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1.
NPJ Biofilms Microbiomes ; 8(1): 96, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36509765

RESUMO

Extracellular DNA (eDNA) is a key component of many microbial biofilms including dental plaque. However, the roles of extracellular deoxyribonuclease (DNase) enzymes within biofilms are poorly understood. Streptococcus gordonii is a pioneer colonizer of dental plaque. Here, we identified and characterised SsnA, a cell wall-associated protein responsible for extracellular DNase activity of S. gordonii. The SsnA-mediated extracellular DNase activity of S. gordonii was suppressed following growth in sugars. SsnA was purified as a recombinant protein and shown to be inactive below pH 6.5. SsnA inhibited biofilm formation by Streptococcus mutans in a pH-dependent manner. Further, SsnA inhibited the growth of oral microcosm biofilms in human saliva. However, inhibition was ameliorated by the addition of sucrose. Together, these data indicate that S. gordonii SsnA plays a key role in interspecies competition within oral biofilms. Acidification of the medium through sugar catabolism could be a strategy for cariogenic species such as S. mutans to prevent SsnA-mediated exclusion from biofilms.


Assuntos
Placa Dentária , Streptococcus gordonii , Humanos , Streptococcus gordonii/genética , Streptococcus mutans , Biofilmes , Saliva
2.
PLoS One ; 17(11): e0276293, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36350830

RESUMO

Members of the mitis group streptococci are the most abundant inhabitants of the oral cavity and dental plaque. Influenza A virus (IAV), the causative agent of influenza, infects the upper respiratory tract, and co-infection with Streptococcus pneumoniae is a major cause of morbidity during influenza epidemics. S. pneumoniae is a member of mitis group streptococci and shares many features with oral mitis group streptococci. In this study, we investigated the effect of viable Streptococcus oralis, a representative member of oral mitis group, on the infectivity of H1N1 IAV. The infectivity of IAV was measured by a plaque assay using Madin-Darby canine kidney cells. When IAV was incubated in growing culture of S. oralis, the IAV titer decreased in a time- and dose-dependent manner and became less than 100-fold, whereas heat-inactivated S. oralis had no effect. Other oral streptococci such as Streptococcus mutans and Streptococcus salivarius also reduced the viral infectivity to a lesser extent compared to S. oralis and Streptococcus gordonii, another member of the oral mitis group. S. oralis produces hydrogen peroxide (H2O2) at a concentration of 1-2 mM, and its mutant deficient in H2O2 production showed a weaker effect on the inactivation of IAV, suggesting that H2O2 contributes to viral inactivation. The contribution of H2O2 was confirmed by an inhibition assay using catalase, an H2O2-decomposing enzyme. These oral streptococci produce short chain fatty acids (SCFA) such as acetic acid as a by-product of sugar metabolism, and we also found that the inactivation of IAV was dependent on the mildly acidic pH (around pH 5.0) of these streptococcal cultures. Although inactivation of IAV in buffers of pH 5.0 was limited, incubation in the same buffer containing 2 mM H2O2 resulted in marked inactivation of IAV, which was similar to the effect of growing S. oralis culture. Taken together, these results reveal that viable S. oralis can inactivate IAV via the production of SCFAs and H2O2. This finding also suggests that the combination of mildly acidic pH and H2O2 at low concentrations could be an effective method to inactivate IAV.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A , Influenza Humana , Humanos , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Vírus da Influenza A/metabolismo , Vírus da Influenza A Subtipo H1N1/metabolismo , Streptococcus mitis , Streptococcus oralis , Estreptococos Viridans/metabolismo , Streptococcus gordonii/metabolismo , Ácidos/metabolismo , Concentração de Íons de Hidrogênio
3.
Am J Case Rep ; 23: e937271, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36355628

RESUMO

BACKGROUND Chronic prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty, resulting in significant morbidity and mortality. The criterion standard of treatment for chronic PJI is two-stage revision arthroplasty consisting of complete hardware removal, thorough irrigation and debridement, placement of an antibiotic spacer, prolonged intravenous antibiotics based on culture sensitivities, and revision total knee arthroplasty once the infection resolves. The most common organism implicated in chronic PJI is Staphylococcus aureus. CASE REPORT In this report, we have summarized the case of a 75-year-old woman who developed chronic PJI caused by an unusual organism, Streptococcus gordonii, 1 year after a right total knee arthroplasty. S. gordonii is a gram-positive organism that is an oral flora and a colonizer of human teeth. This organism is known to create biofilm on the human teeth, more commonly known as dental plaque. S. gordonii has the ability to travel to extraoral sites and cause infection. It has been found to be a cause of subacute bacterial endocarditis, but it has been rarely described in the literature as a cause of prosthetic joint infection. Treatment of S. gordonii requires a tailored approach. CONCLUSIONS This case report highlights the clinical presentation, diagnosis, and treatment of chronic prosthetic joint infection caused by S. gordonii and identifies a rare cause of PJI that is not well documented in the literature. Streptococcal PJI portends a poorer prognosis, and identification of this organism is crucial for prompt treatment and improved outcomes for PJI.


