Phenotypic and genotypic heterogeneity of 8 new human Coxiella burnetti isolates.

Eight new strains of Coxiella burnetii were isolated from chronic Q fever patients using centrifugationashell vial technique. Seven patients had endocarditis (including one patient with an immunodeficiency syndrome), and one had a vascular prosthesis infection. Three prototype strains, Nine Mile phase II, Q212 and Priscilla and eight new isolates were cultured in L 929 cells. Heterogeneity of their cytopathic effect was observed. DNAs of the eleven strains have been isolated and purified by standard procedures. Plasmid DNA was separated from chromosomal DNA by a low melting point gel. Electrophoresis in agarose gel showed that seven of the eight new strains had plasmids which were about 40 kb (plasmid V517 was used as size marker). Endonuclease-restriction analysis of the 8 human isolates is currently under investigation.