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PubMed1979

Resistance to Babesia spp. and Plasmodium sp. in mice pretreated with an extract of Coxiella burnetii.

Mice injected intravenously with a commercially available extract of Coxiella burnetii prepared for use as the antigen in the complement fixation diagnostic test for Q fever were subsequently resistant to infection with Babesia microti, Babesia rodhaini, and Plasmodium vinckei petteri. The parasites appeared to die inside circulating erythrocytes. Protection was unaffected by exposing the pretreated mice to 900 rads on the day before they were infected. To explain these findings, it is postulated that pretreatment with Coxiella extract protects by potentiating the interferon-inducing capacity of the challenge dose of protozoa, which perhaps leads to enhanced of natural killer cells. Tumor necrosis factor also warrants investigation.

Animals↗

PubMed1982

Different sugar compositions of lipopolysaccharides isolated from phase I and pure phase II cells of Coxiella burnetii.

The compositions of lipopolysaccharides I and II, isolated from Coxiella burnetii phase I and pure phase II cells, respectively, showed drastic and clear-cut differences. Lipopolysaccharide II exhibited a comparatively simple composition. It contained, in addition to glucosamine (from lipid A) and a 2-keto-3-deoxyoctulosonic acid-related, thiobarbituric acid-positive substance, only two aldoses in high amounts, namely D-mannose and D-glycero-D-mannoheptose. Lipopolysaccharide I contained the same components, but it also contained at least eight other constituents including neutral sugars, e.g., an unusual branched sugar (3-C-methyl-6-deoxy-hexose) and unusual aminohexoses. Some components were characterized by a very high retention time in gas-liquid chromatography. The similarity of the phase variation in C. burnetii to the well-known smooth-to-rough mutation found in Enterobacteriaceae is discussed. Cells of phase I correspond to enterobacterial smooth forms, whereas cells of phase II might be compared to the rough forms.

Amino Sugars↗

PubMed2001

Isolation and evaluation of Coxiella burnetii O-polysaccharide antigen as an immunodiagnostic reagent.

A lipid A - deprived lipopolysaccharide (LPS) from Coxiella burnetii (C.b.) Priscilla strain in virulent phase I was separated by steric-exclusion chromatography and high performance liquid chromatography (HPLC). The isolated O-specific polysaccharide (PS) fractions were analyzed by different physico-chemical methods and showed noticeable differences in their overall composition. The antigenic potential of the PS fractions was evaluated by ELISA with animal and human sera and in comparison with those of the native C.b. LPSs and phase I and II C.b. Nine Mile stain cells of which the latter are routinely used in diagnosis of Q fever. The results indicate that the high molecular mass PS antigen SG501 could be used in ELISA for a sensitive and specific detection of anti-C.b. antibodies in the examined sera.

Antibodies, Bacterial↗

PubMed1993

Q fever: prevalence of antibodies to Coxiella burnetii in the Basque country.

The aim of this study was to ascertain the prevalence of Coxiella burnetii infection in the Basque population. To this end a stratified sampling was carried out taking as a criterion the size of the population in a given area of residence. Residents in sparsely populated areas were found to have a prevalence of 38.5%, significantly greater than in highly populated areas (odds ratio [OR] = 1.56; 95% confidence interval [CI]: 1.08-2.27 and OR = 1.58; 95% CI: 1.09-2.30). The prevalence was significantly higher in males (36.3%) than in females (29%), and was found to increase significantly with age. Current or previous participation in activities relating to agriculture and/or livestock farming or even having contact with cattle, goats or sheep were also found to be risk factors for the infection. A fuller study of the determinants of chronic Q fever should be initiated.

Adolescent↗

PubMed1995

Characterization of the non-specific humoral and cellular antiviral immunity stimulated by the chloroform-methanol residue (CMR) fraction of Coxiella burnetii.