Assuntos
Artrite Infecciosa , Artroplastia do Joelho , Infecções Relacionadas à Prótese , Feminino , Humanos , Idoso , Streptococcus gordonii , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/terapia , Infecções Relacionadas à Prótese/etiologia , Desbridamento/métodos , Artrite Infecciosa/complicações , Artroplastia do Joelho/efeitos adversos , Antibacterianos/uso terapêutico
4.
Mol Oral Microbiol ; 37(6): 244-255, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36156446

RESUMO

Dental caries (tooth-decay) is caused by biofilms harboring polymicrobial communities on teeth that leads to the onset of localized areas of enamel demineralization. Streptococcus mutans has been clinically associated with severe caries in childhood. Although commensal bacteria can combat S. mutans using self-generated antimicrobials such as hydrogen peroxide (H2 O2 ), constant sugar-rich diet consumption disrupts microbial homeostasis shifting toward cariogenic community. Recently, Streptococcus oralis subsp. tigurinus strain J22, an oral isolate, was identified as a uniquely potent H2 O2 producer. Here, we assess whether a high H2 O2 -producing commensal streptococcus can modulate the spatial organization and virulence of S. mutans within biofilms. Using an experimental biofilm model, we find that the presence of S. oralis J22 can effectively inhibit the clustering, accumulation, and spatial organization of S. mutans on ex vivo human tooth surface, resulting in significant reduction of enamel demineralization. Notably, the generation of H2 O2 via pyruvate oxidase (SpxB) from S. oralis J22 is not repressed by sugars (a common repressor in other mitis group streptococci), resulting in enhanced inhibition of S. mutans growth (vs. Streptococcus gordonii). We further investigate its impact on biofilm virulence using an in vivo rodent caries model under sugar-rich diet. Coinfection of S. mutans with S. oralis results in reduced caries development compared to either species infected alone, whereas coinfection with S. gordonii has negligible effects, suggesting that the presence of an efficient, high H2 O2 -producer can disrupt S. mutans virulence. This work demonstrates that oral isolates with unusual high H2 O2 production may be capable of modulating biofilm cariogenicity in vivo. The findings also highlight the importance of bacterial antagonistic interactions within polymicrobial communities in health and in disease-causing state.


Assuntos
Coinfecção , Cárie Dentária , Humanos , Streptococcus mutans/fisiologia , Cárie Dentária/microbiologia , Suscetibilidade à Cárie Dentária , Streptococcus gordonii/fisiologia , Biofilmes , Açúcares/farmacologia
5.
J Bacteriol ; 204(6): e0011822, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35652671

RESUMO

Many oral bacteria employ cell wall-anchored adhesins to bind to the salivary films coating the teeth and mucosal surfaces. Surface binding prevents clearance and facilitates catabolism of salivary film glycoproteins. We asked whether Streptococcus gordonii adhesin expression changes in response to surface salivary cues using a eukaryote-like, outside-in recognition and signaling circuit. To determine whether the cues were discriminated, S. gordonii was tested during cell adhesion and biofilm formation on a MUC5B-rich or lower-molecular-mass salivary fraction or an uncoated abiotic surface. Cells were recovered and analyzed for differences in gene expression and proteins in cell wall fractions. In salivary-free conditions, planktonic S. gordonii presented three prominent cell wall LPXTG-motif proteins, SGO_1487, SGO_0890, and MbpA (mucin-binding protein A; SGO_0707). During biofilm formation on MUC5B-coated surfaces, MbpA, a MUC5B-binding protein, and key genes in the tagatose and quorum-sensing pathways were strongly promoted. The response to MUC5B required the two-component system (TCS), streptococcal regulator of adhesins sensor and regulator (SraSR, SGO_1180/81), lipoteichoic acid (LTA), and the homologous paired adhesins, SspA and SspB (SspAB). LTA appears to link the outside signal (MUC5B) to intramembrane SraSR. Tagatose pathway gene expression may poise cells to metabolize MUC5B glycans and, with a quorum-sensing gene (luxS), may direct formation of a consortium to facilitate glycan cross-feeding by S. gordonii. We now show that a Gram-positive bacterium discriminates specific surface environmental cues using an outside-in signaling mechanism to apparently optimize colonization of saliva-coated surfaces. IMPORTANCE All organisms throughout the tree of life sense and respond to their surface environments. To discriminate among mucosal surface environmental cues, we report that Streptococcus gordonii recognizes a high-molecular-weight mucin glycoprotein, MUC5B, using the paired adhesins SspAB and lipoteichoic acid; the latter bridges the outside signal to an intramembrane two-component system to transcriptionally regulate a MUC5B-specific adhesin and genes that may facilitate glycan catabolism.


