The authors studied the morpho-biochemical characteristics and antibiotic sensitivity of 19 strains of bacteria isolated from clinical specimens and identifyed as Mima polymorpha var. oxidans, Mima polymorpha and Herellea vaginicola. The biochemical study indicated Herellea vaginicola to be oxidase negative and in complex nitrogenous media effetively utilize glucose, galactose, manose, arabinose, xylose, 10% lactose and irregularly utilize rhamnose and cellobiose; in the synthetic base media the strains produced acid from lactose and have the same sugar oxidations as described before. Mima polymorpha was oxidase-negative and failed to utilize the carbohidrates tested in either the complex nitrogenous media or the synthetic base media. Mima polymorpha var. oxidans was oxidase-positive and failed to utilize the carbohydrates tested. The Herellea vaginicola and Mima polymorpha was very susceptible to gabromycin, knamycin, neomycin, colistin and the former was very sensitive to chloranphenicol and rovamycin. Mima polymorpha var. oxidans presented high sensibility to kanamycin, neomycin, colistin, chloranphenicol and nalidixic acid. With the results obtained by the sensibility of strains to the 1 and 0,1 unity of penicillin by milliliter, it was impossible to separate the oxidase-positive and oxidase-negative strains in discordance with the data obtained by Baumann, Dodoroff & Stanier (1968a).