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Systematic and Applied Microbiology Oct 2016Two bacterial strains, Am4 and G10 were isolated from rumen fluid of different ruminants: cow (Holstein-Friesian) and sheep (Slovenskè merino), respectively. They were...
Two bacterial strains, Am4 and G10 were isolated from rumen fluid of different ruminants: cow (Holstein-Friesian) and sheep (Slovenskè merino), respectively. They were isolated from different hosts and regions, but showed 99.2% similarity of the 16S rRNA genes. Both strains are versatile and ferment various sugars to mainly succinate and lactate and small amounts of acetate and formate. The 16S rRNA sequences of Am4 and G10 revealed that they belonged to the genus Actinomyces, and are related to Actinomyces ruminicola JCM 13352 with 97.0% and 97.4% similarity, respectively. DDH showed strain Am4 and G10 had only 55.8 and 43.3% similarity with the Actinomyces ruminicola JCM 13352, and had 69.9% similarity among each other. Comparing strain Am4 and G10, gANI value and dDDH were 92.9% and 68.6%, respectively. Additionally, AAI between the strains was 95.8%. MLSA of housekeeping genes showed difference of metG and pheS. The G+C% contents of strain Am4 and G10 were 69.8% and 68.5%, respectively. MK-10(H) was the principal quinone for strain Am4 (82%) and G10 (91%) with small amounts of MK-10(H) and MK-10(H) for both strains. Only MK-9(H) was detected in strain Am4. MALDI-TOF analysis of protein profiles also revealed that Am4 and G10 are different from each other and from Actinomyces ruminicola JCM 13352. Based on phylogenetic and physiological characteristics, together with genome comparison and MLSA we propose two novel species in the genus Actinomyces: Actinomyces succiniciruminis sp. nov. (type strain Am4=TISTR 2317=DSM 10376) and Actinomyces glycerinitolerans sp. nov. (type strain G10=TISTR 2318=DSM 10377).
Topics: Actinomyces; Animals; Bacterial Typing Techniques; Base Composition; Base Sequence; Cattle; Cell Wall; DNA, Bacterial; Fatty Acids; Female; Genes, Essential; Glycerol; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Rumen; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Sheep; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Succinic Acid
PubMed: 27613227
DOI: 10.1016/j.syapm.2016.08.001 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Nov 2023Cyclodipeptide (CDP) composed of two amino acids is the simplest cyclic peptide. These two amino acids form a typical diketopiperazine (DKP) ring by linking each other... (Review)
Review
Cyclodipeptide (CDP) composed of two amino acids is the simplest cyclic peptide. These two amino acids form a typical diketopiperazine (DKP) ring by linking each other with peptide bonds. This characteristic stable ring skeleton is the foundation of CDP to display extensive and excellent bioactivities, which is beneficial for CDPs' pharmaceutical research and development. The natural CDP products are well isolated from actinomycetes. These bacteria can synthesize DKP backbones with nonribosomal peptide synthetase (NRPS) or cyclodipeptide synthase (CDPS). Moreover, actinomycetes could produce a variety of CDPs through different enzymatic modification. The presence of these abundant and diversified catalysis indicates that actinomycetes are promising microbial resource for exploring CDPs. This review summarized the pathways for DKP backbones biosynthesis and their post-modification mechanism in actinomycetes. The aim of this review was to accelerate the genome mining of CDPs and their isolation, purification and structure identification, and to facilitate revealing the biosynthesis mechanism of novel CDPs as well as their synthetic biology design.
Topics: Actinobacteria; Actinomyces; Biological Products; Bacteria; Diketopiperazines; Amino Acids
PubMed: 38013180
DOI: 10.13345/j.cjb.230068 -
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 -
BMC Microbiology Oct 2020Actinomyces oris is an early colonizer and has two types of fimbriae on its cell surface, type 1 fimbriae (FimP and FimQ) and type 2 fimbriae (FimA and FimB), which...
Short chain fatty acids induced the type 1 and type 2 fimbrillin-dependent and fimbrillin-independent initial attachment and colonization of Actinomyces oris monoculture but not coculture with streptococci.
