensive hardware to prevent physical damage or data loss and, when required, future obturators are digitally designed, and 3D printed. Our objective was to construct and validate an economic in-house smartphone-integrated stereophotogrammetry (SPINS) 3D scanner and to evaluate its accuracy in designing prosthetics using open source/free (OS/F) digital pipeline. Palatal defect models were scanned using SPINS and its accuracy was compared against the standard laser scanner for virtual area and volumetric parameters. SPINS derived 3D models were then used to design obturators by using (OS/F) software. The resultant obturators were virtually compared against standard medical software designs. There were no significant differences in any of the virtual parameters when evaluating the accuracy of both SPINS, as well as OS/F derived obturators. However, limitations in the design process resulted in minimal dissimilarities. With further improvements, SPINS based prosthetic rehabilitation could create a viable, low cost method for rural and developing health services to embrace maxillofacial record keeping and digitised prosthetic rehabilitation.

Matched MeSH terms: Mouth Diseases/rehabilitation*
Fulltext Kinematics of mouthbrooding in Oreochromis niloticus (Cichlidae)

Van Wassenbergh S, Joris I, Desclée M, Liew HJ, De Boeck G, Adriaens D, et al.

J Exp Biol, 2016 05 15;219(Pt 10):1535-41.
PMID: 27207955 DOI: 10.1242/jeb.131631

Many species from several different families of fishes perform mouthbrooding, where one of the sexes protects and ventilates the eggs inside the mouth cavity. This ventilation behaviour differs from gill ventilation outside the brooding period, as the normal, small-amplitude suction-pump respiration cycles are alternated with actions including near-simultaneous closed-mouth protrusions and high-amplitude depressions of the hyoid. The latter is called churning, referring to its hypothetical function in moving around and repositioning the eggs by a presumed hydrodynamic effect of the marked shifts in volume along the mouth cavity. We tested the hypothesis that churning causes the eggs located posteriorly in the mouth cavity to move anteriorly away from the gill entrance. This would prevent or clear accumulations of brood at the branchial basket, which would otherwise hinder breathing by the parent. Dual-view videos of female Nile tilapias (Oreochromis niloticus) during mouthbrooding showed that churning involves a posterior-to-anterior wave of expansion and compression of the head volume. Flow visualisation with polyethylene microspheres revealed a significant inflow of water entering the gill slits at the zone above the pectoral fin base, followed by a predominantly ventral outflow passing the ventrolaterally flapping branchiostegal membranes. X-ray videos indicated that particularly the brood located close to the gills is moved anteriorly during churning. These data suggest that, in addition to mixing of the brood to aid its oxygenation, an important function of the anterior flow through the gills and buccal cavity during churning is to prevent clogging of the eggs near the gills.

Matched MeSH terms: Mouth/physiology*
CD3-positive plasmablastic lymphoma reported in two cases: A potential diagnostic caveat

Wong YP, Masir N, Chew MX

Indian J Pathol Microbiol, 2021 8 4;64(3):579-583.
PMID: 34341278 DOI: 10.4103/IJPM.IJPM_616_20

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.

Matched MeSH terms: Mouth/pathology
Efficacy of oral brush biopsy in potentially malignant disorder management

Goodson ML, Smith DR, Thomson PJ

J Oral Pathol Med, 2017 Nov;46(10):896-901.
PMID: 28833675 DOI: 10.1111/jop.12627

BACKGROUND: Oral potentially malignant disorders (PMD) harbour unpredictable risk for squamous cell carcinoma development. Current management requires tissue biopsy for histopathology characterisation, dysplasia grading and targeted intervention to "high-risk" lesions, although evidence-based guidelines are limited and diagnoses subjective. This study investigated the use of adjunctive oral brush biopsy techniques during the management of PMD in a UK hospital population.
METHODS: Retrospective review of a 310 PMD patient cohort presenting to Maxillofacial Surgery in Newcastle upon Tyne with new, single-site lesions between December 2009 and May 2014. Patients underwent Orcellex® brush biopsy and liquid-based cytology examination in addition to conventional biopsy techniques, with management proceeding along established care pathways. Patient demographics, cytology data, most significant histopathology diagnoses and clinical outcome were all documented at the study census date (31.12.15).
RESULTS: A total of 170 male & 140 female patients (age range 18-91 years), exhibiting primarily leukoplakia (86.5%) at floor of mouth and ventrolateral tongue sites (44.9%), were identified. Management comprised: observation (49.7%), laser surgery (44.9%), antifungal treatment (3.5%) and Head & Neck clinic referral following cancer diagnosis (1.9%). Clinical outcomes were as follows: disease free (51.3%), persistent PMD (42.3%) and malignant transformation (6.4%). Histology and cytology diagnoses strongly correlated (r = .305). Treatment modality, lesion site, histology and cytology diagnoses were the best predictors of clinical outcome.
CONCLUSIONS: Orcellex® brush cytology provides reliable diagnoses consistent with conventional histopathology and offers less invasive, adjunctive assessment appropriate for long-term monitoring of patients in specialist clinics.

