Most Candida spp. infections are associated with biofilm formation on host surfaces. Cells within these communities display a phenotype resistant to antimicrobials and host defenses, so biofilm-associated infections are difficult to treat, representing a source of reinfections. The present study evaluated the effect of eugenol on the adherence properties and biofilm formation capacity of Candida dubliniensis and Candida tropicalis isolated from the oral cavity of HIV-infected patients. All isolates were able to form biofilms on different substrate surfaces. Eugenol showed inhibitory activity against planktonic and sessile cells of Candida spp. No metabolic activity in biofilm was detected after 24 h of treatment. Scanning electron microscopy demonstrated that eugenol drastically reduced the number of sessile cells on denture material surfaces. Most Candida species showed hydrophobic behavior and a significant difference in cell surface hydrophobicity was observed after exposure of planktonic cells to eugenol for 1 h. Eugenol also caused a significant reduction in adhesion of most Candida spp. to HEp-2 cells and to polystyrene. These findings corroborate the effectiveness of eugenol against Candida species other than C. albicans, reinforcing its potential as an antifungal applied to limit both the growth of planktonic cells and biofilm formation on different surfaces.

Mechanisms of viral oncogenesis are diverse and include the off‐target activity of enzymes expressed by the infected cells, which evolved to target viral genomes for controlling their infection. Among these enzymes, the single‐strand DNA editing capability of APOBECs represent a well‐conserved viral infection response that can also cause untoward mutations in the host DNA. Here we show, after evaluating somatic single‐nucleotide variations and transcriptome data in 240 gastric cancer samples, a positive correlation between APOBEC3s mRNA‐expression and the APOBEC‐mutation signature, both increased in EBV+ tumors. The correlation was reinforced by the observation of APOBEC mutations preferentially occurring in the genomic loci of the most active transcripts. This EBV infection and APOBEC3 mutation‐signature axis were confirmed in a validation cohort of 112 gastric cancer patients. Our findings suggest that APOBEC3 upregulation in EBV+ cancer may boost the mutation load, providing further clues to the mechanisms of EBV‐induced gastric carcinogenesis. After further validation, this EBV‐APOBEC axis may prove to be a secondary driving force in the mutational evolution of EBV+ gastric tumors, whose consequences in terms of prognosis and treatment implications should be vetted.

Ovarian cancer (OC) is the deadliest gynecological malignancy. Most patients are diagnosed when they are already in the later stages of the disease. Earlier detection of OC dramatically improves the overall survival, but this is rarely achieved as there is a lack of clinically implemented biomarkers of early disease. Extracellular vesicles (EVs) are small cell-derived vesicles that have been extensively studied in recent years. They contribute to various aspects of cancer pathology, including tumor growth, angiogenesis and metastasis. EVs are released from all cell types and the macromolecular cargo they carry reflects the content of the cells from which they were derived. Cancer cells release EVs with altered cargo into biofluids, and so, they represent an excellent potential source of novel biomarkers for the disease. In this review, we describe the latest developments in EVs as potential biomarkers for earlier detection of OC. The field is still relatively young, but many studies have shown that EVs and the cargo they carry, including miRNAs and proteins, can be used to detect OC. They could also give insights into the stage of the disease and predict the likely therapeutic outcome. There remain many challenges to the use of EVs as biomarkers, but, through ongoing research and innovation in this exciting field, there is great potential for the development of diagnostic assays in the clinic that could improve patient outcome.

The opportunistic fungal pathogen Candida albicans causes serious hematogenic hospital acquired candidiasis with worldwide impact on public health. Because of its importance as a nosocomial etiologic agent, C. albicans genome has been largely studied to identify intraspecific variation and several typing methods have been developed to distinguish closely related strains. Mitochondrial DNA can be useful for this purpose because, as compared to nuclear DNA, its higher mutational load and evolutionary rate readily reveals microvariants. Accordingly, we sequenced and assembled, with 8-fold coverage, the mitochondrial genomes of two C. albicans clinical isolates (L296 and L757) and compared these sequences with the genome sequence of reference strain SC5314. The genome alignment of 33,928 positions revealed 372 polymorphic sites being 230 in coding and 142 in non-coding regions. Three intergenic regions located between genes tRNAGly/COX1, NAD3/COB and ssurRNA/NAD4L, named IG1, IG2 and IG3, respectively, which showed high number of neutral substitutions, were amplified and sequenced from 18 clinical isolates from different locations in Latin America and 2 ATCC standard C. albicans strains. High variability of sequence and size were observed, ranging up to 56bp size difference and phylogenies based on IG1, IG2 and IG3 revealed three groups. Insertions of up to 49bp were observed exclusively in Argentinean strains relative to the other sequences which could suggest clustering by geographical polymorphism. Because of neutral evolution, high variability, easy isolation by PCR and full length sequencing these mitochondrial intergenic regions can contribute with a novel perspective in molecular studies of C. albicans isolates, complementing well established multilocus sequence typing methods.

