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Disinfection of the instruments used in orthodontic clinic is essential in order to prevent the transmission of disease to the practitioner, auxiliary staff and patients. Present study aims to evaluate the effectiveness of 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam sprays on the disinfection of orthodontic pliers. Methodology: The efficacy of disinfection methods of orthodontic pliers used in everyday practice by orthodontists was evaluated using 30 sterile pliers. They were contaminated in vitro with bacteria commonly found in the oral cavity, Streptococcus salivarius [ATCC 13419], Staphylococcus aureus [ATCC 25923] and Pseudomonas aeruginosa [ATCC27853]. Following contamination of the pliers, each of ten pliers underwent one of the three disinfectant protocols in a solution of 2% Glutaraldehyde, alcohol-free wipes containing quaternary ammonium compounds and spraying a foam containing quaternary ammonium compound. The plier heads were spread on the surface of sterile blood agar plates after contamination and after disinfection. Results: 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam sprays were found to be effective with regards to disinfection of orthodontic pliers. Conclusion: As per the results of our study, we conclude that 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam spray were found to be effective with regards to disinfection of orthodontic pliers contaminated with standard strains of Pseudomonas aeruginosa , Staphylococcus aureus and Streptococcus salivarius .

We aimed to assess the effect of oral probiotics containing the Streptococcus salivarius K12 strain on the salivary level of secretory immunoglobulin A, salivation rate, and oral biofilm. Thirty-one consenting patients meeting the inclusion criteria were recruited in this double-blind, placebo-controlled, two-arm, parallel-group study and randomly divided into probiotic (n = 15) and placebo (n = 16) groups. Unstimulated salivation rate, concentration of salivary secretory immunoglobulin A, Turesky index, and Papillary-Marginal-Attached index were assessed after 4 weeks of intervention and 2 weeks of washout. Thirty patients completed the entire study protocol. We found no increase in salivary secretory immunoglobulin A levels and salivary flow rates in the probiotic group compared with placebo. Baseline and outcome salivary secretory immunoglobulin A concentrations (mg/L) were 226 ± 130 and 200 ± 113 for the probiotic group and 205 ± 92 and 191 ± 97 for the placebo group, respectively. A significant decrease in plaque accumulation was observed in the probiotic group at 4 and 6 weeks. Within the limitations of the present study, it may be concluded that probiotic intake (Streptococcus salivarius K12) does not affect salivation rates and secretory immunoglobulin A salivary levels but exhibits a positive effect on plaque accumulation. Trial registration NCT05039320. Funding: none.

In populations with similar prevalence of Helicobacter pylori infection, cancer risk can vary dramatically. Changes in composition or structure of bacterial communities in the stomach, either at the time of exposure or over the course of H. pylori infection, may contribute to gastric pathology. In this study, a population of 37 patients from the low-gastric-cancer-risk (LGCR) region of Tumaco, Colombia, and the high-gastric-cancer-risk (HGCR) region of Túquerres, Colombia, were recruited for gastric endoscopy. Antral biopsy specimens were processed for histology and bacterial isolation. Fifty-nine distinct species among 26 genera were isolated by aerobic, anaerobic, and microaerobic culture and confirmed by 16S rRNA analysis. Urease-positive Staphylococcus epidermidis and Streptococcus salivarius were frequently isolated from gastric biopsy specimens. We asked whether coinfection of H. pylori with urease-positive

The development of probiotics targeting non-intestinal body sites continues to generate interest amongst researchers, biotech companies and consumers alike. A key consideration for any bacterial strain to be developed into a probiotic is a robust assessment of its safety profile.

Approximately 25% of the world population suffer from halitosis, making it a significant medico-social issue. It is one of the clinical signs of chronic inflammatory diseases of the oropharynx and is commonly caused by the persistence some bacteria in the oral cavity and in the oropharynx. These in turn facilitate formation of volatile sulphur compounds.To evaluate the effectiveness and safety of the probiotic strain45 patients diagnosed with a diagnosis of exacerbation of chronic pharyngitis were studied, gastroesophageal reflux disease was found in 33 patients. After a microbiological testing, all patients were prescribed probiotic strainAccording to the microbiological analysis was revealed the growth ofTopical application of a drug containing a probioticГалитоз является важной медико-социальной проблемой, встречается примерно у 25% населения в мире, часто становится одним из основных клинических признаков хронических воспалительных заболеваний ротоглотки и возникает в результате образования летучих соединений серы в процессе жизнедеятельности ряда микроорганизмов полости рта и ротоглотки.Оценить эффективность и безопасность пробиотического штаммаПод наблюдением находились 45 пациентов с катаральным хроническим фарингитом; подтвержденный гастроэозофагеальный рефлюкс зарегистрирован у 33 человек в общей группе. После микробиологического исследования всем пациентам назначен пробиотический штаммПри микробиологическом исследовании у всех пациентов выявленыПодтверждена хорошая эффективность местного применения продукта, содержащего пробиотик

Poor taste and smell function are widely thought to contribute to the development of poor appetite and undernutrition in older adults. It has been hypothesized that the oral microbiota play a role as well, but evidence is scarce. In a cross-sectional cohort of 356 older adults, we performed taste and smell tests, collected anthropometric measurements and tongue swabs for analysis of microbial composition (16S rRNA sequencing) and Candida albicans abundance (qPCR). Older age, edentation, poor smell and poor appetite were associated with lower alpha diversity and explained a significant amount of beta diversity. Moreover, a lower Streptococcus salivarius abundance was associated with poor smell identification score, whereas high C. albicans abundance seemed to be associated with poor smell discrimination score. In our population, neither the tongue microbiota, nor C. albicans were associated with poor taste or directly with undernutrition. Our findings do suggest a host-microbe interaction with regard to smell perception and appetite.

