Search Results (407)

The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes. Full article

Background: Prematurely born newborns with low birth weight constitute a group of patients who require special care from the first days of life. Prematurity and low birth weight affect about 13.4 million infants. Risk factors include placental disorders but also factors related to the mother, such as smoking, alcohol drinking, drug use, malnutrition, or certain diseases. It is imperative to educate women of reproductive age (15–49) about the basic factors influencing embryonic development, such as oral health, diet, medicine intake, and harmful habits. Even though most women are aware of the negative impact of harmful habits on the fetus, still too little attention is paid to oral health in pregnant women. Poor oral health may influence the well-being of the future mother, as well as of the child. Therefore, women of reproductive age and those who are pregnant must have adequate knowledge on this subject. The aim of this study was to assess the knowledge of Polish women of reproductive age (15–49) regarding oral health during pregnancy, including the impact of dental treatment, oral hygiene, and maternal oral conditions on pregnancy outcomes and the health of the newborn. Materials and Methods: This was a cross-sectional study of 508 women, in the reproductive age, whose age ranged from 18 to 49 years old. The surveys were conducted from April 2020 to November 2020. The questionnaire was originally developed based on the available literature and consisted of seven sections: basic information, general health and habits, pregnancy status and dental care, knowledge of treatment options during pregnancy, oral health status and its association with the risk of preterm birth, prematurity and the child’s oral health, and breastfeeding and oral development. Results: After excluding incomplete questionnaires, a total of 499 questionnaires were included in the analysis. Women participating in the study had a fairly good understanding of the impact of oral health on the fetus and the role of breastfeeding in the development of the stomatognathic system (from 50% to 70% correct answers). However, even though most respondents had completed higher education (344/68.94%), their knowledge of oral health, preterm birth, and low birth weight was very limited (including the impact of inflammation on the intrauterine development of the child or bacteria and transfer across the placenta). In these sections, the percentage of correct answers ranged from less than 20% to 50%. When analyzing knowledge by age, education, number of births, and place of residence, the highest levels of knowledge were observed among respondents with higher education, particularly those aged 27–32. Conclusions: Respondents had a fairly good understanding of the general impact of oral health during pregnancy and recognition of the importance of breastfeeding for infants. However, their knowledge about the impact of bacteria and inflammation in the mother’s oral cavity on prematurity and low birth weight was limited. Therefore, educating women of reproductive age and pregnant women on this topic is essential, as it may help reduce the adverse consequences of prematurity. Full article

The involvement of oral bacteria in the pathogenesis of distant organs, such as the heart, lungs, brain, liver, and intestine, has been shown. We analyzed the distribution of bacterial species in the resected aortic valve by 16S rRNA metagenomic analysis and directly compared their gene sequences with those in the oral cavity. Thirty-two patients with aortic stenosis or aortic regurgitation who underwent aortic valve replacement were enrolled in this study. Antibody titer against periodontal pathogenic bacteria in the patient’s serum was analyzed. The genetic background and distribution of bacterial species on subgingival plaque, the dorsal surface of the tongue, and the resected aortic valve were analyzed. Patients with aortic valve disease were shown to have more severe periodontal disease by the detection of antibodies against Socransky’s red-complex bacteria of periodontitis. Bacterial DNA was detected in the aortic valves of 12 out of 32 patients. The genomic sequences of the V3-V4 region of the 16S rRNA in some bacteria isolated from the aortic valves of six patients who underwent metagenomic analysis were identical to those found in the oral cavity. The findings indicate that bacteria detected in the aortic valve may be introduced through oral dysbiosis, a condition characterized by an imbalance in the oral microbiota that increases the risk of periodontal disease and dental caries. Oral dysbiosis and the resulting potential bacteremia are associated with the pathogenesis of aortic valve diseases. Full article

