Strains Of Streptococci Research Articles

A gut-derived Streptococcus salivarius produces the novel nisin variant designated nisin G and inhibits Fusobacterium nucleatum in a model of the human distal colon microbiome.

Fusobacterium nucleatum is a human pathogen associated with intestinal conditions including colorectal cancer. Screening for gut-derived strains that exhibit anti-F. nucleatum activity in vitro revealed Streptococcus salivarius DPC6487 as a strain of interest. Whole-genome sequencing of S. salivarius DPC6487 identified a nisin operon with a novel structural variant designated nisin G. The structural nisin G peptide differs from the prototypical nisin A with respect to seven amino acids (Ile4Tyr, Ala15Val, Gly18Ala, Asn20His, Met21Leu, His27Asn, and His31Ile), including differences that have not previously been associated with a natural nisin variant. The nisin G gene cluster consists of nsgGEFABTCPRK with transposases encoded between the nisin G structural gene (nsgA) and nsgF, notably lacking an equivalent to the nisI immunity determinant. S. salivarius DPC6487 exhibited a narrower spectrum of activity in vitro compared to the nisin A-producing Lactococcus lactis NZ9700. Nisin G-producing S. salivarius DPC6487 demonstrated the ability to control F. nucleatum DSM15643 in an ex vivo model colonic environment while exerting minimal impact on the surrounding microbiota. The production of this bacteriocin by a gut-derived S. salivarius, its narrow-spectrum activity, and its anti-F. nucleatum activity in a model colonic environment indicates that this strain merits further attention with a view to harnessing its probiotic potential.IMPORTANCEFusobacterium nucleatum is a human pathogen associated with intestinal conditions, including colorectal cancer, making it a potentially important therapeutic target. Bacteriocin-producing probiotic bacteria demonstrate the potential to target disease-associated taxa in situ in the gut. A gut-derived strain Streptococcus salivarius DPC6487 was found to demonstrate anti-F. nucleatum activity, which was attributable to a gene encoding a novel nisin variant designated nisin G. Nisin G-producing S. salivarius DPC6487 demonstrated the ability to control an infection of F. nucleatum in a simulated model of the human distal colon while exerting minimal impact on the surrounding microbiota. Here, we describe this nisin variant produced by S. salivarius, a species that is frequently a focus for probiotic development. The production of nisin G by a gut-derived S. salivarius, its narrow-spectrum activity against F. nucleatum, and its anti-F. nucleatum activity in a model colonic environment warrants further research to determine its probiotic-related applications.

Cell-Free Supernatant of Vaginal Viridans Streptococcus Induces Membrane Permeabilization and Transcriptional Regulation in Methicillin-Resistant Staphylococcus aureus.

The genus Streptococcus is a heterogenous group of commensal and pathogenic bacteria that are normal inhabitants of the human body, including the female genital tract (FGT). In the FGT microbiome, streptococci represent two major groups: the pathogenic group B Streptococci (GBS) and the commensal viridans group streptococci (VGS). Though members of the VGS are frequently detected from the FGT, their role in the FGT microbiome remains underexplored. Here, we report the characterization of Streptococcus sp. K0074, isolated from the vaginal swab of an endometrial cancer patient admitted to the hospital, with no evidence of bacterial vaginosis. Phylogenetic analysis revealed that the strain is a member of the commensal VGS and possibly represents a novel species in the mitis subgroup. The strain demonstrated the production of low molecular weight bacteriocin-like substance with narrow-spectrum antagonistic activity, affecting the growth, biofilm formation, and colonization of aerobic vaginitis (AV)-causing bacterium methicillin-resistant Staphylococcus aureus (MRSA). The putative bacteriocin exhibited cell membrane-permeabilizing activity and exerted negative regulatory effect on the accessory gene regulator and SaeRS two-component systems of MRSA. Collectively, our results suggest that the isolate may modulate the FGT microbiome by inhibiting or displacing specific pathogen. Furthermore, the results presented here highlight new perspectives regarding the existence of VGS in the FGT microbiome and in particular pinpoint the potential clinical significance of the isolated VGS strain Streptococcus sp. K0074 for the treatment of AV caused by MRSA.