The members of the infant microbiome are governed by feeding method (breastmilk vs. formula). Regardless of the source of nutrition, a competitive growth advantage can be provided to commensals through prebiotics - either human milk oligosaccharides (HMOs) or plant oligosaccharides that are supplemented into formula. To characterize how prebiotics modulate commensal - pathogen interactions, we have designed and studied a minimal microbiome where a pathogen, Streptococcus agalactiae engages with a commensal, Streptococcus salivarius. We discovered that while S. agalactiae suppresses the growth of S. salivarius via increased lactic acid production, galacto-oligosaccharides (GOS) supplementation reverses the effect. This result has major implications in characterizing how single species survive in the gut, what niche they occupy, and how they engage with other community members.

Gamma-aminobutyric acid (GABA) is an important chemical compound in the human brain. GABA acts as an inhibitory neurotransmitter by inducing hyperpolarization of cellular membranes. Usually, this pharmaceutically important compound is synthesized using a chemical process, but in this short overview we have only analysed microbial processes, which have been studied for the biosynthesis of this commercially important compound. The content of this article includes the following summarised information: the search for biological processes showed a number of lactic acid bacteria and certain species of fungi, which could be effectively used for the production of GABA. Strains found to possess GABA-producing pathways include Lactobacillus brevis CRL 1942, L. plantarum FNCC 260, Streptococcus salivarius subsp. thermophilus Y2, Bifidobacterium strains, Monascus spp., and Rhizopus spp. Each of these strains required specific growth conditions. However, several factors were common among these strains, such as the use of two main supplements in their fermentation medium—monosodium glutamate and pyridoxal phosphate—and maintaining an acidic pH. Optimization studies of GABA production were comprised of altering the media constituents, modifying growth conditions, types of cultivation system, and genetic manipulation. Some strains increased the production of GABA under anaerobic conditions. Genetic manipulation focused on silencing some genes or overexpression of gadB and gadC. The conclusion, based on the review of information available in published research, is that the targeted manipulation of selected microorganisms, as well as the culture conditions for an optimised bioprocess, should be adopted for an increased production of GABA to meet its increasing demand for food and pharmaceutical applications.

Streptococcus salivarius (S. salivarius) K12 supplementation has been found to reduce the risk of recurrent upper respiratory tract infections. Yet, studies have not reported the effect of supplementation on oral S. salivarius K12 levels or the salivary microbiome. This clinical trial was designed to determine how supplementation with S. salivarius K12 influences the oral microbiome. In a randomized, double-blind, placebo-controlled trial, 13 healthy adults received a probiotic powder (PRO) containing Lactobacillus acidophilus, Bifidobacterium lactis, and S. salivarius K12 and 12 healthy adults received a placebo-control powder (CON) (n = 12) for 14 consecutive days. Oral S. salivarius K12 and total bacteria were quantified by qPCR and the overall oral microbiome was measured using 16S rRNA amplicon sequencing. Supplementation significantly increased mean salivary S. salivarius K12 levels by 5 logs compared to baseline for the PRO group (p < 0.0005), which returned to baseline 2 weeks post-supplementation. Compared with the CON group, salivary S. salivarius K12 was 5 logs higher in the PRO group at the end of the supplementation period (p < 0.001). Neither time nor supplementation influenced the overall oral microbiome. Supplementation with a probiotic cocktail containing S. salivarius K12 for two weeks significantly increased levels of salivary S. salivarius K12.

COVID-19 is mainly associated with respiratory distress syndrome, but a subset of patients often present gastrointestinal (GI) symptoms. Imbalances of gut microbiota have been previously linked to respiratory virus infection. Understanding how the gut–lung axis affects the progression of COVID-19 can provide a novel framework for therapies and management. In this study, we examined the gut microbiota of patients with COVID-19 (n = 47) and compared it to healthy controls (n = 19). Using shotgun metagenomic sequencing, we have identified four microorganisms unique in COVID-19 patients, namely Streptococcus thermophilus, Bacteroides oleiciplenus, Fusobacterium ulcerans, and Prevotella bivia. The abundances of Bacteroides stercoris, B. vulgatus, B. massiliensis, Bifidobacterium longum, Streptococcus thermophilus, Lachnospiraceae bacterium 5163FAA, Prevotella bivia, Erysipelotrichaceae bacterium 6145, and Erysipelotrichaceae bacterium 2244A were enriched in COVID-19 patients, whereas the abundances of Clostridium nexile, Streptococcus salivarius, Coprococcus catus, Eubacterium hallii, Enterobacter aerogenes, and Adlercreutzia equolifaciens were decreased (p < 0.05). The relative abundance of butyrate-producing Roseburia inulinivorans is evidently depleted in COVID-19 patients, while the relative abundances of Paraprevotella sp. and the probiotic Streptococcus thermophilus were increased. We further identified 30 KEGG orthology (KO) modules overrepresented, with 7 increasing and 23 decreasing modules. Notably, 15 optimal microbial markers were identified using the random forest model to have strong diagnostic potential in distinguishing COVID-19. Based on Spearman’s correlation, eight species were associated with eight clinical indices. Moreover, the increased abundance of Bacteroidetes and decreased abundance of Firmicutes were also found across clinical types of COVID-19. Our findings suggest that the alterations of gut microbiota in patients with COVID-19 may influence disease severity. Our COVID-19 classifier, which was cross-regionally verified, provides a proof of concept that a set of microbial species markers can distinguish the presence of COVID-19.