Matched MeSH terms: Mouth Neoplasms/pathology*
Fulltext Mouth-clicks used by blind expert human echolocators - signal description and model based signal synthesis

Thaler L, Reich GM, Zhang X, Wang D, Smith GE, Tao Z, et al.

PLoS Comput Biol, 2017 Aug;13(8):e1005670.
PMID: 28859082 DOI: 10.1371/journal.pcbi.1005670

Echolocation is the ability to use sound-echoes to infer spatial information about the environment. Some blind people have developed extraordinary proficiency in echolocation using mouth-clicks. The first step of human biosonar is the transmission (mouth click) and subsequent reception of the resultant sound through the ear. Existing head-related transfer function (HRTF) data bases provide descriptions of reception of the resultant sound. For the current report, we collected a large database of click emissions with three blind people expertly trained in echolocation, which allowed us to perform unprecedented analyses. Specifically, the current report provides the first ever description of the spatial distribution (i.e. beam pattern) of human expert echolocation transmissions, as well as spectro-temporal descriptions at a level of detail not available before. Our data show that transmission levels are fairly constant within a 60° cone emanating from the mouth, but levels drop gradually at further angles, more than for speech. In terms of spectro-temporal features, our data show that emissions are consistently very brief (~3ms duration) with peak frequencies 2-4kHz, but with energy also at 10kHz. This differs from previous reports of durations 3-15ms and peak frequencies 2-8kHz, which were based on less detailed measurements. Based on our measurements we propose to model transmissions as sum of monotones modulated by a decaying exponential, with angular attenuation by a modified cardioid. We provide model parameters for each echolocator. These results are a step towards developing computational models of human biosonar. For example, in bats, spatial and spectro-temporal features of emissions have been used to derive and test model based hypotheses about behaviour. The data we present here suggest similar research opportunities within the context of human echolocation. Relatedly, the data are a basis to develop synthetic models of human echolocation that could be virtual (i.e. simulated) or real (i.e. loudspeaker, microphones), and which will help understanding the link between physical principles and human behaviour.

Matched MeSH terms: Mouth/physiology
Identification and Characterization of Intraoral and Dermal Fibroblasts Revisited

Mohd Nor NH, Berahim Z, Azlina A, Mokhtar KI, Kannan TP

Curr Stem Cell Res Ther, 2017;12(8):675-681.
PMID: 28969579 DOI: 10.2174/1574888X12666170929124621

BACKGROUND: Fibroblasts are the common cells used in clinical regenerative medicine and dentistry. These cells are known to appear heterogeneous in vivo. Previous studies have only investigated the biological properties of these cell subpopulations in vitro. Despite sharing similarity in their spindle-shaped appearance, previous literatures revealed that they play distinguished functional and biological activities in the body.
OBJECTIVE: This paper highlights the similarities and differences among these cell subpopulations, particularly between intraoral fibroblasts (human periodontal ligament, gingival and oral mucosa fibroblasts) and dermal fibroblasts based on several factors including their morphology, growth and proliferation rate.
RESULTS: It could be suggested that each subpopulation of fibroblasts demonstrate different positionspecified gene signatures and responses towards extracellular signals. These dissimilarities are crucial to be taken into consideration to employ specific methodologies in stimulating these cells in vivo.
CONCLUSION: A comparison of the characteristics of these cell subpopulations is desired for identifying appropriate cellular applications.

Matched MeSH terms: Mouth Mucosa/cytology
Perceptions of oral health among older Cambodians and their caregivers: A qualitative study

Horn R, Heng C, Chea C, Sieng C, Louv C, Turton B, et al.