Streptococcus agalactiae strain COH1 transcriptome in association with stem cell-derived brain-like endothelial cells.

Streptococcus agalactiae (Group B Streptococcus) strain COH1 is a representative strain of serotype III, multi-locus sequence type 17, which is disproportionately associated with neonatal meningitis. Here we report the transcriptome of COH1 when interacting with human brain endothelial cells compared with COH1 alone.

Nanoenzyme MOFs as hydrogen peroxide scavenger and chemodynamic antibacterial agent to alleviate streptococcus pneumoniae infection

Most strains of Streptococcus pneumoniae (SP) strains are capable of secreting hydrogen peroxide (H2O2), which disrupts the DNA double strands, promotes apoptosis and necrosis, and increases vascular permeability. However, there are few nanoenzymes reported that can effectively scavenge H2O2 while also exhibiting antibacterial properties. In this study, we utilized MIL-100(Fe) nanoparticles (NPs) modified with bovine serum albumin (MIL-100(Fe)-BSA NPs) as catalase-like enzymes to scavenge H2O2 by Fenton/Fenton-like reactions, and we evaluated their scavenging capability. Following intravenous injection, the MIL-100(Fe)-BSA NPs showed effective accumulation in the lungs, attributed to dysfunction of the alveolar-capillary barrier in mice infected with SP. During the subsequent Fenton/Fenton-like reaction, the generated Fe2+ ions reacted with H2O2 to generate hydroxyl radicals, which exhibited chemodynamic bactericidal effects. Consequently, these MIL-100(Fe)-BSA NPs rapidly decomposed H2O2, thereby reducing DNA damage in endothelial cells. Additionally, as nanoenzymes, the MIL-100(Fe)-BSA NPs inhibited bacterial infection through their chemodynamic bactericidal effects. This research presented a novel approach for the clinical treatment of SP, demonstrating significant potential for future applications.

A respiratory Streptococcus strain inhibits Acinetobacter baumannii from causing inflammatory damage through ferroptosis

BackgroundMicroecological equilibrium is essential for human health. Previous research has demonstrated that Streptococcus strain A, the main bacterial group in the respiratory tract, can suppress harmful microbes and protect the body. In this study, Streptococcus strain D19T was isolated from the oral and pharyngeal cavities of healthy children. Its antibacterial mechanism against Acinetobacter baumannii was examined, as well as its potential to prevent inflammatory damage to cells. We evaluated the effect of the fermentation conditions of D19T on inhibition of Acinetobacter baumannii growth; Isolation and purification of antibacterial active components of strain D19T and molecular mechanism of inhibition of Acinetobacter baumannii; Molecular mechanism of D19T antibacterial protein reversing cellular inflammatory injury induced by Acinetobacter baumannii.ResultsThe supernatant of fermentation broth of Streptococcus D19T was the active component against Acinetobacter baumannii, but the bacteria had no antibacterial activity. The supernatant of D19T fermentation broth was precipitated by (NH4)2SO4 solution, and the protein was the active antibacterial component. After gel filtration chromatography and anion gel filtration chromatography, the molecular weight of antibacterial protein was 53kD. D19T antibacterial protein can improve cell membrane permeability, limit extracellular soluble protein release, inhibit Acinetobacter baumannii biofilm formation, and prevent Acinetobacter baumannii adhesion. Acinetobacter baumannii induces inflammatory damage to respiratory cells via ferroptosis, and the D19T antibacterial protein can counteract this damage, protecting the respiratory tract.ConclusionStreptococcus strain D19T, as a potential probiotic, inhibits the growth of Acinetobacter baumannii and the inflammatory damage of respiratory cells, playing a protective role in human respiratory health.

The Decontamination Effect of an Oscillating Chitosan Brush Compared With an Ultrasonic PEEK-Tip: An InVitro Study Using a Dynamic Biofilm Model.

