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Microorganisms Jan 2020The study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim...
The study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim of this study was to characterize-with an emphasis on biofilm formation and composition and metabolic activity-single- and dual-species biofilms of S. mutans or A. naeslundii, and to use a drip flow reactor (DFR) to evaluate biofilm stress responses to 0.2% chlorhexidine diacetate (CHX). Single- and dual-species biofilms were grown for 24 h. The following factors were evaluated: cell viability, biomass and total proteins in the extracellular matrix, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide-"XTT"-reduction and lactic acid production. To evaluate stress response, biofilms were grown in DFR. Biofilms were treated with CHX or 0.9% sodium chloride (NaCl; control). Biofilms were plated for viability assessment. Confocal laser-scanning microscopy (CLSM) was also performed. Data analysis was carried out at 5% significance level. viability and lactic acid production in dual-species biofilms were significantly reduced. showed a higher resistance to CHX in dual-species biofilms. Total protein content, biomass and XTT reduction showed no significant differences between single- and dual-species biofilms. CLSM images showed the formation of large clusters in dual-species biofilms. In conclusion, dual-species biofilms reduced viability and lactic acid production and increased resistance to chlorhexidine.
PubMed: 32023892
DOI: 10.3390/microorganisms8020194 -
Microorganisms Jan 2023The aim of this study was to investigate and clarify the ambiguous taxonomy of and its closely related species using state-of-the-art high-throughput sequencing...
The aim of this study was to investigate and clarify the ambiguous taxonomy of and its closely related species using state-of-the-art high-throughput sequencing techniques, and, furthermore, to determine whether sub-clusters identified within and in a previous study by multi locus sequence typing (MLST) using concatenation of seven housekeeping genes should either be classified as subspecies or distinct species. The strains in this study were broadly classified under group as genospecies I and genospecies II. Based on MLST data analysis, these were further classified as and . The whole genome sequencing of selected strains of ( = 17) and ( = 19) was carried out using Illumina Genome Analyzer IIxe and Roche 454 allowing paired-end and single-reads sequencing, respectively. The sequences obtained were aligned using CLC Genomic workbench version 5.1 and annotated using RAST (Rapid Annotation using Subsystem Technology) release version 59 accessible online. Additionally, genomes of seven publicly available strains of (k20, MG1, c505, OT175, OT171, OT170, and ) were also included. Comparative genomic analysis (CGA) using Mauve, Progressive Mauve, gene-by-gene, Core, and Pan Genome, and finally Digital DNA-DNA homology (DDH) analysis was carried out. DDH values were obtained using in silico genome-genome comparison. Evolutionary analysis using ClonalFrame was also undertaken. The mutation and recombination events were compared using chi-square test among and isolates (analysis methods are not included in the study). CGA results were consistent with previous traditional classification using MLST. It was found that strains of k20, MG1, c505, and OT175 clustered in group of isolates, while OT171, OT170, and appeared as separate branches. Similar clustering to MLST was observed for other isolates. The mutation and recombination events were significantly higher in than , highlighting the diversity of strains in the oral cavity. These findings suggest that forms six distinct groups, whereas forms three. The correct designation of isolates will help in the identification of clinical isolates found in dental plaque. Easily accessible online genomic sequence data will also accelerate the investigation of the biochemical characterisation and pathogenesis of this important group of micro-organisms.
PubMed: 36838222
DOI: 10.3390/microorganisms11020254 -
BMJ Case Reports Jul 2013A 48-year-old man with an unremarkable medical history was admitted with vague conditions of fever, chills, myalgias and malaise. Physical examination was remarkable for... (Review)
Review
A 48-year-old man with an unremarkable medical history was admitted with vague conditions of fever, chills, myalgias and malaise. Physical examination was remarkable for only scleral icterus. Laboratory evaluation revealed elevated aminotransferases, alkaline phosphatase and bilirubin. Imaging demonstrated two masses in the right lobe of his liver, which were ultimately drained and cultures demonstrated Actinomyces and Eikenella. He continued to have fever on broad-spectrum antibiotics until catheter drainage of the abscesses was performed. He was eventually discharged in improved condition on amoxicillin-clavulanate. His aminotransferases, alkaline phosphatase and bilirubin continued to improve and he remained afebrile and asymptomatic. A repeat CT 2 months after discharge demonstrated resolution of the abscesses. Actinomyces and Eikenella are rare causes of liver abscesses and treatment requires drainage and an extended course of antibiotics. The polymicrobial character typical of liver abscesses makes antibiotic therapy challenging when cultures reveal rare organisms such as Actinomyces and Eikenella.