This study aimed to evaluate the antimicrobial effect of Thymoquinone (TQ) on four different oral microorganisms. Minimum Bactericidal Concentration (MBC), Minimum Inhibition Concentration (MIC), Broth microdilution, and Well diffusion tests were used to determine the optimum antimicrobial concentrations of TQ against Streptococcus salivarius, Streptococcus oralis, Streptococcus mutans, and Staphylococcus aureus over 1, 3, 6, 12 and 24 h. Chlorhexidine 0.12% was selected as a positive control. The inhibitory effect of TQ on bacterial growth was most noticeable with S. salivarius, while the least affected was S. aureus. TQ’s MBC and MIC for S. oralis and S. aureus were comparable 2 mg/mL and 3 mg/mL, respectively. S. salivarius was most resistant to TQ and displayed a value of 5 mg/mL and 4 mg/mL for MIC and MBC, respectively. The viable count of different strains after exposure to TQ’s MBC values was most noticeable with S. aureus followed by S. oralis and S. mutans, while S. salivarius was least affected. This study emphasized the promising antimicrobial effect of TQ against the four main oral microorganisms. It has a potential preventive effect against dental caries as well as other oral diseases.

Patients suffering functional dyspepsia symptoms have been shown to possess a greater relative abundance of Streptococcus compared to asymptomatic controls. Here, we describe the isolation and genomic features of a new Streptococcus isolate, from the duodenal tissue of a subject reporting dyspeptic symptoms, taxonomically assigned to Streptococcus salivarius and designated strain AGIRA0003.

Streptococcus salivarius, an easily missed and commonly disregarded Viridians strep species, is usually written off as a culture contaminant, but has been implicated as a rare cause of bacterial endocarditis with serious complications. It is a normal commensal microorganism of the mouth and gut, S. salivarius is usually harmless and even demonstrates anti-inflammatory properties. However, the literature about the complications of a S. salivarius bacteremia remains unclear. This case highlights a patient with mycotic aneurysms due to infective endocarditis in the setting of S. salivarius bacteremia., Highlights • Streptococcus salivarius is easily missed and usually a culture contaminant, but it is also a rare cause of bacterial endocarditis with serious complications. • Infective endocarditis is diagnosed based on the modified Duke's criteria and commonly presents with a low-grade fever, a new onset heart murmur, petechiae, subungual hemorrhages, Janeway lesions, Osler nodes, or Roth spots. • It is critical to recognize S. salivarius's role in bacterial endocarditis and its serious complications; therefore, rapid identification and treatment with antibiotics are imperative to avoid complications.