This study aimed to assess the effect of an oscillating chitosan brush (OCB) compared with an ultrasonic device with PEEK tip (US-PEEK) for mechanical implant surface decontamination using an invitro model combining 3D models and a validated dynamic multispecies biofilm. A multispecies biofilm using six bacterial strains (Streptococcus oralis, Veillonella parvula, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans) was seeded on dental implants with machined and sandblasted, large-grit and acid-etched (SLA) surfaces. These were installed in 3D models depicting peri-implant defect. Mechanical decontamination was performed for 120 s using either an OCB or a US-PEEK. A negative control group received no treatment. Scanning electron microscopy (SEM) was used to evaluate the bacterial composition and quantitative PCR (qPCR) analyzed the number of each bacterial species [colony-forming units per milliliter (CFU/mL)]. Well-structured biofilms with a dense microbial distribution were observed on the negative control implants after 72 h. qPCR following mechanical decontamination showed a scarce bacterial reduction in the OCB group. The US-PEEK group exhibited a significant decrease in bacterial species compared to both OCB and control groups (p < 0.05). A biofilm removal effect was also observed in the OCB group for the machined implant surfaces. In vitro assessment using an anatomical 3D model showed that mechanical decontamination effectively reduced biofilm. The US-PEEK group demonstrated biofilm reduction on the SLA surface, while the OCB group showed a reduction on the machined implant surface. Additionally, the US-PEEK group demonstrated greater efficacy in reducing bacterial numbers.

Development of bioluminescent Group B streptococcal strains for longitudinal infection studies.

Group B Streptococcus (GBS) remains the leading bacterial cause of invasive neonatal disease, resulting in substantial morbidity and mortality. New therapeutic approaches beyond antibacterial treatment to prevent neonatal disease outcomes are urgent. One significant limitation in studying GBS disease and progression is the lack of non-invasive technologies for longitudinal studies. Here, we develop and compare three bioluminescent GBS strains for in vivo pathogenic analysis. Bioluminescence is based on the luxABCDE operon on a replicative vector (luxGBS-CC17), and the red-shifted firefly luciferase on a replicative vector (fflucGBS-CC17) or integrated in the genome (glucGBS-CC17). We show that luxGBS-CC17 is suitable for in vitro analysis but does not produce a significant bioluminescent signal in infected pups. In contrast, the fflucGBS-CC17 results in a strong bioluminescent signal proportional to the organ colonisation level. However, the stability of the replicative vector depends on the route of infection, especially when pups acquire the bacteria from infected vaginal mucosa. Stable chromosomal integration of luciferase in glucGBS-CC17 leads to significant bioluminescence in both haematological and vertical infection models associated with high systemic colonisation. These strains will allow the preclinical evaluation of treatment efficacy against GBS invasive disease using whole-mouse bioluminescence imaging.

Lactococcus garvieae as a Novel Pathogen in Cultured Pufferfish (Takifugu obscurus) in China

In October 2023, a disease outbreak in pufferfish (Takifugu obscurus) farms in Zhongshan City, Guangdong, China, caused high mortality. Diseased fish (mean length: 15 ± 1 cm) exhibited swimming disorders, fin rot, hemorrhage, and an enlarged spleen. Histopathological observations generally revealed inflammation, necrosis, and congestion in the spleen, kidneys, and brain tissues. The most severe pathological changes included interstitial edema and tubular atrophy in the kidneys, hemosiderin deposition in the spleen, massive red blood cell infiltration, and a decrease in lymphocytes. A single strain of bacteria (Tol-1) was isolated from the diseased pufferfish and identified as a Gram-positive streptococcus strain, exhibiting α-hemolysis on sheep blood agar plates. Through biochemical characterization, 16S rDNA sequencing, morphological analysis, and specific primer-based identification, the Tol-1 strain was identified as Lactococcus garvieae, serotype I. Antimicrobial susceptibility testing indicated that Tol-1 was sensitive to Chloramphenicol, Ampicillin, Cephalexin, and Doxycycline, but resistant to Kanamycin, Gentamicin and Ciprofloxacin. In addition, 15 common virulence factors were detected in the Tol-1 strain, including adhPav, adhPsaA, adhC I–II, adh, and hly 1–3. Pufferfish (mean length: 17 ± 1 cm) subjected to artificial infection via intraperitoneal injection (IP) with the Tol-1 strain exhibited clinical symptoms and histopathological damage similar to those observed in naturally infected fish. An infection dose of 1 × 105 CFU/fish resulted in 80% mortality. The study fulfilled Koch’s postulates, indicating that the disease outbreak in pufferfish was caused by L. garvieae, which exhibited a high mortality rate in pufferfish despite the subtle clinical symptoms. These results serve as a warning for pufferfish farming areas and provide a scientific basis for future prevention and control efforts.

