The bacterial cellulose (BC) secreted by Gluconacetobacter xylinus is a network of pure cellulose nanofibres which has high crystallinity, wettability and mechanical strength. These characteristics...

Two yeast strains, 153MT and NCYC 3133, isolated from clinical sources in separate hospitals were found to be almost identical in the sequences of the D1/D2 domain of large-subunit rDNA, the PCR fingerprinting profiles and physiological characteristics. The isolates are phenotypically similar, although not identical, to Candida glabrata and Kluyveromyces delphensis (recently renamed Nakaseomyces delphensis). Sequence analysis of the 26S rDNA D1/D2 gene variable region revealed that the two clinical isolates were closely related phylogenetically to C. glabrata and K. delphensis, but differed sufficiently to justify their assignment as representatives of a separate species. The name Candida bracarensis sp. nov. is proposed for the novel species with the type strain 153MT (=CBS 10154T=NCYC D3853T=CECT 12000T).

Five new microsatellite loci were described and characterized for use as molecular markers for the identification and genetic differentiation of Candida albicans strains. Following the typing of 72 unrelated clinical isolates, the analysis revealed that they were all polymorphic, presenting from 5 to 30 alleles and 8 to 46 different genotypes. The discriminatory power obtained by combining the information generated by three microsatellites used in a multiplex PCR amplification strategy was 0.99, the highest ever reported. The multiplex PCR was later used to test a total of 114 C. albicans strains, including multiple isolates from the same patient collected from different body locations and along episodes of vulvovaginal infections. Three different scenarios for strain relatedness were identified: (i) different isolates that were revealed to be the same strain, (ii) isolates that were the same strain but that apparently underwent a process of microevolution, and (iii) isolates that corresponded to different strains. Analysis of the microevolutionary changes between isolates from recurrent infections indicated that the genotype alterations observed could be the result of events that lead to the loss of heterozygosity (LOH). In one case of recurrent infection, LOH was observed at the CAI locus, and this could have been related to exposure to fluconazole, since such strains were exposed to this antifungal during treatment. The analysis of microsatellites by a multiplex PCR strategy was found to be a highly efficient tool for the rapid and accurate differentiation of C. albicans strains and adequate for the identification of fine microevolutionary events that could be related to strain microevolution in response to environmental stress conditions.

Significance: Our findings demonstrate that metabolic supplementation of mucosal T cells, isolated from patients with active ulcerative colitis (UC), with N -acetylglucosamine (GlcNAc) leads to the enhancement of branched N-glycosylation on the T cell receptor, which was associated with the control of T cell activation and function. These results were validated in “glycoengineered” mouse models with severe colitis. Overall, our results open new avenues for a targeted-specific therapy in inflammatory bowel disease (IBD). The therapeutic use of GlcNAc (either alone or in combination with other antiinflammatory therapies) represents a simple immunomodulatory strategy in IBD, with absence of side effects, low costs, and the possibility of being used as a simple rescue therapy to avoid unnecessary toxic effects and step-up therapies in IBD.

Candida albicans secreted aspartyl proteinases (Saps) are considered virulence-associated factors. Several members of the Sap family were claimed to play a significant role in the progression of candidiasis established by the hematogenous route. This assumption was based on the observed attenuated virulence of sap -null mutant strains. However, the exclusive contribution of SAP genes to their attenuated phenotype was not unequivocally confirmed, as the Ura status of these mutant strains could also have contributed to the attenuation. In this study, we have reassessed the importance of SAP1 to SAP6 in a murine model of hematogenously disseminated candidiasis using sap -null mutant strains not affected in their URA3 gene expression and compared their virulence phenotypes with those of Ura-blaster sap mutants. The median survival time of BALB/c mice intravenously infected with a mutant strain lacking SAP1 to SAP3 was equivalent to that of mice infected with wild-type strain SC5314, while those infected with mutant strains lacking SAP5 showed slightly extended survival times. Nevertheless, no differences could be observed between the wild type and a Δ sap456 mutant in their abilities to invade mouse kidneys. Likewise, a deficiency in SAP4 to SAP6 had no noticeable impact on the immune response elicited in the spleens and kidneys of C. albicans -infected mice. These results contrast with the behavior of equivalent Ura-blaster mutants, which presented a significant reduction in virulence. Our results suggest that Sap1 to Sap6 do not play a significant role in C. albicans virulence in a murine model of hematogenously disseminated candidiasis and that, in this model, Sap1 to Sap3 are not necessary for successful C. albicans infection.