This study aimed to evaluate in vitro the pharmacological stability of a herbal mouthwash based on Libidibia ferrea extract after aging, establishing its organoleptic and microbiological characteristics. It is a 7.5% hydroalcoholic extract from Libidibia ferrea pods, using the reflux decoction technique, and spray dried. The stability, pH, sedimentation, density, and antimicrobial activity tests of the mouthwash were performed with the solutions stored after 24 months. Contaminant control was carried out by determining the total number of microorganisms and researching Salmonella sp., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The formulation's antimicrobial activity against microorganisms present in the dental biofilm was analyzed: Streptococcus mutans, Streptococcus salivarius, Lactobacillus casei, and Candida albicans., The data were analyzed using the Tukey test to assess pH and density, and the other results were described using descriptive statistics., The color observed in the organoleptic characters, was “Ceramics”, with a fluid/serous consistency, shiny appearance, and a strong minty, woody odor. In the sedimentation phase, the separation was observed, and the pH and density analyzes showed a mean value of 5.46 and 1.029 g/cm3, respectively. The contaminant assessment test was negative for all microorganisms surveyed, within 24 months. The mouthwash showed bactericidal/fungicidal activity against all the microorganisms tested at all concentrations for S. mutans and C. albicans. At concentrations 0.5 mg/ml for S. salivarius and 0.6 mg/ml for L casei. It was concluded that after 24 months, the formulation of the mouthwash based on L. ferrea, its initial characteristics remained stable except for the homogeneity and pH of the solution. El objetivo de este estudio fue evaluar in vitro la estabilidad farmacológica de un enjuague bucal herbal a base de extracto de Libidibia ferrea tras la crianza, estableciendo sus características organolépticas y microbiológicas. Las pruebas de estabilidad, pH, sedimentación, densidad y actividad antimicrobiana del colutorio se realizaron con las soluciones almacenadas a los 24 meses. El control de contaminantes se llevó a cabo determinando el número total de microorganismos e investigando Salmonella sp., Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Se analizó la actividad antimicrobiana de la formulación frente a los microorganismos presentes en el biofilm dental: Streptococcus mutans, Streptococcus salivarius, Lactobacillus casei y Candida albicans, determinando la concentración mínima inhibitoria. Para evaluar el pH y la densidad, los datos se analizaron mediante la prueba de Tukey y los demás resultados se describieron mediante estadística descriptiva. En los caracteres organolépticos, el color observado fue “Cerámico”, de consistencia fluida/serosa, aspecto brillante y fuerte olor a menta amaderada. En la fase de sedimentación se observó separación y los análisis de pH y densidad arrojaron como promedio el valor de 5.46 y 1.029 g/cm3, respectivamente. La prueba de evaluación de contaminantes fue negativa para todos los microorganismos estudiados, en 24 meses. El enjuague bucal mostró actividad bactericida / fungicida contra todos los microorganismos probados en todas las concentraciones para los microorganismos S. mutans y C. albicans y en concentraciones de 0,5 mg/ml para S. salivarius y 0,6 mg/ml para L. casei. Se concluyó que luego de 24 meses, la formulación del enjuague bucal a base de L. ferrea, sus características iniciales permanecieron estables, a excepción de la homogeneidad y pH de la solución. O objetivo deste estudo foi avaliar in vitro a estabilidade farmacológica de um enxaguatório bucal fitoterápico à base do extrato de Libidibia ferrea após envelhecimento, estabelecendo suas características organolépticas e microbiológicas. Trata-se de um extrato hidroalcóolico a 7,5%, a partir da vagem de Libidibia ferrea, pela técnica de decocção por refluxo, e seco por aspersão. Os testes de estabilidade, pH, sedimentação, densidade e atividade antimicrobiana do enxaguatório foram realizados com as soluções armazenadas após 24 meses. Realizou-se o controle de contaminantes, através da determinação do número total de microrganismos e pesquisa de Salmonella sp., Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus. Analisou-se a atividade antimicrobiana da formulação frente a microrganismos presentes no biofilme dental: Streptococcus mutans, Streptococcus salivarius, Lactobacillus casei e Candida albicans determinando-se a concentração inibitória mínima. Para avaliação do pH e densidade, os dados foram analisados pelo teste de Tukey e os demais resultados foram descritos pela estatística descritiva. Nos caracteres organolépticos, a coloração observada foi “Cerâmica”, com consistência fluida/serosa, aspecto brilhante e odor forte amadeirado mentolado. Na sedimentação observou-se separação de fases e as análises de pH e densidade apresentaram como média o valor de 5,46 e 1,029 g/cm3, respectivamente. O teste de avaliação de contaminantes foi negativo para todos os microrganismos pesquisados, em 24 meses. O enxaguatório apresentou atividade bactericida/fungicida frente a todos os microrganismos testados em todas as concentrações para os microrganismos S. mutans e C. albicans e nas concentrações 0,5 mg/ml para o S.salivarius e 0,6 mg/ml para L. casei. Concluiu-se que após 24 meses, a formulação do enxaguatório bucal à base de L. ferrea suas características iniciais mantiveram-se estáveis com exceção da homogeneidade e pH da solução.

The commensal microflora is a source for multiple antigens that may induce cross-reactive antibodies against host proteins and pathogens. However, whether commensal bacteria can induce cross-reactive antibodies against SARS-CoV-2 remains unknown. Here we report that several commensal bacteria contribute to the generation of cross-reactive IgA antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein. We identified SARS-CoV-2 unexposed individuals with RBD-binding IgA antibodies at their mucosal surfaces. Conversely, neutralising monoclonal anti-RBD antibodies recognised distinct commensal bacterial species. Some of these bacteria, such as Streptococcus salivarius, induced a cross-reactive anti-RBD antibodies upon supplementation in mice. Conversely, severely ill COVID-19 patients showed reduction of Streptococcus and Veillonella in their oropharynx and feces and a reduction of anti-RBD IgA at mucosal surfaces. Altogether, distinct microbial species of the human microbiota can induce secretory IgA antibodies cross-reactive for the RBD of SARS-CoV-2.

Streptococcus salivarius K12 is an oral probiotic known to contribute to protection against oral pathogenic bacteria in humans. Studies of immune responses to S. salivarius K12 have focused on the oral cavity, and systemic immune responses have not yet been reported. The aim of this study was to identify acute systemic immune responses to the commercial product, S. salivarius BLIS K12, in a double-blinded, placebo-controlled human clinical trial. It was hypothesised that consumption of S. salivarius BLIS K12 would induce an anti-inflammatory response and a decrease in pro-inflammatory cytokines. Blood samples were obtained from participants prior to a single dose of S. salivarius BLIS K12 or a placebo and then secondary blood samples were obtained 24 h and 7 days post-consumption. Samples were analysed using multi-parametric flow cytometry, to quantify immune cell frequency changes, and by a LEGENDplex assay of human inflammatory cytokines. Consumption of S. salivarius BLIS K12 was associated with increased levels of IL-8 at 24 h. The frequency of Tregs increased in samples taken 7 days after probiotic consumption, and IL-10 concentrations were higher at 7 days than 24 h after consumption. There was no difference in the frequency and/or activation of CD4

Peritonitis is the most common infectious complication of chronic peritoneal dialysis in children and the most common reason for hospitalization. Although the most common organisms responsible for peritonitis are gram-positive bacteria, peritonitis has not previously been reported secondary to Streptococcus salivarius, one of the 26 species in the Streptococcus viridians group. We describe a 4-month-old male who developed S. salivarius peritonitis while receiving automated peritoneal dialysis and who was successfully treated with a 14-day course of intraperitoneal vancomycin. Subtyping episodes of S. viridans-related infection is essential for the identification of S. salivarius.