Assuntos
Aderência Bacteriana , Streptococcus gordonii , Adesinas Bacterianas/metabolismo , Lipopolissacarídeos , Mucinas/metabolismo , Streptococcus gordonii/metabolismo , Ácidos Teicoicos/metabolismo
6.
Appl Environ Microbiol ; 88(13): e0069822, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35695569

RESUMO

Extracellular DNA (eDNA) is an important component of biofilm matrix that serves to maintain biofilm structural integrity, promotes genetic exchange within the biofilm, and provides protection against antimicrobial compounds. Advances in microscopy techniques have provided evidence of the cobweb- or lattice-like structures of eDNA within biofilms from a range of environmental niches. However, methods to reliably assess the abundance and architecture of eDNA remain lacking. This study aimed to address this gap by development of a novel, high-throughput image acquisition and analysis platform for assessment of eDNA networks in situ within biofilms. Utilizing Streptococcus gordonii as the model, the capacity for this imaging system to reliably detect eDNA networks and monitor changes in abundance and architecture (e.g., strand length and branch number) was verified. Evidence was provided of a synergy between glucans and eDNA matrices, while it was revealed that surface-bound nuclease SsnA could modify these eDNA structures under conditions permissive for enzymatic activity. Moreover, cross talk between the competence and hexaheptapeptide permease systems was shown to regulate eDNA release by S. gordonii. This novel imaging system can be applied across the wider field of biofilm research, with potential to significantly advance interrogation of the mechanisms by which the eDNA network architecture develops, how it can influence biofilm properties, and how it may be targeted for therapeutic benefit. IMPORTANCE Extracellular DNA (eDNA) is critical for maintaining the structural integrity of many microbial biofilms, making it an attractive target for the management of biofilms. However, our knowledge and targeting of eDNA are currently hindered by a lack of tools for the quantitative assessment of eDNA networks within biofilms. Here, we demonstrate use of a novel image acquisition and analysis platform with the capacity to reliably monitor the abundance and architecture of eDNA networks. Application of this tool to Streptococcus gordonii biofilms has provided new insights into how eDNA networks are stabilized within the biofilm and the pathways that can regulate eDNA release. This highlights how exploitation of this novel imaging system across the wider field of biofilm research has potential to significantly advance interrogation of the mechanisms by which the eDNA network architecture develops, how it can influence biofilm properties, and how it may be targeted for therapeutic benefit.


Assuntos
Biofilmes , Streptococcus gordonii , DNA , DNA Bacteriano/genética , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Streptococcus gordonii/fisiologia
7.
Appl Environ Microbiol ; 88(14): e0043422, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35758758

RESUMO

Spatially resolving chemical landscapes surrounding microbial communities can provide insight into chemical interactions that dictate cellular physiology. Electrochemical techniques provide an attractive option for studying these interactions due to their robustness and high sensitivity. Unfortunately, commercial electrochemical platforms that are capable of measuring chemical activity on the micron scale are often expensive and do not easily perform multiple scanning techniques. Here, we report development of an inexpensive electrochemical system that features a combined micromanipulator and potentiostat component capable of scanning surfaces while measuring molecular concentrations or redox profiles. We validate this experimental platform for biological use with a two-species biofilm model composed of the oral bacterial pathogen Aggregatibacter actinomycetemcomitans and the oral commensal Streptococcus gordonii. We measure consumption of H2O2 by A. actinomycetemcomitans biofilms temporally and spatially, providing new insights into how A. actinomycetemcomitans responds to this S. gordonii-produced metabolite. We advance our platform to spatially measure redox activity above biofilms. Our analysis supports that redox activity surrounding biofilms is species specific, and the region immediately above an S. gordonii biofilm is highly oxidized compared to that above an A. actinomycetemcomitans biofilm. This work provides description and validation of a versatile, quantitative framework for studying bacterial redox-mediated physiology in an integrated and easily adaptable experimental platform. IMPORTANCE Scanning electrochemical probe microscopy methods can provide information of the chemical environment along a spatial surface with micron-scale resolution. These methods often require expensive instruments that perform optimized and highly sensitive niche techniques. Here, we describe a novel system that combines a micromanipulator that scans micron-sized electrodes across the surface of bacterial biofilms and a potentiostat, which performs various electrochemical techniques. This platform allows for spatial measurement of chemical gradients above live bacteria in real time, and as proof of concept, we utilize this setup to map H2O2 detoxification above an oral pathogen biofilm. We increased the versatility of this platform further by mapping redox potentials of biofilms in real time on the micron scale. Together, this system provides a technical framework for studying chemical interactions among microbes.


Assuntos
Biofilmes , Peróxido de Hidrogênio , Aggregatibacter actinomycetemcomitans , Peróxido de Hidrogênio/metabolismo , Oxirredução , Streptococcus gordonii/metabolismo
8.
Front Cell Infect Microbiol ; 12: 879423, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35573793

