Genotypic and Phenotypic Study of Antiviral Resistance Mutations in Refractory Cytomegalovirus Infection.

BACKGROUND: This study describes the genotypic and phenotypic characterization of novel human cytomegalovirus (HCMV) genetic variants of a cohort of 94 clinically resistant HCMV patients. METHODS AND RESULTS: Antiviral-resistant mutations were detected in the UL97, UL54, and UL56 target genes of 25 of 94 (26.6%) patients. The genotype-phenotype correlation study resolved the status of 5 uncharacterized UL54 deoxyribonucleic acid polymerase (G441S, A543V, F460S, R512C, A928T) and 2 UL56 terminase (F345L, P800L) mutations found in clinical isolates. A928T conferred high, triple resistance to ganciclovir, foscarnet, and cidofovir, and A543V had 10-fold reduced susceptibility to cidofovir. Viral growth assays showed G441S, A543V, F345L, and P800L impaired viral growth capacities compared with wild-type AD169 HCMV. Three-dimensional modeling predicted A543V and A928T phenotypes but not R512C, reinforcing the need for individual characterization of mutations by recombinant phenotyping. CONCLUSIONS: Extending mutation databases is crucial to optimize treatments and to improve the assessment of patients with resistant/refractory HCMV infection.

Optimization of the molecular diagnosis of the acute hepatitis E virus infection.

To evaluate the diagnostic value of the combination of two broad-range PCR assays targeting two different and conserved regions of the viral genome for the diagnosis of acute Hepatitis E virus (HEV) infection. Patients with acute hepatitis were prospectively recruited. In all, HEV-IgM antibodies were tested together with evaluation of HEV viraemia by two PCR assays (ORF3 and ORF1). The number of individuals exhibiting negative IgM antibody results but carrying viral RNA was calculated by each PCR assay. Four-hundred and seventy individuals were included, of whom 145 (30.8%) were diagnosed as having acute HEV. Of them, 122 (84.1%) exhibited HEV-IgM antibodies, and 81 (55.8%) had detectable viral RNA for at least one PCR. Using the ORF3 molecular assay, 70 (48.3%) individuals were identified with HEV infection. When the ORF1 molecular assay was applied, 49 (33.8%) individuals were identified. The ORF3 assay detected viral RNA in 32 patients not detected by the ORF1 assay. In contrast, the ORF1 assay could amplify viral RNA in 11 patients who were not detected by the ORF3 assay. The parallel use of two broad-range PCR assays significantly increased the performance of the molecular diagnosis of HEV.

Temporal changes in the genotypes of Paslahepevirus balayani in southern Spain and their possible link with changes in pig trade imports.

Introduction: Paslahepevirus balayani (HEV) is an endemic zoonotic disease ranked as a major cause of acute hepatitis in Europe. Most infections occurring in Europe are due to the endemic several subtypes of genotype 3, through the consumption of raw or undercooked pork, observing a genotype geographical distribution pattern among countries Because of global changes in the pig and pork trading markets, subtype distribution might vary. We aimed to evaluate the temporal distribution of HEV genotypes in patients from southern Spain with acute hepatitis to determine whether these changes were related to the pig import trade during the study period between 2018 and 2022. Methods: Prospective longitudinal study including patients with acute hepatitis from southern Spain between 2018 and 2022. HEV RNA and antibodies was tested in all patients. In patients with detectable HEV RNA, genotype was obtained. To determine the number of imported pigs and their origins, we checked the official data from the Spanish statistics on international trade of Spanish Minister of Industry during by country of origin during the same study period. Results: A total of 659 patients with acute hepatitis were included in the study. Among them, 162 (24.5%) had at least one marker (IgM or RNA) of acute HEV infection. Among the 71 patients with detectable viral RNA, genotypes could be obtained for 58 (81.6%). The most prevalent HEV genotype was 3f (n = 48; 78.6%), showing a decreasing prevalence of over time, from 100% in 2018 to 70.6% in 2022. Since 2021, the emergence of other genotypes has been determined. A significant increase in the number of animals imported was observed since the beginning of the study. Denmark experienced a significant rise, from 0.03% in 2018 of total imports to 10.4% in 2022. Conclusions: HEV molecular diversity is changing in Spain, could be linked to changes in fattening pig import origin.