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PubMed1998

Determination of Coxiella burnetii rpoB sequence and its use for phylogenetic analysis.

The nucleotide sequence of the rpoB, encoding the beta-subunit of RNA polymerase of the obligate intracellular bacterium Coxiella burnetii, was determined using a polymerase chain reaction amplification and direct sequencing methodology. Comparison between C. burnetii and other eubacterial rpoB sequences indicated sequence similarity ranging from 53.6% to 67.6%. Coxiella burnetii rpoB consists of 4128 base pairs with a 45.3% GC content encoding 1375 amino acids with a calculated molecular mass of 153.67 kDa. Comparison of 512 bases of the rpoB variable region I, from eight C. burnetii strains isolated from various sources, revealed fewer than four base differences, although the distribution of these did not correlate with previously determined genotypic groupings with the species. Phylogenetic analysis of C. burnetii based on comparison of its rpoB sequence with sequences available for other bacteria is consistent with those previously derived from 16S rRNA gene sequence, and indicate that C. burnetii belongs to the gamma-group of Proteobacteria. Furthermore, phylogeny inferred from comparison of RpoB, or homologous sequences including Archae, Bacteria and Eukarya, concurred with these results.

Coxiella burnetii↗

PubMed1995

Osteoarticular infection due to Coxiella burnetii in children.

We report three cases of chronic osteoarticular infections associated with Q fever in children. In two of them, serologic diagnosis was confirmed by direct immunofluorescence of Coxiella burnetii in the synovial and bone biopsy specimen. We suspect that bone infections due to Coxiella burnetii could be underdiagnosed because this etiology is not frequently seen.

Abscess↗

PubMed1991

[Enzootic abortion in a goat herd, caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Case report].

We report on an outbreak of enzootic abortion in a herd of goats with high losses caused by mixed infection with Coxiella burnetii and Chlamydia psittaci. Both agents could be detected by microscopic investigation of smears from afterbirths by Giménez staining and by a capture enzyme-linked immunofluorescence assay (Capture ELIFA). Additionally, Coxiella burnetii was isolated from the same tissues in BGM cell cultures. Serological investigations with CF, indirect ELIFA, and IF tests revealed high antibody titers against both agents in most animals. Coxiella antigen was still detected 91 days later in milk samples of two infected goats by Capture ELIFA.

Abortion, Veterinary↗

PubMed2004

[Coxiella burnetii as zoonotic pathogen with special regard to food hygiene].

In Hesse, Germany, bulk milk of farms producing raw milk cheese is examined by PCR for Coxiella burnetii yearly. In 2003 the pathogen has been detected unusually frequent. By means of two examples the hygienic measures are shown, which were initiated by the veterinary administration. To detect Coxiella burnetii means always the preoccupation with unsolved questions. It is particularly uncertain, whether there is a risk of oral infection for the human being. From the point of view of food hygiene, surveys are needed urgently to work out a risk assessment. Based on this a uniform risk management and a reasonable risk communication can be fixed.

Animals↗

PubMed2004

Use of monoclonal antibodies for analyses of Coxiella burnetii major antigens.

Monoclonal antibodies (MAbs) to major antigens of Coxiella burnetii were produced. Some of the MAbs to a 62-kDa protein antigen, peptidoglycan protein complex and lipopolysaccharide (LPS) O-chains reacted with other bacteria whereas none of the MAbs to outer membrane proteins and LPS outer-core did. The LPS outer-core and OMPs may be useful antigens for specifically detecting antibodies to C. burnetii.

Antibodies, Bacterial↗

PubMed1983

Comparison of the ultrastructure of small dense forms of chlamydiae and Coxiella burnetii.

In the course of passaging of Coxiella burnetii (C.b.) in Alveonasus lahorensis ticks, the haemocytes contained cell forms with electrondense cytoplasm, intracytoplasmic lamellar membranes, and a peculiar limiting membrane--25 to 30 nm thick "envelope complex". Similar small forms occurred when C.b. had been cultured in the yolk sack of chick embryos. The dense forms of C.b. were similar to those of Rickettsiella cells. Dense forms (elementary bodies) surrounded by an "envelope complex" were found also in some chlamydiae cultured in yolk sacs of chick embryos.

Animals↗

PubMedDate not supplied

Steroids treatment of granulomatous hepatitis complicating Coxiella burnetii acute infection.

Granulomatous hepatitis associated with Coxiella burnetii acute infection has an adverse clinical course in some patients. Surprisingly, it does not respond to antibiotic but to steroids treatment. A hypersensitivity mechanism has been implicated. A case of granulomatous hepatitis complicating C. burnetii acute infection is reported, which was refractory to antibiotics but, as in four other cases previously reported, showed a complete response to steroids. This case was found to support findings that moderate doses of steroids can be useful in patients with granulomatous hepatitis complicating C. burnetii infection and showing no response to antibiotic treatment.

Acute Disease↗

PubMed2006

Role for the CD28 molecule in the control of Coxiella burnetii infection.