RESUMO

In subgingival plaque biofilms, Fusobacterium nucleatum is closely related to the occurrence and development of periodontitis. Streptococcus gordonii, as an accessory pathogen, can coaggregate with periodontal pathogens, facilitating the subgingival colonization of periodontal pathogens. Studies have shown that F. nucleatum can coaggregate with S. gordonii and colonize the subgingival plaque. However, most studies have focused on monocultures or coinfection of species and the potential impact of coaggregation between the two species on periodontal interactions to human gingival epithelial cells (hGECs) remains poorly understood. The present study explored the effect of coaggregation between F. nucleatum and S. gordonii on subgingival synergistic virulence to hGECs. The results showed that coaggregation inhibited the adhesion and invasion of F. nucleatum to hGECs compared with that in the F. nucleatum monoculture and coinfection group. Coaggregation and coinfection with F. nucleatum both enhanced S. gordonii adhesion to hGECs, but neither of the two groups affected S. gordonii invasion to hGECs compared with S. gordonii monoculture. The gene expression levels of TLR2 and TLR4 in hGECs in the coaggregation group were higher than those in the monoculture groups but lower than those in the coinfection group. Compared with coinfection, the coaggregation inhibited apoptosis of hGECs and promoted the secretion of the proinflammatory cytokines TNF-α and IL-6 by hGECs, showed a synergistic inflammatory effect, while coaggregation inhibited the secretion of the anti-inflammatory cytokine TGF-ß1. Coaggregation enhanced the phosphorylation of p65, p38, and JNK proteins and therefore activated the NF-κB and MAPK signaling pathways. Pretreatment with a pathway antagonist/inhibitor decreased the phosphorylation levels of proteins and the secretion of TNF-α and IL-6. In conclusion, coaggregation inhibited the adhesion and invasion of F. nucleatum to hGECs. However, it enhanced the adhesion of S. gordonii to hGECs. Compared with coinfection, coaggregation inhibited the apoptosis of hGECs. The coaggregation coordinately promoted the secretion of TNF-α and IL-6 by hGECs through the TLR/NF-κB and TLR/MAPK signaling pathways while inhibiting the secretion of TGF-ß1, thus aggravating the inflammatory response of hGECs.


Assuntos
Coinfecção , Fusobacterium nucleatum , Aderência Bacteriana , Células Epiteliais/microbiologia , Humanos , Interleucina-6 , NF-kappa B , Streptococcus gordonii/genética , Fator de Crescimento Transformador beta1 , Fator de Necrose Tumoral alfa/farmacologia , Virulência
9.
Sci Rep ; 12(1): 7742, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35546602

RESUMO

Current biomaterials effectively replace biological structures but are limited by infections and long-term material failures. This study examined the molecular mechanisms of radio frequency glow discharge treatments (RFGDT) in mediating the disinfection of biomaterial surfaces and concurrently promoting cell attachment and proliferation. Dental biomaterials were subjected to RFGDT, and viability of oral microbial species, namely Streptococcus mutants (SM), Streptococcus gordonii (SG), Moraxella catarrhalis (MC), and Porphyromonas gingivalis (PG), were assessed. Cell attachment and survival of a pre-odontoblast cell line, MDPC-23, was examined. Finally, mechanistic investigations into redox generation and biological signaling were investigated. Based on their compositions, dental biomaterials induced reactive oxygen species (ROS) following dose-dependent RFGDT. Reduced microbial viability was evident following RFGDT in the catalase-negative (SM and SG) species more prominently than catalase-positive (MC and PG) species. Cell adhesion assays noted improved MDPC-23 attachment and survival. Pretreatments with N-acetylcysteine (NAC) and catalase abrogated these responses. Immunoassays noted redox-induced downstream expression of a laminin receptor, Ribosomal Protein SA, following RFGDT. Thus, RFGDT-induced redox mediates antimicrobial and improves cell responses such as adhesion and proliferation. These observations together provide a mechanistic rationale for the clinical utility of RFGDT with dental biomaterials for regenerative clinical applications.


Assuntos
Laminina , Streptococcus gordonii , Materiais Biocompatíveis/farmacologia , Catalase/farmacologia , Adesão Celular , Laminina/farmacologia , Oxirredução , Porphyromonas gingivalis , Receptores de Laminina , Proteínas Ribossômicas
10.
Appl Environ Microbiol ; 88(10): e0011622, 2022 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-35506689

RESUMO

Candida albicans can coaggregate with Streptococcus gordonii and cocolonize in the oral cavity. Saliva provides a vital microenvironment for close interactions of oral microorganisms. However, the level of fermentable carbohydrates in saliva is not sufficient to support the growth of multiple species. Glycoside hydrolases (GHs) that hydrolyze glycoproteins are critical for S. gordonii growth in low-fermentable-carbohydrate environments such as saliva. However, whether GHs are involved in the cross-kingdom interactions between C. albicans and S. gordonii under such conditions remains unknown. In this study, C. albicans and S. gordonii were cocultured in heart infusion broth with a low level of fermentable carbohydrate. Planktonic growth, biofilm formation, cell aggregation, and GH activities of monocultures and cocultures were examined. The results revealed that the planktonic growth of cocultured S. gordonii in a low-carbohydrate environment was elevated, while that of cocultured C. albicans was reduced. The biomass of S. gordonii in dual-species biofilms was higher than that of monocultures, while that of cocultured C. albicans was decreased. GH activity was observed in S. gordonii, and elevated activity of GHs was detected in S. gordonii-C. albicans cocultures, with elevated expression of GH-related genes of S. gordonii. By screening a mutant library of C. albicans, we identified a tec1Δ/Δ mutant strain that showed reduced ability to promote the growth and GH activities of S. gordonii compared with the wild-type strain. Altogether, the findings of this study demonstrate the involvement of GHs in the cross-kingdom metabolic interactions between C. albicans and S. gordonii in an environment with low level of fermentable carbohydrates. IMPORTANCE Cross-kingdom interactions between Candida albicans and oral streptococci such as Streptococcus gordonii have been reported. However, their interactions in a low-fermentable-carbohydrate environment like saliva is not clear. The current study revealed glycoside hydrolase-related cross-kingdom communications between S. gordonii and C. albicans under the low-fermentable-carbohydrate condition. We demonstrate that C. albicans can promote the growth and metabolic activities of S. gordonii by elevating the activities of cell-wall-anchored glycoside hydrolases of S. gordonii. C. albicans gene TEC1 is critical for this cross-kingdom metabolic communication.


