Coxiella burnetii
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ABSTRACT:
PROVIDER: PRJNA109859 | ENA |
REPOSITORIES: ENA
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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 organismâ??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 organismâ??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. Host cell-free growth, Vero cell growth and carryover baseline of Coxiella burnetii
2010-06-20 | E-GEOD-13338 | biostudies-arrayexpress
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.
2009-10-21 | GSE13338 | GEO
Project description:Q fever is a zoonosis caused by Coxiella burnetii, an obligate intracellular bacterium usually found in myeloid cells. The infection is a source of severe obstetrical complications in humans and cattle, and of chronic evolution in pregnant women. As C. burnetii is found in the placenta of aborted foetuses in humans and ruminants, we wondered if it may infect trophoblasts. In this work, we showed that C. burnetii, infected JEG trophoblastic cells without replication and was localized within phagolysosomes. We analyzed gene expression programs induced by C. burnetii in JEG trophoblastic cell line and compared it with transcriptomic program of BeWo trophoblasts in which C. burnetii replicates. These transcriptomic programs induced by C. burnetii in JEG trophoblasts was poor and markedly different from that induced by C. burnetii in BeWo trophoblasts. Hence, the differences in transcriptomic programs may explain the different intracellular fate of C. burnetii in JEG and BeWo cells. Our results suggest that C. burnetii may use trophoblastic cells as a reservoir by interfering with gene expression. Comparaison between unstimulated JEG cell line and Coxiella burnetii stimulated JEG cell line (bacterial ratio 200:1) for 6 hours
2012-12-07 | E-GEOD-30330 | biostudies-arrayexpress
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.
2014-05-25 | GSE46335 | GEO
Project description:Transcriptional profiling of Coxiella burnetii phase I (RSA 493) submitting either to Cold and Heat shock comparing to control untreated Coxiella burnetii phase I (RSA 493) grown at 35°C.
2011-01-01 | GSE21778 | GEO
Project description:Q fever is a zoonosis caused by Coxiella burnetii, an obligate intracellular bacterium usually found in myeloid cells. The infection is a source of severe obstetrical complications in humans and cattle, and of chronic evolution in pregnant women. As C. burnetii is found in the placenta of aborted foetuses in humans and ruminants, we wondered if it may infect trophoblasts. In this work, we showed that C. burnetii, infected JEG trophoblastic cells without replication and was localized within phagolysosomes. We analyzed gene expression programs induced by C. burnetii in JEG trophoblastic cell line and compared it with transcriptomic program of BeWo trophoblasts in which C. burnetii replicates. These transcriptomic programs induced by C. burnetii in JEG trophoblasts was poor and markedly different from that induced by C. burnetii in BeWo trophoblasts. Hence, the differences in transcriptomic programs may explain the different intracellular fate of C. burnetii in JEG and BeWo cells. Our results suggest that C. burnetii may use trophoblastic cells as a reservoir by interfering with gene expression.
2012-12-07 | GSE30330 | GEO
Project description:Q fever is due to Coxiella burnetii, an obligate intracellular bacterium. We investigated the mechanism of establishment of chronic form of the Q fever that mainlym anifested by endocarditis. We showed that patients with acute Q fever and valvulopathy, who have the higher risk to develop an endocarditis, exhibited high levels of circulating apoptotic cells. We further investigated the effect of the uptake of dead cells on the intracellular fate of the bacterium and the immune response of monocytes and macrophages.
2008-10-09 | E-MEXP-1289 | biostudies-arrayexpress
Project description:Coxiella burnetii undergoes a biphasic developmental cycle within its host cell that generates morphologically and physiologically distinct large cell variants (LCV) and small cell variants (SCV). During the lag phase of the C. burnetii growth cycle, non-replicating SCV differentiate into replicating LCV that in turn differentiate back into SCV during stationary phase. Nearly homogeneous SCV are observed in infected Vero cells after extended incubation (21 to 28 days). In the current study, we sought to establish whether C. burnetii developmental transitions in host cells are recapitulated during host cell-free (axenic) growth in first and second generation acidified citrate cysteine media (ACCM-1 and ACCM-2, respectively). We show that ACCM-2 supported developmental transitions and viability. Although ACCM-1 also supported SCV to LCV transition, LCV to SCV transition did not occur after extended incubation (21 days). Instead, C. burnetii exhibited a ghost-like appearance with bacteria containing condensed chromatin but otherwise devoid of cytoplasmic content. This phenotype correlated with a near total loss in viability between 14 and 21 days of cultivation. Transcriptional profiling of C. burnetii following 14 days of incubation revealed elevated expression of oxidative stress genes in ACCM-1 cultivated bacteria. ACCM-2 differs from ACCM-1 by the substitution of methyl-b-cyclodextrin (Mb-CD) for fetal bovine serum. Addition of Mb-CD to ACCM-1 at 7 days post-inoculation rescued C. burnetii viability and lowered expression of oxidative stress genes. Thus, Mb-CD appears to alleviate oxidative stress in ACCM-2 to result in C. burnetii developmental transitions and viability that mimic host cell-cultivated organisms. Axenic cultivation of C. burnetii in ACCM-2 and new methods Coxiella axenic media 1 vs 2
2013-12-02 | E-GEOD-51135 | biostudies-arrayexpress
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. 3T3-L1 (ATCC) differentiated adipocytes were stimulated or not with Coxiella burnetii (NMI) at a ratio of 50 bacteria per cell. Four biological replicates were analyzed in each group. Due to technical reason, one unstimulated sample was discarded from the analysis.
2014-05-25 | E-GEOD-46335 | biostudies-arrayexpress
Project description:Mast cells (MCs) are critical mediators of inflammation; however, their microbicidal activity against invading pathogens remains largely unknown. Here, we describe a nonpreviously reported antibacterial mechanism used by MCs against Coxiella burnetii, the agent of Q fever. We show that C. burnetii interaction with MCs does not result in bacterial uptake but rather induces the formation of extracellular actin filaments named cytonemes. MC cytonemes express cathelicidin and neutrophil elastase and mediate the capture and destruction of entrapped bacteria. We provide evidence that MC cytoneme formation and microbicidal activity are dependent on the cooperation of the scavenger receptor CD36 and Toll-like receptor 4. Taken together, our results suggest that MCs use an extracellular sophisticated mechanism of defense to eliminate intracellular pathogens, such as C. burnetii, before their entry into host cells.
2019-03-13 | GSE111971 | GEO