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1.
Oral Health Prev Dent ; 19(1): 25-31, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33491375

RESUMEN

Purpose: The aim of this study was to verify how the prevalence of viridans-streptococci is changed by two appointments of professional prophylaxis and after the subgingival instrumentation via scaling and root planing (SRP). Material and Methods: Samples of the subgingival biofilm were collected from 19 individuals with periodontitis receiving two appointments of professional prophylaxis and SRP before and after the treatment procedures and the presence of viridans-streptococci was analysed by microbiological cultivation. Non-parametric statistical testing using Friedman/Wilcoxon tests and chi-square testing was used for statistical analysis. Results: No statistically significant changes over time were found for the mutans-group. The prevalence of Streptococcus mitis decreased after two appointments of professional prophylaxis (p = 0.013). The prevalence of S. mitis decreased again after SRP (p <0.001). The prevalence of Streptococcus anginosus decreased after two appointments of professional prophylaxis (p = 0.002). After SRP five positive results for S. anginosus were detected (p = 0.026). For Streptococcus oralis and Streptococcus gordonii tendencies to statistical significance were found. The number of positive results for S. oralis increased after the first appointment of professional oral prophylaxis (p = 0.055). The number of positive results for S. gordonii increased after the first appointment of professional oral prophylaxis (p = 0.055). Conclusion: The step-wise periodontal therapy influences the prevalence of viridans-streptococci, especially S. mitis and S. anginosus. No tremendous increase of streptococci especially related to the carious process occurs in the subgingival biofilm. Clinical Relevance: The study reveals knowledge on changes of the composition of the subgingival biofilm due to different steps of periodontal therapy.


Asunto(s)
Raspado Dental , Periodontitis , Biopelículas , Humanos , Aplanamiento de la Raíz , Streptococcus oralis
2.
Arch Oral Biol ; 117: 104822, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32592931

RESUMEN

OBJECTIVE: Overcoming substantial shortcomings of soft liners as physico-chemical changes and liner-biofilm-related infections remains a challenge in the rehabilitation treatment. In this study, protective non-thermal plasma (NTP) treatments were developed on the soft liner surface to improve its surface and physico-chemical properties and to reduce fungal colonization after biofilm inhibition challenge. METHODS: Resinous liner specimens (Coe-Soft) were prepared and distributed in 3 groups according to the surface treatments: (1) untreated (control); (2) treated with sulfur hexafluoride-based NTP (SF6); and (3) treated with hexamethyldisiloxane-based NTP (HMDSO). To test the NTP stability and their protective and antimicrobial effect on the liner surface over time, the morphology, chemical composition, roughness, water contact angle, shore A hardness, sorption and solubility were evaluated before and after the specimens were exposed to dual-species biofilm of Candida albicans and Streptococcus oralis for 14 days. Colony forming units and biofilm structure were assessed. Data were submitted to ANOVA and Tukey tests (α = 0.05). RESULTS: Both treatments modified the surface morphology, increased hydrophobicity and roughness of the liner, and were effective to reduce C. albicans adhesion without affecting the commensal health-associated S. oralis. HMDSO presented chemical stability and lower hardness in both periods, whereas SF6 exhibited higher initial hardness than control and the highest sorption; contrarily, similar solubility was noted for all groups. CONCLUSION: HMDSO-based film showed improved physico-chemical properties and inhibited C. albicans biofilm. Thus, it has potential for use to control candida-related stomatitis and improve liner's stability even after being exposed to biofilm inhibition challenge.