Q fever is an infectious disease caused by Coxiella burnetii, an obligate intracellular bacterium that replicates in macrophages. As cell-mediated immune response to microbial pathogens requires signals mediated by T-cell receptors and costimulatory molecules such as CD28, we wondered if CD28 is involved in protection against C. burnetii infection. CD28-deficient (CD28-/-) mice were inoculated with C. burnetii by intraperitoneal and intravenous routes. With both wild-type and CD28-/- mice, C. burnetii organisms were detected exclusively in spleen and liver. The antibody response against C. burnetii was impaired in CD28-/- animals, but, surprisingly, the lack of CD28 decreased C. burnetii burden in the infected tissues, whatever the manner of inoculation of bacteria. The CD28 deficiency had no effect on either granuloma formation, which reflects cell-mediated immunity against C. burnetii, or the production of gamma interferon and tumor necrosis factor, two cytokines known to be involved in granuloma formation. On the other hand, the production of interleukin-10 (IL-10) by peritoneal macrophages was highly impaired in CD28-/- mice. The results suggest that CD28 initiates a signal that favors C. burnetii replication through the modulation of the IL-10 pathway.

Animals↗

PubMed1998

Coxiella burnetii induces reorganization of the actin cytoskeleton in human monocytes.

Coxiella burnetii, an obligate intracellular bacterium which survives in myeloid cells, causes Q fever in humans. We previously demonstrated that virulent C. burnetii organisms are poorly internalized by monocytes compared to avirulent variants. We hypothesized that a differential mobilization of the actin cytoskeleton may account for this distinct phagocytic behavior. Scanning electron microscopy demonstrated that virulent C. burnetii stimulated profound and polymorphic changes in the morphology of THP-1 monocytes, consisting of membrane protrusions and polarized projections. These changes were transient, requiring 5 min to reach their maximum extent and vanishing after 60 min of incubation. In contrast, avirulent variants of C. burnetii did not induce any significant changes in cell morphology. The distribution of filamentous actin (F-actin) was then studied with a specific probe, bodipy phallacidin. Virulent C. burnetii induced a profound and transient reorganization of F-actin, accompanied by an increase in the F-actin content of THP-1 cells. F-actin was colocalized with myosin in cell protrusions, suggesting that actin polymerization and the tension of actin-myosin filaments play a role in C. burnetii-induced morphological changes. In addition, contact between the cell and the bacterium seems to be necessary to induce cytoskeleton reorganization. Bacterial supernatants did not stimulate actin remodeling, and virulent C. burnetii organisms were found in close apposition with F-actin protrusions. The manipulation of the actin cytoskeleton by C. burnetii may therefore play a critical role in the internalization strategy of this bacterium.

Actins↗

PubMed1963

CONVERSION OF THE PHASE I ANTIGEN OF COXIELLA BURNETII TO HAPTEN BY PHENOL TREATMENT.

Anacker, R. L. (Rocky Mountain Laboratory, Hamilton, Mont.), W. T. Haskins, D. B. Lackman, E. Ribi, and E. G. Pickens. Conversion of the phase I antigen of Coxiella burnetii to hapten by phenol treatment. J. Bacteriol. 85:1165-1170. 1963.-Trichloroacetic acid extracts of Coxiella burnetii are converted to hapten by treatment with phenol. Such extracts react, like the original trichloroacetic acid extract, at high dilution in the complement-fixation test and produce zones of precipitate with specific antibody in gel diffusion tests; but, unlike the parent extract, injection of the phenol-treated extract neither induces resistance to challenge in guinea pigs nor antibody formation in guinea pigs, rabbits, or mice. This loss of antigenicity is correlated with removal of protein from the original product.

Animals↗

PubMed1996

A developmental stage-specific histone H1 homolog of Coxiella burnetii.

Two DNA-binding proteins have been detected in Coxiella burnetii by southwestern (DNA-protein) blotting. One of these, termed Hq1, is enriched in the small cell variant stage of the developmental cycle and displays compositional and primary amino acid sequence similarities to eukaryotic histone H1. C. burnetii appears to be another example of an intracellular parasite with morphologically distinct developmental forms whose nucleoid structure may be controlled by histone H1 homologs.

Amino Acid Sequence↗

PubMed1998

Immunological consequences of Coxiella burnetii phase variation.

The influence of the number of passages in chick embryo yolk sac (EPs) on the properties of the lipopolysaccharide (LPS) and other antigens of Coxiella burnetii Priscilla strain in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS-PAGE), immunoblot analysis, enzyme-linked immunosorbent assay (ELISA) and complement-fixation reaction (CFR) test has been studied. Three phases in the phase variation of Coxiella burnetii could be distinguished by these methods: phase I lasting up to the 20th passage (EP 20), intermediate phase corresponding to EP 20-EP 70, and phase II beginning at EP 80. The changes in LPS were more marked than those in proteins which conserved their immunoblot profile up to EP 80. The phase II was clearly demonstrated by all the methods used.

Animals↗

PubMed1992

Molecular characterization of cloned variants of Coxiella burnetii isolated in China.