This study aims to determine if the presence of Streptococcus salivarius biofilm changes the tribological response of the tooth/zirconia contact pair. Reciprocating pin-on-plate wear tests were carried out at 37 °C and pH 7, using an appropriate lubricant to simulate an oral environment accounting for the presence of a S. salivarius surface biofilm. Reference wear tests were also carried out in artificial saliva with and without added glucose in aseptic conditions. Tests lasted a total of 21600 cycles under an applied normal load of 1.98 N. Human molar cusps served as pins while medical grade Y-TZP samples were used as sliding plates. Microscopy and profilometry readings were employed for the characterization of pristine and worn surfaces. Enamel/zirconia contact during sliding is notably affected by the presence of a Streptococcus salivarius biofilm. When compared to aseptic reference testing with and without added glucose, the S. salivarius biofilm decreased the dimensional wear factor by 87% and 81% respectively, and decreased the coefficient of friction by 77% and 68% respectively. Results clearly show that a streptococcus biofilm can change the tribological performance of a dental system. This work demonstrates that the presence of biofilm should be appreciated for a dental tribo-sytem, and the authors propose that further works regarding dental wear testing be carried out introducing asepsis level as a fundamental testing parameter.

BackgroundSore throat resulting from pharyngotonsillitis is one of the commonest reasons for primary care consultation and inappropriate antibiotic prescription and finding effective alternative treatments is important.ObjectivesTo review the evidence for using the probiotic Streptococcus salivarius K12 (SsK12) for the prevention or treatment of pharyngotonsillitis.Data SourcesPubMed, Embase, CINAHL and Cochrane Library.Study eligibility criteriaRandomized controlled trials (RCTs).ParticipantsAdults or children.InterventionsSsK12 as active treatment or prophylaxis, against pharyngotonsillitis.MethodsLiterature search.ResultsFour articles were identified (1846 participants). All were deemed to be of poor quality using the Cochrane risk-of-bias assessment. Two trials studied SsK12 prophylaxis for streptococcal pharyngitis (children without history of recurrence). One compared daily administration of SsK12 to no treatment over 6 months (n = 222, age 33–45 months), reporting significantly lower incidence in the SsK12 group (16.2% vs. 48.6%, p n = 1314, 5–14 years) found no significant difference (7.8% vs. 8.8%, p 0.34) with SsK12 (administered on school days). Another trial found daily SsK12 to significantly protect children (n = 250, 6–7 years) against chronic adenoiditis exacerbation over 3 months compared to no treatment (71.7% vs. 100%, p SsK12 for acute pharyngotonsillitis (concurrently with penicillin) showed no significant benefit. In all trials, SsK12 was safe and well tolerated.ConclusionsSsK12 appears safe and well tolerated. However, further RCTs are required to establish its role as a prophylactic therapy, particularly among patients experiencing frequent exacerbations of pharyngitis. In the acute setting, SsK12 is unlikely to be effective if given concurrently with antibiotics; however, further RCTs should establish its role as an alternative to antibiotics in nonsevere cases or when prescribed after antibiotic therapy for the prevention of disease recurrence and/or secondary infection.

AIM To investigate whether glycosaminoglycans (GAGs) binding to high-dose LL37 eliminates its cytotoxicity to dental pulp cells (hDPCs) whilst retaining undiminished antimicrobial and LPS-neutralizing abilities. METHODOLOGY hDPCs were stimulated with varying concentrations of LL37, and their cell viability was analysed by MTT. Then, high-dose LL37 (10 μmol L-1 ) was bound to varying concentrations of three GAGs, heparin, chondroitin sulphate and hyaluronic acid, and their cytotoxic effects on hDPCs and antimicrobial effects were evaluated and compared. Furthermore, the LPS-neutralizing ability of heparin (5 μg mL-1 )-LL37 (10 μmol L-1 ) complexes, which were found to be less cytotoxic for hDPCs with undiminished antimicrobial ability, was investigated. Statistical analysis was performed using one-way analysis of variance (anova), followed by Dunnett's test. P values below 0.05 were considered significant. RESULTS LL37 significantly reduced the cell viability of hDPCs in a dose-dependent manner (P

We present the case of a 92-year-old man with septic arthritis of a prosthetic hip joint due to Streptococcus salivarius one week following a high-risk dental procedure despite preprocedure amoxicillin. S. salivarius is a commensal bacterium of the human oral mucosa that is an uncommon cause of bacteremia. S. salivarius has previously been described as a causative agent of infective endocarditis and spontaneous bacterial peritonitis but was only recently recognized as a cause of prosthetic joint infection. This case highlights the potential pathogenicity of a common commensal bacteria and the questionable utility of prophylactic antibiotics before dental procedures to prevent periprosthetic joint infections.

Direct antagonism towards pathogens including Streptococcus pyogenes is a proposed mechanism of pharyngeal probiosis but off-target effects on the symbiotic microbiota of the throat are possible and may be beneficial, harmful or neutral. We have assessed the bacteriological effects of two candidate Lactobacillus probiotics and the established pharyngeal probiotic Streptococcus salivarius K12. Antagonism towards S. pyogenes and potential off-target effects were determined using sessile monospecies biofilms and pharyngeal microcosms, respectively. The candidate probiotics were antagonistic towards S. pyogenes (rank order of increasing potency, Lactobacillus acidophilus < Lactobacillus plantarum < Streptococcus salivarius) in the absence of significant acidification or cell-cell contact. Streptococcus salivarius and L. plantarum caused significant reductions in viable counts of streptococci in pharyngeal microbiotas, whilst S. salivarius also caused reductions in staphylococci. In contrast, changes in pharyngeal eubacterial DNA profiles were limited overall. In summary, the three candidate probiotics suppressed axenic Streptococcus pyogenes biofilms by mechanisms that did not depend on cell-cell contact or acidification and did not markedly destabilize complex pharyngeal microbiotas derived from healthy individuals. SIGNIFICANCE AND IMPACT OF THE STUDY: Candidate probiotic bacteria deployed to prevent or treat bacterial pharyngitis will interact with the target bacteria such as Streptococcus pyogenes as well as with the microbiota of the throat, where off-target effects are possible. Three candidate probiotics Lactobacillus acidophilus, Lactobacillus plantarum and Streptococcus salivarius reduced viability within extant S. pyogenes biofilms through the elaboration of diffusible factors other than fermentation acids but did not markedly disrupt ex situ pharyngeal microcosms. This work demonstrates the application of in vitro pharyngeal models in the preclinical testing of the safety and efficacy of candidate pharyngeal probiotics.