Asunto(s)
Antiinfecciosos , Biopelículas , Alineadores Dentales , Gases em Plasma , Antiinfecciosos/farmacología , Candida albicans , Ensayo de Materiales , Gases em Plasma/farmacología , Streptococcus oralis , Propiedades de Superficie
3.
Biofouling ; 36(3): 245-255, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32326753

RESUMEN

Dental plaque is a biofilm composed of a complex oral microbial community. The accumulation of plaque in the pit and fissures of dental elements often leads to the development of tooth decay (dental caries). Here, potent anti-biofilm materials were developed by incorporating zinc methacrylates or di-n-butyl-dimethacrylate-tin into the light-curable sealant and their physical, mechanical, and biological properties were evaluated. The data revealed that 5% di-n-butyl-dimethacrylate-tin (SnM 5%) incorporated sealant showed strong anti-biofilm efficacy against various single-species (Streptococcus mutans or Streptococcus oralis or Candida albicans) and S. mutans-C. albicans cross-kingdom dual-species biofilms without either impairing the mechanical properties of the sealant or causing cytotoxicities against mouse fibroblasts. The findings indicate that the incorporation of SnM 5% in the experimental pit and fissure self-adhesive sealant may have the potential to be part of current chemotherapeutic strategies to prevent the formation of cariogenic oral biofilms that cause dental caries.


Asunto(s)
Adhesivos/farmacología , Biopelículas/efectos de los fármacos , Caries Dental/prevención & control , Selladores de Fosas y Fisuras/farmacología , Zinc/química , Adhesivos/química , Animales , Biopelículas/crecimiento & desarrollo , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Caries Dental/microbiología , Humanos , Metacrilatos/química , Ratones , Microbiota/efectos de los fármacos , Selladores de Fosas y Fisuras/química , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/crecimiento & desarrollo , Streptococcus oralis/efectos de los fármacos , Streptococcus oralis/crecimiento & desarrollo
4.
PLoS One ; 15(4): e0231101, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32302339

RESUMEN

Mast cells and basophils are central players in allergic reactions triggered by immunoglobulin E (IgE). They have intracellular granules containing allergic mediators (e.g., histamine, serotonin, inflammatory cytokines, proteases and ß-hexosaminidase), and stimulation by IgE-allergen complex leads to the release of such allergic mediators from the granules, that is, degranulation. Mast cells are residents of mucosal surfaces, including those of nasal and oral cavities, and play an important role in the innate defense system. Members of the mitis group streptococci such as Streptococcus oralis, are primary colonizers of the human oral cavity. They produce hydrogen peroxide (H2O2) as a by-product of sugar metabolism. In this study, we investigated the effects of streptococcal infection on RBL-2H3 mast cell/basophil cell line. Infection by oral streptococci did not induce degranulation of the cells. Stimulation of the RBL-2H3 cells with anti-dinitrophenol (DNP) IgE and DNP-conjugated human serum albumin triggers degranulation with the release of ß-hexosaminidase. We found that S. oralis and other mitis group streptococci inhibited the IgE-triggered degranulation of RBL-2H3 cells. Since mitis group streptococci produce H2O2, we examined the effect of S. oralis mutant strain deficient in producing H2O2, and found that they lost the ability to suppress the degranulation. Moreover, H2O2 alone inhibited the IgE-induced degranulation. Subsequent analysis suggested that the inhibition of degranulation was related to the cytotoxicity of streptococcal H2O2. Activated RBL-2H3 cells produce interleukin-4 (IL-4); however, IL-4 production was not induced by streptococcal H2O2. Furthermore, an in vivo study using the murine pollen-induced allergic rhinitis model suggested that the streptococcal H2O2 reduces nasal allergic reaction. These findings reveal that H2O2 produced by oral mitis group streptococci inhibits IgE-stimulated degranulation by inducing cell death. Consequently, streptococcal H2O2 can be considered to modulate the allergic reaction in mucosal surfaces.


Asunto(s)
Alérgenos/metabolismo , Hipersensibilidad/inmunología , Inmunoglobulina E/inmunología , Infecciones Estreptocócicas/tratamiento farmacológico , Alérgenos/inmunología , Animales , Basófilos/inmunología , Basófilos/microbiología , Basófilos/patología , Degranulación de la Célula/inmunología , Supervivencia Celular/inmunología , Dinitrofenoles/farmacología , Humanos , Peróxido de Hidrógeno/metabolismo , Hipersensibilidad/tratamiento farmacológico , Hipersensibilidad/patología , Inmunoglobulina E/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Mastocitos/inmunología , Mastocitos/microbiología , Mastocitos/patología , Ratones , Extractos Vegetales/química , Extractos Vegetales/farmacología , Albúmina Sérica Humana/inmunología , Albúmina Sérica Humana/metabolismo , Infecciones Estreptocócicas/inmunología , Streptococcus oralis/inmunología , Streptococcus oralis/patogenicidad , Azúcares/metabolismo
5.
Klin Lab Diagn ; 65(1): 55-60, 2020.
Artículo en Ruso | MEDLINE | ID: mdl-32155008

