Association between Dental Scores and Saliva Uremic Toxins.

Dental health is frequently altered in patients with chronic kidney disease. We conducted a prospective study on dental health in CKD patients with a specific interest in the association between dental health issues and the accumulation of uremic toxins in the saliva. A total of 88 patients were included in the study, with chronic kidney disease stage 2 to 5 (without kidney replacement). We analysed the total concentrations of eight uremic toxins (trimethylamine N-oxide -TMAO-, Indoxyl Sulfate, P-cresyl-sulfate, Indole 3-acetic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid -CMPF-, Kynurenine, Hippuric acid and Phenylacetylglutamine) and three precursors of uremic toxins (Tyrosine, Phenylalanine and Tryptophan) in the saliva using LC-MS/MS. We observed, for the first time, the association between various dental scores: DMFT, FST, CPITN, and OHIS, and saliva uremic toxins and precursors: TMAO, indoxyl sulfate, or hippuric acid. Further prospective interventional studies are required to confirm our results.

The association between oral health and nutritional status in older adults: a cross-sectional study.

OBJECTIVES: This work aimed to describe the nutritional status of French older adults (age ≥ 90 years) and studied the association between oral health and nutritional status. METHODS: A cross-sectional study was carried out in 2014 among the participants of a cohort on cerebral and functional aging in France at their 25-year follow up (the PAQUID cohort). Nutritional status (Mini Nutritional Assessment [MNA]) and oral health status (number of decayed, missing, and filled teeth [DMFT], number of posterior occluding pairs, xerostomia [Xerostomia Inventory], and prosthetic rehabilitation) were recorded at the participants' living places by two dentists. Univariate and multivariate logistic regressions were used to explore the association between oral health and nutritional status, with adjustments for potential confounders. Odds ratios (OR) were estimated with their 95% confidence interval (CI). RESULTS: 87 participants were included in the analyses: 74.7% were females and the mean age was 94.1 years (± 3.0). Malnutrition or risk of malnutrition (MNA < 24) was present in 23 participants (26.4%), with only one having malnutrition. The mean DMFT score was 26.5 (± 5.3). The mean number of posterior occluding pairs was 1.5 (± 2.3). Twenty-one participants had xerostomia (24.1%). Only 8.1% of the participants had all their teeth or adequate dentures; 47.1% had inadequate dentures, while 44.8% had no dentures despite tooth loss. After adjustment, xerostomia (OR = 8.79; 95% CI = 2.38-39.10; p = 0.002) was found to be associated with malnutrition or risk of malnutrition. CONCLUSION: Being at risk of malnutrition was common among people ≥ 90 years old and was associated with xerostomia. NCT04065828.

Effect of Dermaseptin S4 on C. albicans Growth and EAP1 and HWP1 Gene Expression.

Increasing resistance and changes in the spectrum of Candida infections have generated considerable interest in the development of new antifungal molecules. The use of antimicrobial peptides (AMPs) appears to be a promising approach. Frog skin AMPs (such as dermaseptins) have shown antimicrobial activity against several pathogens. In this study, we aimed to test the antimicrobial efficacy of dermaseptin S4 (DS4) against C. albicans. We determined the minimal inhibitory concentration (MIC) of DS4, and investigated the effects of the DS4 at low concentrations on human primary gingival fibroblasts. Additionally, we evaluated the effect of DS4 on C. albicans growth, form changes, and biofilm formation, as well as the expression of certain virulent genes. Our data show that DS4 completely inhibits C. albicans growth at a concentration of 32 µg/mL referring to the MIC of DS4. It should be noted that even with low concentrations (below 16 µg/mL), DS4 still have significant growth reduction of C. albicans, but were not toxic to human gingival fibroblasts. DS4 inhibited the transition from yeast to hyphae, and decreased the biofilm formation by reducing the biofilm mass weight. Surface morphological changes in the yeast cell membrane were observed following exposure to DS4. The gene expression analyses revealed that DS4 significantly decreased the expression of EAP1 and HWP1 genes. Overall results suggest the potential use of DS4 as an antifungal therapy to prevent C. albicans pathogenesis.