BACKGROUND
Actinomyces oris is an early colonizer and has two types of fimbriae on its cell surface, type 1 fimbriae (FimP and FimQ) and type 2 fimbriae (FimA and FimB), which contribute to the attachment and coaggregation with other bacteria and the formation of biofilm on the tooth surface, respectively. Short-chain fatty acids (SCFAs) are metabolic products of oral bacteria including A. oris and regulate pH in dental plaques. To clarify the relationship between SCFAs and fimbrillins, effects of SCFAs on the initial attachment and colonization (INAC) assay using A. oris wild type and fimbriae mutants was investigated. INAC assays using A. oris MG1 strain cells were performed with SCFAs (acetic, butyric, propionic, valeric and lactic acids) or a mixture of them on human saliva-coated 6-well plates incubated in TSB with 0.25% sucrose for 1 h. The INAC was assessed by staining live and dead cells that were visualized with a confocal microscope.
RESULTS
Among the SCFAs, acetic, butyric and propionic acids and a mixture of acetic, butyric and propionic acids induced the type 1 and type 2 fimbriae-dependent and independent INAC by live A. oris, but these cells did not interact with streptococci. The main effects might be dependent on the levels of the non-ionized acid forms of the SCFAs in acidic stress conditions. GroEL was also found to be a contributor to the FimA-independent INAC by live A. oris cells stimulated with non-ionized acid.
CONCLUSION
SCFAs affect the INAC-associated activities of the A. oris fimbrillins and non-fimbrillins during ionized and non-ionized acid formations in the form of co-culturing with other bacteria in the dental plaque but not impact the interaction of A. oris with streptococci.
Topics: Actinomyces; Bacterial Adhesion; Biofilms; Fatty Acids, Volatile; Fimbriae Proteins; Gene Deletion; Microbial Interactions; Streptococcus
PubMed: 33129273
DOI: 10.1186/s12866-020-01976-4 -
BMC Oral Health May 2019Zinc oxide nanoparticles (ZnONPs) have been widely studied as bactericidal reagents. However, it is still challenging to use ZnONPs as a root canal sealant to eliminate...
BACKGROUND
Zinc oxide nanoparticles (ZnONPs) have been widely studied as bactericidal reagents. However, it is still challenging to use ZnONPs as a root canal sealant to eliminate infecting microorganisms in the root canal system. This study aimed at understanding the antibacterial and biofilm effects of ZnONPs in the infected root canal and their effect on cell function.
METHODS
This study aimed to develop a better understanding of the antibacterial effects of ZnONPs in the infected root canal and their effect on cell function. Experiments were performed in two stages; the first stage included inhibition zone tests and the minimum inhibitory concentration (MIC) test, which were performed to examine the antibacterial activity of ZnONPs against Porphyromonas gingivalis (P. gingivalis) and Actinomyces Naeslundii (A. naeslundii) bacteria in vitro. ZnONPs were further evaluated for their biocompatibility using normal mouse NIH3T3 and OCCM-30 cells by the cell-based MTT assay. In addition, the influence of ZnONPs on matrix metalloproteinases in NIH3T3 cells and their inhibiting factors (Mmp13 and Timp1) were measured using the real-time PCR technique and western blot method.
RESULTS
The MIC of ZnONPs against P. gingivalis and A. naeslundii were confirmed to be 10 μg/mL and 40 μg/mL, respectively. The MTT assay showed that ZnONPs were nontoxic. The RT-PCR and western blotting results showed that Mmp13 was downregulated and Timp1 expression was increased. Meanwhile, ZnONPs were shown to increase the expression of the OCCM-30 osteogenesis-related factors Bsp and Runx2. Finally, there was no significant change in the morphology of NIH3T3 and OCCM-30 cells after the addition of different concentrations of ZnONPs for different periods of time.
CONCLUSION
ZnONPs have excellent antibacterial activity against P. gingivalis and A. naeslundii and have low cell cytotoxicity in vitro.
Topics: Actinomyces; Animals; Anti-Bacterial Agents; Dental Cementum; Mice; NIH 3T3 Cells; Nanoparticles; Porphyromonas gingivalis; Zinc Oxide
PubMed: 31088450
DOI: 10.1186/s12903-019-0780-y -
Infection and Immunity Apr 1984Interbacterial adherence was sought between strains of Actinomyces viscosus indigenous to the human mouth and strains of Streptococcus pyogenes, Streptococcus...
