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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 -
Indian Heart Journal 2018To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE).
OBJECTIVES
To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE).
METHODS
A total of 200 subjects including two groups. Group A- 34 subjects undergoing tooth extraction with periodontitis, 46 subjects undergoing tooth extraction without periodontitis and 40 healthy controls. Group B: 40 confirmed cases of IE (17 with and 23 without periodontitis) and 40 healthy controls. Subgingival plaque and blood samples were obtained and processed by standard procedures.
RESULTS
A total of 53 blood samples (66.25%) yielded positive cultures after tooth extraction. The relationship between the presence of periodontitis and a positive blood culture was significantly higher (p=0.05) for tooth extraction cases with periodontitis (79.40%) than tooth extraction cases without periodontitis (56.50%). Periodontitis was observed in 42.5% of IE cases. Out of the 40 patients of IE, the blood samples yielded 40 different isolates, majority were viridans streptococci 15 (37.5%) and staphylococci nine (22.5%). No statistically significant difference was observed between the subgingival plaque and blood isolates of periodontitis in both the groups, indicating similarity of biotypes of viridans streptococci isolated from the blood and the subgingival plaque. Similarity was also observed between the antibiogram profiles of viridans streptococci from both the groups.
CONCLUSIONS
Periodontitis enhances viridans streptococcal bacteremia and may be a potential risk factor for IE.
Topics: Adult; Bacteremia; Endocarditis, Bacterial; Female; Gingiva; Humans; Male; Middle Aged; Periodontitis; Risk Factors; Streptococcal Infections; Viridans Streptococci
PubMed: 29716699
DOI: 10.1016/j.ihj.2017.06.019 -
Clinical Microbiology and Infection :... Aug 2020Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However,...
OBJECTIVES
Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is becoming the method of choice for bacterial identification. However, correct identification by MALDI-TOF of closely related microorganisms such as viridans streptococci is still cumbersome, especially in the identification of S. pneumoniae. By making use of additional spectra peaks for S. pneumoniae and other viridans group streptococci (VGS). We re-identified viridans streptococci that had been identified and characterized by molecular and phenotypic techniques by MALDI-TOF.
METHODS
VGS isolates (n = 579), 496 S. pneumoniae and 83 non-S. pneumoniae were analysed using MALDI-TOF MS and the sensitivity and specificity of MALDI-TOF MS was assessed. Hereafter, mass spectra analysis was performed. Presumptive identification of proteins represented by discriminatory peaks was performed by molecular weight matching and the corresponding nucleotides sequences against different protein databases.
RESULTS
Using the Bruker reference library, 495 of 496 S. pneumoniae isolates were identified as S. pneumoniae and one isolate was identified as non-S. pneumoniae. Of the 83 non-S. pneumoniae isolates, 37 were correctly identified as non-S. pneumoniae, and 46 isolates as S. pneumoniae. The sensitivity of the MALDI-TOF MS was 99.8% (95% confidence interval (CI) 98.9-100) and the specificity was 44.6% (95% CI 33.7-55.9). Eight spectra peaks were mostly present in one category (S. pneumoniae or other VGS) and absent in the other category and inversely. Two spectra peaks of these (m/z 3420 and 3436) were selected by logistic regression to generate three identification profiles. These profiles could differentiate between S. pneumoniae and other VGS with high sensitivity and specificity (99.4% and 98.8%, respectively).
CONCLUSIONS
Spectral peaks analysis based identification is a powerful tool to differentiate S. pneumoniae from other VGS species with high specificity and sensitivity and is a useful method for pneumococcal identification in carriage studies. More research is needed to further confirm our findings. Extrapolation of these results to clinical strains need to be deeply investigated.
Topics: Bacterial Typing Techniques; Diagnosis, Differential; Humans; Molecular Typing; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcal Infections; Streptococcus pneumoniae; Viridans Streptococci
PubMed: 31811915
DOI: 10.1016/j.cmi.2019.11.024 -
Microbiology Spectrum Jun 2023Non-beta-hemolytic streptococci (NBHS), also referred to as streptococci, represent an underestimated cause of human invasive diseases. Their resistance to antibiotics,...
