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MSphere Mar 2021Virulence properties of cariogenic depend on integral membrane proteins. Bacterial cotranslational protein trafficking involves the signal recognition particle (SRP)...
Virulence properties of cariogenic depend on integral membrane proteins. Bacterial cotranslational protein trafficking involves the signal recognition particle (SRP) pathway components Ffh and FtsY, the SecYEG translocon, and YidC chaperone/insertases. Unlike , survives loss of the SRP pathway and has two paralogs. This study characterized YidC1 and YidC2 interactomes to clarify respective functions alone and in concert with the SRP and/or Sec translocon. Western blots of formaldehyde cross-linked or untreated lysates were reacted with anti-Ffh, anti-FtsY, anti-YidC1, or anti-YidC2 antibodies followed by mass spectrometry (MS) analysis of gel-shifted bands. Cross-linked lysates of wild-type and Δ strains were reacted with anti-YidC2-coupled Dynabeads, and cocaptured proteins were identified by MS. Last, YidC1 and YidC2 C-terminal tail-captured proteins were subjected to two-dimensional (2D) difference gel electrophoresis and MS analysis. Direct interactions of putative YidC1 and YidC2 binding partners were confirmed by bacterial two-hybrid assay. Our results suggest YidC2 works preferentially with the SRP pathway, while YidC1 is preferred for SRP-independent Sec translocon-mediated translocation. YidC1 and YidC2 autonomous pathways were also apparent. Two-hybrid assay identified interactions between holotranslocon components SecYEG/YajC and YidC1. Both YidC1 and YidC2 interacted with Ffh, FtsY, and chaperones DnaK and RopA. Putative membrane-localized substrates HlyX, LemA, and SMU_591c interacted with both YidC1 and YidC2. Identification of several Rgp proteins in the YidC1 interactome suggested its involvement in bacitracin resistance, which was decreased in Δ and SRP-deficient mutants. Collectively, YidC1 and YidC2 interactome analyses has further distinguished these paralogs in the Gram-positive bacterium is a prevalent oral pathogen and major causative agent of tooth decay. Many proteins that enable this bacterium to thrive in its environmental niche and cause disease are embedded in its cytoplasmic membrane. The machinery that transports proteins into bacterial membranes differs between Gram-negative and Gram-positive organisms, an important difference being the presence of multiple YidC paralogs in Gram-positive bacteria. Characterization of a protein's interactome can help define its physiological role. Herein, we characterized the interactomes of YidC1 and YidC2. Results demonstrated substantial overlap between their interactomes but also revealed several differences in their direct protein binding partners. Membrane transport machinery components were identified in the context of a large network of proteins involved in replication, transcription, translation, and cell division/cell shape. This information contributes to our understanding of protein transport in Gram-positive bacteria in general and informs our understanding of pathogenesis.
Topics: Bacterial Proteins; Membrane Transport Proteins; Protein Binding; Protein Transport; Streptococcus mutans
PubMed: 33658280
DOI: 10.1128/mSphere.01308-20 -
Indian Journal of Dental Research :... 2020The aciduric mutans streptococci (MS) group, including Streptococcus mutans (SM) and Streptococcus sobrinus (SS), is highly cariogenic. Relationship between increments...
BACKGROUND AND OBJECTIVES
The aciduric mutans streptococci (MS) group, including Streptococcus mutans (SM) and Streptococcus sobrinus (SS), is highly cariogenic. Relationship between increments in dental caries and the presence of these species is not yet clarified. It is of great importance to separately determine the presence of these two species for understanding their role in dental caries, accurate prediction, and effective prevention. Hence, this study was undertaken to detect the presence of SM and SS in plaque samples of caries-free (CF), early childhood caries (ECC), and severe early childhood caries (S-ECC) and also to compare the possible relationship between these species with the occurrence of ECC.
