Christine Bigaillon

Circulation of genotype 4 hepatitis E virus in Europe: First autochthonous hepatitis E infection in France

BACKGROUND Human HEV infections reported in Europe without previous travel to endemic regions are linked to exposure to genotype 3 Hepatitis E virus (HEV).Genotype 3 is widely distributed through human cases and zoonotic reservoir. The geographical distribution of genotype 4 is limited to Asian countries. OBJECTIVES The first human case of autochthonous genotype 4 hepatitis E infection was reported in France. STUDY DESIGN The HEV infection was described in an immunosuppressed patient, presenting an acute myeloblastic leukemia. Investigation of the case was performed on detection of HEV markers in the patient and in the environment. RESULTS Hepatitis E infection was diagnosed on the basis of HEV RNA viremia, and detection of anti-HEV IgM. The prognostic of leukemia was favorable and HEV was cleared without relapsing. HEV isolate was classified into genotype 4. CONCLUSIONS The recent characterization of genotype 4 HEV through swine surveillance in Europe and the description of the first human case in France open interesting questions about the circulation of this genotype: health risks in human population, transmission patterns, and zoonotic reservoir.

Use of hepatitis E IgG avidity for diagnosis of hepatitis E infection.

The diagnosis of acute hepatitis E infection is based on the detection of HEV RNA or specific IgM in immunocompetent patients. Viraemia and excretion of HEV RNA in faeces are not observed in all patients and commercial kits vary in their performance for anti-HEV IgM detection. Additional diagnostic tests must therefore be considered. The value of anti-HEV IgG avidity index for differentiating between acute infection and previous exposure to HEV in countries of low endemicity was investigated. 132 specimens were included, with 39 serum samples from patients with known HEV infection, studied retrospectively. IgG avidity index was high (>60%) in patients with previous infection (n=16) or polyclonal activation (n=3) but was low (<40%) in patients with acute infection (n=20). Then, 93 serum samples from patients, checking for acute hepatitis (detection of anti-HEV IgM but not of HEV RNA) were investigated. IgG avidity index was <40% in 77 of these patients, consistent with acute infection. It exceeded 60% in 15 patients, providing evidence of contact with HEV up to six months previously. One patient had an uninterpretable biological profile, with an IgG avidity index between 40% and 60%. IgG mature slowly during HEV infection, over a period of six months. IgG avidity index can therefore be used to exclude primary infection. This method should improve the diagnosis of acute hepatitis E.

Clinical isolates of escherichia coli solely resistant to mecillinam: prevalence and epidemiology.

In routine susceptibility testing of Gram-negative bacteria, a particular resistance phenotype was observed: an Escherichia coli isolate from a urine sample exhibited resistance solely to mecillinam (MEC) but was fully susceptible to other β-lactam antibiotics (MEC-R-BL-S). The objectives as this study were to determine the prevalence of this phenotype and to describe the phenotype, molecular epidemiology and genetic background. Between 1 January 2014 and 31 January 2016, MEC-R-BL-S E. coli isolates from urine were collected and genes previously reported as mostly involved in MEC resistance were analysed. The genetic relatedness among isolates was investigated by repetitive element sequence-based PCR (rep-PCR) and multilocus sequence typing (MLST). Ten MEC-R-BL-S isolates were collected, accounting for 0.4% (10/2547) of all E. coli obtained from urine samples, 0.9% (10/1135) of ampicillin-susceptible E. coli isolates and 9.6% (10/104) of MEC-R E. coli isolates. The isolates appeared as small colonies with round morphology and had impaired fitness. The isolates were not clonal and belonged to various extraintestinal or commensal E. coli phylogroups. Mutations in the cysB gene were evidenced in all clinical isolates. In conclusion, microbiologists should be aware of these isolates with a particular susceptibility phenotype, which is not due to error in disk diffusion but is a real non-enzymatic antibiotic resistance pattern.