GENOTYPIC AND PHENOTYPIC RELATEDNESS OF 80 STRAINS OF BRANHAMELLA-CATARRHALIS OF WORLDWIDE ORIGIN

80 clinical Branhamella catarrhalis strains of worldwide origin were e xamined for genotypic relatedness and phenotypic characteristics. Usin g a quantitative bacterial dot method for DNA-DNA hybridization the st rains were found to form a homogeneous group with Delta T-m-values ran ging from 0.0-2.3 degrees C. In Minibact-N, an identification kit for oxidase positive, Gram-nega- tive diplococci using eight phenotypic ch aracteristics, all isolates were correctly identified and also demonst rated complete homogeneity except for beta-lactamase production. Type strains representing the genera Branhamella, Moraxella and Neisseria w ere also examined for comparison. B. catarrhalis strain NCTC 4103-know n to be atypical-had a Delta T-m-value of 5.7 degrees C and produced g amma-glutamylaminopeptidase, in contrast to all other B. catarrhalis s trains. In GN MicroPlateTM, a kit which tests utilizable carbon source s, B. catarrhalis strains were found to be able to utilize up to 16 to 95 carbon sources.