Gerodontology, 2018 Mar;35(1):45-50.
PMID: 29226455 DOI: 10.1111/ger.12315

OBJECTIVE: Older adults (those above the age of 60) are an emerging demographic in Cambodia, and very little is understood about their oral health experiences, needs, perceptions and behaviours. The aim of this study was to explore the oral health experiences, practices and perceptions of a convenience sample of a small but diverse group of older adults in Cambodia.
METHOD: A cross-sectional qualitative study in which focus group interviews were conducted by 5 trained senior Cambodian dental students. A convenience sample of 56 older adults and caregivers was recruited across urban, semi-urban and rural locations. Focus group conversations were recorded, transcribed and analysed thematically.
RESULTS: The themes that emerged were around low expectations for both general health and oral health. A communal responsibility for health was expressed, and both money and transport were identified as key barriers to accessing care. Participants recognised that they had oral health problems, and acknowledged the impact of poor oral function on health and nutrition.
CONCLUSION: This study is an important first step in better understanding the oral health experiences and perceptions of older people in Cambodia. Participants described the impacts of poor oral health as being important, even when compared with other general health conditions.

Matched MeSH terms: Mouth Diseases/epidemiology
A miRNA-145/TGF-β1 negative feedback loop regulates the cancer-associated fibroblast phenotype

Melling GE, Flannery SE, Abidin SA, Clemmens H, Prajapati P, Hinsley EE, et al.

Carcinogenesis, 2018 05 28;39(6):798-807.
PMID: 29506142 DOI: 10.1093/carcin/bgy032

The dissemination of cancer cells to local and distant sites depends on a complex and poorly understood interplay between malignant cells and the cellular and non-cellular components surrounding them, collectively termed the tumour microenvironment. One of the most abundant cell types of the tumour microenvironment is the fibroblast, which becomes corrupted by locally derived cues such as TGF-β1 and acquires an altered, heterogeneous phenotype (cancer-associated fibroblasts, CAF) supportive of tumour cell invasion and metastasis. Efforts to develop new treatments targeting the tumour mesenchyme are hampered by a poor understanding of the mechanisms underlying the development of CAF. Here, we examine the contribution of microRNA to the development of experimentally-derived CAF and correlate this with changes observed in CAF derived from tumours. Exposure of primary normal human fibroblasts to TGF-β1 resulted in the acquisition of a myofibroblastic CAF-like phenotype. This was associated with increased expression of miR-145, a miRNA predicted in silico to target multiple components of the TGF-β signalling pathway. miR-145 was also overexpressed in CAF derived from oral cancers. Overexpression of miR-145 blocked TGF-β1-induced myofibroblastic differentiation and reverted CAF towards a normal fibroblast phenotype. We conclude that miR-145 is a key regulator of the CAF phenotype, acting in a negative feedback loop to dampen acquisition of myofibroblastic traits, a key feature of CAF associated with poor disease outcome.

Matched MeSH terms: Mouth Neoplasms/metabolism*
Assessment of the likelihood of the introduction of foot-and-mouth disease through importation of live animals into the Malaysia-Thailand-Myanmar peninsula

Wongsathapornchai K, Salman MD, Edwards JR, Morley PS, Keefe TJ, Van Campen H, et al.

Am J Vet Res, 2008 Feb;69(2):252-60.
PMID: 18241023 DOI: 10.2460/ajvr.69.2.252

To assess the likelihood of an introduction of foot-and-mouth disease (FMD) into the Malaysia-Thailand-Myanmar (MTM) peninsula through terrestrial movement of livestock.

Matched MeSH terms: Foot-and-Mouth Disease/prevention & control*
Fatty acid translocase gene CD36 rs1527483 variant influences oral fat perception in Malaysian subjects

Ong HH, Tan YN, Say YH

Physiol Behav, 2017 01 01;168:128-137.
PMID: 27847178 DOI: 10.1016/j.physbeh.2016.11.006

We determined whether single nucleotide polymorphisms (SNPs; rs1761667 and rs1527483) in the fatty acid translocase CD36 gene - a receptor for fatty acids - is associated with oral fat perception (OFP) of different fat contents in custards and commercially-available foods, and obesity measures in Malaysian subjects (n=313; 118 males, 293 ethnic Chinese; 20 ethnic Indians). A 170-mm visual analogue scale was used to assess the ratings of perceived fat content, oiliness and creaminess of 0%, 2%, 6% and 10% fat content-by-weight custards and low-fat/regular versions of commercially-available milk, mayonnaise and cream crackers. Overall, the subjects managed to significantly discriminate the fat content, oiliness and creaminess between low-fat/regular versions of milk and mayonnaise. Females rated the perception of fat content and oiliness of both milks higher, but ethnicity, obesity and adiposity status did not seem to play a role in influencing most of OFP. The overall minor allele frequencies for rs1761667 and rs1527483 were 0.30 and 0.26, respectively. Females and individuals with rs1527483 TT genotype significantly perceived greater creaminess of 10% fat-by-weight custard. Also, individuals with rs1527483 TT genotype and T allele significantly perceived greater fat content of cream crackers, independent of fat concentration. rs1761667 SNP did not significantly affect OFP, except for cream crackers. Both gene variants were also not associated with obesity measures. Taken together, this study supports the notion that CD36 - specifically rs1527483, plays a role in OFP, but not in influencing obesity in Malaysian subjects. Besides, gender is an important factor for OFP, where females had higher sensitivity.