The effects of probiotic fermented sheep’s milk containing Lactobacillus casei 01 on enamel demineralization and microorganism counts in a mixed biofilm model were investigated. Enamel blocks (N = 50) were fixed in polystyrene plates in which a mixed biofilm (Streptococcus mutans 25175, Streptococcus parasanguinis 903, and Streptococcus salivarius 8618) was formed. The mature biofilm was treated for five days with the following: (1) sheep’s milk (SM); (2) fermented sheep’s milk with starter culture (FSMS); (3) fermented sheep’s milk with probiotic culture (FSMP); and (4) fermented sheep’s milk with starter and probiotic cultures (FSMSP). A growth control group was also included (brain–heart–infusion medium with inoculum). The percentage of surface hardness loss (%SHL) and total microorganism and Streptococcus counts (log10 colony-forming units/mL) were calculated. In addition, mean internal mineral density loss determination (ΔZ) by micro–computed tomography and descriptive topographic analysis via scanning electronic microscopy (SEM) were performed. No group prevented %SHL (p = 0.168), with a similarity in values (p > 0.05) confirmed in SEM images. No differences were found between the tested groups and growth control group in terms of total microorganism or Streptococcus counts (p > 0.05). In relation to total microorganism reduction, FSMS and FSMP were similar (p = 0.153), presenting a reduced number of microorganisms. Both were different from FSMSP (p

Whey is a rich dairy by-product emerging mostly during cheese production, with valuable nutritional, functional and bioactive properties and reduced immunogenicity of the protein fractions. The aim of the study was to evaluate therapeutic potential and immunoreactivity with milk antigens of whey prefermented with potentially probiotic bacteria (with Streptococcus salivarius subsp. thermophilus 2 K and Lactobacillus delbrueckii subsp. bulgaricus BK – FW whey, or with S. thermophilus 2 K, L. bulgaricus BK, Lactobacillus plantarum W42, and Bifidobacterium animalis ssp. lactis Bi30 – FW-LB whey). The study was conducted on a mice model with induced cow’s milk proteins allergy (CMPA). Interventional feeding of α-CN + β-LG immunized mice with FW and FW-LB whey changed Th1/Th2 balance towards a Th1 response and enhanced the secretion of regulatory cytokines, and reduced allergy markers level. The presence of L. plantarum W42 and B. lactis Bi30 significantly enhanced the observed therapeutic effect of whey prefermented with yogurt cultures.

The present study aimed to test the antimicrobial activity of Streptococcus dentisani (S. dentisani) supernatant against a collection of microorganisms implicated in dental root infections, and to analyze morphological changes induced in a selection of the tested microorganisms. A total of 22 microbial species were selected, and their growth was monitored by spectrophotometry in the presence and absence of the supernatant of S. dentisani at different assay concentrations (0.2×, 1×, 2×). The generation time and maximum growth rates were evaluated under every tested condition. Scanning electron microscope (SEM) images were obtained to assess the effect on the cell surface following incubation of the pathogens with the concentrated (2×) supernatant of S. dentisani. The supernatant of S. dentisani was found to exert effective inhibitory activity against most of the studied microorganisms implicated in dental root infections (20 out of 22). Total growth inhibition was observed in the case of Streptococcus oralis, Streptococcus sobrinus, Streptococcus salivarius, Prevotella intermedia, and Streptococcus mutans, while the rest of the microorganisms showed an increase in the generation time (between 30 min and 4 h). SEM images revealed structural changes in the membrane consistent with bacteriocin activity, although the effects were heterogeneous among the different species tested.

Over the last decades, probiotic strains for topical administration (including oral cavity) have appeared in clinical practice. Streptococcus salivarius K12 is a promising probiotic for prevention and treatment of the upper respiratory tract and ENT infections, and for maintenance of healthy oral microbiota. The review represents mechanisms of action of oral probiotics and the results of clinical studies of the S. salivarius K12 strain in various medical conditions.

Background: Periodontal diseases comprise a wide range of inflammatory conditions that affect the supporting structures of the teeth, and may lead to severe periodontal destruction and even tooth loss. Streptococcus salivarius K12 (S. salivarius K12), one of oral probiotics, has been reported to be able to inhibit various potentially deleterious bacteria. This study was the first time to investigate the effects of S. salivarius K12 on ligature-induced periodontitis in mice. Methods: A silk ligature was tied around the second left maxillary molar to establish the model of periodontitis, and then, mice in group S. salivarius K12 were administered with S. salivarius K12 (2 x 109 CFU) twice daily for 30 d, the others were treated with isopyknic water. Results: Administration with S. salivarius K12 markedly decreased the anaerobic bacteria accumulation on the teeth, and it also considerably alleviated periodontitis-induced alveolar bone resorption and attachment loss. Moreover, S. salivarius K12 administration increased the relative species abundance of Gram-positive bacterium in oral cavity while decreased Gram-negative bacterium, as well as the diversity of the bacterial community. Conclusion: Oral administration of the probiotic S. salivarius K12 may mitigate the alveolar bone resorption and attachment loss of periodontitis by modulating the oral microbiota.