Molecular characterization of a novel putative pathogen, Streptococcus nakanoensis sp. nov., isolated from sputum culture.

The genus Streptococcus encompasses a wide range of bacteria with more than 60 species. Recently, there has been a notable increase in reports of novel species of α-Streptococcus based on genomic analysis data. However, limited information exists regarding the pathogenicity of these species. In this study, a quinolone-resistant α-hemolytic Streptococcus strain, MTG105, was isolated from a patient with pneumonia. Genetic analysis revealed that this species was a novel species closely related to S. pseudopneumoniae. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that caused by S. pneumoniae and S. pseudopneumoniae, strongly suggesting its potential as a pathogenic α-Streptococcus. The natural transformation abilities of Streptococcus species facilitate gene exchange within the same genus, leading to the emergence of species with increasingly diverse genome structures. Therefore, the identification of this species underscores the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance.

Identification and characterisation of carbapenem-resistant Streptococcus nidrosiense sp. nov. isolated from blood culture

BackgroundThis study aimed to investigate a highly resistant strain of Streptococcus sp. isolated from a patient with bloodstream infection and determine its taxonomic classification. MethodsThe strain was isolated from blood culture from a 65-year-old male patient admitted to St. Olavs University hospital, Trondheim, Norway, in 2023. Antimicrobial susceptibility testing as well as phenotypic and biochemical characterization were performed. Whole genome sequencing was conducted and genomic comparison to Streptococcus type strains was carried out. ResultsThe strain was initially identified as Streptococcus mitis/oralis but showed significant genetic differences, suggesting that it belonged to an undescribed species within the Streptococcus genus. Phenotypic and biochemical characterization identified the strain as a non-motile, facultative anaerobic bacterium with α-hemolysis. Antimicrobial susceptibility testing showed resistance to all beta-lactams tested. Genomic analyses confirmed the classification of the strain as a novel species, which was designated Streptococcus nidrosiense. ConclusionThis study combines conventional phenotypic tests with whole genome sequencing for accurate taxonomic classification of a bacterial strain isolated from blood culture. The identification of a novel species within the Streptococcus genus contributes to the understanding of microbial diversity and antibiotic resistance of the Streptococcus genus in clinical settings.

Genome sequences of 36 Streptococcus pneumoniae strains optimized for the multiplexed opsonophagocytosis killing assay.

A multiplexed opsonophagocytosis assay (MOPA) was developed as a cost-effective, high-throughput biological assay to evaluate the efficacy of pneumococcal vaccines by in vitro measurement of opsonophagocytic activity of anti-capsular antibodies. Here, we report draft genomes of the 36 strains of Streptococcus pneumoniae developed for use in the reference pneumococcal MOPA.