Matched MeSH terms: Mouth/innervation
Genome characterization and taxonomy of Actinomyces acetigenes sp. nov., and Actinomyces stomatis sp. nov., previously isolated from the human oral cavity

Tian X, Teo WFA, Wee WY, Yang Y, Ahmed H, Jakubovics NS, et al.

BMC Genomics, 2023 Dec 04;24(1):734.
PMID: 38049764 DOI: 10.1186/s12864-023-09831-2

BACKGROUND: Actinomyces strains are commonly found as part of the normal microflora on human tissue surfaces, including the oropharynx, gastrointestinal tract, and female genital tract. Understanding the diversity and characterization of Actinomyces species is crucial for human health, as they play an important role in dental plaque formation and biofilm-related infections. Two Actinomyces strains ATCC 49340 T and ATCC 51655 T have been utilized in various studies, but their accurate species classification and description remain unresolved.
RESULTS: To investigate the genomic properties and taxonomic status of these strains, we employed both 16S rRNA Sanger sequencing and whole-genome sequencing using the Illumina HiSeq X Ten platform with PE151 (paired-end) sequencing. Our analyses revealed that the draft genome of Actinomyces acetigenes ATCC 49340 T was 3.27 Mbp with a 68.0% GC content, and Actinomyces stomatis ATCC 51655 T has a genome size of 3.08 Mbp with a 68.1% GC content. Multi-locus (atpA, rpoB, pgi, metG, gltA, gyrA, and core genome SNPs) sequence analysis supported the phylogenetic placement of strains ATCC 51655 T and ATCC 49340 T as independent lineages. Digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI), and average amino acid identity (AAI) analyses indicated that both strains represented novel Actinomyces species, with values below the threshold for species demarcation (70% dDDH, 95% ANI and AAI). Pangenome analysis identified 5,731 gene clusters with strains ATCC 49340 T and ATCC 51655 T possessing 1,515 and 1,518 unique gene clusters, respectively. Additionally, genomic islands (GIs) prediction uncovered 24 putative GIs in strain ATCC 49340 T and 16 in strain ATCC 51655 T, contributing to their genetic diversity and potential adaptive capabilities. Pathogenicity analysis highlighted the potential human pathogenicity risk associated with both strains, with several virulence-associated factors identified. CRISPR-Cas analysis exposed the presence of CRISPR and Cas genes in both strains, indicating these strains might evolve a robust defense mechanism against them.
CONCLUSION: This study supports the classification of strains ATCC 49340 T and ATCC 51655 T as novel species within the Actinomyces, in which the name Actinomyces acetigenes sp. nov. (type strain ATCC 49340 T = VPI D163E-3 T = CCUG 34286 T = CCUG 35339 T) and Actinomyces stomatis sp. nov. (type strain ATCC 51655 T = PK606T = CCUG 33930 T) are proposed.

Matched MeSH terms: Mouth*
Fulltext A Revolutionizing Approach to Autism Spectrum Disorder Using the Microbiome

Johnson D, Letchumanan V, Thurairajasingam S, Lee LH

Nutrients, 2020 Jul 03;12(7).
PMID: 32635373 DOI: 10.3390/nu12071983

The study of human microbiota and health has emerged as one of the ubiquitous research pursuits in recent decades which certainly warrants the attention of both researchers and clinicians. Many health conditions have been linked to the gut microbiota which is the largest reservoir of microbes in the human body. Autism spectrum disorder (ASD) is one of the neurodevelopmental disorders which has been extensively explored in relation to gut microbiome. The utilization of microbial knowledge promises a more integrative perspective in understanding this disorder, albeit being an emerging field in research. More interestingly, oral and vaginal microbiomes, indicating possible maternal influence, have equally drawn the attention of researchers to study their potential roles in the etiopathology of ASD. Therefore, this review attempts to integrate the knowledge of microbiome and its significance in relation to ASD including the hypothetical aetiology of ASD and its commonly associated comorbidities. The microbiota-based interventions including diet, prebiotics, probiotics, antibiotics, and faecal microbial transplant (FMT) have also been explored in relation to ASD. Of these, diet and probiotics are seemingly promising breakthrough interventions in the context of ASD for lesser known side effects, feasibility and easier administration, although more studies are needed to ascertain the actual clinical efficacy of these interventions. The existing knowledge and research gaps call for a more expanded and resolute research efforts in establishing the relationship between autism and microbiomes.

