We have classified 686 strains of methicillin-resistant Staphylococcus aureus(MRSA) which were isolated from clinical specimens at Shinshu University Hospital between October 1991 and October 1993, by phage-typing system for the purpose of epidemiological investigation. Phage-typing was determined by using the international set of phages. The majority (429 strains : 62.5%) of the strains were non-typable, and typable strains were consisted of 170 mixed group strains (24.8%), 30 group V strains (4.4%), 25 group I strains (3.6%), 24 group III strains (3.5%), and 8 miscellaneous group strains (1.2%). The strains, assigned to group I, were lysed with phage 29 or 80. In particular, all strains of group V were lysed with only phase 94 and the strains of miscellaneous group were lysed with phage 95 alone, respectively. Moreover, the strains, assigned to mixed group, were found to be classified into three different lytic groups. The first lytic group involving 125 strains were lysed with phages including phages 29, 52, 71, 83A, 84, 96, and/or 95. Thirty-eight strains of the second lytic group were lysed with phages including phages 80, 3A, 3C, 6, 42E, 47, 54, 75, 94, and/or 81. The third lytic group comprising 7 strains were sensitive to phages that lysed the strains of both the first and second lytic groups.
メチシリン耐性黄色ブドウ球菌(MRSA)のファージ型による疫学的調査
