Transmission of hepatitis C virus among people who inject drugs: viral stability and association with drug preparation equipment.

BACKGROUND: Hepatitis C virus (HCV) transmission among people who inject drugs remains a challenging public health problem. We investigated the risk of HCV transmission by analyzing the direct association of HCV with filters, water to dilute drugs, and water containers. METHODS: Experiments were designed to replicate practices by people who inject drugs and include routinely used injection equipment. HCV stability in water was assessed by inoculation of bottled water with HCV. Viral association with containers was investigated by filling the containers with water, inoculating the water with HCV, emptying the water, and refilling the container with fresh water. Transmission risk associated with drug preparation filters was determined after drawing virus through a filter and incubating the filter to release infectious particles. RESULTS: HCV can survive for up to 3 weeks in bottled water. Water containers present a risk for HCV transmission, as infectious virions remained associated with water containers after washing. Physical properties of the water containers determined the degree of HCV contamination after containers were refilled with water. HCV was also associated with filter material, in which around 10% of the viral inoculum was detectable. CONCLUSIONS: This study demonstrates the potential risk of HCV transmission among injection drug users who share water, filters, and water containers and will help to define public health interventions to reduce HCV transmission.

Stepwise loss of fluorescent core protein V from human adenovirus during entry into cells.

Human adenoviruses (Ads) replicate and assemble particles in the nucleus. They organize a linear double-strand DNA genome into a condensed core with about 180 nucleosomes, by the viral proteins VII (pVII), pX, and pV attaching the DNA to the capsid. Using reverse genetics, we generated a novel, nonconditionally replicating Ad reporter by inserting green fluorescent protein (GFP) at the amino terminus of pV. Purified Ad2-GFP-pV virions had an oversized complete genome and incorporated about 38 GFP-pV molecules per virion, which is about 25% of the pV levels in Ad2. GFP-pV cofractionated with the DNA core, like pV, and newly synthesized GFP-pV had a subcellular localization indistinguishable from that of pV, indicating that GFP-pV is a valid reporter for pV. Ad2-GFP-pV completed the replication cycle, although at lower yields than Ad2. Incoming GFP-pV (or pV) was not imported into the nucleus. Virions lost GFP-pV at two points during the infection process: at entry into the cytosol and at the nuclear pore complex, where capsids disassemble. Disassembled capsids, positive for the conformation-specific antihexon antibody R70, were devoid of GFP-pV. The loss of GFP-pV was reduced by the macrolide antibiotic leptomycin B (LMB), which blocks nuclear export and adenovirus attachment to the nuclear pore complex. LMB inhibited the appearance of R70 epitopes on Ad2 and Ad2-GFP-pV, indicating that the loss of GFP-pV from Ad2-GFP-pV is an authentic step in the adenovirus uncoating program. Ad2-GFP-pV is genetically complete and hence enables detailed analyses of infection and spreading dynamics in cells and model organisms or assessment of oncolytic adenoviral potential.

Specific acquisition of functional CD59 but not CD46 or CD55 by hepatitis C virus.

Viruses of different families encode for regulators of the complement system (RCAs) or acquire such RCAs from the host to get protection against complement-mediated lysis (CML). As hepatitis C virus (HCV) shares no genetic similarity to any known RCA and is detectable at high titers in sera of infected individuals, we investigated whether HCV has adapted host-derived RCAs to resist CML. Here we report that HCV selectively incorporates CD59 while neither CD55, nor CD46 are associated with the virus. The presence of CD59 was shown by capture assays using patient- and cell culture-derived HCV isolates. Association of CD59 with HCV was further confirmed by Western blot analysis using purified viral supernatants from infected Huh 7.5 cells. HCV captured by antibodies specific for CD59 remained infectious for Huh 7.5 cells. In addition, blocking of CD59 in the presence of active complement reduced the titer of HCV most likely due to CML. HCV produced in CD59 knock-down cells were more significantly susceptible to CML compared to wild type virus, but neither replication, assembly nor infectivity of the virus seemed to be impaired in the absence of CD59. In summary our data indicate that HCV incorporates selectively CD59 in its envelope to gain resistance to CML in serum of infected individuals.

New peptaibols from Mycogone cervina.

From cultures of Mycogone cervina, a mycophilic fungus growing on the fruit bodies of ascomycete Paxina acetabulum, two new peptaibols (cervinin, N-Ac-Leu-Aib-Pro-Aib-Leu-Aib-Pro-Ala-Aib-Pro-Val-red-Leu (1) and the red-Leu O-acetylated derivative 2) were isolated. The structures of 1 and 2 were elucidated by spectroscopic techniques. They exhibited weak antibacterial as well as cytotoxic activities. They are the first secondary metabolites described from M. cervina.