RESUMEN

Inflammatory periodontal diseases represent a serious dental and general medical problem due to the high prevalence among the adult population, the presence of clinical forms leading to the destruction of the dentition and tooth loss, insufficient treatment effectiveness and the frequency of relapse, including in connection with the formation of biofilms. A molecular genetic test system has been developed to evaluate the content of periodontopathogenic microorganisms Porphyromonas gingivalis, Treponema denticola, Streptococcus oralis, Streptococcus sanguis and Streptococcus sobrinus in the contents of periodontal pockets. The analytical characteristics of the test system were determined, and testing was carried out on clinical samples of patients with chronic generalized periodontitis of moderate severity. The constructed diagnostic kit allowed us to conduct a comparative analysis of the effectiveness of various types of treatment of inflammatory periodontal diseases based on quantitative data on the content of bacteria in the contents of periodontal pockets.


Asunto(s)
Bolsa Periodontal/microbiología , Periodontitis/diagnóstico , Periodontitis/microbiología , Adulto , Aggregatibacter actinomycetemcomitans , Bacteroides/aislamiento & purificación , Diagnóstico Precoz , Pruebas Genéticas , Humanos , Porphyromonas gingivalis/aislamiento & purificación , Streptococcus oralis/aislamiento & purificación , Streptococcus sanguis/aislamiento & purificación , Streptococcus sobrinus/aislamiento & purificación , Treponema denticola/aislamiento & purificación
6.
Biofouling ; 36(2): 146-158, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32182151

RESUMEN

Following antimicrobial administrations in oral environments, bacteria become exposed to a sub-minimum inhibitory concentration (sub-MIC), which can induce in vitro single-species biofilms. This study explored the effects of chlorhexidine gluconate (CHG) at a sub-MIC on in vitro multi-species biofilms comprising Streptococcus mutans, Streptococcus oralis and Actinomyces naeslundii. CHG at a sub-MIC was found to induce in vitro biofilm growth, although the bacterial growth was not significantly different from that in the control. The gene transcription related to S. mutans multi-species biofilm formation with CHG at a sub-MIC was significantly higher than that of the control, but this was not found in S. mutans single-species biofilms. The bio-volume of extracellular polysaccharides with CHG at a sub-MIC was significantly higher than that of the control. This suggests that CHG at a sub-MIC may promote the development of multi-species biofilms by affecting the gene transcription related to S. mutans biofilm formation.


Asunto(s)
Actinomyces/efectos de los fármacos , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Clorhexidina/análogos & derivados , Streptococcus mutans/efectos de los fármacos , Streptococcus oralis/efectos de los fármacos , Actinomyces/genética , Biopelículas/crecimiento & desarrollo , Clorhexidina/farmacología , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Streptococcus mutans/genética , Streptococcus oralis/genética , Transcriptoma/efectos de los fármacos
7.
ISME J ; 14(5): 1207-1222, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32042100

RESUMEN

Streptococcal glucosyltransferases (Gtf) synthesize α-glucan exopolymers which contribute to biofilm matrix. Streptococcus oralis interacts with the opportunistic pathogen Candida albicans to form hypervirulent biofilms. S. oralis 34 has a single gtf gene (gtfR). However, the role of gtfR in single and mixed species biofilms with C. albicans has never been examined. A gtfR deletion mutant, purified GtfR, and recombinant GtfR glucan-binding domain were tested in single and mixed biofilms on different substrata in vitro. A mouse oral infection model was also used. We found that in single species biofilms growing with sucrose on abiotic surfaces S. oralis gtfR increased biofilm matrix, but not bacterial biomass. In biofilms with C. albicans, S. oralis encoding gtfR showed increased bacterial biomass on all surfaces. C. albicans had a positive effect on α-glucan synthesis, and α-glucans increased C. albicans accretion on abiotic surfaces. In single and mixed infection of mice receiving sucrose S. oralis gtfR enhanced mucosal burdens. However, sucrose had a negative impact on C. albicans burdens and reduced S. oralis burdens in co-infected mice. Our data provide new insights on the GtfR-mediated interactions between the two organisms and the influence of biofilm substratum and the mucosal environment on these interactions.