Reliability of MALDI-TOF mass spectrometry to identify oral isolates of Streptococcus salivarius and Lactobacillus spp.

OBJECTIVE: The aim of this study is to evaluate the performance of MALDI-TOF mass spectrometry in identifying bacteria isolated in the oral cavity known to be of probiotic interest. DESIGN: We evaluated Bruker MALDI Biotyper for the identification of 92 clinical oral isolates of probiotic interest (31 Streptococcus salivarius and 61 Lactobacillus spp.) by comparing direct colony method with on-plate formic acid extraction. Isolates were previously identified by use of biochemical methods and molecular biology. RESULTS: Using the manufacturer's suggested genus and species level cutoff scores, the direct colony method identified 42 (45.7%) isolates at the genus level and 35 (38%) at the species level while the on-plate extraction method correctly identified 90 (97.8%) isolates at the genus level and 82 (89.1%) at the species level. The difference between the two methods was statistically significant at the genus and species levels (P ≤ 0.0001). After dividing the isolates into two subgroups, the analysis was repeated. The direct colony method identified correctly all isolates of Streptococcus salivarius at the species level. In contrast, the direct colony method allowed the identification of only 11 (18%) lactobacilli at the genus level and 4 (6.6%) at the species level. The on-plate extraction method was statistically (P ≤ 0.0001) more efficient since 59 (96.7%) lactobacilli were identified at the genus level and 51 (83.6%) at the species level. CONCLUSIONS: MALDI Biotyper can efficiently identify Streptococcus salivarius regardless of the preparative method but on-plate extraction is superior to direct colony method for the identification of lactobacilli.

Characterization of the First Virulent Phage Infecting Oenococcus oeni, the Queen of the Cellars.

There has been little exploration of how phages contribute to the diversity of the bacterial community associated with winemaking and may impact fermentations and product quality. Prophages of Oenococcus oeni, the most common species of lactic acid bacteria (LAB) associated with malolactic fermentation of wine, have been described, but no data is available regarding phages of O. oeni with true virulent lifestyles. The current study reports on the incidence and characterization of the first group of virulent oenophages named Vinitor, isolated from the enological environment. Vinitor phages are morphologically very similar to siphoviruses infecting other LAB. Although widespread during winemaking, they are more abundant in musts than temperate oenophages. We obtained the complete genomic sequences of phages Vinitor162 and Vinitor27, isolated from white and red wines, respectively. The assembled genomes shared 97.6% nucleotide identity and belong to the same species. Coupled with phylogenetic analysis, our study revealed that the genomes of Vinitor phages are architecturally mosaics and represent unique combinations of modules amongst LAB infecting-phages. Our data also provide some clues to possible evolutionary connections between Vinitor and (pro)phages associated to epiphytic and insect-related bacteria.

Variability and recombination of clinical human cytomegalovirus strains from transplantation recipients.

BACKGROUND: Human cytomegalovirus (HCMV) is the first cause of viral infection in immunocompromised transplanted patients. OBJECTIVES: Here, five HCMV genes were studied to investigate the existence of recombination events in clinical strains ex vivo. STUDY DESIGN: Sequencing and phylogenetic analysis were conducted on 21 strains from 16 renal and 5 lung transplant recipients. RESULTS: Nucleotidic polymorphism ranged from 6.6% (US3) to 12% (UL40), with a significant proportion of missense mutations (39-69%), some of which could have a functional impact. Analysis of the concatenated sequence (4804 nucleotides for each strain) evidenced two clusters of sequences presenting a reticulate topology suggestive of recombination events (SplitsTree). Phi-test pointed numerous phylogenetically conflicting signals indicating a high statistical probability of recombination. The subsequent bootscan analysis was consistent with these data. CONCLUSIONS: These results reinforce the prominent role of recombination in HCMV evolutionary history and adaptation to its host.