Background: The oral microbiome differs in obese patients compared to normal-weight subjects. Microbiologic shifts very often appear after surgical interventions such as bariatric surgery (BS) and in immunocompromised patients. However, the oral microbiome composition and load in subjects after bariatric surgery are unclear. Aim: The aim of this review is to summarize the current state of the art related to the oral microbiome shift induced by bariatric surgery and to discuss its implications on oral cavity health. Methods: Electronic databases: PubMed/Medline, Web of Science, and Cochrane Library were searched for articles published up to March 30, 2025, describing prospective studies focused on changes in the oral microbiota of patients who underwent bariatric surgery. Results: Eight studies measuring the oral microbiome with different approaches—16S ribosomal RNA (16S rRNA) sequencing, polymerase chain reaction (PCR), culture, and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI TOF MS)—were included in this review. The following bariatric techniques were used: sleeve gastrectomy, Roux-en-Y gastric bypass, Omega loop gastric bypass, and laparoscopic gastric plication. The follow-up period ranged from 3 to 12 months. The results of microbiologic studies were unequivocal. There was an increment in Streptococcus mutans reported, high levels of Candida species, and increased rates of some periodontitis-associated bacteria (Porphyromonas gingivalis) in the post-bariatric surgery period, though some studies suggested a shift towards non-pathogenic composition of the oral microbiome in prospective observations. Conclusions: The local oral microbial homeostasis becomes strongly impacted by the bariatric surgical treatment itself as well as its consequences in the further post-operative period. Therefore, obese patients undergoing BS require very careful dental observation. Full article

Background/Objectives: In order to enhance the biological activity, novel complexes of N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives and β-cyclodextrin were obtained. Methods: The inclusion complexes were characterized using spectral and thermal analyses. The antimicrobial activity was determined using the disk diffusion agar method, and completed with the minimum inhibitory concentration (MIC) values obtained by the broth microdilution method. The in vitro anti-inflammatory activity was evaluated using the protease inhibition assay. Results: The computed supramolecular architectures of the inclusion complexes showed that the most stable molecular arrangements correspond to the models in which the N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives are partially included in the cyclodextrin cavity. The antimicrobial screening showed that the compounds were active against Gram-positive bacteria (MIC = 2.5–5.0 mg/mL). Also, the evaluation of the proteinase inhibitory activity showed that the IC₅₀ values of the title compounds (0.04–0.07 mg/mL) were much lower than that of the acetylsalicylic acid (0.4051 ± 0.0026 mg/mL) used as positive control, proving their superior efficiency in inhibiting trypsin activity. Conclusions: The complexation proved to be beneficial for both antimicrobial and anti-inflammatory effects. Full article

Steroids are found in bacteria and eukaryotes, and genes potentially encoding steroid metabolic enzymes have also been identified in giant viruses. For decades, hydroxylated steroids have been utilized in medicine to treat various human diseases. The hydroxylation of steroids can be achieved using microbial enzymes, especially cytochrome P450 monooxygenases (CYPs/P450s) and is well documented. Understanding the structural determinants that govern the regio- and stereoselectivity of steroid hydroxylation by P450s is essential in order to fully exploit their potential. Herein, we present a comprehensive analysis of the steroid-hydroxylating CYP109 family across the domains of life and delineate the structural determinants that govern steroid hydroxylation. Data mining, annotation, and phylogenetic analysis revealed that CYP109 family members are highly populated in bacteria, and indeed, these members passed from bacteria to archaea by horizontal gene transfer, leading to the evolution of P450s in archaea. Analysis of twelve CYP109 crystal structures revealed large, flexible, and dynamic active site cavities that can accommodate multiple ligands. The correct positioning and orientation of the steroid in the active site cavity and the nature of the C17 substituent on the steroid molecule influence catalysis. In an analogous fashion to the CYP107 family, the amino acid residues within the CYP109 binding pocket involve hydrophilic and hydrophobic interactions, influencing substrate orientations and anchoring and determining the site of hydroxylation and catalytic activity. A handful of amino acids, such as Val84, Val292, and Ser387 in CYP109B4, have been found to play a role in determining the catalytic regiospecificity, and a single amino acid, such as Arg74 in CYP109A2, has been found to be essential for the enzymatic activity. This work serves as a reference for the precise understanding of CYP109 structure–function relationships and for P450 enzymes in general. The findings will guide the genetic engineering of CYP109 enzymes to produce valuable steroid molecules of medicinal and biotechnological importance. Full article