MATERIALS AND METHOD
In all, 120 healthy children between 3 and 6 years of age were randomly allocated into three groups: Group A (n = 40) CF, Group B (n = 40) ECC, and Group C (n = 40) S-ECC. Plaque samples were collected from all approximal surface and gingivobuccal surfaces of teeth using a sterile universal scaler and dmft/dmfs scores were taken. The presence of SM and SS was evaluated using real-time polymerase chain reaction.
RESULTS
The presence of SM in CF, ECC, and S-ECC was 10.0%, 27.5%, and 42.5%, respectively, and SS was 5.0%, 40.0%, and 47.5% in CF, ECC, and S-ECC, respectively. Comparison of mean relative quantification (RQ) values of SM between three study groups showed significant results between CF and S-ECC at P value 0.003. Comparison of mean RQ values of SS showed significant results between CF to ECC and CF to S-ECC at P value <0.001. This study showed significant results between the mean dmft/dmfs scores in three study groups and the presence of high levels of SM and SS in ECC and S-ECC groups. However, the study showed weak positive correlation between dmfs scores and both SM and SS species in ECC and S-ECC.
INTERPRETATIONS AND CONCLUSION
Higher levels of SS were more closely related to the caries-active lesions leading to severity of dental disease, that is, both in ECC and S-ECC. There was significant difference between mean dmft/dmfs scores in three study groups and it also showed positive correlation between dmfs scores and SM and SS colonization in ECC and S-ECC status.
Topics: Child; Child, Preschool; Dental Caries; Dental Plaque; Humans; Streptococcus mutans; Streptococcus sobrinus
PubMed: 32246686
DOI: 10.4103/ijdr.IJDR_432_18 -
Liver Transplantation : Official... May 2008
Topics: Bacteremia; Female; Humans; Liver Diseases; Liver Transplantation; Male; Middle Aged; Peritonitis; Streptococcal Infections; Viridans Streptococci
PubMed: 18433054
DOI: 10.1002/lt.21474 -
Applied and Environmental Microbiology Apr 2008Inactivation or selective modification is essential to elucidate the putative function of a gene. The present study describes an improved Cre-loxP-based method for...
Inactivation or selective modification is essential to elucidate the putative function of a gene. The present study describes an improved Cre-loxP-based method for markerless multiple gene deletion in Streptococcus mutans, the principal etiological agent of dental caries. This modified method uses two mutant loxP sites, which after recombination creates a double-mutant loxP site that is poorly recognized by Cre recombinase, facilitating multiple gene deletions in a single genetic background. The effectiveness of this modified strategy was demonstrated by the construction of both single and double gene deletions at the htrA and clpP loci on the chromosome of Streptococcus mutans. HtrA and ClpP play key roles in the processing and maturation of several important proteins, including many virulence factors. Deletion of these genes resulted in reducing the organism's ability to withstand exposure to low pH and oxidative agents. The method described here is simple and efficient and can be easily implemented for multiple gene deletions with S. mutans and other streptococci.
Topics: Attachment Sites, Microbiological; Gene Deletion; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genetic Markers; Genome, Bacterial; Integrases; Streptococcus mutans
PubMed: 18263742
DOI: 10.1128/AEM.02346-07 -
PloS One 2011Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and...
BACKGROUND
Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells.
METHODOLOGY/PRINCIPAL FINDINGS
PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains.
CONCLUSIONS/SIGNIFICANCE
This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits in the Mitis group streptococci.
Topics: Bacterial Proteins; Fimbriae, Bacterial; Molecular Sequence Data; Polymerase Chain Reaction; Streptococcus mitis; Streptococcus oralis; Streptococcus sanguis
PubMed: 21966432
DOI: 10.1371/journal.pone.0025124 -
BMC Biology Jan 2009Methods for assigning strains to bacterial species are cumbersome and no longer fit for purpose. The concatenated sequences of multiple house-keeping genes have been...