Topics: Actinomyces; Actinomycosis; Anti-Bacterial Agents; Drainage; Drug Therapy, Combination; Eikenella corrodens; Gram-Negative Bacterial Infections; Humans; Liver Abscess; Male; Middle Aged; Tomography, X-Ray Computed
PubMed: 23867879
DOI: 10.1136/bcr-2013-009613 -
Journal of Biotechnology May 2017Infections induced by oral biofilms include caries, as well as periodontal, and peri-implant disease, and may influence quality of life, systemic health, and... (Review)
Review
Infections induced by oral biofilms include caries, as well as periodontal, and peri-implant disease, and may influence quality of life, systemic health, and expenditure. As bacterial biofilms are highly resistant and resilient to conventional antibacterial therapy, it has been difficult to combat these infections. An innovative alternative to the biocontrol of oral biofilms could be to use bacteriophages or phages, the viruses of bacteria, which are specific, non-toxic, self-proliferating, and can penetrate into biofilms. Phages for Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, Fusobacterium nucleatum, Lactobacillus spp., Neisseria spp., Streptococcus spp., and Veillonella spp. have been isolated and characterised. Recombinant phage enzymes (lysins) have been shown to lyse A. naeslundii and Streptococcus spp. However, only a tiny fraction of available phages and their lysins have been explored so far. The unique properties of phages and their lysins make them promising but challenging antimicrobials. The genetics and biology of phages have to be further explored in order to determine the most effective way of applying them. Studying the effect of phages and lysins on multispecies biofilms should pave the way for microbiota engineering and microbiota-based therapy.
Topics: Bacterial Infections; Bacteriophages; Biofilms; Humans; Mouth; Mouth Diseases
PubMed: 28108235
DOI: 10.1016/j.jbiotec.2017.01.002 -
Iranian Journal of Public Health May 2014Actinomycosis is an indolent, slowly progressive infection caused by anaerobic or microaerophilic bacteria, primarily of genus Actinomyces, which colonize the mouth,... (Review)
Review
Actinomycosis is an indolent, slowly progressive infection caused by anaerobic or microaerophilic bacteria, primarily of genus Actinomyces, which colonize the mouth, colon and vagina. Mucosal disruption may lead to infection virtually at any sites in the body. The aim of this study was to underline different features of actinomycosis and to represent total data about etiologic agents, clinical, diagnostic and therapeutic approaches these infections. From a total of 38 case reports or series, ninety one cases were obtained by using of relevant articles reported as recorded cases in Iran (1972 to 2012). Analyzed data represented 21 cases of oral-servicofacial (23.1%), 7 cases of thoracic (7.7%), 17 cases of abdominal (18.7%), 21 cases of disseminated forms (23.1%) and 25 cases of others (27.5%). Findings indicated more common of these infections in men (61.5%). Actinomyces naeslundii (21 cases) was found as the most common causative agents in comparison with A. Israeli (15 cases), A. viscosus (3 cases) and A. bovis (1 case). The most patients had been successfully treated with penicillin although some cases needed surgery along with antibiotic therapy. Since some clinical features of actinomycosis are similar to malignancies, so the differential diagnosis of invasive forms must be considered. This report emphasizes on the importance of differential diagnosis of actinomycosis from similar diseases by clinicians.
PubMed: 26060757
DOI: No ID Found -
Infection and Immunity Nov 1976The intraoral establishment and proportional distribution of suspected periodontal pathogens Actinomyces viscosus and Actinomyces naeslundii were studied using a...