Modulation of the immune response by the chloroform-methanol residue (CMR) of phase I Coxiella burnetii whole cell was studied in Rift Valley fever virus-infected, or in naive endotoxin-non-responder C3H/HeJ mice. A single dose of CMR completely protected the mice from viral infection. Treating virus-infected mice with antibodies directed against interferons alpha/beta (IFN-alpha beta) and gamma (IFN-gamma) eliminated the CMR-induced protection. CMR stimulated the production of high levels of IFN-alpha/beta and 2'-5'-oligoadenylate synthetase activities in sera of the CMR-treated mice. IFN-gamma was present in supernatants of cultured spleen cells of CMR-treated, virus-infected mice, but not in their serum. Priming mice with CMR optimized the release of INF-gamma, interleukin-1 alpha (IL-1 alpha) and IL-6 from splenocytes in vitro. When stimulated in vitro, IL-2 and granulocyte-macrophage stimulating factor (GM-CSF) did not require in vivo priming for release from cultured spleen cells. Fluorescence-assisted cytometry of CMR-treated mouse spleen cells showed there was a CMR-dependent increase in the percentage of T-cells and Ia-positive T-cells. There also was a biphasic increase in the ratio between Th (L3T4) and Ts (Lyt2) cells. Biological activities stimulated by CMR indicate that CMR is a potent immunostimulant, which may modulate specific and non-specific antiviral responses.

2',5'-Oligoadenylate Synthetase↗

PubMed1989

Inactivation of Coxiella burnetii by gamma irradiation.

The gamma radiation inactivation kinetics for Coxiella burnetii at -79 degrees C were exponential. The radiation dose needed to reduce the number of infective C. burnetii by 90% varied from 0.64 to 1.2 kGy depending on the phase of the micro-organism, purity of the culture and composition of suspending menstruum. The viability of preparations containing 10(11) C. burnetii ml-1 was completely abolished by 10 kGy without diminishing antigenicity or ability to elicit a protective immune response in vaccinated mice. Immunocytochemical examinations using monoclonal antibodies and electron microscopy demonstrated that radiation doses of 20 kGy did not alter cell-wall morphology or cell-surface antigenic epitopes.

Animals↗

PubMed1989

Titration of Coxiella burnetii in Buffalo green monkey (BGM) cell cultures.

Titration of Coxiella burnetii, strain Nine Mile, phase I, and strain Frankfurt, phase II, in Buffalo green monkey (BGM) cover slip cell cultures yielded reproducible infectivity titers after centrifugation of infected cell cultures (3000 g, 30 min, 37 degrees C) and a subsequent 4-day incubation at 37 degrees C in Minimal Essential Medium (MEM). Compared to other titration procedures (plaque assays, titration in embryonated chicken eggs), this technique proved to be fast, less laborious and economical.

Animals↗

PubMed1990

[Coxiella burnetii: serologic study in various populations].

Complement binding antibodies against Coxiella burnetii were measured in 699 seric samples in order to ascertain the possible relationship between seric prevalence and the following factors: age, sex, living in rural or urban areas and socio-economical level. All patients were healthy: 180 were from a rural area 86 from Guijo (Cáceres); 36 from Chiloeches (Guadalajara) and 58 from Bustarviejo (Madrid); 519 were from an urban area (City of Madrid). The samples from Madrid city were classified by socio-economical level: 386 from medium-low level (MLL) and 133 from medium-high socio-economical (MHL) level. The global seroprevalence was 32.3%, being 46.1% from rural areas; --59.3 from Guijo, 33.3% from Chiloeches and 34.5% from Bustarviejo. In urban areas the seroprevalence was 27.5% this being 30.8% MLL and 18% MHL. We found a statistically significant relationship between both socio-economical levels and the area of living.

Adolescent↗

PubMed1985

Suppression of in vitro lymphocyte proliferation in C57BL/10 ScN mice vaccinated with phase I Coxiella burnetii.

