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A 59-year-old man presented with feverish illness. His Glasgow Coma Scale was 15, had reduced visual acuity in the left eye with partial left ptosis and mild left hemiparesis with an extensor left plantar. Over 48 hours, he accrued multiple cranial nerves palsies and progressed to a flaccid paralysis necessitating admission to an intensive care unit. Cerebrospinal fluid (CSF) study showed 20 lymphocytes and raised protein. Viral and bacterial PCRs were negative. Samples for Lyme, blood-borne viruses, syphilis and autoantibodies were also negative. MRI brain showed T2 abnormalities within the brainstem. Nerve conduction studies revealed an acute motor and sensory axonal neuropathy pattern of Guillian Barre Syndrome (GBS). The patient was treated for both infective and inflammatory causes of brainstem encephalitis and GBS. Retrospective studies confirmed the presence of hepatitis E virus (HEV) RNA in CSF and serum studies showed positive HEV IgG and IgM prior to intravenous infusion. After 3 months of intensive rehabilitation, the patient was discharged home walking with a frame.

Noroviruses are the major cause of nonbacterial gastroenteritis in humans. These viruses have remained refractory to detailed molecular studies because of the lack of a reverse genetics system coupled to a permissive cell line for targeted genetic manipulation. There is no permissive cell line in which to grow infectious human noroviruses nor an authentic animal model that supports their replication. In contrast, murine norovirus (MNV) offers a tractable system for the study of noroviruses with the recent discovery of permissive cells and a mouse model. The lack of a reverse genetic system for MNV has been a significant block to understanding the biology of noroviruses. We report recovery of infectious MNV after baculovirus delivery of viral cDNA to human hepatoma cells under the control of an inducible DNA polymerase (pol) II promoter. Recovered virus replicated in murine macrophage (RAW264.7) cells, and the recovery of MNV from DNA was confirmed through recovery of virus containing a marker mutation. This pol II promoter driven expression of viral cDNA also generated infectious virus after transfection of HEK293T cells, thus providing both transduction and transfection systems for norovirus reverse genetics. We used norovirus reverse genetics to demonstrate by mutagenesis of the protease–polymerase (pro–pol) cleavage site that processing of pro–pol is essential for the recovery of infectious MNV. This represents the first infectious reverse genetics system for a norovirus, and should provide approaches to address fundamental questions in norovirus molecular biology and replication.

Investigations into human norovirus infection, replication and pathogenesis, as well as the development of potential antiviral agents, have been restricted by the lack of a cell culture system for human norovirus. To date, the optimal cell culture surrogate virus model for studying human norovirus biology is the murine norovirus (MNV). In this report we generate a tetracycline-regulated, inducible eukaryotic cell system expressing the entire MNV ORF1 polyprotein. Once induced, the MNV ORF1 polyprotein was faithfully processed to the six mature non-structural proteins that predominately located to a discrete perinuclear region, as has been observed in active MNV infection. Furthermore, we found that expression of the ORF1 polyprotein alone was sufficient to induce apoptosis, characterised by caspase-9 activation and survivin down-regulation. This cell line provides a valuable new tool for studying MNV ORF1 non-structural protein function, screening for potential antiviral agents and acts as a proof-of-principle for such systems to be developed for human noroviruses.

A generally accepted view of norovirus replication is that capsid expression requires production of a subgenomic transcript, the presence of capsid often being used as a surrogate marker to indicate the occurrence of viral replication. Using a polymerase II-based baculovirus delivery system, we observed capsid expression following introduction of a full-length genogroup 3 norovirus genome into HepG2 cells. However, capsid expression occurred as a result of a novel translation termination/reinitiation event between the nonstructural-protein and capsid open reading frames, a feature that may be unique to genogroup 3 noroviruses.

In this article, the author discusses the prevalence of insulin autoantibodies (IAA) and endogenous insulin secretion in Saudi patients at the onset of diabetes. A positive result, defined as a value greater then 3 SD above the mean binding of normal, was found in 8 (7.6%) of 105 of the patients with diabetes and in 3 (5.7%) of 53 of the healthy control subjects. The relation between the presence of IAA and the pancreatic beta cell secretory activity was studied by determining the levels of insulin and C-peptide in the fasting state and 6 minutes after intravenous injection of 1 mg glucagon. All the IAA positive subjects had a response to glucagon stimulation test. A positive correlation was found between basal and after stimulation for both insulin and C-peptide (r = 0.79, P < 0.001; r = 0.85, P < 0.001 for insulin and r = 0.76, P < 0.001; r = 0.81, P < 0.001 for C-peptide, respectively). Therefore, the current finding indicates that there is no direct effect of IAA on the pancreatic beta cell potential activity in Saudi patients with diabetes at the time of diagnosis, suggesting further that these patients have no insulin deficiency or have mild insulin dependency.

Background Chlamydia trachomatis is the most common cause of sexually transmitted infections globally and the leading cause of preventable blindness in the developing world. There are two biovariants of C. trachomatis: 'trachoma', causing ocular and genital tract infections, and the invasive 'lymphogranuloma venereum' strains. Recently, a new variant of the genital tract C. trachomatis emerged in Sweden. This variant escaped routine diagnostic tests because it carries a plasmid with a deletion. Failure to detect this strain has meant it has spread rapidly across the country provoking a worldwide alert. In addition to being a key diagnostic target, the plasmid has been linked to chlamydial virulence. Analysis of chlamydial plasmids and their cognate chromosomes was undertaken to provide insights into the evolutionary relationship between chromosome and plasmid. This is essential knowledge if the plasmid is to be continued to be relied on as a key diagnostic marker, and for an understanding of the evolution of Chlamydia trachomatis. Results The genomes of two new C. trachomatis strains were sequenced, together with plasmids from six C. trachomatis isolates, including the new variant strain from Sweden. The plasmid from the new Swedish variant has a 377 bp deletion in the first predicted coding sequence, abolishing the site used for PCR detection, resulting in negative diagnosis. In addition, the variant plasmid has a 44 bp duplication downstream of the deletion. The region containing the second predicted coding sequence is the most highly conserved region of the plasmids investigated. Phylogenetic analysis of the plasmids and chromosomes are fully congruent. Moreover this analysis also shows that ocular and genital strains diverged from a common C. trachomatis progenitor. Conclusion The evolutionary pathways of the chlamydial genome and plasmid imply that inheritance of the plasmid is tightly linked with its cognate chromosome. These data suggest that the plasmid is not a highly mobile genetic element and does not transfer readily between isolates. Comparative analysis of the plasmid sequences has revealed the most conserved regions that should be used to design future plasmid based nucleic acid amplification tests, to avoid diagnostic failures.