Asunto(s)
Biopelículas , Candida albicans/fisiología , Glucosiltransferasas/metabolismo , Streptococcus oralis/fisiología , Animales , Candida albicans/genética , Glucanos , Sistema de la Enzima Desramificadora del Glucógeno , Ratones , Streptococcus , Streptococcus mutans/genética , Streptococcus oralis/genética
8.
Transpl Infect Dis ; 22(2): e13246, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31943573

RESUMEN

We reported the case of a patient with leukemia who developed febrile neutropenia after hematopoietic stem cell transplantation. Blood culture results revealed the presence of Streptococcus oralis, while antimicrobial susceptibility testing showed the resistance to penicillin and cephem. Furthermore, isolates were not susceptible to either meropenem or daptomycin but not to vancomycin. S oralis is known to belong to Streptococcus mitis group and be a causative agent of bacteremia in the neutropenic patients, but multidrug resistance of S oralis is rare. Our findings suggest that we might pay attention to the emergence of the microorganisms acquiring multidrug resistance in neutropenic patients.


Asunto(s)
Antibacterianos/uso terapéutico , Bacteriemia/diagnóstico , Farmacorresistencia Bacteriana Múltiple , Neutropenia Febril/complicaciones , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Infecciones Estreptocócicas/diagnóstico , Adulto , Bacteriemia/tratamiento farmacológico , Neutropenia Febril/microbiología , Femenino , Humanos , Leucemia/terapia , Pruebas de Sensibilidad Microbiana , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus oralis/efectos de los fármacos , Resultado del Tratamiento
9.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 1): 8-13, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31929180

RESUMEN

PitA is the putative tip adhesin of the pilus islet 2 (PI-2)-encoded sortase-dependent pilus in the Gram-positive Streptococcus oralis, an opportunistic pathogen that often flourishes within the diseased human oral cavity. Early colonization by S. oralis and its interaction with Actinomyces oris seeds the development of oral biofilm or dental plaque. Here, the PI-2 pilus plays a vital role in mediating adherence to host surfaces and other bacteria. A recombinant form of the PitA adhesin has now been produced and crystallized. Owing to the large size (∼100 kDa), flexibility and complicated folding of PitA, obtaining diffraction-quality crystals has been a challenge. However, by the use of limited proteolysis with α-chymotrypsin, the diffraction quality of the PitA crystals was considerably enhanced to 2.16 Šresolution. These crystals belonged to space group P1, with unit-cell parameters a = 61.48, b = 70.87, c = 82.46 Å, α = 80.08, ß = 87.02, γ = 87.70°. The anomalous signal from the terbium derivative of α-chymotrypsin-treated PitA crystals prepared with terbium crystallophore (Tb-Xo4) was sufficient to obtain an interpretable electron-density map via terbium SAD phasing.


Asunto(s)
Adhesinas Bacterianas/química , Placa Dental/química , Fimbrias Bacterianas/química , Streptococcus oralis/química , Actinomyces , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/aislamiento & purificación , Adhesinas Bacterianas/metabolismo , Biopelículas , Quimotripsina/metabolismo , Cristalización , Cristalografía por Rayos X , Placa Dental/metabolismo , Placa Dental/microbiología , Escherichia coli , Fimbrias Bacterianas/genética , Expresión Génica/genética , Humanos , Streptococcus oralis/patogenicidad , Difracción de Rayos X
10.
Org Lett ; 22(2): 537-541, 2020 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-31887057

RESUMEN

Herein we report an efficient total synthesis of lipid-anchor-appended core trisaccharides of lipoteichoic acids of Streptococcus pneumoniae and Streptococcus oralis Uo5. The key features include the expedient synthesis of the rare sugar 2,4,6-trideoxy-2-acetamido-4-amino-d-Galp building block via one-pot sequential SN2 reactions and the α-selective coupling of d-thioglucoside with the diacyl glycerol acceptor to construct a common disaccharide acceptor, which was utilized in the total synthesis of target molecules 1 and 2.


