Microbiology & Virology

Wiley Microbiology Special Virtual Issue

This material is exclusive and copyrighted journal content normally available only as a paid subscription with Wiley. Through a special arrangement, we are pleased to offer you access to the full text of the abstracts below until 31 December 2012, some of which may also be offered with special permission from our valued Society partners. If you wish to subscribe to any of the journals, please contact Wiley customer service at cs-journals@wiley.com.

Cellular Microbiology
Innate immune control of West Nile virus infection
West Nile virus (WNV), from the Flaviviridae family, is a re-emerging zoonotic pathogen of medical importance. In humans, WNV infection may cause life-threatening meningoencephalitis or long-term neurologic sequelae. WNV is transmitted by Culex spp. mosquitoes and both the arthropod vector and the mammalian host are equipped with antiviral innate immune mechanisms sharing a common phylogeny. As far as the current evidence is able to demonstrate, mosquitoes primarily rely on RNA interference, Toll, Imd and JAK-STAT signalling pathways for limiting viral infection, while mammals are provided with these and other more complex antiviral mechanisms involving antiviral effectors, inflammatory mediators, and cellular responses triggered by highly specialized pathogen detection mechanisms that often resemble their invertebrate ancestry. This mini-review summarizes our current understanding of how the innate immune systems of the vector and the mammalian host react to WNV infection and shape its pathogenesis.
[READ FULL ARTICLE]

BioEssays
Sex influences immune responses to viruses, and efficacy of prophylaxis and treatments for viral diseases
The intensity and prevalence of viral infections are typically higher in males, whereas disease outcome can be worse for females. Females mount higher innate and adaptive immune responses than males, which can result in faster clearance of viruses, but also contributes to increased development of immunopathology. In response to viral vaccines, females mount higher antibody responses and experience more adverse reactions than males. The efficacy of antiviral drugs at reducing viral load differs between the sexes, and the adverse reactions to antiviral drugs are typically greater in females than males. Several variables should be considered when evaluating male/female differences in responses to viral infection and treatment: these include hormones, genes, and gender-specific factors related to access to, and compliance with, treatment. Knowledge that the sexes differ in their responses to viruses and to treatments for viral diseases should influence the recommended course of action differently for males and females.
[READ FULL ARTICLE]

Reviews in Medical Virology
The ubiquitin-proteasome system in positive-strand RNA virus infection
Positive-stranded RNA viruses, like many other viruses, have evolved to exploit the host cellular machinery to their own advantage. In eukaryotic cells, the ubiquitin-proteasome system (UPS) that serves as the major intracellular pathway for protein degradation and modification plays a crucial role in the regulation of many fundamental cellular functions. A growing amount of evidence has suggested that the UPS can be utilized by positive-sense RNA viruses. The UPS eliminates excess viral proteins that prevent viral replication and modulates the function of viral proteins through post-translational modification mediated by ubiquitin or ubiquitin-like proteins. This review will discuss the current understanding of how positive RNA viruses have evolved various mechanisms to usurp the host UPS to modulate the function and stability of viral proteins. In addition to the pro-viral function, UPS-mediated viral protein degradation may also constitute a host defense process against some positive-stranded RNA viral infections.
[READ FULL ARTICLE]

Journal of Clinical Psychology
Findings of Long-Term Depression up to 8 Years Post Infection From West Nile Virus
The objective of this study was to examine the psychological sequelae following West Nile virus (WNV) infection among a large cohort of participants over an 8-year period. We conducted a longitudinal study to assess mental health outcomes among a cohort of 171 WNV-positive participants in Houston, Texas, and found 35% of participants met the Center for Epidemiologic Studies Depression scale definition for new onset clinical depression. Multivariate analysis found that severe depression was significantly associated with gender and physical disability (Barthel index score <100) at 5 years post-WNV infection
[READ FULL ARTICLE]

Journal of Basic Microbiology
Evidence for a vast peptide overlap between West Nile virus and human proteomes
The primary amino acid sequence of West Nile virus (WNV) polyprotein, GenBank accession number M12294, was analyzed by computional biology. WNV is a mosquito-borne neurotropic flavivirus that has emerged globally as a significant cause of viral encephalitis in humans. Using pentapeptides as scanning units and the perfect peptide match program from PIR International Protein Sequence Database, we compared the WNV polyprotein and the human proteome. WNV polyprotein showed significant sequence similarities to a number of human proteins. Several of these proteins are involved in embryogenesis, neurite outgrowth, cortical neuron branching, formation of mature synapses, semaphorin interactions, and voltage dependent L-type calcium channel subunits. The biocomputional study suggest that common amino acid segments might represent a potential platform for further studies on the neurological pathophysiology of WNV infections.
[READ FULL ARTICLE]

Journal of Medical Virology
Acute West Nile virus neuroinvasive infections: Cross-reactivity with dengue virus and tick-borne encephalitis virus
Cross-reactions in serology are common among flaviviruses. During the outbreak of West Nile virus (WNV) infections in Greece in 2010, WNV IgM-positive serum and cerebrospinal fluid samples were tested for the presence of IgM and IgG antibodies against Dengue virus (DENV) and tick-borne encephalitis virus. Higher cross-reactivity was observed in IgM antibodies between WNV and DENV; however, the index of the WNV antibodies was in all cases higher than that of the DENV antibodies. There is a need for caution when evaluating serologic results of flaviviral infections, while efforts have to be focused on the development of diagnostic assays with increased specificity.
[READ FULL ARTICLE]

Persistence of West Nile virus immunoglobulin M antibodies, Greece
A major outbreak of West Nile virus (WNV) lineage 2 infections was observed in 2010 in Greece. In order to check the persistence of WNV IgM antibodies, a second serum sample taken 75–180 days after onset of the illness from 29 patients with WNV infection was tested. A third sample was obtained 181–270 days after onset of the illness from 8 of the 12 patients with IgM-positive second sample. Mixed effects linear regression analysis indicated that the approximate time at which IgM index became negative was 164 (95% confidence interval, 95% CI 99–236) days after the symptoms' onset. Persistence of IgM antibodies was observed in 12% of patients at 181–270 days of follow-up. A sharp decrease in the IgM levels was observed, mainly in patients who had high IgM index value in the acute phase. All patients were WNV IgG positive at the follow-up.
[READ FULL ARTICLE]