Search Results (30)

Staphylococcus aureus is one of the most common potentially pathogenic bacteria that may asymptomatically colonize many sites of healthy carriers. Non-nasal carriage, especially in the oral cavity, and its role in transmitting antimicrobial-resistant S. aureus strains in the healthcare community, is poorly understood. This study aimed to assess the prevalence and antimicrobial susceptibility of S. aureus in both oral and nasal cavities among preclinical dentistry students. A total of 264 oral and nasal swabs were taken from 132 participants, and all specimens were cultured using standard diagnostic procedures and antimicrobial susceptibility testing (EUCAST). The prevalence of S. aureus exclusively in the nasal (11.4%) or oral (9.1%) cavity was comparable, while concurrent oral and nasal carriage was present in 27.3% of participants. Although antibiotic resistance rates observed in both oral and nasal isolates were similar (ranging from 2.7% to 95.5%), 16.7% of carriers exhibited distinct antibiotic resistance profiles between oral and nasal isolates. Three (2.7%) methicillin-resistant S. aureus (MRSA) were isolated from the mouth and nose but multidrug resistance (27.3%) was more frequent in the oral than in the nasal isolates: 34% and 21.1%, respectively. This study demonstrated that preclinical dentistry students have a similar rate of oral S. aureus carriage as the nasal carriage rate, and that the oral cavity can be colonized by antimicrobial-resistant strains that do not originate from the nose. Consequently, the oral cavity seems to be an unjustly overlooked body site in screening for S. aureus carriage. Full article

Infections due to antimicrobial-resistant bacteria have become a major threat to global health. Some patients may carry resistant bacteria in their gut microbiota. Specific risk factors may trigger the conversion of these carriages into infections in hospitalized patients. Preventively eradicating these carriages has been postulated as a promising preventive intervention. However, previous attempts at such eradication using oral antibiotics or probiotics have led to discouraging results. Phage therapy, the therapeutic use of bacteriophage viruses, might represent a worthy alternative in this context. Taking inspiration from this clinical challenge, we built Gut-On-A-Chip (GOAC) models, which are tridimensional cell culture models mimicking a simplified gut section. These were used to better understand bacterial dynamics under phage pressure using two relevant species: Pseudomonas aeruginosa and Escherichia coli. Model mucus secretion was documented by ELISA assays. Bacterial dynamics assays were performed in GOAC triplicates monitored for 72 h under numerous conditions, such as pre-, per-, or post-bacterial timing of phage introduction, punctual versus continuous phage administration, and phage expression of mucus-binding properties. The potential genomic basis of bacterial phage resistance acquired in the model was investigated by variant sequencing. The bacterial “escape growth” rates under phage pressure were compared to static in vitro conditions. Our results suggest that there is specific bacterial prosperity in this model compared to other in vitro conditions. In E. coli assays, the introduction of a phage harboring unique mucus-binding properties could not shift this balance of power, contradicting previous findings in an in vivo mouse model and highlighting the key differences between these models. Genomic modifications were correlated with bacterial phage resistance acquisition in some but not all instances, suggesting that alternate ways are needed to evade phage predation, which warrants further investigation. Full article

Objective: This study aimed to identify the salivary levels of six hormones (progesterone, estradiol, testosterone, cortisol, thyroxine T3, and triiodothyronine T4) in pregnant women, and to assess the association between salivary hormones, dental caries, and cariogenic microorganisms. Methods: This cross-sectional study included 181 low-income US pregnant women who were in their third trimester. Demographic details, oral hygiene practices, and medical backgrounds were obtained via questionnaires and medical records. Calibrated dentists obtained data on plaque index and caries status through comprehensive oral examinations. Unstimulated saliva was collected 2 h before eating and brushing. Salivary hormones were measured with a multiplex assay. Oral Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) were quantified via colony-forming unit (CFU) counts. A latent model was used to generate clusters of pregnant women based on salivary hormone levels, followed by post-clustering analysis. Factors associated with salivary cariogenic microorganisms were further evaluated via multiple regression analyses. Results: Estradiol, progesterone, testosterone, cortisol, T3, and T4 in saliva were detectable at rates of 92%, 97%, 77%, 99%, 71%, and 50%, respectively. Three distinct participant clusters (high, intermediate, and low) were identified based on salivary hormone levels. Intermediate-level and high-level clusters had increased numbers of decayed teeth, decayed surfaces, ICDAS scores, and salivary S. mutans and C. albicans, compared to the low-level cluster (p < 0.05). Covariate analysis demonstrated that the high-level cluster was positively associated with salivary carriage of S. mutans (CFU/mL) (p < 0.05). Participants with higher levels of progesterone, estradiol, testosterone, and cortisol were associated with a high carriage status of S. mutans in saliva (>10⁵ CFU/mL) (p < 0.05). Conclusions: This study demonstrated the feasibility of detecting salivary hormones during pregnancy and revealed the positive association between salivary steroid hormones and cariogenic pathogens. Full article

