Submitted to: Journal of Proteomics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/10/2011
Publication Date: 9/6/2011
Citation: Skultety, L., Hajduch, M., Flores-Ramirez, G., Miernyk, J.A., Ciampor, F., Toman, R., Sekeyova, Z. 2011. Proteomic comparison of phase I and II coxiella burnetii cells reveals potential virulence biomarkers. Journal of Proteomics. 74(10):1974-1984. Interpretive Summary: Bacteria were grown under specific conditions so that they could be distinguished as human disease-causing or not. The appearance of the surface of the strain that did not cause disease looked different from that of the disease-causing strain. The results from chemical identification of the major proteins from both strains indicated that some enzymes responsible for forming sugars necessary for formation of the cell wall were not present in the non-disease causing bacteria. It was concluded that there is a direct link between the proteins responsible for making certain cell wall sugars and the ability of bacteria to cause disease. This information will be useful to researchers in their efforts to improve animal health and agricultural production through both classical breeding and application of biotechnology-based strategies.
Technical Abstract: Coxiella burnetii, a category B biological warfare agent, causes several worldwide outbreaks of zoonotic disease each year. In order to identify C. burnetii virulence factors, the virulent phase I and avirulent phase II variants of the Nine Mile RSA strains, were propagated in embryonated hen eggs and then purified by centrifugation through Renografin gradients. Total protein fractions were isolated from each bacterial phase and subjected to analysis by one-dimensional electrophoresis plus tandem mass spectrometry. A total of 235 and 215 unique proteins were identified from the phase I and II cells, respectively. Many of these proteins had not been reported in previous proteomic studies of C. burnetii. The newly identified proteins are potential disease markers, and could provide additional insight into the pathogenesis of Q fever. Most of the proteins identified are involved in metabolism and biosynthesis. Forty-four of the proteins have been annotated as having distinct roles in the survival, pathogenesis, and virulence of C. burnetii within the harsh phagolysosomal environment. We propose that nine of these proteins that are associated with lipopolysaccharide biosynthesis and metabolism, and that are uniquely present in phase I cells, are virulence factors.