Interbacterial adherence was sought between strains of Actinomyces viscosus indigenous to the human mouth and strains of Streptococcus pyogenes, Streptococcus agalactiae, and Pseudomonas aeruginosa. Six of nine strains of S. pyogenes, three of five strains of S. agalactiae, and two of four strains of P. aeruginosa were found to coaggregate with each of five strains of A. viscosus tested. Some coaggregation reactions were inhibited by 0.05 M lactose and were dependent upon heat- and protease-sensitive Actinomyces components. Such reactions appear to involve the galactosyl-binding adhesin previously described in type 2 fimbriae on A. viscosus. Other coaggregation reactions were dependent upon heat- and protease-sensitive components of the pathogen. That such pathogen strains possessed an adhesin(s) was further suggested by the observation that they agglutinated human erythrocytes. The ability of coaggregation-positive and -negative strains of S. pyogenes and S. agalactiae to adhere to Actinomyces-coated agarose beads was also studied. Coaggregation-positive streptococcal strains attached in higher numbers to the Actinomyces-coated beads than did strains which were coaggregation negative. Lactose (0.05 M) inhibited the attachment of those streptococcal strains which coaggregated with A. viscosus in a lactose-sensitive manner. The adherence of those streptococcal strains whose coaggregation appeared to depend upon the galactosyl-binding adhesin of A. viscosus was also reduced by components of human saliva. Crude sonic extracts of coaggregation-positive streptococci or of P. aeruginosa were also effective in aggregating Actinomyces cells. The effect of lactose and of salivary components on this extract-induced aggregation of Actinomyces cells generally paralleled that observed in other assays. The apparent prevalence and diversity of adherent reactions between the pathogens studied and indigenous strains of A. viscosus suggest that some may affect host susceptibility to these infectious agents.
Topics: Actinomyces; Bacterial Proteins; Hemagglutination; Hot Temperature; Humans; Lactose; Peptide Hydrolases; Pseudomonas aeruginosa; Saliva; Sonication; Streptococcus agalactiae; Streptococcus pyogenes
PubMed: 6423545
DOI: 10.1128/iai.44.1.86-90.1984 -
Current Issues in Molecular Biology 2019Oral streptococci are among the most abundant genera present in the oral cavity. They are usually the first colonizers of oral surfaces and they develop extensive... (Review)
Review
Oral streptococci are among the most abundant genera present in the oral cavity. They are usually the first colonizers of oral surfaces and they develop extensive microbial interactions, playing a fundamental role in the pathogenesis of oral diseases such as dental caries and periodontitis. In addition to physical adherence, streptococcal cells also exchange messages with cells from another spp. and other microorganisms in the form of metabolites and signaling molecules. In this review, we focused on these intrageneric and intergeneric interactions, and their association with oral diseases.
Topics: Actinomyces; Bacterial Adhesion; Bacterial Proteins; Biofilms; Candida albicans; Dental Caries; Dietary Carbohydrates; Gene Expression Regulation, Bacterial; Humans; Microbial Interactions; Mouth; Porphyromonas gingivalis; Quorum Sensing; Signal Transduction; Streptococcal Infections; Streptococcus; Virulence
PubMed: 31166176
DOI: 10.21775/cimb.032.377 -
The ISME Journal Dec 2020Host range is a fundamental component of symbiotic interactions, yet it remains poorly characterized for the prevalent yet enigmatic subcategory of bacteria/bacteria...
Host range is a fundamental component of symbiotic interactions, yet it remains poorly characterized for the prevalent yet enigmatic subcategory of bacteria/bacteria symbioses. The recently characterized obligate bacterial epibiont Candidatus Nanosynbacter lyticus TM7x with its bacterial host Actinomyces odontolyticus XH001 offers an ideal system to study such a novel relationship. In this study, the host range of TM7x was investigated by coculturing TM7x with various related Actinomyces strains and characterizing their growth dynamics from initial infection through subsequent co-passages. Of the twenty-seven tested Actinomyces, thirteen strains, including XH001, could host TM7x, and further classified into "permissive" and "nonpermissive" based on their varying initial responses to TM7x. Ten permissive strains exhibited growth/crash/recovery phases following TM7x infection, with crash timing and extent dependent on initial TM7x dosage. Meanwhile, three nonpermissive strains hosted TM7x without a growth-crash phase despite high TM7x dosage. The physical association of TM7x with all hosts, including nonpermissive strains, was confirmed by microscopy. Comparative genomic analyses revealed distinguishing genomic features between permissive and nonpermissive hosts. Our results expand the concept of host range beyond a binary to a wider spectrum, and the varying susceptibility of Actinomyces strains to TM7x underscores how small genetic differences between hosts can underly divergent selective trajectories.