BACKGROUND
Methods for assigning strains to bacterial species are cumbersome and no longer fit for purpose. The concatenated sequences of multiple house-keeping genes have been shown to be able to define and circumscribe bacterial species as sequence clusters. The advantage of this approach (multilocus sequence analysis; MLSA) is that, for any group of related species, a strain database can be produced and combined with software that allows query strains to be assigned to species via the internet. As an exemplar of this approach, we have studied a group of species, the viridans streptococci, which are very difficult to assign to species using standard taxonomic procedures, and have developed a website that allows species assignment via the internet.
RESULTS
Seven house-keeping gene sequences were obtained from 420 streptococcal strains to produce a viridans group database. The reference tree produced using the concatenated sequences identified sequence clusters which, by examining the position on the tree of the type strain of each viridans group species, could be equated with species clusters. MLSA also identified clusters that may correspond to new species, and previously described species whose status needs to be re-examined. A generic website and software for electronic taxonomy was developed. This site http://www.eMLSA.net allows the sequences of the seven gene fragments of a query strain to be entered and for the species assignment to be returned, according to its position within an assigned species cluster on the reference tree.
CONCLUSION
The MLSA approach resulted in the identification of well-resolved species clusters within this taxonomically challenging group and, using the software we have developed, allows unknown strains to be assigned to viridans species via the internet. Submission of new strains will provide a growing resource for the taxonomy of viridans group streptococci, allowing the recognition of potential new species and taxonomic anomalies. More generally, as the software at the MLSA website is generic, MLSA schemes and strain databases for other groups of related species can be hosted at this website, providing a portal for microbial electronic taxonomy.
Topics: Alleles; Bacteria; Classification; Cluster Analysis; Databases, Genetic; Genetic Variation; Internet; Phenotype; Species Specificity; Viridans Streptococci
PubMed: 19171050
DOI: 10.1186/1741-7007-7-3 -
Dental and Medical Problems 2019It has been reported that patients with rheumatoid arthritis (RA) are more likely to exhibit periodontitis than patients without RA. However, the frequency and severity...
BACKGROUND
It has been reported that patients with rheumatoid arthritis (RA) are more likely to exhibit periodontitis than patients without RA. However, the frequency and severity of dental caries in patients with RA is still unknown.
OBJECTIVES
The aim of the study was to investigate whether higher counts of cariogenic bacteria are present in RA patients in contrast to healthy subjects, and to ascertain whether the frequency and severity of dental caries are increased in RA patients.
MATERIAL AND METHODS
The study involved 160 adults: an RA group (n = 80) and a control group matched by age and gender (n = 80). The participants' dental status scores were determined based on the following indices: the Decayed, Missing and Filled Teeth (DMFT) index, the Filled and Sound Teeth (FS-T) index, Treatment Needs Index (TNI), Care Index (CI), and Integrative Dental Caries Index (IDCI). DNA copies of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) were quantified using realtime polymerase chain reaction (PCR).
RESULTS
The IDCI showed that the RA group was more affected, mainly presenting moderate to severe dental caries. The RA group also had higher global DMFT scores than the control group and scored higher on the decayed component of the DMFT index. The TNI and CI indicated that RA patients required more dental attention and appropriate treatment. The Streptococcus mutans count was significantly higher in the RA group.
CONCLUSIONS
A complete basic oral examination, along with oral health instruction including adequate oral and dental hygiene, is crucial to prevent dental caries and associated complications in RA patients, since they appear to be more vulnerable than the non-RA population.
Topics: Adult; Arthritis, Rheumatoid; Dental Caries; Dental Plaque; Humans; Streptococcus mutans; Streptococcus sobrinus
PubMed: 31274251
DOI: 10.17219/dmp/105340 -
Revista Espanola de Quimioterapia :... Sep 2007Viridans group streptococci (VGS) are part of the oropharyngeal, intestinal and genital flora, but they may cause endocarditis and bacteremia in susceptible patients....