Asunto(s)
Lípidos/química , Lipopolisacáridos/química , Streptococcus oralis/química , Streptococcus pneumoniae/química , Ácidos Teicoicos/química , Trisacáridos/síntesis química , Conformación Molecular , Estereoisomerismo , Trisacáridos/química
11.
BMC Infect Dis ; 19(1): 960, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31711423

RESUMEN

BACKGROUND: Streptococcus oralis belongs to the Streptococcus mitis group and is part of the normal flora of the nasal and oropharynx (Koneman et al., The Gram-positive cocci part II: streptococci, enterococci and the 'Streptococcus-like' bacteria. Color atlas and textbook of diagnostic microbiology, 1997). Streptococcus oralis is implicated in meningitis in patients with decreased immune function or from surgical manipulation of the central nervous system. We report a unique case of meningitis by Streptococcus oralis in a 58-year-old patient with cerebral spinal fluid leak due to right sphenoid meningoencephalocele. CASE PRESENTATION: A 58-year-old female presented in the emergency department due to altered mental status, fevers, and nuchal rigidity. Blood cultures were positive for Streptococcus oralis. Magnetic resonance stereotactic imaging of head with intravenous gadolinium showed debris in lateral ventricle occipital horn and dural thickening/enhancement consistent with meningitis. There was also a right sphenoidal roof defect, and meningoencephalocele with cerebrospinal fluid leak as a result. The patient was treated with ceftriaxone and had endoscopic endonasal repair of defect. She had complete neurologic recovery 3 months later. CONCLUSIONS: Cerebrospinal fluid leak puts patients at increased risk for meningitis. Our case is unique in highlighting Streptococcus oralis as the organism implicated in meningitis due to cerebrospinal fluid leak.


Asunto(s)
Pérdida de Líquido Cefalorraquídeo/complicaciones , Encefalocele/complicaciones , Meningitis Bacterianas/etiología , Meningocele/complicaciones , Infecciones Estreptocócicas/microbiología , Streptococcus oralis/aislamiento & purificación , Antibacterianos/uso terapéutico , Ceftriaxona/uso terapéutico , Endoscopía , Femenino , Humanos , Persona de Mediana Edad , Procedimientos Quírurgicos Nasales , Hueso Esfenoides/patología , Resultado del Tratamiento
12.
Adv Exp Med Biol ; 1197: 69-78, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31732935

RESUMEN

Candida albicans is an opportunistic pathogen colonizing the oropharyngeal, esophageal, and gastrointestinal mucosa in most healthy humans. In immunocompromised hosts, this fungal organism can cause mucosal candidiasis in these sites. C. albicans also causes fungemia, a serious consequence of cancer cytotoxic chemotherapy, which is thought to develop from fungal translocation through compromised mucosal barriers. Changes in endogenous bacterial population size or composition as well as changes in the host environment can transform fungal commensals into opportunistic pathogens in the upper and lower GI tract. Pioneering studies from our group have shown that a ubiquitous oral commensal of the mitis streptococcal group (Streptococcus oralis) has a mutualistic relationship with C. albicans, with C. albicans enabling streptococcal biofilm growth at mucosal sites, and S. oralis facilitating invasion of the oral and esophageal mucosa by C. albicans. In these studies, we used a cortisone-induced immunosuppression mouse model. More recently, the development of a novel mouse chemotherapy model has allowed us to examine the interactions of C. albicans with the endogenous bacterial microbiota in the oral and small intestinal mucosa, two sites adversely affected by cytotoxic chemotherapy. In this model, oral inoculation with C. albicans causes severe dysbiosis in the mucosal bacterial composition in both sites. We also found that antibiotic treatment ameliorates invasion of the oral mucosa but aggravates dissemination through the intestinal mucosa. In this chapter, we discuss work from our laboratory and others examining the relationships of C. albicans with oral bacteria and their role in mucosal homeostasis or disease.


