Bacterial community associated with gingivitis and periodontitis in dogs.

Periodontal disease is a chronic condition characterized by bacterial adhesion, followed by biofilm formation, and subsequently by an inflammatory process that progresses to gingivitis and later to periodontitis. The variations in the oral microbiota have been associated with the progression of this disease. This study evaluated the alteration of the cultivable oral microbiota in dogs with different oral health status. Thirty dogs were selected and divided into three groups: healthy, gingivitis, and periodontitis. The collected oral samples were seeded, and colonies with distinct phenotypic characteristics were isolated and classified using sequencing of the 16S rRNA gene. The DNA sequences were aligned, and a phylogenetic tree was constructed. Simpson's diversity index was calculated, and a dissimilarity matrix based on the Jaccard similarity index was used to plot a principal coordinate analysis. A total of 119 bacteria with different colony morphologies were isolated and classified into 4 phyla, 29 genera, and 45 species based on phylogenetic analysis. The results indicated an increase in bacteria belonging to the Proteobacteria phylum and a less extended decrease in Actinobacteria, Firmicutes, and Bacteroidetes phyla in dogs with periodontal disease (gingivitis and periodontitis) compared to healthy dogs. Representatives of the genera Neisseria sp., Corynebacterium sp., Pasteurella sp., and Moraxella sp. increased through the worsening of the periodontal disease, while Staphylococcus sp. decreased. All groups exhibited moderate to high levels of biodiversity index, and the plotted PCoA show a clear separation in the oral microbiome of dogs with periodontitis compared to dogs with gingivitis and the healthy group.

Yeast biodiversity in honey produced by stingless bees raised in the highlands of southern Brazil.

The physicochemical characteristics and yeasts diversity in honey samples from 17 species of stingless bees of the genera Nannotrigona, Melipona, Plebeia, Scraptotrigona, and Tetragonisca cultivated in Southern Brazil were determined. The sugar content, moisture, water activity, pH, reducing sugars/total sugar ratio, and total yeast population varied significantly among the honey from the different bee species. The highest yeast population was found in the Plebeia's honey samples and correlated with their high water-activity. Sixteen yeast species were identified based on the nuclear large subunit (26S) ribosomal RNA partial sequences. The genera Starmerella and Zygosaccharomyces were found predominant, with a high prevalence of Starmerella sp., S. etchellsii, and S. apicola. Some yeast species were only identified in honey samples from specific bee species indicating a close relationship between the yeasts and the insects. For the first time, Wickerhamomyces sydowiorum in honey is being reported. In general, the yeast species isolated from stingless bee honey samples demonstrated high osmotolerance and low sugar assimilation.