Cariogenic microorganisms are crucial pathogens contributing to the development of early childhood caries. Snacks provide fermentable carbohydrates, altering oral pH levels and potentially affecting microorganism colonization. However, the relationship between snack intake and cariogenic microorganisms like Candida and Streptococcus mutans in young children is still unclear. This study aimed to assess this association in a prospective underserved birth cohort. Data from children aged 12 to 24 months, including oral microbial assays and snack intake information, were analyzed. Sweet and non-sweet indices based on the cariogenic potential of 15 snacks/drinks were created. Mixed-effects models were used to assess the associations between sweet and non-sweet indices and S. mutans and Candida carriage. Random forest identified predictive factors of microorganism carriage. Higher non-sweet index scores were linked to increased S. mutans carriage in plaques (OR = 1.67, p = 0.01), potentially strengthening with age. Higher sweet index scores at 12 months were associated with increased Candida carriage, reversing at 24 months. Both indices were top predictors of S. mutans and Candida carriage. These findings underscore the associations between snack intake and cariogenic microorganism carriage and highlight the importance of dietary factors in oral health management for underserved young children with limited access to dental care and healthy foods. Full article

Introduction: Candida dubliniensis was reclassified from the C. albicans genotype D, and reports show its frequent detection in HIV-positive individuals and easy acquisition of antifungal drug resistance. However, the oral carriage rate in healthy people and contribution to candidiasis in Japan is unclear. Methods: We conducted a cross-sectional survey of the C. dubliniensis carriage rate, performed genotyping and tested antifungal drug susceptibility and protease productivity. Specimens from 2432 Japanese subjects in six regions (1902 healthy individuals, 423 with candidiasis individuals, 107 HIV-positive individuals) were cultured using CHROMagar^TMCandida, and the species was confirmed via 25S rDNA amplification and ITS sequences analyzed for genotyping. Results: The C. dubliniensis carriage rate in healthy Japanese was low in the central mainland (0–15%) but high in the most northerly and southerly areas (30–40%). The distribution of these frequencies did not differ depending on age or disease (HIV-infection, candidiasis). Genotype I, previously identified in other countries, was most frequent in Japan, but novel genotypes were also observed. Six antifungal drugs showed higher susceptibility against C. albicans, but protease productivity was low. Conclusions: Oral C. dubliniensis has low pathogenicity with distribution properties attributed to geography and not dependent on age or disease status. Full article

The impact of Candida sp. in the development of oral cancer remains uncertain and requires sensitive analytical approaches for clarification. Given the invasive capabilities of these microorganisms in penetrating and invading host tissues through hyphal invasion, this study sought to detect the presence of five Candida sp. in oral biopsy tissue samples from non-smoker patients. Samples were obtained from patients at varying stages of oral carcinogenesis, including dysplasia, carcinoma in situ, OSCC, and histologically benign lesions, and analyzed using Real-Time PCR. Oral tissue samples from 80 patients (46 males and 34 females) were included. Significantly higher C. albicans presence was detected in the mild/moderate dysplasia group compared to the healthy (p = 0.001), carcinoma in situ (p = 0.031) and OSCC groups (p = 0.000). Similarly, C. tropicalis carriage was higher in tissues with mild/moderate dysplasia compared to healthy (p = 0.004) and carcinoma in situ (p = 0.019). Our results showed a significant increase in the presence of C. albicans and C. tropicalis within the mild/moderate dysplasia group compared to other cohorts. Coexistence of these two microorganisms was observed, suggesting a potential transition from a commensal state to an opportunistic pathogen, which could be particularly linked to the onset of oral neoplasia. Full article