Matched MeSH terms: Mouth/microbiology
Health-Seeking Behaviour and Delayed Presentation of Oral Cancer Patients in a Developing Country: A Qualitative Study based on the Self-Regulatory Model

Azhar N, Doss JG

Asian Pac J Cancer Prev, 2018 Oct 26;19(10):2935-2941.
PMID: 30362327

Background: The aim of this study was to explore reasons for delayed health-seeking for late stage oral cancer patients. Methods: Semi-structured in-depth interviews were conducted with 35 oral cancer patients with TNM stage III to IV disease, who were treated at six tertiary regional centres managing oral cancer throughout Malaysia. Interviews were audio-recorded, transcribed verbatim, coded using NVivo (version 10.0) qualitative software and analysed using framework analysis. Results: Participants interpreted their early symptoms as a minor condition and did not consider it as requiring immediate attention. Four types of coping strategies causing delayed help-seeking emerged: 1) self-remedy 2) self-medication 3) seeking traditional healers and 4) consulting general medical practitioners (GPs) instead of dentists. Socio-economic factors, cultural beliefs and religious practices have some influence on diagnostic delay. Conclusion: Low levels of public knowledge and awareness regarding early signs and symptoms of oral cancer as well as GPs’ misdiagnosis of early lesions results in delayed diagnosis.

Matched MeSH terms: Mouth Neoplasms/pathology*
Fulltext Salivary Amylase as a Marker of Salivary Gland Function in Patients Undergoing Radiotherapy for Oral Cancer

Vedam VKV, Boaz K, Natarajan S, Ganapathy S

J Clin Lab Anal, 2017 May;31(3).
PMID: 27637993 DOI: 10.1002/jcla.22048

BACKGROUND: The aim of this study was to evaluate salivary amylase in patients with primary oral cancer undergoing radiotherapy as the main modality of treatment.
MATERIALS/METHODS: The study was conducted on ten histologically proven cases of oral cancer undergoing radiotherapy. Stimulated whole saliva was collected at three stages of radiotherapy-0, 3, and 6 weeks. Salivary amylase was estimated using Henry-Chiamori method and comparison was made with appropriate age- and gender-matched controls.
RESULTS: Salivary amylase levels showed significant decrease in healthy subjects when compared to oral cancer patients (P < 0.001). The latter group also showed changing trend with initial decrease from 0 to 3 weeks followed by increase from 3 to 6 weeks following radiotherapy (P < 0.0528).
CONCLUSIONS: The trend in changes in the levels of salivary amylase could be used as a surrogate marker of salivary gland function in patients with oral cancer undergoing radiotherapy as primary treatment.

Matched MeSH terms: Mouth Neoplasms/radiotherapy*
Fulltext Construction of an infectious cDNA clone of Enterovirus 71: insights into the factors ensuring experimental success

Lazouskaya NV, Palombo EA, Poh CL, Barton PA

J Virol Methods, 2014 Mar;197:67-76.
PMID: 24361875 DOI: 10.1016/j.jviromet.2013.12.005

Enterovirus 71 (EV 71) is a causative agent of mild Hand Foot and Mouth Disease but is capable of causing severe complications in the CNS in young children. Reverse genetics technology is currently widely used to study the pathogenesis of the virus. The aim of this work was to determine and evaluate the factors which can contribute to infectivity of EV 71 RNA transcripts in vitro. Two strategies, overlapping RT-PCR and long distance RT-PCR, were employed to obtain the full-length genome cDNA clones of the virus. The length of the poly(A) tail and the presence of non-viral 3'-terminal sequences were studied in regard to their effects on infectivity of the in vitro RNA transcripts of EV 71 in cell culture. The data revealed that only cDNA clones obtained after long distance RT-PCR were infectious. No differences were observed in virus titres after transfection with in vitro RNA harbouring a poly(A) tail of 18 or 30 adenines in length, irrespective of the non-viral sequences at the 3'-terminus.

Matched MeSH terms: Hand, Foot and Mouth Disease/virology*

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