Non-beta-hemolytic streptococci (NBHS), also referred to as streptococci, represent an underestimated cause of human invasive diseases. Their resistance to antibiotics, including beta-lactam agents, often complicate their therapeutic management. A prospective multicenter study was conducted by the French National Reference Center for Streptococci between March and April 2021 to describe the clinical and microbiological epidemiology of invasive infections due to NBHS, excluding pneumococcus. A total of 522 NBHS invasive cases were collected. Distribution among streptococcal groups was: Streptococcus anginosus (33%), Streptococcus mitis (28%), Streptococcus sanguinis (16%), Streptococcus bovis (15%), Streptococcus salivarius (8%), and Streptococcus mutans (<1%). Median age of infection was 68 years old (range <1 day to 100 years). Cases were more frequent in male patients (gender ratio M/F 2.1:1) and manifested mainly as bacteremia without focus (46%), intra-abdominal infections (18%) and endocarditis (11%). All isolates were susceptible to glycopeptides and displayed low-level inherent gentamicin resistance. All isolates of the S. bovis, , and S. mutans groups were susceptible to beta-lactams. Conversely, nonsusceptibility to beta-lactams was found in 31%, 28%, and 52% of S. mitis, , and S. sanguinis isolates, respectively. The screening for beta-lactam resistance using the recommended one unit benzylpenicillin disk screening failed to detect 21% of resistant isolates (21/99). Last, overall resistance rates to the alternative anti-streptococcal molecules clindamycin and moxifloxacin were 29% (149/522) and 1.6% (8/505), respectively. NBHS are recognized as opportunistic pathogens particularly involved in infections of the elderly and immunocompromised patients. This study underlines their importance as common causes of severe and difficult-to-treat infections such as endocarditis. Although species of the and S. bovis/ groups remain constantly susceptible to beta-lams, resistance in oral streptococci exceeds 30% and screening techniques are not fully reliable. Therefore, accurate species identification and antimicrobial susceptibility testing by MICs determination appears essential for the treatment of NBHS invasive infections, together with continued epidemiological surveillance.
Topics: Humans; Male; Aged; Infant, Newborn; Prospective Studies; Streptococcus; Anti-Bacterial Agents; beta-Lactams; Endocarditis
PubMed: 37199642
DOI: 10.1128/spectrum.00160-23 -
BMJ Case Reports Jan 2013
Topics: Endocarditis, Subacute Bacterial; Hand Dermatoses; Humans; Male; Middle Aged; Streptococcal Infections; Tooth Extraction; Viridans Streptococci
PubMed: 23302546
DOI: 10.1136/bcr-2012-007564 -
Microbiology (Reading, England) Mar 2013Despite the enormous contributions of the bacterial paradigms Escherichia coli and Bacillus subtilis to basic and applied research, it is well known that no single... (Review)
Review
Despite the enormous contributions of the bacterial paradigms Escherichia coli and Bacillus subtilis to basic and applied research, it is well known that no single organism can be a perfect representative of all other species. However, given that some bacteria are difficult, or virtually impossible, to cultivate in the laboratory, that some are recalcitrant to genetic and molecular manipulation, and that others can be extremely dangerous to manipulate, the use of model organisms will continue to play an important role in the development of basic research. In particular, model organisms are very useful for providing a better understanding of the biology of closely related species. Here, we discuss how the lifestyle, the availability of suitable in vitro and in vivo systems, and a thorough understanding of the genetics, biochemistry and physiology of the dental pathogen Streptococcus mutans have greatly advanced our understanding of important areas in the field of bacteriology such as interspecies biofilms, competence development and stress responses. In this article, we provide an argument that places S. mutans, an organism that evolved in close association with the human host, as a novel Gram-positive model organism.
Topics: Biofilms; DNA Transformation Competence; Humans; Streptococcus mutans; Stress, Physiological
PubMed: 23393147
DOI: 10.1099/mic.0.066134-0 -
Clinical Microbiology Reviews Jul 1989This review traces the history of the human, nonhemolytic, or viridans, streptococci and describes improvements in their taxonomy wrought by study of their biochemical... (Review)
Review
This review traces the history of the human, nonhemolytic, or viridans, streptococci and describes improvements in their taxonomy wrought by study of their biochemical profiles and analysis of their nucleic acids. The goal was to define species on the basis of genetic relationships and to describe these species by their phenotypic characteristics so that they can be easily identified. This method has resulted in the division of some species. Streptococcus mutans has been divided into four species, two of which are common in humans. Three more mutans group species are indigenous to animals. Conversely, S. constellatus, S. intermedius, and "S. milleri" have been combined under S. anginosus. S. mitis (or "S. mitior") can be well-defined and includes S. sanguis II. There is genetic heterogeneity within S. sanguis, but the species is usually easy to identify. There is also some heterogeneity in S. bovis, but most human isolates are genetically related. Discussions of the taxonomy of these species are accompanied by descriptions of the characteristics by which these streptococci can be identified. Among these species are potential pathogens which should be suspected in cases of endocarditis and purulent infections of liver, brain, and other tissues.
Topics: Animals; Humans; Species Specificity; Streptococcus
PubMed: 2670193
DOI: 10.1128/CMR.2.3.315 -
Indian Journal of Medical Microbiology 2016The viridans group streptococci are a heterogeneous group of organisms which exist as commensals in the oropharynx and the gut. They cause serious infections when they... (Review)
Review
The viridans group streptococci are a heterogeneous group of organisms which exist as commensals in the oropharynx and the gut. They cause serious infections when they gain entry into sterile sites particularly in patients with predisposing conditions. Classification and species differentiation of these organisms has always been a challenge because of phenotypic differences between strains of the same species. Facklam's typing scheme based on six metabolic properties has been the most widely used and many commercial identification systems are based on it. Due to the ambiguity in species differentiation based on phenotypic tests, nucleic acid-based methods have been developed to improve the identification of these organisms. Results using genotypic methods such as 16S rRNA and sodA gene sequencing have been promising. Multilocus sequence analysis of seven house-keeping genes map, pfl, pyk, ppaC, rpoB, soda and tuf amplified by polymerase chain reaction was found to be an accurate alternative to other methods and could be useful in the characterisation of larger collections of isolates.
