Alterations in gut bacterial and fungal microbiomes are associated with bacterial Keratitis, an inflammatory disease of the human eye.

Dysbiosis, or imbalance in the gut microbiome, has been implicated in auto-immune, inflammatory, neurological diseases as well as in cancers. More recently it has also been shown to be associated with ocular diseases. In the present study, the association of gut microbiome dysbiosis with bacterial Keratitis, an inflammatory eye disease which significantly contributes to corneal blindness, was investigated. Bacterial and fungal gut microbiomes were analysed using fecal samples of healthy controls (HC, n = 21) and bacterial Keratitis patients (BK, n = 19). An increase in abundance of several antiinflammatory organisms including Dialister, Megasphaera, Faecalibacterium, Lachnospira, Ruminococcus and Mitsuokella and members of Firmicutes, Veillonellaceae, Ruminococcaceae and Lachnospiraceae was observed in HC compared to BK patients in the bacterial microbiome. In the fungal microbiome, a decrease in the abundance of Mortierella, Rhizopus, Kluyveromyces, Embellisia and Haematonectria and an increase in the abundance of pathogenic fungi Aspergillus and Malassezia were observed in BK patients compared to HC. In addition, heatmaps, PCoA plots and inferred functional profiles also indicated significant variations between the HC and BK microbiomes, which strongly suggest dysbiosis in the gut microbiome of BK patients. This is the first study demonstrating the association of gut microbiome with the pathophysiology of BK and thus supports the gut-eye axis hypothesis. Considering that Keratitis affects about 1 million people annually across the globe, the data could be the basis for developing alternate strategies for treatment like use of probiotics or fecal transplantation to restore the healthy microbiome as a treatment protocol for Keratitis.

Candida infanticola and Candida spencermartinsiae yeasts: Possible emerging species in cancer patients.

Opportunistic infections due to Candida species occur frequently in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast isolates, Candida albicans was the most commonly isolated species (n = 34, 52.3%), whereas other Candida species comprised 47.7% (n = 31) and consisted of Candida glabrata (n = 14, 21.5%), Candida tropicalis (n = 5, 7.7%) and uncommon Candida species (n = 12, 18.5%) such as Candida pelliculosa (n = 3, 4.6%), Pichia kudriavzevii (= Candida krusei, n = 2, 3.1%), Candida orthopsilosis (n = 2, 3.1%), Candida parapsilosis (n = 1, 1.5%), Candida infanticola (n = 2, 3.1%), Candida spencermartinsiae (n = 1, 1.5%), and Kluyveromyces marxianus (=Candida kefyr, n = 1, 1.5%). Candida infanticola and Candida spencermartinsiae were recovered from oral lesions of cancer patients. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) easily confirmed these isolates as less common Candida isolates (4.6%). The in vitro antifungal susceptibilities of C. spencermartinsiae and the two strains of C. infanticola were determined according to CLSI guidelines (M27-A3). MIC results among these isolates showed they were susceptible to isavuconazole, posaconazole and voriconazole, however, fluconazole and caspofungin had high MIC values. These Candida species that may occur more commonly in infections remain unnoticed using commonly used phenotypical methods in routine microbiology laboratories. MALDI-TOF MS proved to be a more fast and robust diagnostic technique for identification of the yeasts isolated from different clinical specimens of cancer patients.

Variation in phenolic compounds, anthocyanins, and color in red wine treated with enzymatic extract of Kluyveromyces marxianus.

The effect of the addition of enzymatic extract of Kluyveromyces marxianus NRRL-Y-7571 during the maceration and fermentation steps of Cabernet Sauvignon wine production was evaluated. The results obtained in the analytical determinations of the wines showed levels within the limits established by legislation and similar to values found in other studies. The results show that by adding the enzyme to the red wines these showed color characteristics considered to be superior to those of the control wine and accelerated the extraction of phenolic compounds and anthocyanins. It was observed that by using the commercial enzyme preparation there was an increase of 15 % in polyphenol content compared to the control wine and an increase of 28 % when the crude enzyme extract was used. Anthocyanin content in the wine increased after treatment with the commercial enzyme preparation (10 %) and with the use of the crude enzymatic extract (22 %). Considering all comparison criteria, the K. marxianus enzymatic extract showed results statistically similar or superior to those obtained with the commercial enzyme preparation.

Gene order evolution and paleopolyploidy in hemiascomycete yeasts.

The wealth of comparative genomics data from yeast species allows the molecular evolution of these eukaryotes to be studied in great detail. We used "proximity plots" to visually compare chromosomal gene order information from 14 hemiascomycetes, including the recent Génolevures survey, to Saccharomyces cerevisiae. Contrary to the original reports, we find that the Génolevures data strongly support the hypothesis that S. cerevisiae is a degenerate polyploid. Using gene order information alone, 70% of the S. cerevisiae genome can be mapped into "sister" regions that tile together with almost no overlap. This map confirms and extends the map of sister regions that we constructed previously by using duplicated genes, an independent source of information. Combining gene order and gene duplication data assigns essentially the whole genome into sister regions, the largest gap being only 36 genes long. The 16 centromere regions of S. cerevisiae form eight pairs, indicating that an ancestor with eight chromosomes underwent complete doubling; alternatives such as segmental duplications can be ruled out. Gene arrangements in Kluyveromyces lactis and four other species agree quantitatively with what would be expected if they diverged from S. cerevisiae before its polyploidization. In contrast, Saccharomyces exiguus, Saccharomyces servazzii, and Candida glabrata show higher levels of gene adjacency conservation, and more cases of imperfect conservation, suggesting that they split from the S. cerevisiae lineage after polyploidization. This finding is confirmed by sequences around the C. glabrata TRP1 and IPP1 loci, which show that it contains sister regions derived from the same duplication event as that of S. cerevisiae.

Phylogeny of the genus Kluyveromyces inferred from the mitochondrial cytochrome-c oxidase II gene.

A phylogenetic analysis of 17 species belonging to the genus Kluyveromyces and 12 reference and outgroup species was performed using mitochondrial cytochrome-c oxidase II gene sequences. The genus Kluyveromyces appears as a polyphyletic taxon formed by species included within the following four main groups. The Kluyveromyces phaffii group encompasses the species Kluyveromyces blattae, K. phaffii and Kluyveromyces yarrowii. The Kluyveromyces marxianus group is a monophyletic group consisting of the species Kluyveromyces aestuarii, Kluyveromyces dobzhanskii, Kluyveromyces lactis, K. marxianus and Kluyveromyces wickerhamii. The monophyletic Kluyveromyces thermotolerans group is formed by K. thermotolerans, Kluyveromyces waltii and Saccharomyces kluyveri (which appears in the mitochondrial tree as the sister clade of the K. marxianus group). Finally, the Saccharomyces cerevisiae group contains the remaining Kluyveromyces species, as well as the reference Saccharomyces species (sensu lato and sensu stricto) and Candida glabrata (the phylogenetic relationships within this group are unclear according to the bootstrap test). The phylogenetic relationships obtained for this mitochondrial gene are, for the most part, congruent with previous trees based on nuclear rRNA sequences, except for the position of K. yarrowii and the close relationship between the K. marxianus and K. thermotolerans groups. These differences, as well as the existence of these groups, are discussed in the context of previous studies based on phenotypic, genetic and molecular data. Although additional studies are required to decipher the phylogenetic relationships between the genus Kluyveromyces and the closely related genera Saccharomyces, Torulaspora and Zygosaccharomyces, future changes to their taxonomic status should take account of the existence of these four groups of Kluyveromyces species.