GENOTYPIC AND PHENOTYPIC CHARACTERIZATION OF 2 SWEDISH ISOLATES AND 2PROTOTYPIC STRAINS OF COXIELLA-BURNETII

Two Swedish isolates of Coxiella burnetii and the two prototype strain s of the species, Nine Mile and Priscilla, were characterized with reg ard to their multiplication and cytopathic effect on BGM cells and by PCR-based amplification of repetitive element DNA and the C. burnetii- specific plasmids QpH1 and QpRS. Moreover, 1330 bp of each 16S rRNA ge ne were sequence-determined. All four strains multiplied at virtually the same rate and displayed the same type of vacuoles in the BGM cells . Genetic homogeneity was observed inasmuch as the 16S rDNA sequences were identical and the strains showed identical PCR amplification patt erns using primers specific to enterobacterial repetitive intragenic c onsensus DNA sequences. The two Swedish strains and the Priscilla stra in also showed identical patterns after PCR amplification of repetitiv e extragenic palindromic DNA sequences, whereas the Nine Mile strain d emonstrated a similar, but nor identical pattern. Thus, the investigat ed strains demonstrated very similar phenotypic and genotypic characte ristics. This finding is discussed in view of the very rare occurrence of domestic Q fever in Sweden. (C) 1998 Federation of European Microb iological Societies. Published by Elsevier Science B.V.