Topics: Actinomyces; Bacteria; Host Specificity; Symbiosis
PubMed: 32839546
DOI: 10.1038/s41396-020-00736-6 -
Microbial Ecology Jan 2016Despite many examples of obligate epibiotic symbiosis (one organism living on the surface of another) in nature, such an interaction has rarely been observed between two...
Despite many examples of obligate epibiotic symbiosis (one organism living on the surface of another) in nature, such an interaction has rarely been observed between two bacteria. Here, we further characterize a newly reported interaction between a human oral obligate parasitic bacterium TM7x (cultivated member of Candidatus Saccharimonas formerly Candidate Phylum TM7), and its basibiont Actinomyces odontolyticus species (XH001), providing a model system to study epiparasitic symbiosis in the domain Bacteria. Detailed microscopic studies indicate that both partners display extensive morphological changes during symbiotic growth. XH001 cells manifested as short rods in monoculture, but displayed elongated and hyphal morphology when physically associated with TM7x. Interestingly, these dramatic morphological changes in XH001 were also induced in oxygen-depleted conditions, even in the absence of TM7x. Targeted quantitative real-time PCR (qRT-PCR) analyses revealed that both the physical association with TM7x as well as oxygen depletion triggered up-regulation of key stress response genes in XH001, and in combination, these conditions act in an additive manner. TM7x and XH001 co-exist with relatively uniform cell morphologies under nutrient-replete conditions. However, upon nutrient depletion, TM7x-associated XH001 displayed a variety of cell morphologies, including swollen cell body, clubbed-ends, and even cell lysis, and a large portion of TM7x cells transformed from ultrasmall cocci into elongated cells. Our study demonstrates a highly dynamic interaction between epibiont TM7x and its basibiont XH001 in response to physical association or environmental cues such as oxygen level and nutritional status, as reflected by their morphological and physiological changes during symbiotic growth.
Topics: Actinomyces; Bacteria; Bacterial Physiological Phenomena; Humans; Mouth; Phenotype; Symbiosis
PubMed: 26597961
DOI: 10.1007/s00248-015-0711-7 -
Microbiology and Immunology Dec 2013Actinomyces are predominant oral bacteria; however, their cariogenic potential in terms of acid production and fluoride sensitivity has not been elucidated in detail and... (Comparative Study)
Comparative Study
Actinomyces are predominant oral bacteria; however, their cariogenic potential in terms of acid production and fluoride sensitivity has not been elucidated in detail and compared with that of other caries-associated oral bacteria, such as Streptococcus. Therefore, this study aimed to elucidate and compare the acid production and growth of Actinomyces and Streptococcus in the presence of bicarbonate and fluoride to mimic conditions in the oral cavity. Acid production from glucose was measured by pH-stat at pH 5.5 and 7.0 under anaerobic conditions. Growth rate was assessed by optical density in anaerobic culture. Although Actinomyces produced acid at a lower rate than did Streptococcus, their acid production was more tolerant of fluoride (IDacid production 50 = 110-170 ppm at pH 7.0 and 10-13 ppm at pH 5.5) than that of Streptococcus (IDacid production 50 = 36-53 ppm at pH 7.0 and 6.3-6.5 ppm at pH 5.5). Bicarbonate increased acid production by Actinomyces with prominent succinate production and enhanced their fluoride tolerance (IDacid production 50 = 220-320 ppm at pH 7.0 and 33-52 ppm at pH 5.5). Bicarbonate had no effect on these variables in Streptococcus. In addition, although the growth rate of Actinomyces was lower than that of Streptococcus, Actinomyces growth was more tolerant of fluoride (IDgrowth 50 = 130-160 ppm) than was that of Streptococcus (IDgrowth 50 = 27-36 ppm). These results indicate that oral Actinomyces are more tolerant of fluoride than oral Streptococcus, and bicarbonate enhances the fluoride tolerance of oral Actinomyces. Because of the limited number of species tested here, further study is needed to generalize these findings to the genus level.
Topics: Actinomyces; Anaerobiosis; Anti-Bacterial Agents; Bicarbonates; Carboxylic Acids; Fluorides; Glucose; Humans; Hydrogen-Ion Concentration; Mouth; Spectrophotometry; Streptococcus
PubMed: 24102761
DOI: 10.1111/1348-0421.12098