Is plasmid based differentiation of Coxiella burnetii in 'acute' and 'chronic' isolates still valid?

Ten human Coxiella burnetii isolates from french patients with acute hepatitis or chronic endocarditis were characterized according to their polymorphism in DNA restriction patterns and differentiated by plasmid-specific PCR. The aim of this investigation was to clarify if the present classification of so called 'acute' and 'chronic' Coxiella burnetii isolates--based on plasmid profile of a so far limited number of partly ancient isolates--could be confirmed with lately isolated organisms of this agent. The data obtained in this investigation indicate that this classification based on C. burnetii plasmid content is no longer justified.