Design and structure-activity relationships of ether-linked alkylides: Hybrids of 3-O-descladinosyl macrolides and quinolone motifs

Ketolides (3-keto) such as TE-802 and acylides (3-O-acyl) like TEA0929 are ineffective against constitutively resistant pathogens harboring erythromycin ribosomal methylation (erm) genes. Following our previous work on alkylides (3-O-alkyl), we explored the structure–activity relationships of hybrids combining (R/S) 3-descladinosyl erythromycin with 6/7-quinolone motifs, featuring extended ether-linked spacers, with a focus on their efficacy against pathogens bearing constitutive erm gene resistance. Optimized compounds 17a and 31f not only reinstated efficacy against inducibly resistant pathogens but also demonstrated significantly augmented activities against constitutively resistant strains of Streptococcus pneumoniae and Streptococcus pyogenes, which are typically refractory to existing C-3 modified macrolides. Notably, hybrid 31f (coded ZN-51) represented a pioneering class of agents distinguished by its dual modes of action, with ribosomes as the primary target and topoisomerases as the secondary target. As a novel chemotype of macrolide-quinolone hybrids, alkylide 31f is a valuable addition to our armamentarium against macrolide-resistant bacteria.

Antibacterial and Antibiofilm Effects of L-Carnitine-Fumarate on Oral Streptococcal Strains Streptococcus mutans and Streptococcus sobrinus.

Streptococcus mutans is a major pathogenic habitant of oral caries. Owing to its physiological and biochemical features, it prevails in the form of plaque biofilm together with another important mutans streptococci species, Streptococcus sobrinus. Both species are considered as initiators of cavity lesions, and biofilm is essential to the dental caries process. Compared with the planktonic populations, the biofilm form has higher resistance to environmental conditions and antibiotics. Dental plaques also secure the long-term survival of microorganisms and protection from any stress conditions. To address the need for new antibiofilm agents, we have focused on L-carnitine-fumarate, a fumarate-conjugated quaternary ammonium compound. Using the macro-broth susceptibility testing method, we established its MIC value as 6.0 mg/mL. The MBC value, determined from the broth dilution minimum inhibitory concentration test by sub-culturing it to BHI agar plates, was established as 7.0 mg/mL. Antibiofilm efficacy was tested in 96-well plates coated with saliva using BHI broth supplemented with 1% sucrose as a standard approach. The obtained results allowed us to assess the MIBC as 7.5 mg/mL and the MBBC value as 10.0 mg/mL. The latter concentration also caused approximately 20% eradication of pre-existing biofilm. EPS-rich matrix, forming the core of the biofilm and enabling a confined acidic microenvironment, was also examined and confirmed the effectiveness of 10.0 mg/mL L-carnitine-fumarate concentration in inhibiting EPS formation. Furthermore, the anti-adherent and anti-aciduric impacts of L-carnitine-fumarate were investigated and revealed significant inhibitory effects at sub-MIC concentrations. The influence of L-carnitine-fumarate on the phosphotransferase system was investigated as well. Our results provide a new insight into the antibacterial potential of L-carnitine-fumarate as a valuable compound to be considered for alternative or adjunct anti-caries and antibiofilm preventive approaches.

A Green Approach by Employing Two Bacterial Strains(Streptococcus thermophilus) and (Bacillus coagulans) to Reduce Graphene Oxide

A Green Approach by Employing Two Bacterial Strains(Streptococcus thermophilus) and (Bacillus coagulans) to Reduce Graphene Oxide

Design, synthesis, and antibacterial activity of pleuromutilin derivatives.

This paper reports the design, synthesis, and antibacterial activity study of pleuromutilin derivatives with 2-methyl-4-nitroaniline and 2-methoxy-4-nitroaniline side chains at the C22 position. The structures of the new compounds were characterized by 1H-NMR, 13C-NMR and HRMS. The inhibitory activity of the compounds against MSSA, pyogeniccoccus, streptococcus, and MRSA strains was determined using the micro broth dilution method. The results showed that the compounds exhibited certain activity against Gram-positive bacteria, among which compounds A8a, A8b, A8c, A8d, and A7 demonstrated superior antibacterial activity against MSSA, MRSA, and pyogeniccoccus compared to tiamulin, although the derivatives showed lower antibacterial activity against streptococcus compared to the control drug. Based on the favorable invitro activity of A8c, the time-kill kinetics against MRSA were evaluated, revealing that compound A8c could inhibit bacterial proliferation in a concentration-dependent manner.