Antimicrobial resistance (AMR) is a major public health concern influenced by antimicrobial use (AMU) in animal production systems. In swine, metaphylactic treatments may contribute to the emergence and dissemination of resistance genes. In this study, we isolated bacteria from the nasal cavities of 50 sows across 10 farms in the Federal District, Brazil. A total of 132 bacterial isolates were obtained and tested for phenotypic resistance to 23 antimicrobials using the disk diffusion method. Resistance was detected against all tested antimicrobials, with an overall resistance rate of 55.6% (1605/2888 tests). The highest resistance rates were observed for bacitracin (92.4%) and penicillin (79.2%), while lower resistance rates were found for aminoglycosides. Most isolates exhibited multidrug resistance to 7–9 classes of antimicrobials, including strains of Staphylococcus, Escherichia coli, and Klebsiella—all of which are relevant in the context of One Health. Actinobacillus suis showed the highest resistance levels among all identified species. AMR was positively correlated with both the duration and the number of antimicrobial agents used in feed, reinforcing the need for prudent AMU practices. The use of autogenous vaccines against Pasteurella multocida was associated with reduced lung lesions, underscoring the value of vaccination in disease control. AMR surveillance programs may benefit from including bacterial colonizers from the microbiota, though further studies are necessary to better understand the resistance dynamics of these commensals. Full article

Background/Objectives: Patients with head and neck cancer frequently develop oral complications such as oral mucositis, infections, necrosis, and periodontal disease among others as a consequence of antineoplastic therapy. It is mainly radiotherapy that promotes oral dysbiosis, favouring the overgrowth of opportunistic microorganisms. Identifying effective adjunctive strategies to prevent or mitigate these adverse effects is crucial. Recent studies have suggested that probiotics could be used to restore microbial homeostasis and modulate inflammatory responses in the oral cavity. This systematic review and meta-analysis assessed the efficacy of probiotics in alleviating oral complications associated with antineoplastic treatments in this patient population. Methods: A comprehensive search was conducted in PubMed, LILACS, Scopus and the Cochrane Central Register of Controlled Trials, following the PRISMA 2020 guidelines. Only randomised controlled trials (RCTs) were included. Results: Nine eligible RCTs were analysed using a random-effects meta-analysis. Probiotic use was significantly associated with a reduced incidence of severe (grade 3–4) oral mucositis (RR = 0.58; 95% CI: 0.41–0.81). Moderate benefits were also observed in modulating the oral microbiota and reducing levels of pathogenic bacteria and Candida spp. However, no significant improvements were noted in periodontal parameters or plaque indices. Conclusions: Probiotics show promise in the management of oral mucositis, but further well-designed trials are needed to evaluate their broader impact on oral health during cancer therapy. This review is not registered on PROSPERO. Full article

Gram-negative enteric rods (GNERs) are transient members of the oral microbiota and are considered a superinfection in patients with periodontitis that poses local and systemic risks due to associations with infections and multidrug resistance, including extended-spectrum beta-lactamases. These pathogens often resist antibiotics such as amoxicillin, doxycycline, and ciprofloxacin, complicating dental treatments. Though their resistance patterns vary, links between specific resistance genes and phenotypic resistance remain unclear. Objectives: To determine the correlation between resistance genes (blaTEM, blaSHV, tetQ, tetM, qnrB, qnrS, and mph(A)) and phenotypic resistance in GNERs isolated from oral cavity samples. Methods: A total of 90 oral isolates of GNERs were isolated from patients in a dental clinic, and bacteria were identified by the BD BBL Crystal biochemical panel. The antibiotic susceptibility testing was conducted through broth microdilution following CLSI standards for drives such as amoxicillin, amoxicillin/clavulanic acid, doxycycline, ciprofloxacin, and azithromycin. Resistance genes, including blaTEM, blaSHV, tetQ, tetM, qnrS, qnrB, and mph(A), were detected using polymerase chain reaction and gel electrophoresis. The proportions of species, resistance genes, and minimum inhibitory concentration values were statistically analyzed. Conclusions: As expected, most enteric bacteria showed natural resistance to beta-lactams. Significant resistance to azithromycin was observed in some species. Genotypic and phenotypic profiles suggest the existence of alternative resistance mechanisms; therefore, other mechanisms associated with antibiotic resistance should be investigated. Full article

