Although the hypothesis of transmission of Q fever by tick bite still remains controversial, to further study this point is of interest. Acknowledgements We thank Dr. Marco Quevedo, from the Institute of Virology, Bratislava, Slovakia, and Dra. Fatima Bacelar from the Centro de Estudos de Vectores y Doenças Infecciosas, Aguas de Moura, Portugal, for their help in setting up the culture method for C. burnetii, and Aleida Villa, from EXOPOL, Zaragoza, Spain, for providing local

strains from livestock. We are grateful to COST action B28 C05.0103 “Array technologies for BSL3 and BSL4 pathogens” FG-4592 manufacturer for providing a platform of cooperation and for the exchanging of bacterial strains with other European Doxorubicin mouse laboratories, specifically with the Bundeswehr Institute of Microbiology, Munich, Germany (Dr. Dimitrios Frangoulidis) and the Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia (Dr. Rudolf Toman). Grant support for this work was from FIS PI10/00165, FUNCIS 26/03 from the Gobierno de Canarias “Diagnóstico directo de rickettsiosis prevalentes en nuestro medio (fiebre Q y tifus murino)”, from the “Departamento de Agricultura y Pesca, Gobierno Vasco” “Ensayo de control de la fiebre Q

en la cabaña ovina lechera de la CAPV”, INIA FAU2006-00002-C04-01 to -04 “Ecología y control de la fiebre Q: Epidemiología molecular de Coxiella burnetii”, and AGL2010-21273-C03-01-GAN from CICYT “Interacciones-inmuno endocrinas materno-fetal y con Coxiella burnetii en vacas lecheras de alta producción”.

Electronic supplementary material Additional file 1: Table S1. Samples and reference isolates used in the study. (DOC 214 KB) Additional file 2: Table S2. Oligonucleotides used in the study. (DOC 52 KB) References 1. Raoult D, Marrie TJ, Mege JL: Natural history and pathophysiology of Q fever. Lancet Infect Dis 2005, 5:219–226.PubMedCrossRef 2. Rotz LD, Khan AS, Lillibridge SR, Ostroff SM, Hughes JM: Public health assessment of potential biological terrorism agent. Emerg Infect Dis 2002, 8:225–230.PubMedCrossRef 3. Minnick MF, ever Heinzen RA, Reschke DK, Frazier ME, Mallavia LP: A plasmid-encoded surface protein found in chronic-disease isolates of Coxiella burnetti. Infect Immun 1991, 59:4735–4739.PubMed 4. Samuels JE, Frazier ME, Mallavia LP: Correlation of plasmid type and disease caused by Coxiella burnetii. Infect Immun 1985, 49:775–779. 5. Stein A, Raoult D: Lack of pathotype specific gene in human Coxiella burnetii isolates. Microb Pathog 1993, 15:177–185.PubMedCrossRef 6. Nguyen SV, Hirai K: Differentiation of Coxiella burnetii isolates by sequence determination and PCR-restriction fragment length polymorphism analysis of isocitrate dehydrogenase gene. FEMS Microbiol Lett 1999, 180:249–254.PubMedCrossRef 7.