The gastrointestinal tract (GIT) environment has an intricate and complex nature, limiting drugs’ stability, oral bioavailability, and adsorption. Additionally, due to the drugs’ toxicity and side effects, renders are continuously seeking novel delivery systems. Lipid-based drug delivery vesicles have shown various loading capacities and high stability levels within the GIT. Indeed, most vesicular platforms fail to efficiently deliver drugs toward this route. Notably, the stability of vesicular constructs is different based on the different ingredients added. A low GIT stability of liposomes and niosomes and a low loading capacity of exosomes in drug delivery have been described in the literature. Bilosomes are nonionic, amphiphilic, flexible surfactant vehicles that contain bile salts for the improvement of drug and vaccine delivery. The bilosomes’ stability and plasticity in the GIT facilitate the efficient carriage of drugs (such as antimicrobial, antiparasitic, and antifungal drugs), vaccines, and bioactive compounds to treat infectious agents. Considering the intricate and harsh nature of the GIT, bilosomal formulations of oral substances have a remarkably enhanced delivery efficiency, overcoming these conditions. This review aimed to evaluate the potential of bilosomes as drug delivery platforms for antimicrobial, antiviral, antifungal, and antiparasitic GIT-associated drugs and vaccines. Full article

The α-actinin-3 (ACTN3) gene rs1815739 (C/T, R577X) polymorphism is a variant frequently associated with athletic performance among different populations. However, there is limited research on the impact of this variant on athlete status and physical performance in basketball players. Therefore, the aim of this study was twofold: (1) to determine the association of ACTN3 rs1815739 polymorphism with changes in physical performance in response to six weeks of training in elite basketball players using 30 m sprint and Yo-Yo Intermittent Recovery Test Level 2 (IR 2) tests, and (2) to compare ACTN3 genotype and allelic frequencies between elite basketball players and controls. The study included a total of 363 individuals, comprising 101 elite basketball players and 262 sedentary individuals. Genomic DNA was isolated from oral epithelial cells or leukocytes, and genotyping was performed by real-time PCR using KASP genotyping method or by microarray analysis. We found that the frequency of the ACTN3 rs1815739 XX genotype was significantly lower in basketball players compared to controls (10.9 vs. 21.4%, p = 0.023), suggesting that RR/RX genotypes were more favorable for playing basketball. Statistically significant (p = 0.045) changes were observed in Yo-Yo IRT 2 performance measurement tests in basketball players with the RR genotype only. In conclusion, our findings suggest that the carriage of the ACTN3 rs1815739 R allele may confer an advantage in basketball. Full article

The carriage of Candida albicans in children’s oral cavities is associated with a higher risk for early childhood caries, so controlling this fungus in early life is essential for preventing caries. In a prospective cohort of 41 mothers and their children from 0 to 2 years of age, this study addressed four main objectives: (1) Evaluate in vitro the antifungal agent susceptibility of oral Candida isolates from the mother-child cohort; (2) compare Candida susceptibility between isolates from the mothers and children; (3) assess longitudinal changes in the susceptibility of the isolates collected between 0 and 2 years; and (4) detect mutations in C. albicans antifungal resistance genes. Susceptibility to antifungal medications was tested by in vitro broth microdilution and expressed as the minimal inhibitory concentration (MIC). C. albicans clinical isolates were sequenced by whole genome sequencing, and the genes related to antifungal resistance, ERG3, ERG11, CDR1, CDR2, MDR1, and FKS1, were assessed. Four Candida spp. (n = 126) were isolated: C. albicans, C. parapsilosis, C. dubliniensis, and C. lusitaniae. Caspofungin was the most active drug for oral Candida, followed by fluconazole and nystatin. Two missense mutations in the CDR2 gene were shared among C. albicans isolates resistant to nystatin. Most of the children’s C. albicans isolates had MIC values similar to those from their mothers, and 70% remained stable on antifungal medications from 0 to 2 years. For caspofungin, 29% of the children’s isolates showed an increase in MIC values from 0 to 2 years. Results of the longitudinal cohort indicated that clinically used oral nystatin was ineffective in reducing the carriage of C. albicans in children; novel antifungal regimens in infants are needed for better oral yeast control. Full article

