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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 -
Critical Reviews in Oral Biology and... 1999Actinomyces are among the predominant bacteria in the oral microflora. This review discusses the glucose and lactate metabolism of Actinomyces naeslundii and its... (Review)
Review
Actinomyces are among the predominant bacteria in the oral microflora. This review discusses the glucose and lactate metabolism of Actinomyces naeslundii and its ecological significance in dental plaque. This bacterium has the Embden-Meyerhof-Parnas (EMP) pathway as the main route to degrade glucose. The EMP pathway-derived metabolic intermediates, phosphoenolpyruvate (PEP) and pyruvate, are further converted into different end-products, depending on the environment. Under anaerobic conditions in the absence of bicarbonate, the pyruvate is converted into lactate by a lactate dehydrogenase. In the presence of bicarbonate, the PEP is combined with bicarbonate and then converted into succinate through the succinate pathway, while the pyruvate is converted into formate and acetate through the pyruvate formate-lyase pathway. Under aerobic conditions, the pyruvate liberates acetate and CO2 through a pathway initiated by a pyruvate dehydrogenase. A. naeslundii strains also degrade lactate, aerobically, to acetate and CO2 through the conversion of lactate into pyruvate by a NAD-independent lactate dehydrogenase. These strains also synthesize glycogen from a glycolytic intermediate, glucose 6-phosphate. Besides atmospheric conditions and bicarbonate, the intracellular reduction-oxidation potential, carbohydrate concentration, and environmental pH also modulate the metabolism of A. naeslundii. Some of the phosphorylating enzymes involved in A. naeslundii metabolism--e.g., GTP/polyphosphate (PPn)-dependent glucokinase, pyrophosphate (PPi)-dependent phosphofructokinase, UDP-glucose pyrophosphorylase, and GDP/IDP-dependent PEP carboxykinase--are unique to A. naeslundii and have not been found in other oral bacteria. The utilization of PPn and PPi as phosphoryl donors, together with glycogen synthesis and lactate utilization, could contribute to the efficient energy metabolism found in A. naeslundii. Through this flexible and efficient metabolic capacity, A. naeslundii can adapt to fluctuating environments and compete with other bacteria in dental plaque. Further, this bacterium may modify the dental plaque environment and promote the microbial population shifts in dental plaque.
Topics: Actinomyces; Aerobiosis; Anaerobiosis; Bicarbonates; Dental Plaque; Ecology; Glucose; Glycogen; Glycolysis; Humans; Hydrogen-Ion Concentration; L-Lactate Dehydrogenase; Lactic Acid; Lyases; Mouth; Oxidation-Reduction; Phosphoenolpyruvate; Pyruvate Dehydrogenase Complex; Pyruvic Acid
PubMed: 10634585
DOI: 10.1177/10454411990100040501 -
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 -
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 -
Case Reports in Infectious Diseases 2015Actinomyces rarely causes endocarditis with 25 well-described cases reported in the literature in the past 75 years. We present a case of prosthetic valve endocarditis...
Actinomyces rarely causes endocarditis with 25 well-described cases reported in the literature in the past 75 years. We present a case of prosthetic valve endocarditis (PVE) caused by Actinomyces naeslundii. To our knowledge, this is the first report in the literature of endocarditis due to this organism and the second report of PVE caused by Actinomyces.
PubMed: 26697243
DOI: 10.1155/2015/602462 -
Indian Journal of Pathology &... 2019Actinomyces naeslundii is a commensal flora of the oral cavity and is generally considered as an avirulent saprophytic bacterium in immunocompetent patients. It can...
Actinomyces naeslundii is a commensal flora of the oral cavity and is generally considered as an avirulent saprophytic bacterium in immunocompetent patients. It can become an opportunistic anaerobic pathogen in oral cavity in patients with poor oral hygiene or tooth extraction and can cause periodontal disease. Pulmonary Actinomycosis is a rare manifestation and may be suspected in middle-aged male patients with cough and hemoptysis showing radiological findings of a peripheral mass or chronic consolidation in whom repeated aerobic cultures have yielded negative results. Here, we report isolation of A. naeslundii from the bronchoalveolar lavage sample from an immunocompetent patient who presented with chronic nonresolving pneumonia of 6 months duration.
Topics: Actinomyces; Actinomycosis; Bronchi; Bronchoalveolar Lavage Fluid; Female; Humans; Immunocompetence; Lung; Middle Aged; Pneumonia; Tomography, X-Ray Computed
PubMed: 30971569
DOI: 10.4103/IJPM.IJPM_706_17 -
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 -
Journal of Microbiological Methods Feb 2015Actinomyces naeslundii is an early colonizer with important roles in the development of the oral biofilm. The effects of butyric acid, one of short chain fatty acids in...