The intraoral establishment and proportional distribution of suspected periodontal pathogens Actinomyces viscosus and Actinomyces naeslundii were studied using a recently developed differential plating medium, CNAC-20. Saliva and dental plaque samples were collected from 108 subjects ranging in age from infants to young adults; tongue and buccal mucosa samples were collected from only the adult subjects. Catalase-negative A. naeslundii was isolated from 40% of the predentate infants' and almost all other subjects' saliva samples. It predominated among CNAC-20 isolates in the saliva of subjects of all age groups, in the plaques of young children, and in the adult tongue samples. In contrast, catalase-positive A. viscosus was not isolated from predentate infant samples, and its frequency of isolation increased slowly with age (greater than 50% detection by age 7). A. viscosus was isolated in highest relative proportions from dental plaque and buccal mucosa samples. The two closely related species A. viscosus and A. naeslundii apparently differ in respect to factors determining the host age at which they colonize and their relative intraoral distribution in humans.
Topics: Actinomyces; Adolescent; Adult; Anaerobiosis; Child; Child, Preschool; Dental Plaque; Humans; Infant; Mouth; Mouth Mucosa; Saliva; Tongue
PubMed: 977124
DOI: 10.1128/iai.14.5.1119-1124.1976 -
Antibiotics (Basel, Switzerland) Oct 2020Actinomycosis is a chronic bacterial infection characterized by continuous local spread, irrespective of anatomical barriers, and granulomatous suppurative inflammation....
Actinomycosis is a chronic bacterial infection characterized by continuous local spread, irrespective of anatomical barriers, and granulomatous suppurative inflammation. Due to its expansive local growth, it can simulate a malignant tumour. Subsequent hematogenous dissemination to distant organs can mimic metastases and further increase suspicion for malignancy. A case of severe disseminated pelvic actinomycosis associated with intrauterine device is described here. The patient presented with a pelvic mass mimicking a tumour, bilateral ureteral obstruction, ascites, multinodular involvement of the liver, lungs and spleen, inferior vena cava thrombosis and extreme cachexia. Actinomycosis was diagnosed by liver biopsy and confirmed by culture of from extracted intrauterine contraceptive device (IUD). Prolonged treatment with aminopenicillin and surgery resulted in recovery with moderate sequelae.
PubMed: 33137889
DOI: 10.3390/antibiotics9110748 -
Journal of Dental Research Mar 2022An intuitive, clinically relevant index of microbial dysbiosis as a summary statistic of subgingival microbiome profiles is needed. Here, we describe a subgingival...
An intuitive, clinically relevant index of microbial dysbiosis as a summary statistic of subgingival microbiome profiles is needed. Here, we describe a subgingival microbial dysbiosis index (SMDI) based on machine learning analysis of published periodontitis/health 16S microbiome data. The raw sequencing data, split into training and test sets, were quality filtered, taxonomically assigned to the species level, and centered log-ratio transformed. The training data set was subject to random forest analysis to identify discriminating species (DS) between periodontitis and health. DS lists, compiled by various "Gini" importance score cutoffs, were used to compute the SMDI for samples in the training and test data sets as the mean centered log-ratio abundance of periodontitis-associated species subtracted by that of health-associated ones. Diagnostic accuracy was assessed with receiver operating characteristic analysis. An SMDI based on 49 DS provided the highest accuracy with areas under the curve of 0.96 and 0.92 in the training and test data sets, respectively, and ranged from -6 (most normobiotic) to 5 (most dysbiotic) with a value around zero discriminating most of the periodontitis and healthy samples. The top periodontitis-associated DS were spp., and , while and were the top health-associated DS. The index was highly reproducible by hypervariable region. Applying the index to additional test data sets in which nitrate had been used to modulate the microbiome demonstrated that nitrate has dysbiosis-lowering properties in vitro and in vivo. Finally, 3 genera (, and ) were identified that could be used for calculation of a simplified SMDI with comparable accuracy. In conclusion, we have developed a nonbiased, reproducible, and easy-to-interpret index that can be used to identify patients/sites at risk of periodontitis, to assess the microbial response to treatment, and, importantly, as a quantitative tool in microbiome modulation studies.
Topics: Dysbiosis; Humans; Microbiota; Periodontitis; RNA, Ribosomal, 16S; Treponema denticola
PubMed: 34428955
DOI: 10.1177/00220345211035775 -
Infection and Immunity Sep 2001The ability of Actinomyces naeslundii to convert sucrose to extracellular homopolymers of fructose and to catabolize these types of polymers is suspected to be a...