The emergence of Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections among indigenous populations has been reported. Usually, indigenous communities live in extreme poverty and are at risk of acquiring infections. In Brazil, healthcare inequality is observed in this population. To date, there are no reports of CA-MRSA infections, and no active search for asymptomatic S. aureus carriage has been conducted among Brazilian Indians. The aim of this study was to investigate the prevalence of colonization with S. aureus and CA-MRSA among Brazilian Indians. We screened 400 Indians (from near urban areas and remote hamlets) for S. aureus and CA-MRSA colonization. The isolates were submitted to clonal profiling by pulsed-field gel electrophoresis (PFGE), and selected isolates were submitted to multilocus sequence typing (MLST). Among 931 specimens (nasal and oral) from different indigenous individuals in remote hamlets, S. aureus was cultured in 190 (47.6%). Furthermore, CA-MRSA was found in three isolates (0.7%), all SCCmec type IV. PFGE analysis identified 21 clusters among the S. aureus isolates, and MLST analysis showed a predominance of sequence type 5 among these isolates. Our study revealed a higher prevalence of S. aureus carriage among Shanenawa ethnicity individuals (41.1%). Therefore, ethnicity appears to be associated with the prevalence of S. aureus in these populations. Full article

North America is a large producer of beef and contains approximately 12% of the world’s cattle inventory. Feedlots are an integral part of modern cattle production in North America, producing a high-quality, wholesome protein food for humans. Cattle, during their final stage, are fed readily digestible high-energy density rations in feedlots. Cattle in feedlots are susceptible to certain zoonotic diseases that impact cattle health, growth performance, and carcass characteristics, as well as human health. Diseases are often transferred amongst pen-mates, but they can also originate from the environment and be spread by vectors or fomites. Pathogen carriage in the gastrointestinal tract of cattle often leads to direct or indirect contamination of foods and the feedlot environment. This leads to the recirculation of these pathogens that have fecal–oral transmission within a feedlot cattle population for an extended time. Salmonella, Shiga toxin-producing Escherichia coli, and Campylobacter are commonly associated with animal-derived foods and can be transferred to humans through several routes such as contact with infected cattle and the consumption of contaminated meat. Brucellosis, anthrax, and leptospirosis, significant but neglected zoonotic diseases with debilitating impacts on human and animal health, are also discussed. Full article

Background: This study sought to characterize the saliva microbiota of Candida carriage Sjögren’s syndrome (SS) patients compared to oral candidiasis and healthy patients by high-throughput sequencing. Methods: Fifteen patients were included, with five Candida carriage SS patients (decayed, missing, and filled teeth (DMFT) score 22), five oral candidiasis patients (DMFT score 17), and five caries active healthy patients (DMFT score 14). Bacterial 16S rRNA was extracted from rinsed whole saliva. PCR amplification generated DNA amplicons of the V3–V4 hypervariable region, which were sequenced on an Illumina HiSeq 2500 sequencing platform and compared and aligned to the SILVA database. Taxonomy abundance and community structure diversity was analyzed using Mothur software v1.40.0. Results: A total of 1016/1298/1085 operational taxonomic units (OTUs) were obtained from SS patients/oral candidiasis patient/healthy patients. Treponema, Lactobacillus, Streptococcus, Selenomonas, and Veillonella were the primary genera in the three groups. The most abundant significantly mutative taxonomy (OTU001) was Veillonella parvula. Microbial diversity (alpha diversity and beta diversity) was significantly increased in SS patients. ANOSIM analyses revealed significantly different microbial compositional heterogeneity in SS patients compared to oral candidiasis and healthy patients. Conclusion: Microbial dysbiosis differs significantly in SS patients independent of oral Candida carriage and DMFT. Full article