Coffee is a widely consumed beverage containing organic compounds with antibacterial activity. To investigate its possible effect on the growth of oral indigenous microbiota, saliva samples collected from nine young adults were inoculated into brain heart infusion (BHI) medium with or without addition of coffee compounds and cultured at 37°C in 5% CO2 for 12 h. The total bacterial density and composition after cultivation for 0, 6, and 12 h were determined by quantitative PCR analysis and 16S rRNA gene sequencing, respectively. The increase in total bacterial load was significantly inhibited by addition of the coffee compounds. The microbiota was mostly composed of Streptococcus species after culture in BHI medium regardless of the addition of coffee compounds. The proportion of Streptococcus salivarius was significantly reduced after addition of coffee relative to that in untreated medium alone, whereas the proportions of Streptococcus mitis and Streptococcus infantis were increased. These results suggest that exposure to coffee affects the composition of the oral Streptococcus population, in addition to inhibiting the overall growth of salivary bacteria. Considered in the light of data from earlier epidemiological studies, it is possible to conclude that coffee consumption contributes to better health.

Although the most common bacteria in the supragingival plaque are Gram-positive streptococci, no extensive investigations have been conducted into the susceptibility of these species to chlorhexidine and cetylpyridinium chloride. Therefore, in this study, we investigated the susceptibility of 80 streptococcal strains in planktonic or biofilm states to these two antimicrobial agents. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the planktonic streptococci were measured using the microdilution method, as were the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) measured on streptococcal biofilms formed on 96-well plates. In all species, the MIC, MBC, MBIC, and MBEC values were higher for chlorhexidine than for cetylpyridinium chloride, with sensitivity values varying according to species. For chlorhexidine, the MIC, MBC, and MBIC values showed statistically significant differences among species. However, only MBEC values showed statistically significant differences for cetylpyridinium chloride. The MIC against Streptococcus mutans and the MBC against Streptococcus salivarius were significantly lower than those against the other species. With he exception of a few species, most of the bacterium susceptibility values were higher in the biofilm state than in the planktonic state.

Previous studies have clearly demonstrated that the addition of lentisk oil (LO) to streptococcal cultures makes it possible to differentiate Streptococcus spp. into three categories with Streptococcus mitis and Streptococcus intermedius sensitive, Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus mutans partially sensitive, and Streptococcus salivarius insensitive to the product. We have investigated here whether the winterization of LO, an easy and cheap procedure that removes some of the fatty substances contained within, resulted in a better antimicrobial effect on human pathogens affecting the pharyngeal mucosa and middle ear such as S. pyogenes, S. pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae, without affecting, or minimally affecting, S. salivarius strains, oral probiotics commonly used to reduce oral and middle ear infection recurrence, especially in children. Our results not only demonstrated a stronger antimicrobial action of winterized LO (WLO) on S. pyogenes, compared to what was seen with LO, but also demonstrated a strong antimicrobial action vs. S. pneumoniae and M. catarrhalis and a very limited effect on S. salivarius (strains K12 and M18). Moreover, WLO demonstrated a co-acting action when tested along with the antibiotics amoxicillin (A) and amoxicillin clavulanate (AC), effects clearly visible also on H. influenzae. Our results also showed that at least part of the antimicrobial effect observed was due to the presence of anacardic acids (AAs). Finally, WLO, when tested with human peripheral blood mononuclear cells (h-PBMCs), reduced the release of IL-6 and TNF-α and, in the case of cells stimulated by LPS, the release of IFN-γ. In conclusion, our study highlights an enhanced antimicrobial role for LO when winterized, suggests a co-acting effect of this when given with antibiotics, identifies AAs as possible active ingredients, and proposes a possible anti-inflammatory role for it.

BackgroundOral mucositis is the most common oral complication of cancer patients receiving radiotherapy and/or chemotherapy, leading to poor quality of life. Limitations of the current interventions on radiation-induced oral mucositis (RIOM) urge the development of novel therapeutics. Here, we evaluated the treatment outcome of probiotic Streptococcus salivarius K12 on RIOM mice, and oral microbiota that is associated with the progress of RIOM was further investigated.MethodsAn experimental RIOM mouse model was established, and S. salivarius K12 was applied to the mouse oral cavity daily. Histological analyses were performed to evaluate the severity of oral mucositis and the treatment outcome of S. salivarius K12. The oral microbiota of mice was further analyzed by 16S rRNA sequencing, microbial culture and qPCR.Results Irradiation induced conspicuous mucositis in the oral cavity of mice. S. salivarius K12 treatment was beneficial for the healing of RIOM, as reflected by reduced ulcer size, increased basal layer epithelial cellularity and mucosal thickness, and elevated epithelial proliferation and attenuated apoptosis. RIOM mice presented significant oral microbial dysbiosis, with an overgrowth of oral anaerobes. S. salivarius K12 treatment reconstituted the oral microbiota and decreased the abundance of oral anaerobes of RIOM mice. In addition, S. salivarius K12 treatment inhibited NI1060 in Pasteurella genus and downregulated the expression of nitrate reductase.ConclusionsS. salivarius K12 treatment can alleviate RIOM and reconstituted the dysbiotic oral microbiota in mice. S. salivarius K12 may represent a promising adjuvant treatment to improve the quality of life of cancer patients receiving radiotherapy.

