[The isolation and study of the properties of current influenza A viruses (H1N1) with a natural resistance to remantadine].

Studies of influenza A viruses (H1N1) isolated in 1985-1988 revealed 4 strains with natural resistance to chemical drugs (remantadine, adapromine, deitiforin). Three of them were isolated in Mongolia (A/Mongolia/230/85, A/Mongolia/231/85, and A/Mongolia/128/86) and one in the USSR (A/Moscow/771/88). These strains differed from other isolates by the following features: (i) antigenic remoteness from reference A/Chile/1/83 and A/Taiwan/1/86; (ii) similarity in antigenic specificity with A/Khabarovsk/74/77; (iii) resistance to chemical drugs; (iv) high electrophoretic mobility of genes M and NS in PAG. The possible origin of these strains is discussed.