Background: The accurate and rapid diagnosis of infections is critical for effective and timely treatment. Misdiagnosis often leads to the prescription of antibiotics not targeting the causing agent of infection and thus be the possible development of multidrug resistance. This collectively worsens the condition and might lead to unnecessary intervention or death. The abundance of Pseudomonas spp. in healthcare-settings and the environment may lead to the inaccurate diagnosis of P. aeruginosa, making the treatment of its infections challenging. P. aeruginosa is a Gram-negative, opportunistic pathogen commonly linked to healthcare-associated infections. Its pathogenicity is attributed to several virulence factors correlated to enhanced survivability and colonization, invasion of the host tissues, and the development of multidrug resistance. When advanced diagnostic facilities are limited or unaffordable, the prescription of antibiotics solely relies on identifying the bacteria by culture-based methods. Objectives: This study aims to validate the accuracy of diagnosis of fifty clinical isolates preidentified as P. aeruginosa in three healthcare facilities in Jordan. Methods: The isolates were from infected areas of patients, including skin, wounds, ears, urine, and peritoneal cavities. Morphological and biochemical tests were performed, and the validation relied on the polymerase chain reaction (PCR) amplification of the 16S ribosomal ribonucleic acid (rRNA) gene. This molecular method is affordable for medical facilities with limited finances in contrast to advanced high-cost techniques. Results: The PCR confirmed that only 60% of the isolates were P. aeruginosa. All the confirmed isolates could produce different pigments and form biofilms. Conclusions: The high percentage of isolates mistakenly identified as P. aeruginosa raises concern about the suitability of prescribed antibiotics. The present study strongly recommends using advanced molecular methods to identify the pathogens. If conventional methods remain the only diagnostic option, this study recommends frequent external validation for tests in addition to performing an antibiotic susceptibility test to pinpoint the effective antibiotics against biofilm-producing P. aeruginosa. Full article

Staphylococcus aureus, an opportunistic bacterium found in the oral cavity, has been reported as a causative agent of infective endocarditis and pneumonia. Salt is an essential mineral for cell maintenance in the human body. This study was conducted to clarify how salt affects the formation of biofilms by S. aureus and Streptococcus mutans, pathogens implicated in dental caries. Bacteria were cultivated with various concentrations of NaCl on a 96-well microtiter plate in tryptic soy broth with 0.25% sucrose or 0.25% glucose (TSBs and TSBg, respectively) for 16 h. The effects of glucosyltransferase in S. mutans membrane vesicles (MVs) and extracellular DNA during biofilm formation were also analyzed. S. aureus biofilms were induced by 0.004–0.25 M NaCl but not by NaCl at concentrations greater than 0.25 M in TSBs. The mixed S. aureus and S. mutans biofilms gradually grew and were constructed by dead cells in a NaCl concentration-dependent manner in both TSBs and TSBg. Moreover, biofilms were slightly induced by glucan generation mediated by the glucosyltransferases in MVs under high-salinity conditions. The formation of mixed-species S. aureus and S. mutans biofilms increased in the presence of both extracellular DNA and MVs. Therefore, extracellular DNA, MVs, and dead cells are factors that promote S. aureus biofilm formation under harsh conditions containing NaCl. The sugar (sucrose and glucose) ingestion-induced S. mutans biofilm may be a risk factor for infection by opportunistic pathogens such as S. aureus in individuals who consume food and drinks containing high concentrations of salt. Full article

Allergic rhinitis and asthma are significant public health concerns worldwide. While previous studies have explored how nasal and buccal bacteriotas influence these conditions, few have directly compared their bacteriomes within the same cohort. To bridge this gap, I analyzed 16S rRNA next-generation sequencing data from 347 individuals, including participants with allergic rhinitis, asthma and healthy controls. The nasal and buccal bacteriomes shared all dominant bacterial taxa but differed significantly in their phylum- and genus-level relative abundances. Alpha-diversity was significantly higher in the buccal cavity, while beta-diversity varied significantly across all indices and clinical groups. Over 80% of the predicted metabolic pathways were differentially regulated between the two cavities, yet these functional differences remained fairly consistent across clinical groups. Naso-buccal bacterial networks exhibited striking differences in structure, complexity and hub nodes. Notably, the network of healthy controls showed a clear segregation between nasal and buccal bacteria, with 93.5% of the interactions occurring within each respective cavity, and contained few pathogenic keystone taxa. In contrast, bacterial networks from diseased individuals exhibited reduced ecological specialization and more pathogenic keystone taxa linked to airway disease. These findings, thus, demonstrate that the naso-buccal bacteriome plays distinct yet interconnected roles in allergic rhinitis and asthma. Full article