Profile of pathogenic bacteria isolated from cow's milk in N'Djamena: associated risk factors and antibiotic resistance

Raw milk and its derivatives are foodstuffs vulnerable to contamination by microorganisms including pathogenic bacteria and failure to comply with hygiene rules. The objective of this study was to determine the profile of pathogenic bacteria isolated from cow's milk and to evaluate the effectiveness of antibiotics commonly used in veterinary and human medicine against these bacteria in Chad. This was a prospective and analytical study based on bacteriological examination including 180 milk samples collected in 10 districts of N'Djamena. The isolation, identification and testing of sensitivity of isolated bacteria to antibiotics were carried out under standard food bacteriology conditions. Among 180 milk samples which were screened by bacteriological examination, 71 (34.44%) cases were positive. The bacterial strains isolated were: Staphylococcus aureus (38.03%), Streptococcus agalactiae (18.31%), Staphylococcus hyicus (11.27%), Streptococcus uberis (7.04%), Escherichia coliO157H7 (7.04%), Streptococcus pyogenes (5.63%), Aeromonas hydrophila (5.63%), Listeria monocytogenes (4.22%) and Mycobacterium tuberculosis (2.81%). The risk factors most frequently associated with milk contamination were hand milking (100%) followed by unsanitary environment (65%), 35% of milks were sold in reused bottles and 58% of vendors and producers were uneducated. The antibiogram of the 69 isolated bacterial agents showed reduced sensitivities to beta-lactams and aminoglycosides, and varied resistance to cyclins and fluoroquinolones. Streptomycin remains an aminoglycoside most sensitive to all strains of pathogenic bacteria with an average level of 95.7%. Staphylococci (Staphylococcus aureus and Staphylococcus hyicus) developed an average resistance of 80.15% to methycillin, 80.1% to vancomycin and all bacteria showed an average resistance of 85% to metronidazole. Streptococci strains (Streptococcus agalactiae, Streptococcus uberis and Streptococcus pyogenes) were very sensitive (76.3%) to vancomycin. The isolated Listeria monocytogenes strains were 100%sensitive to aminoglycosides and beta-lactams. The two-strains of Mycobacterium tuberculosis detected by GeneXpert had a profile of 50%sensitivity and 50%resistance to rifampicin. This study not only made it possible to know the high rate and frequency of pathogenic bacteria in cow's milk as well as the associated risk factors, but also showed a reduction in sensitivity of bacteria to aminopenicillins and aminoglycosides, a strong resistance of Staphylococcus aureus to methicillin and vancomycin and a high sensitivity of streptococci to vancomycin.

Pathology of the gastrointestinal tract in overweight and obese children

Obesity and diseases of the gastrointestinal tract are widespread among the children and have common developmental mechanisms. The article provides a literature review on the relationships between certain pathological conditions of the digestive system (gastroesophageal reflux disease, gastritis, functional intestinal disorders, Crohn’s disease, diverticular disease) in children with overweight and obesity. Excess body weight and obesity can become risk factors for the development of gastrointestinal pathology. The data available in modern literature on changes in the composition of the intestinal and stomach microbiocenosis with increasing body weight are summarized (changes in enterotype, increase in the Firmicutеs/Bacteroides ratio, increase in the number of bacteria Methanobrevibacter, Escherichia coli, Lactobacillus rhamnosus, Lactobacillus delbrueckii and Lactobacillus reuteri). The strains of bacteria that contribute to the anorexigenic effect are considered: Lactobacillus gasseri, some strains of Bifidobacterium, Saccharomyces, Streptococcus and Enterococcus. The pathogenetic aspects of obesity and overweight caused by microbiota are presented: activation of lipid synthesis, breakdown of polysaccharides, absorption of mono- and disaccharides, development of metabolic endotoxemia, etc. Features of the functioning of the autonomic nervous system in obesity in children are presented, indicating the predominance of the hypersympathicotonic variant of autonomic reactivity.