Viridans group streptococci (VGS) are part of the oropharyngeal, intestinal and genital flora, but they may cause endocarditis and bacteremia in susceptible patients. Penicillin- and macrolide-resistant strains are increasing every year. The aim of this study was to investigate genetic mechanisms of resistance to macrolides in clinically relevant isolates. We identified 85 isolates from January 2004 to June 2006. Susceptibility to penicillin, cefotaxime, erythromycin, clindamycin and gentamycin was determined. A resistance phenotype was assigned according to the disk approximation test (erythromycin-clindamycin). The mechanism of resistance was determined by PCR for the following genes: ermB, ermA, ermC, ermA (TR) and mefA/E. We identified 51 isolates belonging to Streptococcus anginosus species, most of which were obtained from abdominal abscesses, and 34 isolates belonging to other species, most of which were obtained from blood cultures. The macrolide resistance rate was 28.2% (24/85). The MLS(B) phenotype was observed in 66.7% of the isolates, primarily in the S. anginosus group. The M phenotype was predominant in S. mitis and S. oralis. Isolates that expressed the constitutive MLS(B) phenotype carried the ermB gene, and those that expressed the inducible MLSB phenotype carried the ermA gene. Isolates that expressed the M phenotype carried the mefA/E gene. There was coresistance with penicillin in 20.8% (5/24) of the isolates. Coresistance with penicillin was low. These results suggest that screening for macrolide resistance in VGS would be desirable because of the potential transmission of resistance genes to other pathogenic streptococci.
Topics: Anti-Bacterial Agents; Bacterial Proteins; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Humans; Lincosamides; Macrolides; Membrane Proteins; Methyltransferases; Microbial Sensitivity Tests; Phenotype; Polymerase Chain Reaction; Streptococcal Infections; Viridans Streptococci
PubMed: 18080028
DOI: No ID Found -
International Journal of Molecular... Mar 2017() is considered a leading cause of dental caries. The capability of to tolerate low pH is essential for its cariogenicity. Aciduricity of is linked to its adaptation...
() is considered a leading cause of dental caries. The capability of to tolerate low pH is essential for its cariogenicity. Aciduricity of is linked to its adaptation to environmental stress in oral cavity. This study aimed to investigate the effect of biofilm age and starvation condition on acid tolerance of biofilm formed by clinical isolates. clinical strains isolated from caries-active (SM593) and caries-free (SM18) adults and a reference strain (ATCC25175) were used for biofilm formation. (1) Both young and mature biofilms were formed and then exposed to pH 3.0 for 30 min with (acid-adapted group) or without (non-adapted group) pre-exposure to pH 5.5 for three hours. (2) The mature biofilms were cultured with phosphate-buffered saline (PBS) (starved group) or TPY (polypeptone-yeast extract) medium (non-starved group) at pH 7.0 for 24 h and then immersed in medium of pH 3.0 for 30 min. Biofilms were analyzed through viability staining and confocal laser scanning microscopy. In all three strains, mature, acid-adapted and starved biofilms showed significantly less destructive structure and more viable bacteria after acid shock than young, non-adapted and non-starved biofilms, respectively (all < 0.05). Furthermore, in each condition, SM593 biofilm was denser, with a significantly larger number of viable bacteria than that of SM18 and ATCC25175 (all < 0.05). Findings demonstrated that mature, acid-adapted and starvation might protect biofilms of all three strains against acid shock. Additionally, SM593 exhibited greater aciduricity compared to SM18 and ATCC25175, which indicated that the colonization of high cariogenicity of clinical strains may lead to high caries risk in individuals.
Topics: Acids; Adaptation, Physiological; Adult; Biofilms; Humans; Hydrogen-Ion Concentration; Streptococcus mutans
PubMed: 28358306
DOI: 10.3390/ijms18040713 -
The Ceylon Medical Journal Jun 2011
Topics: Child, Preschool; Drug Resistance, Bacterial; Humans; Male; Meningitis, Pneumococcal; Microbial Sensitivity Tests; Quinine; Streptococcal Infections; Streptococcus pneumoniae; Viridans Streptococci
PubMed: 21789877
DOI: 10.4038/cmj.v56i2.3123