GENOTYPIC CHARACTERIZATION OF RICKETTSIAE DNA PROBES GENERATED FROM RICKETTSIA-PROWAZEKII DNA

Southern blot analysis of HindIII-cleaved rickettsial DNA was used for genotypic characterization of the typhus group (TG) species (R. prowa zekii, R. typhi, R. canada) and a few species of the spotted fever gro up (SFG) rickettsiae (R. sibirica, R. conorii, R. akari). Four differe nt DNA probes were employed. PBH11 and PBH13 probes were morphospecifi c HindIII fragments of R. prowazekii DNA. MW218 probe contained the ge ne for 51 K antigen and MW264 probe contained the citrate synthase gen e of R. prowazekii. All the probes hybridized with the tested TG and S FG rickettsial DNAs, forming from 1 to 5 bands, but they did not with R. tsutsugamushi or C. burnetii DNAs. All the probes demonstrated spec ific hybridization patterns with TG species and R. akari. PBH11, PBH13 and MW264 probes clearly distinguished R sibirica and R. conorii from the other tested rickettsiae, but not from each other. However, these two species differed slightly with MW218 probe. Several strains of ea ch species were analyzed in this way and except for strains of R. cono rii identical intraspecies patterns were obtained. These data lead us to consider the obtained hybridization patterns as criteria for genoty pic identification.