The ability of Actinomyces naeslundii to convert sucrose to extracellular homopolymers of fructose and to catabolize these types of polymers is suspected to be a virulence trait that contributes to the initiation and progression of dental caries and periodontal diseases. Previously, we reported on the isolation and characterization of the gene, ftf, encoding the fructosyltransferase (FTF) of A. naeslundii WVU45. Allelic exchange mutagenesis was used to inactivate ftf, revealing that FTF-deficient stains were completely devoid of the capacity to produce levan-type (beta2,6-linked) polysaccharides. A polyclonal antibody was raised to a histidine-tagged, purified A. naeslundii FTF, and the antibody was used to localize the enzyme in the supernatant fluid. A sensitive technique was developed to detect levan formation by proteins that had been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the method was used to confirm that the levan-synthesizing activity of A. naeslundii existed predominantly in a cell-free form, that a small amount of the activity was cell associated, and that the ftf mutant was unable to produce levans. By using the nucleotide sequence of the levanase gene of a genospecies 2 A. naeslundii, formerly Actinomyces viscosus, a portion of a homologue of this gene (levJ) was amplified by PCR and inserted into a suicide vector, and the resulting construct was used to inactivate the levJ gene in the genospecies 1 strain WVU45. A variety of physiologic and biochemical studies were performed on the wild-type and LevJ-deficient strains to demonstrate that (i) this enzyme was the dominant levanase and sucrase of A. naeslundii; (ii) that LevJ was inducible by growth in sucrose; (iii) that the LevJ activity was found predominantly (>90%) in a cell-associated form; and (iv) that there was a second, fructose-inducible fructan hydrolase activity produced by these strains. The data provide the first detailed molecular analysis of fructan production and catabolism in this abundant and important oral bacterium.
Topics: Actinomyces; Bacterial Proteins; Culture Media; Electrophoresis, Polyacrylamide Gel; Fructans; Gene Expression Regulation, Bacterial; Glycoside Hydrolases; Hexosyltransferases; Humans; Sucrase; Sucrose
PubMed: 11500409
DOI: 10.1128/IAI.69.9.5395-5402.2001 -
Journal of Bacteriology Nov 1967This study was an attempt to develop a fluorescent-antibody (FA) test to differentiate Actinomyces israelii and A. naeslundii as an aid in their laboratory... (Comparative Study)
Comparative Study
This study was an attempt to develop a fluorescent-antibody (FA) test to differentiate Actinomyces israelii and A. naeslundii as an aid in their laboratory identification. Two strains of A. israelii (X522 and A601) and two strains of A. naeslundii (X454 and X600), which had received intensive study by several investigators, were used for the immunization of rabbits. Working titers, based on tests with antigens prepared from the homologous strains and from well-established heterologous strains, were determined for each labeled antibody preparation. These conjugates and their normal serum control conjugates were used separately to stain 85 cultures of Actinomyes species and 23 strains of other species that might be confused with them. Acetone-precipitated soluble antigens from these same strains were tested with different antisera in the agar-gel diffusion test. Results showed that A. israelii (X522 and A601) and A. naeslundii (X454 and X600) labeled antiglobulins, when used at their working titers, stained most strains of their homologous species. Agar-gel diffusion results showed general agreement with those of the FA tests. The two tests appear to be equal in sensitivity, but the FA test is more specific, since several cross-reactions were noted with the agar-gel diffusion test whereas no cross-reactions were obtained with the FA reagents. Agar-gel and FA studies suggest that at least two serotypes of A. israelii may be associated with human disease. Although the majority of strains tested in this study appear to belong to a common serotype, "serotype 1," two strains of an apparent second serotype, "serotype 2," were encountered. FA staining of tissue impression smears from experimentally infected mice was successful when a counterstain, Evans Blue dye, was used.
Topics: Actinomyces; Actinomycosis; Animals; Antigen-Antibody Reactions; Antigens; Clinical Laboratory Techniques; Diagnosis, Differential; Fluorescent Antibody Technique; Humans; Immune Sera; Immunodiffusion; Mice; Rabbits
PubMed: 4964473
DOI: 10.1128/jb.94.5.1287-1295.1967