In Vitro Evaluation of Mangostanin as an Antimicrobial and Biocompatible Topical Antiseptic for Skin and Oral Tissues.

Skin and oral tissue infections pose significant health challenges worldwide, necessitating the exploration of new antiseptic agents that are both effective and biocompatible. This study evaluated the antibacterial efficacy and biocompatibility of mangostanin (MGTN), a xanthone derived from Garcinia mangostana L., against commercial antiseptics across various bacterial strains (Porphyromonas gingivalis, Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Cutibacterium acnes) and in vitro models of skin and oral tissues. MGTN demonstrated significant antimicrobial activity against all tested pathogens concurrently exhibiting negligible cytotoxic effects on human gingival fibroblasts as well as on three-dimensional (3D) models of human epidermis and oral epithelium. Furthermore, using pooled human saliva, MGTN effectively inhibited plaque biofilm formation, suggesting its potential as a natural, biocompatible antiseptic for skin and oral health applications. These findings position MGTN as a promising candidate for further development into antiseptic formulations, offering a natural alternative to current synthetic options.

Antimicrobial, Probiotic, and Immunomodulatory Potential of Cannabis sativa Extract and Delivery Systems.

The compounds present in hemp show multidirectional biological activity. It is related to the presence of secondary metabolites, mainly cannabinoids, terpenes, and flavonoids, and the synergy of their biological activity. The aim of this study was to assess the activity of the Henola Cannabis sativae extract and its combinations with selected carriers (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, magnesium aluminometasilicate, and hydroxypropyl-β-cyclodextrin) in terms of antimicrobial, probiotic, and immunobiological effects. As a result of the conducted research, the antimicrobial activity of the extract was confirmed in relation to the following microorganisms: Clostridium difficile, Listeria monocytogenes, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus pyrogenes, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Pseudomonas aereuginosa, and Candida albicans (microorganism count was reduced from ~102 CFU mL-1 to <10 CFU mL-1 in most cases). Additionally, for the system with hydroxypropyl-β-cyclodextrin, a significant probiotic potential against bacterial strains was established for strains Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus rhamnosus, Lactobacillus reuteri, Pediococcus pentosaceus, Lactococcus lactis, Lactobacillus fermentum, and Streptococcus thermophilus (microorganism count was increased from ~102 to 104-107). In terms of immunomodulatory properties, it was determined that the tested extract and the systems caused changes in IL-6, IL-8, and TNF-α levels.

A survey of the knowledge, attitude, and practice of using probiotics for oral health among dental students in Kerala

Background: Widespread prevalence of dental caries, particularly in developing countries, poses a major public health challenge. Traditional approaches using fillings and remineralizing agents have limitations. Probiotics offer a potentially self-administered, multifaceted alternative for both preventing and managing caries, with additional health benefits beyond oral health. Methods: A cross-sectional study with a validated questionnaire was conducted among 308 final-year students and 292 interns from dental colleges in Kerala. Data were analyzed using descriptive and inferential statistics. Results: Over 74% of interns and final-year students recognized probiotic benefits. Awareness about prebiotics was limited in both groups (59.7% and 62.3%, respectively). Notably, 65.6% of students and 72.6% of interns demonstrated knowledge about the probiotic potential of streptococcus strains. Almost 43% of students and 55% of interns reported current or past probiotic use and recommendations. A substantial majority in both groups (over 87%) expressed willingness to try recommended probiotic products. Notably, 47.4% of final-year students and 44.5% of interns had not used probiotics therapeutically, with gastrointestinal issues being the primary indication for those who did. Conclusions: High awareness of probiotics with knowledge gaps in certain areas (e.g., prebiotics) was observed. The majority showed a willingness to utilize probiotics in their practice. Educational interventions focused on these areas could equip dental professionals to provide informed advice and recommendations about probiotics to their patients.