SUMMARYGoose erythrocyte membranes were isolated and tested for their ability to compete with red cell receptors for vesicular stomatitis virus (VSV) attachment and fusion at acidic pH. Crude membranes, solubilized with Triton X-100, Tween 80 and octyl-/~-Dglucopyranoside, showed a dose-dependent inhibitory effect on virus binding and haemolysis. The chemical nature of the active molecules was investigated by enzyme digestion and by separation of purified components. Only the lipid moiety, specifically phospholipid and glycolipid, was found to inhibit VSV attachment; a more detailed analysis of these molecules showed that phosphatidylinositol, phosphatidylserine and GM3 ganglioside were responsible for the inhibitory activity and could therefore represent VSV binding sites on goose erythrocyte membranes. Removal of negatively charged groups from these molecules by enzymic treatment significantly reduced their activity, suggesting that electrostatic interactions play an important role in the binding of VSV to the cell surface. Enzymic digestion of whole erythrocytes confirmed the involvement of membrane lipid molecules in the cell surface receptor for VSV.

We determined the incidence, risk factors, and outcomes of bloodstream infections (BSI) subsequent to Clostridium difficile infection (CDI). We performed a retrospective study of all patients with definite diagnosis of CDI admitted from January 2014 to December 2014 in two large hospitals in Rome. C lostridium difficile infection (CDI) is an emerging infection, usually occurring after exposure to broad-spectrum antibiotics (1-3). This infection can be mild and self-limiting but might progress to severe disease with ileus, toxic megacolon, and eventually, death. The incidence, severity, and acquisition of infection of people formerly classified as being at low risk seem to be increasing, and a hypervirulent, fluoroquinolone-resistant C. difficile strain, named NAP1/BI/027, is associated with severe symptoms, high recurrence rates, and poor outcomes (4-6).The alterations occurring in the intestinal flora, which is recognized as a microbiome, may promote the translocation of pathogens in the blood and the development of nosocomial bloodstream infections (BSIs) (7). Recently, we reported our experience of studying candidemia subsequent to severe CDI (8-10), and we observed an association between Candida species BSI and CDI, especially if caused by ribotype 027 strains. We reported a case of severe community-onset health care-associated CDI complicated by carbapenemase-producing Klebsiella pneumoniae BSI (11). Thus, it was hypothesized that antibiotic therapy and/or other clinical characteristics related to CDI (i.e., severity, recurrence, disease caused by a highly virulent strain, etc.) contribute to alterations of the colon indigenous microbiota and eventually predispose patients to .The aim of our study was to analyze the clinical findings for patients with CDI and primary nosocomial BSI to determine the risk factors and outcomes associated with these infections.(This work was presented as an oral communication during the 55th Interscience Conference on Antimicrobial Agents and Chemotherapy, San Diego, CA, 17 to 21 September 2015 [15].) MATERIALS AND METHODSStudy design and study patients. This was a retrospective study of patients who were admitted from January 2014 to December 2014 to two large hospitals in Rome: Policlinico Umberto I-Sapienza University Hospital (1,200 beds and 49,000 admissions/year in 2014) and the San Giovanni-Addolorata Hospital (700 beds and 30,000 admissions/year in 2014). All adults (aged Ͼ18 years) with a documented CDI initially were included in the study. Patients for whom we could not obtain medical records were excluded from the final analysis. The ethics committee of the Policlinico Umberto I approved the study.Data were extracted from the medical records of patients and from hospital computerized databases or clinical charts according to a prepared questionnaire. The following data were reviewed: demographics, clinical and laboratory findings, comorbidity conditions (like diabetes mellitus, cardiovascular disease, pulmonary disease, renal disease, hepatic disease, central nervous...

BK virus infectivity was inhibited by gangliosides extracted from Vero cells and by standard preparations of different gangliosides. Gangliosides were also able to restore the susceptibility of glycosidase-treated Vero cells to BK virus infection.

SUMMARYThe role of gangliosides in rabies virus infection of chick embryo-related (CER) cells was investigated. Cultured cells were pretreated with neuraminidase to render the cells transiently non-susceptible to viral infection. Incubation of these desialylated cells with gangliosides allowed them to incorporate exogenous gangliosides and they recovered their susceptibility to rabies virus infection. Infection of CER cells was monitored by specific fluorescence 24 h after virus inoculation. The use of individual purified gangliosides or mixtures of two gangliosides to restore cellular susceptibility to viral infection showed that GTlb and GQlb were the most effective. The disialogangliosides were also active, principally GD 1 b, whereas GM 1, GM3 were poorly active and GD3 inactive. Incubation of rabies virus with gangliosides prior to virus infection reduced the percentage of infected cells. The results indicate that highly sialylated gangliosides are part of the cellular membrane receptor structure for the attachment of infective rabies virus. However, it is possible that other glycoconjugates such as glycoproteins or glycolipids also participate as components of a receptor structure for rabies virus.

Fluoro-substituted flavones and 2-styrylchromones, related to natural and synthetic flavonoids previously described, were prepared, characterized and tested for anti-rhinovirus activity. Structural elucidation of the new compounds was performed by IR, NMR spectra and X-ray crystal structure analysis for 6-fluoro-3-hydroxy-2-styrylchromone. The antiviral potency was evaluated by a plaque reduction assay in HeLa cell cultures infected with rhinoviruses 1B and 14, selected as representative serotypes for viral groups B and A of human rhinoviruses, respectively. In comparison with results previously obtained, the introduction of the fluorine atom seems to exert a positive influence on the activity against serotype 14 while counteracting the effect against serotype 1B.