Actinomyces naeslundii is an early colonizer with important roles in the development of the oral biofilm. The effects of butyric acid, one of short chain fatty acids in A. naeslundii biofilm formation was observed using a flow cell system with Tryptic soy broth without dextrose and with 0.25% sucrose (TSB sucrose). Significant biofilms were established involving live and dead cells in TSB sucrose with 60mM butyric acid but not in concentrations of 6, 30, 40, and 50mM. Biofilm formation failed in 60mM sodium butyrate but biofilm level in 60mM sodium butyrate (pH4.7) adjusted with hydrochloric acid as 60mM butyric media (pH4.7) was similar to biofilm levels in 60mM butyric acid. Therefore, butyric acid and low pH are required for significant biofilm formation in the flow cell. To determine the mechanism of biofilm formation, we investigated initial A. naeslundii colonization in various conditions and effects of anti-GroEL antibody. The initial colonization was observed in the 60mM butyric acid condition and anti-GroEL antibody inhibited the initial colonization. In conclusion, we established a new biofilm formation model in which butyric acid induces GroEL-dependent initial colonization of A. naeslundii resulting in significant biofilm formation in a flow system.
Topics: Actinomyces; Bacterial Adhesion; Biofilms; Butyric Acid; Chaperonin 60; Hydrogen-Ion Concentration
PubMed: 25555820
DOI: 10.1016/j.mimet.2014.12.021 -
International Journal of Systematic and... Mar 2009Actinomyces naeslundii is an important early colonizer in the oral biofilm and consists of three genospecies (1, 2 and WVA 963) which cannot be readily differentiated...
Emended description of Actinomyces naeslundii and descriptions of Actinomyces oris sp. nov. and Actinomyces johnsonii sp. nov., previously identified as Actinomyces naeslundii genospecies 1, 2 and WVA 963.
Actinomyces naeslundii is an important early colonizer in the oral biofilm and consists of three genospecies (1, 2 and WVA 963) which cannot be readily differentiated using conventional phenotypic testing or on the basis of 16S rRNA gene sequencing. We have investigated a representative collection of type and reference strains and clinical and oral isolates (n=115) and determined the partial gene sequences of six housekeeping genes (atpA, rpoB, pgi, metG, gltA and gyrA). These sequences identified the three genospecies and differentiated them from Actinomyces viscosus isolated from rodents. The partial sequences of atpA and metG gave best separation of the three genospecies. A. naeslundii genospecies 1 and 2 formed two distinct clusters, well separated from both genospecies WVA 963 and A. viscosus. Analysis of the same genes in other oral Actinomyces species (Actinomyces gerencseriae, A. israelii, A. meyeri, A. odontolyticus and A. georgiae) indicated that, when sequence data were obtained, these species each exhibited <90 % similarity with the A. naeslundii genospecies. Based on these data, we propose the name Actinomyces oris sp. nov. (type strain ATCC 27044(T) =CCUG 34288(T)) for A. naeslundii genospecies 2 and Actinomyces johnsonii sp. nov. (type strain ATCC 49338(T) =CCUG 34287(T)) for A. naeslundii genospecies WVA 963. A. naeslundii genospecies 1 should remain as A. naeslundii sensu stricto, with the type strain ATCC 12104(T) =NCTC 10301(T) =CCUG 2238(T).
Topics: Actinomyces; Actinomycosis; Animals; Bacterial Proteins; Bacterial Typing Techniques; Blood; Cerebrospinal Fluid; DNA, Bacterial; Humans; Molecular Sequence Data; Mouth; Phenotype; Plague; Sequence Analysis, DNA; Species Specificity
PubMed: 19244431
DOI: 10.1099/ijs.0.000950-0 -
Journal of Cranio-maxillo-facial... Oct 2015Bisphosphonates-related osteonecrosis of the jaws (BRONJ) is a severe complication of BPs therapy with unknown pathogenesis. This study aimed to evaluate the impact of... (Comparative Study)
Comparative Study
Bisphosphonates-related osteonecrosis of the jaws (BRONJ) is a severe complication of BPs therapy with unknown pathogenesis. This study aimed to evaluate the impact of Actinomyces naeslundii (A. naeslundii) on the progression of BRONJ in ovariectomized (OVX) rat model with periodontal diseases. Sixty rats were randomly assigned into four groups. All rats underwent bilateral ovariectomy. Six weeks after surgery, animals with periodontitis induced by ligature placement were administrated with normal saline (NS), NS &A. naeslundii inoculation, zolecdronic acid (ZA) and ZA &A. naeslundii inoculation for 12 weeks, respectively. Loads of total bacteria and A. naeslundii in the mouth were assessed by real time PCR. After sacrifice, the mandibles were harvested for micro-computed tomography (micro-CT) and histological examination. Real-time PCR demonstrated that A. naeslundii was not routinely found in the rats and ZA treatment did not promote its accumulation. Micro-CT examination disclosed that ligature placement induced significant alveolar bone loss, which was greatly attenuated by ZA treatment and aggravated by A. naeslundii. Histological assessment demonstrated that ZA treatment increased the risk of developing BRONJ-like disease but this condition was not worsen with the presence of A. naeslundii. Our study suggested that oral A. naeslundii inoculation aggravated periodontal disease but not BRONJ in our animal model.
Topics: Actinomyces; Actinomycosis; Alveolar Bone Loss; Animals; Bacterial Load; Bisphosphonate-Associated Osteonecrosis of the Jaw; Bone Density; Bone Density Conservation Agents; Cancellous Bone; Diphosphonates; Disease Models, Animal; Disease Progression; Female; Imidazoles; Mandibular Diseases; Ovariectomy; Periodontitis; Random Allocation; Rats; Rats, Sprague-Dawley; X-Ray Microtomography; Zoledronic Acid
PubMed: 26293192
DOI: 10.1016/j.jcms.2015.07.001