Asunto(s)
Candida albicans , Microbiota , Mucosa Bucal , Animales , Candida albicans/fisiología , Candidiasis/microbiología , Modelos Animales de Enfermedad , Homeostasis , Humanos , Ratones , Microbiota/fisiología , Mucosa Bucal/microbiología , Streptococcus oralis
14.
mBio ; 10(5)2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-31481387

RESUMEN

From a common ancestor, Streptococcus pneumoniae and Streptococcus mitis evolved in parallel into one of the most important pathogens and a mutualistic colonizer of humans, respectively. This evolutionary scenario provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. We performed detailed comparisons of 60 genomes of S. pneumoniae, S. mitis, Streptococcus pseudopneumoniae, the three Streptococcus oralis subspecies oralis, tigurinus, and dentisani, and Streptococcus infantis Nonfunctional remnants of ancestral genes in both S. pneumoniae and in S. mitis support the evolutionary model and the concept that evolutionary changes on both sides were required to reach their present relationship to the host. Confirmed by screening of >7,500 genomes, we identified 224 genes associated with virulence. The striking difference to commensal streptococci was the diversity of regulatory mechanisms, including regulation of capsule production, a significantly larger arsenal of enzymes involved in carbohydrate hydrolysis, and proteins known to interfere with innate immune factors. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. In addition to loss of these virulence-associated genes, adaptation of S. mitis to a mutualistic relationship with the host apparently required preservation or acquisition of 25 genes lost or absent from S. pneumoniae Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.IMPORTANCE Streptococcus pneumoniae is one of the most important human pathogens but is closely related to Streptococcus mitis, with which humans live in harmony. The fact that the two species evolved from a common ancestor provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. By detailed comparisons of genomes of the two species and other related streptococci, we identified 224 genes associated with virulence and 25 genes unique to the mutualistic species. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.


Asunto(s)
Hibridación Genómica Comparativa , Genes Bacterianos/genética , Genoma Bacteriano/genética , Streptococcus/genética , Factores de Virulencia/genética , Factores de Virulencia/aislamiento & purificación , Evolución Biológica , Endocarditis/microbiología , Humanos , Streptococcus/clasificación , Streptococcus/fisiología , Streptococcus mitis/genética , Streptococcus oralis/genética , Streptococcus pneumoniae/genética , Simbiosis , Virulencia/genética
15.
J Bacteriol ; 201(22)2019 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-31501281

RESUMEN

The mitis group streptococci include the major human pathogen Streptococcus pneumoniae and the opportunistic pathogens Streptococcus mitis and Streptococcus oralis, which are human oral cavity colonizers and agents of bacteremia and infective endocarditis in immunocompromised patients. Bacterial membrane lipids play crucial roles in microbe-host interactions; for many pathogens, however, the composition of the membrane is poorly understood. In this study, we characterized the lipidomes of selected species of mitis group streptococci and investigated the mechanistic basis for biosynthesis of the phospholipid phosphatidylcholine (PC). PC is a major lipid in eukaryotic cellular membranes, but it is considered to be comparatively rare in bacterial taxa. Using liquid chromatography-mass spectrometry in conjunction with stable isotope tracing, we determined that mitis group streptococci synthesize PC via a rare host-metabolite-scavenging pathway, the glycerophosphocholine (GPC) pathway, which is largely uncharacterized in bacteria. Our work demonstrates that mitis group streptococci, including S. pneumoniae, remodel their membranes in response to the major human metabolites GPC and lysophosphatidylcholine.IMPORTANCE We lack fundamental information about the composition of the cellular membrane even for the best-studied pathogens of critical significance for human health. The mitis group streptococci are closely linked to humans in health and disease, but their membrane biology is poorly understood. Here, we demonstrate that these streptococci scavenge major human metabolites and use them to synthesize the membrane phospholipid PC. Our work is significant because it identifies a mechanism by which the major human pathogen S. pneumoniae and the primary human oral colonizers S. mitis and S. oralis remodel their membranes in response to host metabolites.


