Epidemiology and Microbiologic Characterization of Nosocomial Candidemia from a Brazilian National Surveillance Program

Candidemia is a growing problem in hospitals all over the world. Despite advances in the medical support of critically ill patients, candidiasis leads to prolonged hospitalization, and has a crude mortality rate around 50%. We conducted a multicenter surveillance study in 16 hospitals distributed across five regions of Brazil to assess the incidence, species distribution, antifungal susceptibility, and risk factors for bloodstream infections due to Candida species. From June 2007 to March 2010, we studied a total of 2,563 nosocomial bloodstream infection (nBSI) episodes. Candida spp. was the 7^th most prevalent agent. Most of the patients were male, with a median age of 56 years. A total of 64 patients (46.7%) were in the ICU when candidemia occurred. Malignancies were the most common underlying condition (32%). The crude mortality rate of candidemia during the hospital admission was 72.2%. Non-albicans species of Candida accounted for 65.7% of the 137 yeast isolates. C. albicans (34.3%), Candida parapsilosis (24.1%), Candida tropicalis (15.3%) and Candida glabrata (10.2%) were the most prevalent species. Only 47 out of 137 Candida isolates were sent to the reference laboratory for antifungal susceptibility testing. All C. albicans, C. tropicalis and C. parapsilosis isolates were susceptible to the 5 antifungal drugs tested. Among 11 C. glabrata isolates, 36% were resistant to fluconazole, and 64% SDD. All of them were susceptible to anidulafungin and amphotericin B. We observed that C. glabrata is emerging as a major player among non-albicans Candida spp. and fluconazole resistance was primarily confined to C. glabrata and C. krusei strains. Candida resistance to echinocandins and amphotericin B remains rare in Brazil.Mortality rates remain increasingly higher than that observed in the Northern Hemisphere countries, emphasizing the need for improving local practices of clinical management of candidemia, including early diagnosis, source control and precise antifungal therapy.     

Early endosomes and endosomal coatomer are required for autophagy

Autophagy, an intracellular degradative pathway, maintains cell homeostasis under normal and stress conditions. Nascent double-membrane autophagosomes sequester and enclose cytosolic components and organelles, and subsequently fuse with the endosomal pathway allowing content degradation. Autophagy requires fusion of autophagosomes with late endosomes, but it is not known if fusion with early endosomes is essential. We show that fusion of AVs with functional early endosomes is required for autophagy. Inhibition of early endosome function by loss of COPI subunits (β′, β, or α) results in accumulation of autophagosomes, but not an increased autophagic flux. COPI is required for ER-Golgi transport and early endosome maturation. Although loss of COPI results in the fragmentation of the Golgi, this does not induce the formation of autophagosomes. Loss of COPI causes defects in early endosome function, as both transferrin recycling and EGF internalization and degradation are impaired, and this loss of function causes an inhibition of autophagy, an accumulation of p62/SQSTM-1, and ubiquitinated proteins in autophagosomes.     

The Impacts of Using Smartphone Dating Applications on Sexual Risk Behaviours in College Students in Hong Kong

Dating applications (apps) on smartphones have become increasingly popular. The aim of this study was to explore the association between the use of dating apps and risky sexual behaviours. Data were collected in four university campuses in Hong Kong. Subjects completed a structured questionnaire asking about the use of dating apps, sexual behaviours, and sociodemographics. Multiple linear and logistics regressions were used to explore factors associated with sexual risk behaviours. Six hundred sixty-six subjects were included in the data analysis. Factors associated with having unprotected sexual intercourse with more lifetime sexual partners included use of dating apps (β = 0.93, p<0.01), having one’s first sexual intercourse before 16 years of age (β = 1.74, p<0.01), being older (β = 0.4, p<0.01), currently being in a relationship (= 0.69, p<0.05), having a monthly income at least HKD$5,000 (β = 1.34, p<0.01), being a current smoker (β = 1.52, p<0.01), and being a current drinker (β = 0.7, p<0.01). The results of a multiple logistic regression analysis found that users of dating apps (adjust odds ratio: 0.52, p<0.05) and current drinkers (adjust odds ratio: 0.40, p<0.01) were less likely to have consistent condom use. Users of dating apps (adjust odds ratio: 1.93, p<0.05), bisexual/homosexual subjects (adjust odds ratio: 2.57, p<0.01) and female subjects (adjust odds ratio: 2.00, p<0.05) were more likely not to have used condoms the last time they had sexual intercourse. The present study found a robust association between using dating apps and sexual risk behaviours, suggesting that app users had greater sexual risks. Interventions that can target app users so that they can stay safe when seeking sexual partners through dating apps should be developed.     