Oral probiotics are increasingly used in the harmonization of the oral microbiota in the prevention or therapy of various oral diseases. Investigation of the antimicrobial activity of the bacteriocinogenic strain Streptococcus salivarius K12 against oral pathogens shows promising results, not only in suppressing growth, but also in eliminating biofilm formation. Based on these findings, we decided to investigate the antimicrobial and antibiofilm activity of the neutralized cell-free supernatant (nCFS) of S. salivarius K12 at various concentrations against selected potential oral pathogens under in vitro conditions on polystyrene microtiter plates. The nCFS of S. salivarius K12 significantly reduced growth (p &lt, 0.01) in Streptococcus mutans Clarke with increasing concentration from 15 to 60 mg/mL and also in Staphylococcus hominis 41/6 at a concentration of 60 mg/mL (p &lt, 0.001). Biofilm formation significantly decreased (p &lt, 0.001) in Schaalia odontolytica P10 at nCFS concentrations of 60 and 30 mg/mL. Biofilm inhibition (p &lt, 0.001) was also observed in Enterobacter cloacae 4/2 at a concentration of 60 mg/mL. In Schaalia odontolytica P10 and Enterobacter cloacae 4/2, the nCFS had no effect on their growth.

Previously, we showed that the growth, antibiotic resistance, and biofilm formation properties of the pathogens Pseudomonas aeruginosa and Klebsiella pneumonia were tremendously inhibited by the cell-free supernatant of the oral probiotic Streptococcus salivarius M18. These anti-pathogenic activities of the supernatant were more efficient under acidic conditions. The present approach takes advantage of the acidic nature of the tumor microenvironment to evaluate the effect of the S. salivarius M18 postbiotics on colon cancer cells. In both two-dimensional (2D) and three-dimensional (3D) cell culture models, S. salivarius M18 cell-free supernatant showed anti-cancer actions in the pH conditions mimicking the acidity of the tumor. The inhibitory effect was more prominent when the colon cancer cells have been treated with the cell-free supernatant obtained from the inulin incubated S. salivarius M18. The results of this study point out the potential of the S. salivarius M18 functional probiotic products to be used for targeting low pH environments including the unique acidic microenvironment of tumors.

Background Periodontal disease represents a major health concern. The administration of beneficial microbes has been increasing in popularity over efforts to manipulate the microbes using antimicrobial agents. This study determined the ability of Streptococcus salivarius to inhibit IL-6 and IL-8 production by gingival fibroblasts when activated by periodontal pathogens and their effect on the salivary microbiome. Methods Primary human gingival fibroblasts were challenged with Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum and a combination of all three. IL-6 and IL-8 cytokine release were measured. Using this same model, S. salivarius K12, M18 and different supernatant and whole-cell lysate fractions of S. salivarius K12 were administered to pathogen-induced fibroblasts. A patient study of healthy participants was also conducted to determine the effect S. salivarius K12 had on the native microbiome using 16S next generation sequence analysis. Results All pathogens tested induced a significant IL-6 and IL-8 response. S. salivarius K12 or M18, did not exhibit an increase in inflammatory cytokines. When either of the probiotic strains were co-administered with a pathogen, there were significant reductions in both IL-6 and IL-8 release. This effect was also observed when gingival fibroblasts were pre-treated with either S. salivarius K12 or M18 and then stimulated with the oral pathogens. Chewing gum containing S. salivarius K12 did not alter the salivary microbiome and did not increase inflammatory markers in the oral cavity. Conclusion S. salivarius K12 and M18 prevented immune activation induced by periodontal disease pathogens. S. salivarius K12 did not alter the salivary microbiome or induce immune activation when administered as a chewing gum. These results warrant further study to determine if it may be an effective treatment in a model of periodontal disease.

Recently discovered preventive effects of probiotics on oral health have attracted interest to their use for the prevention and treatment of various diseases. This study aimed to evaluate the antimicrobial and antibiofilm properties of Weissella cibaria against Streptococcus pyogenes, Staphylococcus aureus, S. pneumoniae, and Moraxella catarrhalis, the major pathogens of upper respiratory tract infections (URTIs). The antimicrobial activities of W. cibaria were compared with those of other oral probiotics using a competitive inhibition assay and the determination of the minimum inhibitory concentrations (MICs). In addition, a time-kill assay, spectrophotometry, and confocal laser scanning microscopy were used to confirm the antimicrobial and antibiofilm abilities of W. cibaria CMU (oraCMU) and CMS1 (oraCMS1). Both live cells and cell-free supernatants of all tested probiotics, except Streptococcus salivarius, showed excellent antimicrobial activities. All target pathogens were killed within 4 to 24 h at twice the MIC of oraCMU and oraCMS1, which showed the highest antimicrobial activities against M. catarrhalis. The antimicrobial substances that affected different target pathogens were different. Both oraCMU and oraCMS1 showed excellent abilities to inhibit biofilm formation and remove preformed biofilms. Our results suggest that the W. cibaria probiotics offer new possibilities for the prevention and treatment of bacterial URTIs.