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next‐generation deep sequencing of TP53—a highly mutated and informative gene in GAC—to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash—GW). We evaluated their potential to reveal tumor‐derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment. Exon‐capture libraries were constructed from 46 patients including tumor biopsies, GW and PL pre and post‐treatment (196 samples), with high vertical coverage >8,000×. At diagnosis, we detected TP53 mutations in 15/46 biopsies (32.6%), 7/46 GW‐ (15.2%) and 6/46 PL‐samples (13%). Biopsies and GW were concordant in 38/46 cases (82.6%) for the presence/absence of mutations and, furthermore, four GW‐exclusive mutations were identified, suggesting tumor heterogeneity. Considering the combined analysis of GW and PL, TP53 mutations found in biopsies were also identified in 9/15 (60%) of cases, the highest detection level reported for GAC. Our study indicates that GW could be useful to track DNA alterations, especially if anchored to a comprehensive gene‐panel designed for this malignancy.

Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings.

The commensal yeast Candida albicans is an opportunistic pathogen. In order to successfully colonize or infect the human body, the fungus must adapt to the host’s environmental conditions, such as low oxygen tension (hypoxia), temperature (37°C), and the different carbon sources available. Previous studies demonstrated the adaptive importance of C. albicans genetic variability for its pathogenicity, although the contributions of epigenetic and the influence of environmental factors are not fully understood. Mitochondria play important roles in fungal energetic metabolism, regulation of nuclear epigenetic mechanisms and pathogenicity. However, the specific impact of inter-strain mitochondrial genome variability and mitochondrial epigenetics in pathogenicity is unclear. Here, we draw attention to this relevant organelle and its potential role in C. albicans pathogenicity and provide preliminary evidence, for the first time, for methylation of the yeast mitochondrial genome. Our results indicate that environmental conditions, such as continuous exposure for 12 weeks to hypoxia and 37°C, decrease the mitochondrial genome methylation in strains SC5314 and L757. However, the methylation decrease is quantitatively different in specific genome positions when strains SC5314 and L757 are compared. We hypothesize that this phenomenon can be promising for future research to understand how physical factors of the host affect the C. albicans mitochondrial genome and its possible impact on adaptation and pathogenicity.

The genetic variability of the opportunistic pathogen Candida albicans is an important adaptive mechanism. Here, we present the whole-genome sequences of the C. albicans SC5314 strain under two different growth conditions, providing useful information for comparative genomic studies and further intraspecific analysis.T he fungus Candida albicans is ubiquitously found in the human body and successfully colonizes diverse niches, such as skin and urogenital and gastrointestinal tracts, including internal organs, after tissue invasion and bloodstream dissemination (reviewed in references 1, 2, and 3). Although part of the human microbiota, C. albicans causes severe mucosal and bloodstream opportunistic infections in immunosuppressed hosts, with nearly 400,000 nosocomial cases worldwide with 46 to 75% mortality rates (4).We used the C. albicans strain SC5314, kindly provided to our laboratory by A. Mitchell in the mid-1990s. This strain is considered a reference strain and was isolated in 1984 from a candidemia patient (5). Since then, samples of this strain have been distributed to many laboratories and used in studies worldwide. The genome of one of these samples was previously sequenced by Muzzey and collaborators (6) using nextgeneration sequencing technologies.Our SC5314 (named SC5314-P0) yeast cells were grown on yeast extract-peptonedextrose (YPD) plates (1% wt/vol yeast extract; 2% wt/vol peptone, 2% wt/vol dextrose, and 2% wt/vol agar), and a single colony was used for overnight growth on YPD broth at 28°C and 150 rpm. Total yeast DNA was extracted from samples as described previously (7), and the complete sequencing of mitochondrial and nuclear genomes was carried out by using the Illumina MiSeq 2 ϫ 300-bp method in paired-end mode. The libraries were prepared with a TruSeq DNA v2 Illumina kit according to the manufacturer's technical specifications. FastQC v.0.11.4 software (8) was used to evaluate sequencing quality. Trimming was performed with the CLC Genomics Workbench v.7.5.1 (Qiagen) software with a quality score limit of 0.005 and removal of 45 bp and 20 bp from the 5= and 3= ends, respectively, and reads smaller than 25 bp were discarded. Once the quality filters were approved, reads were mapped to the assembly 22 of the reference strain SC5314 (A22-s07-m01-r18) (available at http://www .candidagenome.org/download/sequence/C_albicans_SC5314/Assembly22/archive/). Duplicated reads were removed after mapping and local realignment were carried out with the Guided Realignment tool (with "force realignment to guidance variants" selected) implemented in CLC Genomics Workbench v.7.5.1 (Qiagen). Genome annotation was performed with Annotate with the GFF file tool available on the same software using the corresponding GFF file (version A22-S05-M04-r02_features_with_ chromosome_sequences.gff). The fraction of the SC5314 genome sequenced was 0.99