Vol 55, No 4 (2010)

The paper gives the results of sequence analysis of 150 positive samples in real-time RT-PCR, including 47 autopsy materials from patients (including 10 pregnant women), who died from fatal pneumonia mainly in November-December 2009, in whom the lifetime etiological diagnosis had not been made and hence no early etiotropic therapy performed. 70% of the primary materials from the deceased patients were found to have pandemic influenza A(H1N1) v mutants in the lung tissue with D222G (15%), D222N (15%), D222E (2%) substitutions, as well as a mixture of mutants (38%). Nasopharyngeal lavages from 3 Chukotka deceased patients exhibited only consensus (nonmutant) D222 virus variants; there was a mixture of consensus and mutant virus variants in the trachea and a mixture of mutant ones in the lung. Preliminary data from the study of the interaction of the hemagglutinin of two strains having D222G and D222N mutations with 9 oligosaccharides imitating the variants of cell receptors for influenza A virus suggest that there is a double receptor specificity for α2'-3' and α2'-6'-sialosides with a preponderance of α2'-3'-specificity. Further spread of the mutants that have acquired a high virulence and preserved their capacity for the respiratory route of human infection may lead to the situation similar to that seen in the 1918-1919 pandemic. Another scenario for evolution of the virus is to preserve its receptor specificity for α2'-3'-sialosides and high virulence with losses of α2'-6' specificity and capacity for aerosol transmission, by damping the pandemic.

The present study in BALB/c mice was conducted to compare immunogenicity and protective efficacy of several candidate vaccines based on homologous and heterologous strains after challenge with the highly pathogenic avian influenza strain A/Chicken/Kurgan/3/2005. The experimental vaccine composed of an inactivated split A/Vietnam/1194/2004 (H5N1) strain and a plant derived adjuvant has demonstrated better immunogenic properties versus the variant of the vaccine with aluminum hydroxide. Interestingly, the heterosubtypic H1N1 live attenuated vaccine candidate administered intranasally protected 93% of the subject against their challenge with HPIV H5N1.

Light and immunofluorescence microscopies were used to study the cytopathic effect of herpes simplex virus type 1 (HSV-1) grown on the Vero cell cultures in the absence or presence of supernatants of Enterococcus faecium L3, Lactobacillus plantarum 8A-P3, and Escherichia coli M17. The effect of the probiotic strains was evaluated estimating the proportion of changed cells and the infective dose of the virus. The supernatants of the cultures of Lactobacillus sp. and Enterococcus sp., unlike those of E. coli, have antiviral activity. Inhibited viral replication was more evident when the supernatants were added until the cultured HSV-1 cells were infective. An enterococcal supernatant and its obtained peptide extract showed the maximum antiviral activity. This strain may be associated with the production of bacteriocins and bacteriocin-like substances.

The investigators studied the ability of adult ICR mice (a laboratory model that was most approximated to the wild-type populations of mice) to maintain Ebola virus (EV) reproduction in the organism. The adult ICR mice inoculated with EV during 23 passages were shown to maintain viral reproduction in the liver. The elevated levels of platelets and the early generation of fibrin and fibrinogen degradation products suggested there were hemostatic changes that did not, however, progress to severe coagulopathy. The animals were in appearance apparently, other than adynamia observed on days 5-7. Thus, the susceptibility of the adult ICR mice to EV is characterized by their ability to maintain virus reproduction in the liver without evident signs of the infection. This pattern of susceptibility in the mice shows a possible role of this rodent species in the transmissive cycle of EV.

An indirect ELISA (I-ELISA) has been developed for swine vesicular disease virus-specific antibody detection. The analytic sensitivity of I-ELISA testing of serum samples from experimentally infected pigs with the known VN titer was 2 log2. Its diagnostic specificity was demonstrated as 100% in 4485 swine serum samples from different regions of the Russian Federation.