Asunto(s)
Fosfatidilcolinas/biosíntesis , Streptococcus mitis/metabolismo , Streptococcus oralis/metabolismo , Streptococcus pneumoniae/metabolismo , Endocarditis Bacteriana/microbiología , Cromatografía de Gases y Espectrometría de Masas , Glucolípidos/metabolismo , Interacciones Microbiota-Huesped , Humanos , Lipidómica , Redes y Vías Metabólicas , Fosfolípidos/metabolismo
16.
Int Endod J ; 52(12): 1773-1788, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31389008

RESUMEN

AIM: To investigate the anti-biofilm efficacy and working mechanism of several NaOCl concentrations on dual-species biofilms of different architecture as well as the changes induced on the architecture of the remaining biofilms. METHODOLOGY: Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were co-cultured under different growth conditions on saliva-coated hydroxyapatite discs. A constant-depth film fermenter (CDFF) was used to grow steady-state, four-day mature biofilms (dense architecture). Biofilms were grown under static conditions for 4 days within a confined space (less dense architecture). Twenty microlitres of buffer, 2-, 5-, and 10% NaOCl were applied statically on the biofilms for 60 s. Biofilm disruption and dissolution, as well as bubble formation, were evaluated with optical coherence tomography (OCT). The viscoelastic profile of the biofilms post-treatment was assessed with low load compression testing (LLCT). The bacteria/extracellular polysaccharide (EPS) content of the biofilms was examined through confocal laser scanning microscopy (CLSM). OCT, LLCT and CLSM data were analysed through one-way analysis of variance (ANOVA) and Tukey's HSD post-hoc test. Linear regression analysis was performed to test the correlation between bubble formation and NaOCl concentration. The level of significance was set at a < 0.05. RESULTS: The experimental hypothesis according to which enhanced biofilm disruption, dissolution and bubble formation were anticipated with increasing NaOCl concentration was generally confirmed in both biofilm types. Distinct differences between the two biofilm types were noted with regard to NaOCl anti-biofilm efficiency as well as the effect that the several NaOCl concentrations had on the viscoelasticity profile and the bacteria/EPS content. Along with the bubble generation patterns observed, these led to the formulation of a concentration and biofilm structure-dependent theory of biofilm removal. CONCLUSIONS: Biofilm architecture seems to be an additional determining factor of the penetration capacity of NaOCl, and consequently of its anti-biofilm efficiency.


Asunto(s)
Biopelículas , Streptococcus oralis , Actinomyces , Microscopía Confocal , Saliva
18.
Nat Commun ; 10(1): 3493, 2019 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-31375698

RESUMEN

Hydrogen peroxide (H2O2) has a major function in host-microbial interactions. Although most studies have focused on the endogenous H2O2 produced by immune cells to kill microbes, bacteria can also produce H2O2. How microbial H2O2 influences the dynamics of host-microbial interactions is unclear. Here we show that H2O2 released by Streptococcus pneumoniae inhibits inflammasomes, key components of the innate immune system, contributing to the pathogen colonization of the host. We also show that the oral commensal H2O2-producing bacteria Streptococcus oralis can block inflammasome activation. This study uncovers an unexpected role of H2O2 in immune suppression and demonstrates how, through this mechanism, bacteria might restrain the immune system to co-exist with the host.