Elevated serum immunoglobulin (Ig) antibody levels are observed in Crohn’s disease patients. The aim of this study was to evaluate the salivary IgA and IgG antibody levels against Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Prevotella intermedia in Crohn’s disease patients. Eighty-eight participants (47 Crohn’s disease patients and 41 systemically healthy age- and gender-matched controls) were included in the study. Oral and medical health statuses were recorded and salivary samples were collected. Salivary P. gingivalis, T. forsythia, A. actinomycetemcomitans, and P. intermedia carriage were analyzed with DNA sequencing technique, salivary levels of IgG1, IgG2, IgG3, IgG4, and IgM were measured with the Luminex^® xMAP™ technique, and salivary IgA and IgG antibody levels against P. gingivalis, T. forsythia, A. actinomycetemcomitans, and P. intermedia were detected by ELISA. As result, higher salivary IgG2 (p = 0.011) and IgG3 (p = 0.006), P. gingivalis IgA (p < 0.001), A. actinomycetemcomitans IgG (p = 0.001), and P. intermedia IgG (p < 0.001) antibody levels were detected in the Crohn’s disease group compared to the controls. Salivary P. gingivalis carriage was lower in the Crohn’s disease group in comparison to the controls (p = 0.024). In conclusion, salivary IgA antibody responses against P. gingivalis and IgG antibody responses against P. intermedia have independent associations with Crohn’s disease. Full article

At present, multidrug-resistant microorganisms are already responsible for community-acquired infections. Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious public health risk worldwide because of the rapid spread and diversification of pandemic clones that are characterized by increasing virulence and antimicrobial resistance. The aim of this study was to identify the prevalence and factors associated with nasal, oral and rectal carriage of S. aureus and MRSA in bedridden patients and residents of long-term care facilities for the elderly (LTCFs) in Botucatu, SP, Brazil. Nasal, oral and rectal swab isolates obtained from 226 LTCF residents or home-bedridden patients between 2017 and 2018 were submitted to susceptibility testing, detection of the mecA gene, SCCmec characterization, and molecular typing by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Logistic regression analysis was used to identify risk factors associated with the presence of S. aureus and MRSA. The prevalence of S. aureus and MRSA was 33.6% (n = 76) and 8% (n = 18), respectively. At the nine LTCFs studied, the prevalence of S. aureus ranged from 16.6% to 85.7% and that of MRSA from 13.3% to 25%. Living in an LTCF, male gender, a history of surgeries, and a high Charlson Comorbidity Index score were risk factors associated with S. aureus carriage, while MRSA carriage was positively associated with male gender. This study showed a high prevalence of S. aureus among elderly residents of small (<15 residents) and medium-sized (15–49 residents) LTCFs and a higher prevalence of MRSA in the oropharynx. Full article

(1) Background: The link between periodontal disease and rheumatoid arthritis (RA) is now widely reported. Several studies suggest the role of Porphyromonas gingivalis (P. gingivalis) in the pathophysiology of RA and some observations highlight the improvement of the disease activity induced by therapies against P. gingivalis. We have very little data on the prevalence of P. gingivalis carriage in patients with juvenile idiopathic arthritis (JIA) and its possible involvement in the pathophysiology of inflammatory joint diseases in children. (2) Methods: The specific IgG responses against P. gingivalis and Prevotella intermedia (P. intermedia) were determined in a cohort of 101 patients with JIA and 19 patients with other autoimmune diseases (inflammatory bowel disease and type 1 diabetes). (3) Results: Specific anti-P. gingivalis and anti-P. intermedia IgG titers were higher in JIA group than in control groups. These differences were mainly observed in the oligoarthritis group. The same pattern was observed in enthesitis-related arthritis (ERA). (4) Conclusions: Children with oligoarticular and ERA subsets had higher IgG titers to P. gingivalis and P. intermedia. These results suggest involvement of an oral dysbiosis in the occurrence of JIA in these subgroups. Full article