Assuntos
Candida albicans , Glicosídeo Hidrolases , Streptococcus gordonii , Biofilmes , Candida albicans/genética , Carboidratos , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Streptococcus gordonii/genética
11.
Microbiol Spectr ; 10(2): e0242121, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35377225

RESUMO

E-cigarettes (e-cigs) have drastically increased in popularity during the last decade, especially among teenagers. While recent studies have started to explore the effect of e-cigs in the oral cavity, little is known about their effects on the oral microbiota and how they could affect oral health and potentially lead to disease, including periodontitis and head and neck cancers. To explore the impact of e-cigs on oral bacteria, we selected members of the genus Streptococcus, which are abundant in the oral cavity. We exposed the commensals Streptococcus sanguinis and Streptococcus gordonii and the opportunistic pathogen Streptococcus mutans, best known for causing dental caries, to e-liquids and e-cig aerosols with and without nicotine and with and without menthol flavoring and measured changes in growth patterns and biofilm formation. Our results demonstrate that e-cig aerosols hindered the growth of S. sanguinis and S. gordonii, while they did not affect the growth of S. mutans. We also show that e-cig aerosols significantly increased biofilm formation by S. mutans but did not affect the biofilm formation of the two commensals. We found that S. mutans exhibits higher hydrophobicity and coaggregation abilities along with higher attachment to OKF6 cells than S. sanguinis and S. gordonii. Therefore, our data suggest that e-cig aerosols have the potential to dysregulate oral bacterial homeostasis by suppressing the growth of commensals while enhancing the biofilm formation of the opportunistic pathogen S. mutans. This study highlights the importance of understanding the consequences of e-cig aerosol exposure on selected commensals and pathogenic species. Future studies modeling more complex communities will provide more insight into how e-cig aerosols and vaping affect the oral microbiota. IMPORTANCE Our study shows that e-cigarette aerosol exposure of selected bacteria known to be residents of the oral cavity hinders the growth of two streptococcal commensals while enhancing biofilm formation, hydrophobicity, and attachment for the pathogen S. mutans. These results indicate that e-cigarette vaping could open a niche for opportunistic bacteria such as S. mutans to colonize the oral cavity and affect oral health.


Assuntos
Cárie Dentária , Sistemas Eletrônicos de Liberação de Nicotina , Adolescente , Aerossóis , Biofilmes , Humanos , Streptococcus gordonii/fisiologia , Streptococcus mutans/fisiologia
12.
J Oral Biosci ; 64(2): 253-258, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35288286

RESUMO

OBJECTIVES: The Hsa adhesin of Streptococcus gordonii strain DL1 was previously identified as a hemagglutinin that binds specifically to sialoglycoconjugates. We recently found that among oral streptococcal species, S. gordonii strains most frequently express Hsa homologs on the bacterial cell surface. However, the effect of amino acid sequence diversity of nonrepetitive region 2 (NR2), a putative binding site of Hsa, on antigenicity and hemagglutinating (HA) properties is unclear due to difficulties in DNA sequencing the NR2 coding region. The aim of this study was to elucidate the similarity of the low NR2 antigenicity Hsa homolog of strain NDU1118 to that of strain DL1 and the association of the homolog with HA properties of the strain. METHODS: The hsa homolog of NDU1118 was sequenced using a long-read next-generation sequencer, and the Hsa homolog was assessed by alignment analysis of the deduced amino acid sequences. The hsa mutant of NDU1118 was generated by insertion of the erythromycin resistance gene. The HA properties of the wild type and the hsa mutant were assessed with human erythrocytes. RESULTS: The NR2 amino acid sequence of the NDU1118 Hsa homolog was almost identical to that of the S. gordonii M99 Hsa homolog, also known as GspB, and less similar to that of DL1 Hsa. The hsa mutation of NDU1118 induced reduction of HA activity in untreated erythrocytes, but surprisingly increased lactose-inhibitable HA activity in neuraminidase-treated erythrocytes. CONCLUSIONS: The results suggest the existence of an adhesin other than the Hsa homolog on the cell surface of NDU1118.


Assuntos
Ácido N-Acetilneuramínico , Streptococcus gordonii , Adesinas Bacterianas/genética , Sítios de Ligação , Proteínas de Transporte/genética , Hemaglutininas Virais/metabolismo , Humanos , Ácido N-Acetilneuramínico/metabolismo , Streptococcus gordonii/genética
13.
Photodiagnosis Photodyn Ther ; 38: 102767, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35182778

