[O-serotypes, biotypes, and antimicrobial susceptibility of Serratia marcescens isolates from clinical specimens: 3rd...

O-serotypes, biotypes, and drug resistance of Serratia marcescens strains isolated from various clinical specimens in Showa University Fujigaoka Hospital were investigated: period I (1979. 1-1982.3), 122 strains; period II (1983. 1-1985. 3), 198; period III (1985. 4-198. 3), 129; period IV (1989. 1-1991. 3), 99. The frequency of serotype O 3 was higher than those of the other serotypes after the period II and ranged 17 to 37%. The isolation frequency (27%) of serotype O 4 was higher than those of other serotypes in the period I. However, this frequency decreased in the period II to III and, in the period IV (10%), was higher than in the period III. The isolation frequency of serotype O 17 suddenly increased in the period II (27%) alone, and 42% of the biotypes, obtained with API 20E, showed 5305701. The isolation frequency of non-typable strains ranged 9 to 14% through all periods. The group including 5317721 and 5307721 clustered by the furthest neighbor method, more frequently appeared through all periods. The former code of urease positive more frequently appeared in the period II to IV. The isolation frequency of the latter code of urease negative reduced to a minimum (18%) in period II, though it increased in the period II to IV. The isolation frequency (22%) of the pigmented strains in the period IV increased much higher than in the period I to III (ranged 2 to 4%). The frequency of the pigmented strains of serotype O 3, not belonged to the Grimont's biotype, was 27% of all pigmented strains isolated in the period IV.(ABSTRACT TRUNCATED AT 250 WORDS)