Motivation: Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. Results: We present an improved version of EVpedia, a public database for EVs research. This community web portal contains a database of publications and vesicular components, identification of orthologous vesicular components, bioinformatic tools and a personalized function. EVpedia includes 6879 publications, 172 080 vesicular components from 263 high-throughput datasets, and has been accessed more than 65 000 times from more than 750 cities. In addition, about 350 members from 73 international research groups have participated in developing EVpedia. This free web-based database might serve as a useful resource to stimulate the emerging field of EV research. Availability and implementation: The web site was implemented in PHP, Java, MySQL and Apache, and is freely available at http://evpedia.info. Contact:ysgho@postech.ac.kr

Gram-positive bacteria naturally produce extracellular vesicles. However, little is known regarding the functions of Gram-positive bacterial extracellular vesicles, especially in the bacterial community. Here, we investigated the role of Staphylococcus aureus extracellular vesicles in interbacterial communication to cope with antibiotic stress. We found that S. aureus liberated BlaZ, a β-lactamase protein, via extracellular vesicles. These extracellular vesicles enabled other ampicillin-susceptible Gram-negative and Gram-positive bacteria to survive in the presence of ampicillin. However, S. aureus extracellular vesicles did not mediate the survival of tetracycline-, chloramphenicol-, or kanamycin-susceptible bacteria. Moreover, S. aureus extracellular vesicles did not contain the blaZ gene. In addition, the heat-treated S. aureus extracellular vesicles did not mediate the survival of ampicillin-susceptible bacteria. The β-lactamase activities of S. aureus soluble and extracellular vesicle-associated BlaZ were similar, but only the extracellular vesicle-associated BlaZ was resistant to protease digestion, which suggests that the enzymatic activity of BlaZ in extracellular vesicles is largely protected by the vesicle structure. Our observations provide evidence of the important role of S. aureus extracellular vesicles in antibiotic resistance, which allows the polymicrobial community to continue to evolve and prosper against antibiotics.

The time to positivity (TTP) of blood cultures is associated with the microbial load in the blood and prognosis in patients with bloodstream infections caused by various bacterial species. However, relevant information about the TTP for Candida species in candidaemia is limited. We investigated the clinical impact of the TTP on mortality in patients with candidaemia. All consecutive patients ≥18 years of age with candidaemia between January 2006 and July 2012 were included. The demographics, clinical and microbiological characteristics, antifungal treatment and outcomes of the patients were collected retrospectively. A total of 152 patients were identified. The overall mortality rate at 6 weeks was 53%. The median TTP for Candida isolates was 27 h (IQR 19–37 h). A TTP of ≤24 h was significantly related to a higher mortality rate (P = 0.021). In a multivariate Cox regression analysis, the Charlson comorbidity index value [adjusted hazard ratio (HR) 1.15, 95% CI 1.02–1.29, P = 0.018], sequential organ failure assessment score (adjusted HR 1.23, 95% CI 1.13–1.34, P < 0.001), TTP ≤24 h (adjusted HR 2.74, 95% CI 1.51–4.97, P = 0.001), timing of appropriate antifungal therapy >72 h (adjusted HR 2.38, 95% CI 1.26–4.51, P = 0.008) and persistent candidaemia (adjusted HR 2.50, 95% CI 1.33–4.72, P = 0.005) were independently associated with the 6 week mortality rate. A short TTP (≤24 h) for Candida species was independently associated with increased mortality in patients with candidaemia. Additional studies on the relevance of the TTP to clinical outcome in patients with candidaemia are needed.