RESUMO

PURPOSE: The purpose of this study was to evaluate the antimicrobial effects of photothermal therapy using indocyanine green (ICG) and an 810-nm infrared diode laser on Streptococcus gordonii biofilm attached to zirconia surfaces in vitro. METHODS: A biofilm was formed using the static method on zirconia disks placed in a 24-well plate. The biofilms were subdivided into the following six treatment groups: control, commercial photodynamic therapy (PDT), chlorhexidine gluconate (CHX), laser only (L, 810-nm infrared diode), ICG, and laser with ICG (PTT). After treatment, each disk was agitated and the solution with detached bacteria was spread directly on a blood agar plate. Cells were cultured under anaerobic conditions and colony-forming units were counted. Confocal laser-scanning microscopy was used to assess the survival according to the height of the biofilm. RESULTS: The PTT, PDT, and CHX groups showed a significant reduction in S. gordonii viability (p<0.05), while the L and ICG groups showed no significant difference compared to the control group (p = 0.32, p = 0.97; respectively). In confocal laser-scanning microscopy images, the PTT, PDT, and CHX groups presented most of the dead bacteria in both the upper and lower levels of biofilm. CONCLUSION: Within the limitations of this in vitro study, PTT with ICG was effective in significantly reducing the viability of S. gordonii bacteria on zirconia. Further studies are needed to establish a standardized PTT protocol to treat peri­implant diseases.


Assuntos
Anti-Infecciosos , Fotoquimioterapia , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Biofilmes , Verde de Indocianina/farmacologia , Lasers Semicondutores , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Terapia Fototérmica , Streptococcus gordonii , Zircônio
14.
Infect Immun ; 90(3): e0058621, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35099275

RESUMO

The mechanisms through which oral commensal bacteria mitigates uncontrolled inflammatory responses of the oral mucosa remain unknown. Here, we show that representative oral bacterial species normally associated with oral health [S. gordonii (Sg), V. parvula (Vp), A. naeslundii (An), C. sputigena (Cs), and N. mucosa (Nm)] enhanced differential chemokine responses in oral epithelial cells (OECs), with some bacteria (An, Vp, and Nm) inducing higher chemokine levels (CXCL1, CXCL8) than others (Sg, Cs). Although all bacterial species (except Cs) increased CCL20 mRNA levels consistent with protein elevations in cell lysates, only An, Vp, and Nm induced higher CCL20 secretion, similar to the effect of the oral pathogen F. nucleatum (Fn). In contrast, most CCL20 remained associated with OECs exposed to Sg and negligible amounts released into the cell supernatants. Consistently, Sg attenuated An-induced CCL20. MiR-4516 and miR-663a were identified as Sg-specifically induced miRNAs modulating validated targets of chemokine-associated pathways. Cell transfection with miR-4516 and miR-663a decreased An- and Fn-induced CCL20. MiRNA upregulation and attenuation of An-induced CCL20 by Sg were reversed by catalase. Up-regulation of both miRNAs was specifically enhanced by oral streptococci H2O2-producers. These findings suggest that CCL20 levels produced by OECs in response to bacterial challenge are regulated by Sg-induced miR-4516 and miR-663a in a mechanism that involves hydrogen peroxide. This type of molecular mechanism could partly explain the central role of specific oral streptococcal species in balancing inflammatory and antimicrobial responses given the critical role of CCL20 in innate (antimicrobial) and adaptive immunity (modulates Th17 responses).


Assuntos
MicroRNAs , Streptococcus gordonii , Bactérias/genética , Quimiocina CCL20/genética , Quimiocina CCL20/metabolismo , Células Epiteliais/microbiologia , Humanos , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Mucosa Bucal
15.
Microbiol Immunol ; 66(2): 59-66, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34783072

RESUMO

Streptococcus gordonii, one of the early colonizers of oral biofilms, is involved in the development of dental caries, periodontal disease, and infective endocarditis. The Hsa adhesin of S. gordonii DL1 has the ability to bind strongly to the terminal sialic acid groups of host glycoproteins via the binding region, nonrepetitive region 2 (NR2), which is important for the pathogenicity of S. gordonii DL1. Low similarity with the NR2 of Hsa homologs among other streptococcal species has been reported. However, the reports have been limited to certain strains. This study attempted to assess frequency of the expression on the bacterial cell surface and to analyze the diversity of Hsa homologs among different wild strains of oral streptococci. We isolated 186 wild-type strains of oral streptococci from healthy volunteers and analyzed their hemagglutinating (HA) activity on human erythrocytes and their Hsa homologs and NR2 homologous regions by dot immunoblotting using anti-Hsa and anti-NR2 antisera, respectively. We found 30 strains reacted with anti-NR2 antiserum (NR2 positive) and determined the sequence of the NR2 regions. Many strains with high HA activity were also NR2 positive, suggesting that the NR2 region may be associated with HA activity. Among the NR2-positive strains, four different amino acid sequence patterns were observed, demonstrating diversity in the NR2 region. Notably, S. gordonii strains frequently possessed Hsa homologs and NR2-like antigens compared with other streptococci. It is speculated that the possessing frequency of Hsa homologs and the amino acid sequence of NR2 region may vary among streptococcal species.


