Evolutionary characterization of recent human H3N2 influenza A isolates from Japan and China: novel changes in the receptor binding domain

Summary Recent human H3N2 influenza viruses isolated in Japan and China were characterised from an evolutionary point of view. They appeared to have divided into three minor branch clusters, including 1992–1993, 1993–1994 and 1994–1995 isolates. It was of particular interest to reveal that in addition to amino acid substitutions in the antigenic sites of the HA molecule, amino acid changes occurred at position 226 of the receptor binding site from lysine or glutamine to isoleucine in all strains belonging to the 1994–1995 branch cluster. This is the first evidence of human H3N2 influenza isolates, or any other influenza HA serotypes, to contain a conserved amino acid residue other than lysine or glutamine at this key position.     

广东伤寒菌株的Vi Ⅱ噬菌体型别与药物敏感性监测

对从广东省收集的72株伤寒杆菌进行Vi Ⅱ噬菌体分型及药物敏感性测定,结果表明能明确定型的为62株(86.1%)。噬菌体分型以M₁(41.9%)、E₁(30.6%)和A(19.4%)为常见菌型。72株地方株与国家参考标准株一样,对氯霉素、庆大霉素、新霉素和多粘菌素B 100%敏感,而对另14种常用抗菌药物,则有不同程度的敏感或耐药。今昔菌株药敏特性无大变化,氯霉素等仍可作为治疗常选药物。