To study the molecular properties of Coxiella burnetii phase variants we cloned the phase variants of C. burnetii Qiyi (CBQY) strain by the red plaque technique. Three cloned strains, CBQYIC3 (phase I), CBQYIIC7 (phase II) and CBQYIIC5 (semirough-phase) were analysed by SDS-PAGE, immunoblot assay, plasmid isolation and agarose gel electrophoresis of DNA restriction fragments. The results suggest that the unique phase-dependent substance is a lipopolysaccharide and that most protein components of phase I and phase II cells are shared. No significant differences of DNA restriction fragments were found between clonal isolates of phase I and phase II C. burnetii CBQY strains. A plasmid of approximately 56 Kb was isolated from both phase I and phase II variants indicating that phase variation probably could not be attributed to its presence or absence.

Bacterial Proteins↗

PubMedDate not supplied

Isolation of Coxiella burnetii from bull semen.

Previous observations on the dissemination of Coxiella burnetii between laboratory animals strongly support the hypothesis of venereal transmission. Serum and semen samples, from 57 bulls used for artificial insemination, were assayed for specific C. burnetii phase II antibodies and the presence of the organism respectively. Viable C. burnetii were detected in the semen of seropositive bulls. These findings indicate the possibility of sexual transmission of C. burnetii between cattle and further our knowledge of the epidemiology of the organism. The procedures used for investigations into the source of infection and route of tran-mission should be modified to take these findings into account.

Animals↗

PubMed1964

ELECTRON MICROSCOPIC OBSERVATIONS OF THE DEVELOPMENT OF COXIELLA BURNETII IN THE CHICK YOLK SAC.

Anacker, R. L. (Rocky Mountain Laboratory, Hamilton, Mont.), K. Fukushi, E. G. Pickens, and D. B. Lackman. Electron microscopic observations of the development of Coxiella burnetii in the chick yolk sac. J. Bacteriol. 88:1130-1138. 1964.-Yolk sac material, obtained daily over a period of 1 week from embryos inoculated with seed of phase I Coxiella burnetii strain Ohio 314 containing 250 units of penicillin, was examined by electron microscopy and other techniques for the presence of rickettsiae. The concentration of rickettsiae in the yolk sac, as determined by electron microscopy, light microscopy, the complement-fixation test, recovery of organisms, and mouse infectivity, was low for the first 3 days, increased rapidly 3 to 5 days after infection, and then remained relatively constant. Rickettsiae in 3- to 7-day cultures, when observed by electron microscopy, had dense fibrillar centers surrounded by less-dense cytoplasmic material containing granules approximately 15 mmu in diameter. The whole was enclosed by multiple external layers. Many appeared to be in various stages of binary fission, and one form which contained a cross-wall was observed. These forms readily combined with ferritin-labeled specific antibody. In rare instances, several kinds of "atypical" forms which did not combine with ferritin-labeled antibody were found in the cytoplasm of yolk-sac cells 4 to 5 days after inoculation; it is not certain whether these forms are artifacts or normal stages in the maturation of C. burnetii. These atypical forms were not observed in subsequent experiments in which embryonated eggs were inoculated with doses of penicillin varying from 0 to 4,000 units per egg.

Animals↗

PubMedDate not supplied

[Survival of Coxiella burnetii in soil].

For the first time the survival of Coxiella burnetii of five types in soils has been studied. The survival of C. burnetii has been found to depend on the content of organic substances in black earth, as well as soil temperature. The method for the prevention of an epidemic outbreak of Q fever directly under the natural conditions has been proposed.

Animals↗

PubMed1989

[Methods of isolating phospholipids from Coxiella burnetii].

Phospholipids are a part of the outside membrane of Coxiella burnetii (or other gram negative bacteria). It is possible to extract them with a mixture of chloroform-methanol (CM). For extraction of phospholipids from C. burnetii it is important to take account of temperature, proportion of CM, and reaction time. The best results are obtained at CM 2:1, at boiling point of this mixture and reaction time of 2 hours. Longer reaction time does not influence the reaction, the additional amounts of phospholipids can be extracted only with fresh solvent mixture.

Chromatography, Thin Layer↗

PubMed2004

A growth study of Coxiella burnetii Nine Mile Phase I and Phase II in fibroblasts.

Coxiella burnetii, a slow-growing, gram-negative, obligate intracellular bacterium, is the causative agent of Q fever in humans. The avirulent Phase II C. burnetii Nine Mile strain can invade and establish persistent infections in a wide variety of laboratory cell lines, and is generally considered to be easier to grow in culture than the wild-type Phase I organism. Efforts to improve Phase I organism yield in the BHK-21 cell line demonstrated that high CO2 conditions and the use of Dulbecco's modified Eagle's medium (DMEM) with 4.5 g/l glucose supplementation resulted in higher organism yields. Phase II organisms grown in the same cell line and conditions showed lower growth rates. Analysis revealed that increased average numbers of C. burnetii Phase I organisms within fibroblasts was due to higher growth rates within the hosts rather than to increased uptake or to increased cell-to-cell spreading. Addition of the nucleoside cytidine to the growth medium stimulated growth of Phase II but not Phase I organisms.

Animals↗