Assuntos
Adesinas Bacterianas , Cárie Dentária , Infecções Estreptocócicas , Adesinas Bacterianas/genética , Adesinas Bacterianas/metabolismo , Aderência Bacteriana , Proteínas de Transporte , Cárie Dentária/microbiologia , Humanos , Ácido N-Acetilneuramínico , Streptococcus gordonii/genética , Streptococcus gordonii/metabolismo
16.
Medicine (Baltimore) ; 101(51): e32506, 2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36595860

RESUMO

RATIONALE: Streptococcus gordonii is a rare cause of finger suppurative infection. Very few cases have been reported of its treatment. PATIENT CONCERNS: A 68-year-old male of severe finger infection. Bacterial culture of synovial fluid revealed S gordonii.According to the patient's history and auxiliary examination, the patient was diagnosed with S gordonii infection. Here, we review the diagnosis and treatment of this patient and describe the clinical and epidemiological characteristics of the patient. DIAGNOSES: Streptococcus gordonii finger infection.Interventions: In the case of ineffective oral antibiotics, this patient chose to pursue an abscess incision, but in the course of treatment,the flexor digitorum tendon dissolved and eventually ruptured. OUTCOMES: The infection was controlled after intravenous injection of vancomycin. The incision was sutured 2 weeks later. No recurrence of infection was found after 3 months of follow-up. LESSONS: The treatment included antibacterial and abscess treatments. In the absence of drug sensitivity results, antibiotics can be used empirically. If empirical anti-microbial treatment fails, the antibiotic regimen should be changed in a timely manner, Vancomycin may be an antibiotic choice.


Assuntos
Abscesso , Streptococcus gordonii , Masculino , Humanos , Idoso , Abscesso/microbiologia , Vancomicina/uso terapêutico , Vancomicina/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia
17.
São José dos Campos; s.n; 2022. 85 p. ilus, graf.
Tese em Inglês | LILACS, BBO - Odontologia | ID: biblio-1371207

RESUMO

O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU) The general objective of this study was to evaluate the application of lowtemperature plasma under atmospheric pressure (PBTPA) of argon and helium flow, in the control of cariogenic biofilms. For this, the effective physical parameters of PBTPA-argon and helium in mono, dual and polymicrobial biofilms composed of combinations of the species Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans and Actinomyces naeslundii were established. The multi-species biofilms were treated by different PBTPA generating devices, one obtained commercially (kINPen09®) that used argon as working gas, and another prototype developed by FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) that used helium as working gas. Quantitative and microscopic analyzes (confocal, scanning electron microscopy) were performed. Negative control (no treatment), positive control (chlorhexidine 2%) and gas control (argon) were included. Besides that, cellular effects of PBTPA-argon and helium on dual and multi-species biofilms were analyzed by scanning electron microscopy (SEM) and confocal laser scanning microscopy. The results obtained for the treatments of mono, dual or multispecies biofilms with both PBTPA-argon and helium were all significant when compared to the negative control at all times analyzed. For PBTPA-argon, there was no recovery of S. gordonii and S. sanguinis at all analyzed times. For PBTPA-helium, the best results were obtained at 5 and 7 min of exposure of biofilms to PBTPA. All the tests were carried out in triplicate in three independent experiments. The results are tabulated and analyzed in terms of distribution. Next, the most suitable statistical tests were selected. The level of significance was 5%. The results obtained for the treatments of mono, dual or multi-species biofilms with PBTPA-argon and helium were all significant compared to the negative control at all analyzed times. Finally, both PBTPA generating could contribute to the development of new protocols for Minimal Intervention Dentistry (AU)


O objetivo geral do presente estudo foi avaliar a aplicação dos jatos de plasma de baixa temperatura sob pressão atmosférica (PBTPA) produzidos por gás de argônio e hélio como gases de trabalho, no controle de biofilmes cariogênicos. Para tanto, foram estabelecidos os parâmetros físicos dos PBTPA gerados com argônio e hélio que se mostraram efetivos frente a biofilmes mono, dual e polimicrobianos compostos por combinações das espécies Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Lactobacillus casei, Lactobacillus acidophilus, Candida albicans e Actinomyces naeslundii. Os biofilmes mono, dual e multi-espécies foram submetidos ao tratamento com PBTPA produzidos por dois dispositivos diferentes, um obtido comercialmente (kINPen09®) que usou argônio como gás de trabalho, e outro protótipo desenvolvido pela FEG-UNESP (Faculdade de Engenharia de Guaratinguetá) que usou hélio. Análises quantitativas e microscópicas (confocal, microscopia eletrônica de varredura) foram realizadas. Foi incluído controle negativo (sem tratamento), positivo (clorexidina 0,12%) e controle de gás, utilizando apenas fluxo de gás, sem produzir plasma. Além disso, os efeitos celulares do PBTPAargônio e hélio sobre biofilme dual e multi-espécies também foram analisados em microscopia eletrônica de varredura e microscopia de varredura a laser confocal. Todos os ensaios foram realizados em triplicata em três experimentos independentes. Os resultados foram tabulados e analisados quanto à distribuição. A seguir, os testes estatísticos mais adequados foram selecionados. O nível de significância foi de 5%. Os resultados obtidos para os tratamentos dos biofilmes mono, dual ou multi-espécies com PBTPA-argônio e hélio foram todos significativos em comparação ao controle negativo em todos os tempos analisados. Para PBTPA-argônio, não houve recuperação de S. gordonii e S. sanguinis em todos tempos analisados. Para PBTPA-hélio, os melhores resultados foram obtidos em 5 e 7 minutos de exposição dos biofilmes ao PBTPA. Finalmente, tanto o dispositivo gerador de PBTPA que trabalhou com gás argônio quanto o dispositivo que trabalhou com gás hélio, demonstraram resultados promissores e poderão contribuir para o desenvolvimento de novos protocolos de Odontologia de Intervenção Mínima. (AU)


