Proteomic comparison of virulent phase I and avirulent phase II of Coxiella burnetii, the causative agent of Q fever

• Published in: Journal of proteomics 2011-09, Vol.74 (10), p.1974-1984
• Main Authors: Skultety, Ludovit, Hajduch, Martin, Flores-Ramirez, Gabriela, Miernyk, Ján A., Ciampor, Fedor, Toman, Rudolf, Sekeyova, Zuzana
• Format: Article
• Language: English
• Subjects: Bacterial diseases; Biological and medical sciences; biological warfare agents; Centrifugation; Coxiella burnetii; Diverse techniques; Eggs; Electrophoresis; Enzymes; Extracellular matrix; Fundamental and applied biological sciences. Psychology; Human bacterial diseases; Infectious diseases; LC–MS/MS; Lipopolysaccharides; Mass spectroscopy; Medical sciences; Metabolism; Molecular and cellular biology; Phase variants; Proteomics; Q fever; Rickettsial diseases; Tropical bacterial diseases; Virulence-associated proteins
• ISSN: 1874-3919
• DOI: 10.1016/j.jprot.2011.05.017

Coxiella burnetii, a category B biological warfare agent, causes multiple outbreaks of the zoonotic disease Q fever world-wide, each year. The virulent phase I and avirulent phase II variants of the Nine Mile RSA 493 and 439 strains of C. burnetii were propagated in embryonated hen eggs and then purified by centrifugation through Renografin gradients. Total protein fractions were isolated from each phase and subjected to analysis by one-dimensional electrophoresis plus tandem mass spectrometry. A total of 235 and 215 non-redundant proteins were unambiguously identified from the phase I and II cells, respectively. Many of these proteins had not been previously reported in proteomic studies of C. burnetii. The newly identified proteins should provide additional insight into the pathogenesis of Q fever. Several of the identified proteins are involved in the biosynthesis and metabolism of components of the extracellular matrix. Forty-four of the proteins have been annotated as having distinct roles in the pathogenesis or survival of C. burnetii within the harsh phagolysosomal environment. We propose that nine enzymes specifically involved with lipopolysaccharide biosynthesis and metabolism, and that are distinctively present in phase I cells, are virulence-associated proteins. [Display omitted] ► A total of 235 and 215 non-redundant proteins were unambiguously identified from the phase I and II cells of C. burnetii. ► We have employed bioinformatic interpretation to annotate the function of nearly 300 non-redundant proteins from C. burnetii. ► We suggest that 77 of the proteins are important in virulence, pathogenesis, or survival in the phagolysosome. ► We propose that seven enzymes involved in the synthesis/modification of the LPS I biomarker are virulence-related proteins.