RESUMO
Nine strains of Serratia rnarcescens were isolated from clinical samples. In the identification, 20 items of biochemical reactions and 124 items of substrate utilization tests have been used. Two strains, which have not been appointed to a biotype of the species, can utilize 3-hydroxybenzoate, 4-hydroxybenzoate or protoeatechuate as sole carbon source for growth. The growth in protocatechuate medium was more rapid as compared with 3 or 4-hydroxybenzoate medium. So, we here suggest that protocatechuate should be included in the substrate utilization for the genus. The other seven strains have been identified as Grimont' s A_2 subphenon of S. marcescens. Pencillin and other wall-acting antibiotics are all resisted by these strains; aminoglycoside antibiotics are almost all effective. Co-trimoxazole and sulfadiazine, though couldn't inhibite the growth of the strains, do inhibite their pigment production.