Assuntos
Plasma , Streptococcus mutans , Streptococcus sanguis , Actinomicose , Candida albicans , Cárie Dentária , Placa Dentária , Streptococcus gordonii , Lactobacillus acidophilus , Lactobacillus casei
18.
Pesqui. bras. odontopediatria clín. integr ; 22: e210080, 2022. tab, graf
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1386816

RESUMO

Abstract Objective: To assess the antibacterial activity of Psidium guajava fractions and their effects on adhesion of a multispecies biofilm consisting of Streptococcus gordonii, Fusobacterium nucleatum, and Porphyromonas gingivalis in vitro. Material and Methods: Guava leaves were obtained from the mountains of northern Peru, where they grow wild and free of pesticides. The antimicrobial activity of 25 mg/mL petroleum ether, 25 mg/mL dichloromethane and 25 mg/mL methanol fractions of P. guajava was evaluated by measuring inhibition halos, as well as the effect on the adhesion of multispecies biofilms at 4, 7 and 10 days of growth by measuring the optical density. In addition, antimicrobial susceptibility was compared using the Kruskal-Wallis test and its multiple comparison tests, and differences in mean biofilm adhesion between each fraction were assessed by repeated measures analysis and the Tukey multiple comparison test. Results: The rank-based Kruskal-Wallis test highlighted differences in the effects of the fractions on the zone of inhibition for each oral bacterium, including S. gordonii (p=0.000), F. nucleatum (p=0.000), and P. gingivalis (p=0.000), the Tukey test showed that the group treated with 0.12% chlorhexidine exhibited the least amount of adhesion, followed by the group treated with the 1.56 mg/mL methanol fraction. Conclusion: The methanol fraction of P. guajava had an antibacterial effect on S. gordonii and P. gingivalis, and the 1.56 mg/mL methanol fraction decreased biofilm adhesion.


Assuntos
Periodontite/microbiologia , Biofilmes , Psidium/química , Streptococcus gordonii/patogenicidade , Antibacterianos/farmacologia , Infecções Estreptocócicas , Técnicas In Vitro , Estudos de Intervenção , Análise de Variância
19.
PLoS One ; 16(12): e0261568, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34928970

RESUMO

Streptococcus gordonii is an etiological bacterial agent of infective endocarditis. Although the pathogenesis mechanisms are not well understood, the interaction between streptococci and phagocytes is considered important for the development of infective endocarditis. Previous studies show that some S. gordonii strains, including DL1, survive in polymorphonuclear leukocytes (PMNs), whereas other strains such as SK12 are sensitive to PMN-dependent killing. In this study, we assessed the differences between the sensitivity of S. gordonii DL1 and S. gordonii SK12 to PMN-dependent killing. S. gordonii DL1 showed a higher survival when treated with PMNs than SK12. Both S. gordonii DL1 and S. gordonii SK12 showed high resistance to low pH condition. Compared to S. gordonii SK12, S. gordonii DL1 was sensitive to hydrogen peroxide. However, the resistance of S. gordonii DL1 to the tested bactericidal agents, especially lysozyme, was higher than that of SK12. Furthermore, we performed a bactericidal assay by treating a mixture of S. gordonii DL1 and SK12 with PMNs. S. gordonii DL1 did not enhance the survival of S. gordonii SK12 exposed to PMNs. These results indicated that S. gordonii DL1 is resistant to bactericidal agents that degrade bacteria in phagolysosomes. In addition, there was no secretory factor involved in the resistance to bactericidal agents. The findings of this study may help develop treatments for infective endocarditis caused by S. gordonii.


Assuntos
Endocardite Bacteriana/microbiologia , Muramidase/metabolismo , Neutrófilos/fisiologia , Infecções Estreptocócicas/microbiologia , Streptococcus gordonii/fisiologia , Humanos
20.
Medicina (Kaunas) ; 57(12)2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34946243

RESUMO

The COVID-19 pandemic is a new challenge for the diagnosis and treatment of infective endocarditis (IE). Fever and other unspecific symptoms of coronaviral infection could be misleading or masking its manifestations. We present the case of a young patient admitted for persistent fever, profuse sweating, headache, articular pain, myalgias, and weight loss. She reported regression taste and smell disorders compared to a month earlier when diagnosed with moderate COVID-19 pneumonia. While the RT-PCR SARS-COV-2 test was positive, she was admitted to a COVID-19 ward. Investigations of febrile syndrome revealed two positive blood cultures with Streptococcus gordonii and the presence of vegetations on the aortic valve, supporting a certain diagnosis of IE. After six weeks of antibiotic treatment, the patient had clinical and biologic favorable outcomes. Streptococcus gordonii is a common commensal related to the dental biofilm, although there were no caries in our patient. The influence of COVID-19 infection on the human microbiome by modifying the virulence of some commensal germs may be a risk factor for IE pathogenesis on native valves and requires the vigilance of clinicians for suspicion of this disease.


Assuntos
COVID-19 , Endocardite , Endocardite/diagnóstico , Endocardite/tratamento farmacológico , Feminino , Humanos , Pandemias , SARS-CoV-2 , Streptococcus gordonii
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