Rapid and correct identification of intestinal Bacteroides spp. with chromosomal DNA probes by whole-cell dot blot hybridization.

A dot blot hybridization procedure with 32P-labeled whole chromosomal DNA of the type strains as probes was developed as a rapid and simple method for identification of intestinal Bacteroides species. Bacterial cells were fixed onto membrane filters by slight suction, treated with 0.5 N NaOH, and hybridized with these probes. Of 65 Bacteroides strains isolated from 19 human fecal specimens, which were identified as B. fragilis, B. thetaiotaomicron, B. ovatus, B. caccae, B. uniformis, B. stercoris, B. vulgatus, B. distasonis, and B. merdae by conventional phenotypic characterization, 62 (95%) were correctly identified with this hybridization procedure.