The effect of inactivated phase I and phase II Coxiella burnetii whole cell vaccine (WCV) on the response of murine spleen cells to mitogenic and antigenic stimuli was evaluated in C57BL/10 ScN endotoxin nonresponder mice with an in vitro lymphocyte proliferation assay. Intraperitoneal injection of phase I WCV into mice resulted in marked and persistent suppression of the proliferative response of spleen cells to concanavalin A, phytohemagglutinin, and pokeweed mitogen. This response was time and dose dependent and was not associated with decreased lymphocyte viability. By using a standard dose of 100 micrograms of phase I WCV, suppression of mitogenic responsiveness was first detected 3 days postinjection, attained maximum levels by day 14, and persisted for longer than 5 weeks. Suppression of mitogenic lymphocyte proliferation also was demonstrated after inoculation of animals with viable phase I organisms. The observed hyporesponsiveness of spleen cells from phase I WCV-injected animals was not either the result of a shift in the mitogenic dose optimum or due to a change in the day of in vitro peak response. Spleen cells from phase I WCV-injected mice were negatively regulated with homologous antigen. Investigation of the mechanism of action of phase I WCV, with a 51Cr-release assay, and trypan blue dye exclusion showed that phase I WCV was not directly cytolytic or cytotoxic to spleen cells from normal or vaccinated mice. Phase II WCV did not induce significant mitogenic hyporesponsiveness or negative modulation of spleen cells. These findings extend the observations of adverse host responses associated with the phase I WCV and underscore the need to develop a microbial fraction which possesses protective potency but which lacks the propensity to induce deleterious tissue reactions and immunosuppression.

Animals↗

PubMed1995

Coxiella burnetii blood cultures from acute and chronic Q-fever patients.

Q fever, a worldwide zoonosis caused by Coxiella burnetii, may present as either an acute or a chronic disease. We correlated the results of 844 C. burnetii blood cultures with serological, clinical, and therapeutic data. C. burnetii was isolated from 17% of untreated patients with acute Q fever and from 53% of untreated patients with chronic Q fever. C. burnetii was not isolated from patients who were receiving antibiotics active against C. burnetii. For seven culture-positive patients with acute Q fever, serology was negative when C. burnetii was isolated. One patient with acute Q fever had a positive blood culture 25 days after the discontinuation of specific antibiotic therapy, and another had a positive blood culture after the resolution of symptoms. In one case of chronic Q fever, a positive blood culture resulted from noncompliance with treatment. The culture method described in this report is suitable for all laboratories with cell culture facilities. Our findings suggest that blood samples must be collected prior to the initiation of an antibiotic regimen if C. burnetii is to be successfully isolated.

Acute Disease↗

PubMed1992

[Coxiella burnetii and Chlamydia psittaci infection in dogs].

The prevalence of Coxiella burnetii and Chlamydia psittaci antibodies was investigated in 530 dog specimens divided into six groups, i. e. A = private watch dogs, B1 = service dogs from Bratislava, B2 = service dogs from other localities of Slovakia and Moravia, C = watch dogs from farms, I = household dogs, T = stray dogs. The dogs demonstrated the higher seropositivity to C. burnetii (11.7%) than to Ch. psittaci (5.5%). The highest percentage of antibodies to C. burnetii was found in stray dogs (23.7%), less prevalence of antibodies was observed in the animals in group C (13.6%), almost the same positivity was proved in the dogs of group B1 and B2 (10.5 and 10.6%). The highest positivity to Ch. psittaci was demonstrated in the dogs of group A (8.7%), less in group B2 (6.6%) and the least number in group B1 (1.9%). The stray dogs occupied the intermediate position in this data (Tab. I). Ninety four localities were tested, from which 38 were seropositive. Neither acute coxiellosis nor chlamydiosis were proved in any animals examined. Ninety per cent of dogs were found healthy, but 10% of dogs demonstrated hepatopathia and gastroenteritis. Two of them (category A and I) were seropositive to C. burnetii (titer 1:8 to 1:16) and one to Ch. psittaci (titer 1:16). Both C. burnetii and Ch. psittaci attack dogs parallely with the agents of other zoonoses, of which the most common is Toxoplasma gondii (Tab. II). Several dogs demonstrated seropositivity to three up to five zoonotic agents (Tab. III).