Topics: Bacterial Proteins; Bacterial Typing Techniques; Humans; Molecular Diagnostic Techniques; Multilocus Sequence Typing; RNA, Bacterial; RNA, Ribosomal, 16S; Streptococcal Infections; Viridans Streptococci
PubMed: 27934818
DOI: 10.4103/0255-0857.195371 -
BMC Infectious Diseases Mar 2019Streptococcus tigurinus was recently described as a new streptococcal species within the viridans group streptococci (VGS). The objectives of the present work were to...
BACKGROUND
Streptococcus tigurinus was recently described as a new streptococcal species within the viridans group streptococci (VGS). The objectives of the present work were to analyse the clinical and microbiological characteristics of S. tigurinus isolated from patients with bacteraemias, to determine the prevalence of S. tigurinus among VGS endocarditis in Spain, and to compare the clinical characteristics and outcomes of endocarditis caused by S. tigurinus and other VGS.
METHODS
Retrospective nationwide study, performed between 2008 and 2016 in 9 Spanish hospitals from 7 different provinces comprising 237 cases of infective endocarditis. Streptococcal isolates were identified by sequencing fragments of their 16S rRNA, sodA and groEL genes. Clinical data of patients with streptococcal endocarditis were prospectively collected according to a pre-established protocol.
RESULTS
Patients with endocarditis represented 7/9 (77.8%) and 26/86 (30.2%) of the bacteraemias caused by S. tigurinus and other VGS, respectively (p < 0.001), in two of the hospital participants. Among patients with streptococcal endocarditis, 12 different Streptococcus species were recognized being S. oralis, S. tigurinus and S. mitis the three more common. No relevant statistical differences were observed in the clinical characteristics and outcomes of endocarditis caused by the different VGS species.
CONCLUSIONS
In this multicenter study performed in Spain, S. tigurinus showed a higher predilection for the endocardial endothelium as compared to other VGS. However, clinical characteristics and outcomes of endocarditis caused by S. tigurinus did not significantly differ from endocarditis caused by other oral streptococci.
Topics: Adult; Aged; Aged, 80 and over; Bacteremia; Endocarditis, Bacterial; Epidemiological Monitoring; Female; Humans; Male; Middle Aged; Prognosis; Retrospective Studies; Risk Factors; Spain; Streptococcal Infections; Viridans Streptococci; Young Adult
PubMed: 30922322
DOI: 10.1186/s12879-019-3914-6 -
Journal of Global Antimicrobial... Jun 2022In 2018, we isolated multidrug-resistant α-haemolytic streptococci TP1632 from the blood of a 34-year-old patient with bacteraemia. This study aimed to characterise...
OBJECTIVES
In 2018, we isolated multidrug-resistant α-haemolytic streptococci TP1632 from the blood of a 34-year-old patient with bacteraemia. This study aimed to characterise α-haemolytic streptococci TP1632 and elucidate its multidrug resistance mechanisms.
METHODS
TP1632 was characterised by whole genome sequencing and biochemical testing. Based on the genome sequence, digital DNA-DNA hybridization (dDDH) and average nucleotide identity based on BLAST (ANIb) values were calculated. In addition, antimicrobial-resistance mechanisms were evaluated by ResFinder and transformation assay using Streptococcus mitis.
RESULTS
TP1632 showed resistance to β-lactams, macrolides, and quinolones. Genomic analysis revealed that dDDH and ANIb values between TP1632 and S. mitis were 56.3% and 93.63%, respectively, indicating TP1632 as the novel species. TP1632 exhibited macrolide resistance genes such as mef(A), msr(D), and erm(B) and tetracycline resistance gene tet(M). In addition, amino acids at position 81 in GyrA and 79 in ParC were tyrosine and isoleucine, respectively. When penicillin-binding proteins of TP1632 were introduced into S. mitis, recombinants showed β-lactam resistance. Thus, acquired resistance genes and low affinities towards antimicrobial agents contribute to multidrug resistance.
CONCLUSION
Our findings indicated that multidrug-resistant TP1632 is a novel species in the genus Streptococcus. Furthermore, antimicrobial resistance of this strain could transfer horizontally among α-haemolytic streptococci. These data indicated the risk of emergence of multidrug-resistant streptococci not only as a pathogen but also a reservoir of antimicrobial resistance. This isolate was proposed as a novel species, Streptococcus toyakuensis sp. nov. The type strain is TP1632 (= JCM 34623 = CCUG 75492).
Topics: Adult; Anti-Bacterial Agents; DNA; Drug Resistance, Bacterial; Humans; Macrolides; Microbial Sensitivity Tests; Streptococcus
PubMed: 35500839
DOI: 10.1016/j.jgar.2022.04.018