Asunto(s)
Coinfección/inmunología , Peróxido de Hidrógeno/metabolismo , Tolerancia Inmunológica , Inmunidad Innata , Inflamasomas/inmunología , Animales , Proteínas Adaptadoras de Señalización CARD/genética , Proteínas Adaptadoras de Señalización CARD/metabolismo , Coinfección/microbiología , Modelos Animales de Enfermedad , Interacciones Microbiota-Huesped/inmunología , Humanos , Peróxido de Hidrógeno/inmunología , Inflamasomas/metabolismo , Ratones , Ratones Noqueados , Streptococcus oralis/inmunología , Streptococcus oralis/metabolismo , Streptococcus oralis/patogenicidad , Streptococcus pneumoniae/inmunología , Streptococcus pneumoniae/metabolismo , Streptococcus pneumoniae/patogenicidad
19.
Artículo en Inglés | MEDLINE | ID: mdl-31430972

RESUMEN

Dental unit waterlines (DUWLs) can be considered one of the possible routes of H. pylori transmission, although its presence in DUWLs has not yet been investigated thoroughly. The present study aimed to discover the prevalence of H. pylori and oral streptococci (S. oralis and S. mutans) in DUWLs to evaluate the risk of exposure to human pathogens in dental practices. We collected the output water from 60 dental chair units (DCUs) in 26 private dentistry settings in Turin, searching for H. pylori and oral streptococci (OS) DNA, with a polymerase chain reaction (PCR) technique. At the same time, dentists completed a questionnaire about their DCUs, their main activities, the presence of anti-retraction devices, their attitudes about disinfection, etc. No dental chair unit tested was contaminated with H. pylori or S. mutans; only one dental chair was contaminated with S. oralis (1.7%). Considering the results, we can state that: (i) the lack of H. pylori DNA in water samples analyzed, suggests that municipal water is presumably treated with a sufficient chlorine level to inactivate DNA over time; (ii) the aspiration of oral fluids is limited by anti-retraction valves fitted distally to hand pieces; (iii) propidium monoazide qPCR (PMA-qPCR) could be a good technique to investigate and monitor potential environmental sources of infections such as DUWLs.


Asunto(s)
Equipo Dental/microbiología , Exposición a Riesgos Ambientales/análisis , Helicobacter pylori/aislamiento & purificación , Microbiología del Agua , Infección Hospitalaria/etiología , Infección Hospitalaria/prevención & control , Infección Hospitalaria/transmisión , Infecciones por Helicobacter/etiología , Infecciones por Helicobacter/prevención & control , Infecciones por Helicobacter/transmisión , Humanos , Control de Infecciones , Medición de Riesgo , Streptococcus mutans/aislamiento & purificación , Streptococcus oralis/aislamiento & purificación
20.
Clin Exp Dent Res ; 5(4): 427-437, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31452954

RESUMEN

Objective: Polyetheretherketone (PEEK) is a polymer used in devices in orthopedic and dental rehabilitation. The aim of this in vitro study was to compare biofilm formation by a range of important oral bacterial species on PEEK, blasted PEEK, commercially pure titanium (cp-Ti), and titanium-6 aluminium-4 vanadium (Ti6Al4V). Material and methods: Coin-shaped samples were manufactured, and the surfaces were characterized using optical interferometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements. Bacterial species of Streptococcus sanguinis, Streptococcus oralis, Enterococcus faecalis, and Streptococcus gordonii were cultured on the four material surfaces for varying amounts of time. Biofilms were quantified following staining with crystal violet. Results: Roughness and contact angle results showed blasted PEEK > PEEK > cp-Ti = Ti6Al4V. There was increased biofilm formation on blasted PEEK by S. sanguinis, S. oralis, and S. gordonii, whereas the bacterial adhesion was similar on PEEK, cp-Ti, and Ti6Al4V. The bacterial growth of E. faecalis was significantly higher on cp-Ti compared with the other three groups. Conclusion: The results, taking into consideration the biofilm formation, suggest that PEEK should perform as well as cp-Ti or TiAl6V4 when used as a dental restorative material.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Pilares Dentales/microbiología , Cetonas/química , Polietilenglicoles/química , Prostodoncia/instrumentación , Titanio/química , Adhesión Bacteriana , Enterococcus faecalis/aislamiento & purificación , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Streptococcus gordonii/aislamiento & purificación , Streptococcus oralis/aislamiento & purificación , Streptococcus sanguis/aislamiento & purificación , Propiedades de Superficie
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