If you knew what was good for you! The value of environmental enrichments with known welfare benefits is not demonstrated by sows using operant techniques

This study assessed the motivation of gestating sows housed in standard, barren gestation stalls (used for breeding/implantation and/or gestation) for access to environmental enrichment. Enrichment consisted of a cotton rope or rubber mat in comparison to positive (additional food when fed at commercial levels) and negative (empty trough) controls. Although environmental enrichment may improve animal welfare, sows' valuation of enrichments is largely unknown. This study used an operant panel and obtained behavioral measures to quantify motivation. As indicated by a higher price paid and lower latencies to press the panel and enter the treatment stall (all comparisons, p < .05), sows demonstrated higher motivation for food compared with all treatments. Sows housed in gestation stalls did not demonstrate high motivation via operant responding for a cotton rope or a rubber mat; nor did they demonstrate any differences in behavioral measures (all comparisons, p > .10). Although sows' motivation for a mat did not differ from that for an empty trough, previous work has demonstrated the welfare benefits associated with comfort flooring.     

Effect of human leukocyte interferon on human lymphocytes in vitro: cytogenetic studies

Mitogen-stimulated lymphocytes from 8 healthy donors were exposed to interferon, and cytogenetic studies were preformed. The response of lymphocytes to the mitogens phytohemagglutinin (PHA), concanavalin A (con A) and pokeweed mitogen (PWM) was inhibited by interferon, whereas an increased number of structural chromosomal aberrations was not detected. Further investigations of the cytogenetic effects of interferon are needed.     

Periplasmic nitrate reductase (NapABC enzyme) supports anaerobic respiration by Escherichia coli K-12

Periplasmic nitrate reductase (NapABC enzyme) has been characterized from a variety of proteobacteria, especially Paracoccus pantotrophus. Whole-genome sequencing of Escherichia coli revealed the structural genes napFDAGHBC, which encode NapABC enzyme and associated electron transfer components. E. coli also expresses two membrane-bound proton-translocating nitrate reductases, encoded by the narGHJI and narZYWV operons. We measured reduced viologen-dependent nitrate reductase activity in a series of strains with combinations of nar and nap null alleles. The napF operon-encoded nitrate reductase activity was not sensitive to azide, as shown previously for the P. pantotrophus NapA enzyme. A strain carrying null alleles of narG and narZ grew exponentially on glycerol with nitrate as the respiratory oxidant (anaerobic respiration), whereas a strain also carrying a null allele of napA did not. By contrast, the presence of napA+ had no influence on the more rapid growth of narG+ strains. These results indicate that periplasmic nitrate reductase, like fumarate reductase, can function in anaerobic respiration but does not constitute a site for generating proton motive force. The time course of phi(napF-lacZ) expression during growth in batch culture displayed a complex pattern in response to the dynamic nitrate/nitrite ratio. Our results are consistent with the observation that phi(napF-lacZ) is expressed preferentially at relatively low nitrate concentrations in continuous cultures (H. Wang, C.-P. Tseng, and R. P. Gunsalus, J. Bacteriol. 181:5303-5308, 1999). This finding and other considerations support the hypothesis that NapABC enzyme may function in E. coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme.