Project description:Genotyping based on genomic comparative hybridization of different isolates of coxiella burnetii compared to NMI reference strain Two-condition experiment, NMI vs. isolates. One replicate per isolate.
Project description:Coxiella burnetii, the agent of Q fever, persists in humans despite specific immune responses: however, its reservoir remains unknown. We detected C. burnetii in adipose tissue from BALB/c and C57/BL6 mice 4 months after infection when no bacteria were found in other tissues. C. burnetii infected cultivated adipocytes, replicated within late phagosomes and induced a transcriptional program that was enriched for the expression of genes associated with inflammatory response, hormonal responses and cytoskeleton.
Project description:The inability to propagate obligate intracellular pathogens under axenic (host cell-free) culture conditions imposes severe experimental constraints that have negatively impacted progress in understanding pathogen virulence and disease mechanisms. Coxiella burnetii, the causative agent of human Q (Query) fever, is an obligate intracellular bacterial pathogen that replicates exclusively in an acidified, lysosome-like vacuole. To define conditions that support C. burnetii growth, we systematically evaluated the organism’s metabolic requirements using expression microarrays, genomic reconstruction, and metabolite typing. This led to development of a complex nutrient medium that supported substantial growth (~ 3 log10) of C. burnetii in a 2.5% oxygen environment. Importantly, axenically grown C. burnetii were highly infectious for Vero cells and exhibited developmental forms characteristic of in vivo grown organisms. Axenic cultivation of C. burnetii will facilitate studies of the organism’s pathogenesis and genetics, and aid development of Q fever preventatives such as an effective subunit vaccine. Furthermore, the systematic approach used here may be broadly applicable to development of axenic media that support growth of other medically important obligate intracellular pathogens.
