Hepatitis E virus of subtype 3i in chronically infected kidney transplant recipients in southeastern France.

Hepatitis E virus (HEV) is a leading cause of waterborne acute hepatitis in developing countries. In Europe, HEV causes a zoonotic disease and is hyperendemic in southern France. Four HEV genotypes (1 to 4) have been defined, and the most used classification divides them into 24 subtypes. Autochthonous European HEV strains belong in majority to genotype 3. Subtypes 3c, 3f, and 3e are representative of the HEV diversity in France. HEV causes chronic hepatitis in solid-organ transplant recipients in Europe, and viral characteristics associated with chronicity are poorly documented. We sequenced 343-nucleotide-long HEV genomic fragments from the serum of eight chronically infected kidney transplant recipients and a near-full-length genome in one case. We identified in four patients (50%) HEV of subtype 3i, not described previously in France. If shorter genomic fragments were used in phylogenetic analyses, these HEV sequences were clustered with open reading frame 2 (ORF2) fragments labeled as subtype 3c. At least five of the eight HEV 3i sequences recovered from humans in our phylogenetic analyses were from chronically infected kidney transplant recipients. These data show that the description of the prevalence and geographical distribution of HEV subtypes may be partially inaccurate and that criteria for classification as 3i and 3c should be clarified. Extended molecular virology analyses are required to improve knowledge of HEV epidemiology and determinants of chronic HEV infection.

Genome sequence of a hepatitis e virus of genotype 3e from a chronically infected kidney transplant recipient.

Hepatitis E virus (HEV) is an emerging cause of acute and chronic hepatitis in immunocompromised patients in Europe. We report the genome sequence of a genotype 3e HEV from a chronically infected kidney transplant recipient in southeastern France, the second HEV genome sequence from a transplant recipient and the first of subtype 3e.

Emergence of autochthonous infections with hepatitis E virus of genotype 4 in Europe.

In Europe, autochthonous hepatitis E is caused by genotype 3 hepatitis E virus (HEV) in almost all cases. A total of 15 infections with genotype 4 HEV were diagnosed in France from May 2009 to April 2012, and all but one of the HEV-4 strains implicated in these infections were genetically related and highly similar to HEV-4 sequences isolated from swine in Belgium. In addition, 5 autochthonous HEV-4 infections have been described in the region of Lazio, Italy, during March and April 2011, and these HEV sequences were 100% identical to one another but showed relatively low similarity (74-85%) to HEV-4 RNA samples collected in France. We report 6 additional HEV-4 infections that were diagnosed from May to July 2012 which represented 50% of the HEV infections diagnosed during this period in our clinical microbiology laboratory. Five of these HEV-4 strains were associated with autochthonous infections and were clustered together and with the majority of HEV-4 previously described in France, whereas the sixth strain was genetically divergent. Taken together with reports from other teams, these observations indicate that autochthonous infections with HEV-4 are emerging in Europe and have been transmitted by at least two distinct sources.

Tobacco mosaic virus in the lungs of mice following intra-tracheal inoculation.

Plant viruses are generally considered incapable of infecting vertebrates. Accordingly, they are not considered harmful for humans. However, a few studies questioned the certainty of this paradigm. Tobacco mosaic virus (TMV) RNA has been detected in human samples and TMV RNA translation has been described in animal cells. We sought to determine if TMV is detectable, persists, and remains viable in the lung tissues of mice following intratracheal inoculation, and we attempted to inoculate mouse macrophages with TMV. In the animal model, mice were intratracheally inoculated with 10(11) viral particles and were sacrificed at different time points. The virus was detected in the mouse lungs using immunohistochemistry, electron microscopy, real-time RT-PCR and sequencing, and its viability was studied with an infectivity assay on plants. In the cellular model, the culture medium of murine bone marrow derived macrophages (BMDM) was inoculated with different concentrations of TMV, and the virus was detected with real-time RT-PCR and immunofluorescence. In addition, anti-TMV antibodies were detected in mouse sera with ELISA. We showed that infectious TMV could enter and persist in mouse lungs via the intratracheal route. Over 14 days, the TMV RNA level decreased by 5 log(10) copies/ml in the mouse lungs and by 3.5 log(10) in macrophages recovered from bronchoalveolar lavage. TMV was localized to lung tissue, and its infectivity was observed on plants until 3 days after inoculation. In addition, anti-TMV antibody seroconversions were observed in the sera from mice 7 days after inoculation. In the cellular model, we observed that TMV persisted over 15 days after inoculation and it was visualized in the cytoplasm of the BMDM. This work shows that a plant virus, Tobacco mosaic virus, could persist and enter in cells in mammals, which raises questions about the potential interactions between TMV and human hosts.