Vol 59, No 4 (2014)

The wide use of the highly active antiretroviral therapy (HAART) of HIV infection leads to the HIV drug resistance. The simultaneous formation of the resistance to different groups of antiviral drugs compromises the efficacy of HAART. Thus, the problem of the drug resistance becomes of an enormous significance. In this review, a definition of the resistance is given; the problem of the drug-resistant strains transmission is discussed; the assays used for resistance testing are described; recommendations for the antiviral drug-resistance testing are given.

The Syr-Darya valley fever virus (SDVFV) was originally isolated from the blood of the patient with fever in the Kyzylorda province, Kazakhstan, in July 1973 and was classified to the Cardiovirus genus (fam. Picornaviridae). Later, SDVFV was isolated from the ticks Hyalomma as. asiaticum Schulze et Schlottke, 1929 (Hyalomminae) (1 strain) and Dermacentor daghestanicus Olenev, 1929 (Rhipicephalinae) (7 strains), collected in the floodplains of the Syr-Darya river and the ili river. in this paper, complet genome of the SDVFV (strain LEIV-Tur2833) was sequenced using the next-generation sequencing approach (GenBank ID: KJ191558). It was demonstrated that, phylogenetically, the SDVFV is closely related closest to the Theiler’s murine encephalomyelitis virus (TMEV) and Vilyuisk human encephalomyelitis virus (VMEV). The similarity of the sDVFV with VHEV and TMEV based on P1 region of the polyprotein-precursor (structural proteins VP1-VP4), reaches 75% and 91% for nucleotide sequences and 80% and 93% for putative amino acid sequences, respectively. For nonstructural proteins regions P2 (2A-2C) and P3 (3A-3D) similarity of SDVFV with TMEV and VHEV is 96%-98%.

Near full-genome sequence of the Wad Medani Virus (WMV) (strain LEIV-8066Tur) (Orbivirus, Reoviridae) isolated from the ticks Hyalomma asiaticum Schulze et Schlottke, 1929, collected from sheep in Baharly district in Turkmenistan, was determined using next generation sequencing approach. The similarity of the RNA-dependent RNA-polymerase (Pol, VP1) amino acid sequence between WMV and the Kemerovo group orbiviruses (KEMV), as well as of the Baku virus (BAKV), was 64%. The similarity of the conserved structural protein VP3 (T2) of WMV with mosquito-borne and tick-borne orbiviruses reaches 46% and 67%, respectively. For the surface proteins VP2, VP5, and VP7 (T13), which have major antigenic determinants of orbiviruses, the similarity of WMV with tick-borne orbiviruses (KEMV and BAKV) is 26-30%, 45% and, 57%, respectively (ID GenBank: KJ425426-35).

Antiherpetic activity of the double and triple combinations, including original connections 15Lys-bis-Nt and phosphate of acycloguanosine (P-ACG), was studied in vitro. For the first time, it was demonstrated that in case of their combined use with known antiherpetic agents, whose activity does not depend on TK of HSV (PFA, AraA, CDV, Rib, GLN, a-IFN), synergistic or additive effects of interaction was observed. The antiviral effect of the tested combinations was studied on the model of ACG-resistant viral strain. The tested combinations could be of interest for practical medicine.

The results of experimental infection of seronegative calves with three non-cytopathogenic (NCP) isolates of BVDV isolated from cattle with different clinical manifestations of the disease belonging to genotype 1 (subgenotype 1a, 1b and 1d) are presented. All tested isolates showed the virulence for seronegative calves 4 to 6 months of age. Belonging to biotype did not correlate with the ability of the virus to infect the lymphoid tissues and to induce leukopenia. All isolates of the virus led to “transiting” leukopenia (up to 2880-3800 kl/mm3) for 8-10 days after infection. Isolate cluster 1d was more virulent and caused the development of a mild respiratory syndrome and short-term diarrhea. The virulence was “strain-dependent”.