CHARACTERIZATION OF STREPTOCOCCUS-AGALACTIAE STRAINS BY RANDOMLY AMPLIFIED POLYMORPHIC DNA ANALYSIS

A collection of 54 unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid samples from neonates and 60 unrelated strai ns isolated from carriers that had been previously studied by multiloc us enzyme electrophoresis (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin, Microbiol, 33:2576-2581, 199 5) were characterized by randomly amplified polymorphic DNA (RAPD) ass ay, Four primers, 5'AGGGGGTTCC3', 5'AACGCGCAAC3', 5'GCATCAATCT3', and 5'AGTCGGGTGG3', named OPS16, AP42, A4, and OPS11, respectively, were s elected from 29 primers tested, This investigation identified 71 RAPD types, The three families of strains defined by multilocus enzyme elec trophoresis analysis, which contain most of the cerebrospinal fluid is olates, were also identified by clustering analysis of RAPD data, Each of these three groups exhibits specific RAPD patterns or fragments, T he discriminatory power of the RAPD typing method was also evaluated, The simplest typing scheme was obtained by the combination of RAPD typ ing done with primers AP42 and OPS11 and serotyping (index of discrimi nation, 0.97).