Insect-specific pathogens present a sustainable alternative to pesticides for managing the red palm weevil (RPW). This study assessed the efficacy of Steinernema carpocapsae ALL nematodes and their symbiotic bacteria against the third-instar larvae and adults of RPW under laboratory conditions. The symbiotic bacteria were isolated, morphologically characterized, and genetically identified. The results indicated that the mortality rates of RPW larvae treated with S. carpocapsae exceeded 50% in all treatments at 120 h, reaching 93.33% at a concentration of 250 IJs/mL. The morphology of isolated symbiotic bacterium from S. carpocapsae on NBTA medium exhibited a light green color with a glossy surface, a raised center, and a mucilaginous texture. A novel strain of symbiotic bacterium was identified and named as LZ-G7. The bacteria toxicity on RPW adults showed a notable mortality rate of 66.67% at 48 h after feeding with concentration of 10 × 10⁷ CFU/mL. The mortality rate of the third-instar larvae of RPW reached 83.33% after feeding with 0.30 × 10⁸ CFU/g at 96 h and 93.33% after injection into blood cavity with 8 × 10⁶ CFU at 48 h. These results suggest that S. carpocapsae and a novel symbiotic bacterium strain exhibit strong virulence against RPW and have the potential to serve as effective biological control agents in integrated pest management strategies. Full article

Staphylococcus aureus (S. aureus) colonizes the nasal cavities of both healthy individuals and patients with chronic rhinosinusitis (CRS) with (CRSwNP) and without (CRSsNP) nasal polyps. Treatment-resistant S. aureus biofilms and intracellular persistence are common in CRS patients, requiring the expression of specific virulence factor genes to transition into these forms. We hypothesized that S. aureus isolates from non-diseased controls, CRSsNP patients, and CRSwNP patients would exhibit distinct virulence factor patterns contributing to persistence and intracellular survival in CRS patients. Nasal swabs from seventy-seven individuals yielded S. aureus cultures in eight non-diseased controls, eight CRSsNP patients, and five CRSwNP patients. Whole-genome sequencing analyzed stress, antimicrobial resistance, and virulence genes, including plasmids and prophages. Four virulence factor gene patterns emerged: a core set (hlgA, icaC, hlgB, hlgC, hld, and aur) present in all isolates, and accessory sets, including the enterotoxin gene cluster (seo, sem, seu, sei, and sen) and a partial/complete invasive virulence factor set (splE, splA, splB, lukE, and lukD) (p = 0.001). CRSwNP isolates exhibited incomplete carriage of the core set, with frequent loss of scn, icaC, and hlgA (p < 0.05). These findings suggest that S. aureus has clusters of virulence factors that may act in concert to support the survival and persistence of the bacteria, resulting in enhanced pathogenicity. This may manifest clinically with resistant disease and refractoriness to antibiotics. Full article

Abscesses are among the diseases affecting the survival of captive musk deer and are difficult to identify in their early stages. In this study, metagenomic sequencing, 16S rRNA sequencing, and paraffin sectioning were used to analyze the microbiota in the abscess musk deer pus group (AMP), abscess musk deer oral group (AMO), and healthy musk deer oral group (HMO) to compare the differences in microbiota in musk deer. By detecting differences in the oral microbiota through throat swabs, we aimed to monitor the early onset of abscess disease to facilitate timely intervention and treatment. The results showed that the alpha diversity of HMO microbiota was significantly higher than that of the AMP and AMO samples. Beta diversity results indicated that there were significant differences in the bacterial communities of HMO and AMO samples, and no significant difference was found between AMO and AMP samples. A taxonomic analysis of the bacterial species indicated that differences between HMO and AMP groups were found in the Fusobacterium and Trueperella species. Fusobacterium and Trueperella were the main pathogenic bacteria responsible for the occurrence of abscess diseases in forest musk deer in this study. Furthermore, the appearance of Fusobacterium and Trueperella in the oral cavity can serve as biomarkers for the early diagnosis of abscess disease in musk deer. Full article