To assess genetic variability of A H1N1 pan influenza virus (IV) in the course of the epidemic and to detect a set of human nucleotide polymorphisms responsible for a severe course of the disease.
Extraction and purification of viral genomic RNA from the nasopharyngeal smears and genomic human DNA from the leukocytic fraction of venous blood was made in 230 patients from Moscow. Moscow and Sverdlovsk Regions with severe acute respirator, virus infection (ARVI). A flu virus type was established in amplification reaction with on-line detection of the products with application of primers recommended by WHO. Genetic polymorphisms of A H1N1 pan IV and human genes were determined with minisequencing reaction followed by detection of the products of MALDI-time-of-flight mass-spectrometry. Nucleotide sequences of the complete genome were revealed for 15 isolates of A H1N1 pan IV.
A H1N1 IV was identified in 77 cases (46 were pandemic, 31 seasonal). Mutations causing genetically determined resistance to adamants (amantadin, rimantadin) were detected in all 46 samples of genomic RNA of A H1N1 pan IV. Mutation leading to oseltamivir (tamiflu) resistance was found in one sample. It is shown that a severe course of A H1N1 pan IV infection is associated with genotypes predisposing to development of thromboses, bronchopulmonary diseases and hypertention. Genetic tests for prognosis of a complicated course of the flu are proposed. The revealed full-genome sequences of the segments of genomic RNA of 15 A H1N1 pan influenza viruses are deposited in GenBank.
We are the first in Russia to detect a mutant variant of A H1N1 pan IV resistant to oseltamivir We describe a set of nucleotide polymorphisms which determine a complicated course of the flu in patients with identified A H1N1 pan IV.