Animals↗

PubMed2002

[Prevalence and clinical characterization of Coxiella burnetii infection in patients with protracted low-grade fever].

We report here a persistent form of Coxiella burnetii infection. There have been no prospective surveys of chronic C. burnetii infection reported in Japan. Until recently, it was not possible to distinguish between previous and current infection with serological tests for antibody to C. burnetii. The nested PCR method, however, allows us to appreciate the current infection by detecting C. burnetii DNA with high sensitivity. Inoculation method using an A/J mouse was performed to confirm the viability of C. burnetii. To obtain an approximation of the prevalence of C. burnetii infection in the general population, we evaluated a random sample of patients with symptoms of continuous low-grade fever for one month or more. Analysis of 54 subjects with protracted debility and fatigue symptoms identified 13 subjects as carriers of C. burnetii (24.1%). There were no significant differences in age, C-reactive protein levels (0.69 +/- 1.19 mg/dl), white blood cell counts (6,089 +/- 2,189/microliter), eosinophil (3.4 +/- 3.6%) between the patients with C. burnetii infection and infection-free subjects. All thirteen patients had experienced protracted low-grade fever (up to 37.5 degrees C) for four months to seven years (30.5 +/- 27.7 months). Transthoracic echocardiography showed no evidence of endocarditis, or echosonography revealed no abnormal findings in the liver or kidneys. Although domestic animals constitute an important reservoir of C. burnetii, only two of the positive subjects had direct contact with them and none of the positive subjects were occupationally exposed to farm animals or common sources of infection. None had a history of hospitalizations for pneumonia or hepatic disease. Interestingly, five of the thirteen patients had a history of consulting a psychiatrist, and furthermore, one had a history of several admissions in a psychiatric hospital due to chronic fatigue symptoms. Ten of the patients had a high IgE titer (> 295 IU/ml), which shows a higher prevalence than in patients without C. burnetii (76.9%: 22.0%, P = 0.001). Four of them had markedly elevated IgE levels, in excess of 2,000 IU/ml. The mean value of IgE was higher in the patients with C. burnetii infection than in infection-free subjects (1,388 +/- 1,706: 533 +/- 913 IU/ml, p < 0.045). Two subjects were rheumatoid factor positive and another three had autoimmune thyroiditis. Twelve of the 13 subjects provided written informed consent for treatment with minocycline (200 mg/day). One month later, all subject became asymptomatic and apyretic (37.1 +/- 0.43 degrees C to 36.7 +/- 0.56 degrees C; p < 0.025), and nested PCR did not identify C. burnetii DNA in serum samples. It should be noted that persistent symptoms including low-grade fever were observed for two weeks after the start of medication. Furthermore, three patients had persistent symptoms, and DNA detection by the nested PCR method became positive in all three patients within a few months.

Adult↗

PubMed1994

Valvular endocarditis occurs as a part of a disseminated Coxiella burnetii infection in immunocompromised BALB/cJ (H-2d) mice infected with the nine mile isolate of C. burnetii.

BALB/cJ (H-2d) mice were injected intraperitoneally (ip) with cyclophosphamide 2 days after ip inoculation with Coxiella burnetii Nine Mile, phase I. Ten days after infection, disseminated microabscesses, granulomas, and microthrombi were observed in most organs, including spleen and liver, and in bone marrow. In addition, endocarditis of the atrioventricular and semilunar valves, characterized by macrophages and neutrophils, was present. At the same time, C. burnetii antigen was found in most organs and in cardiac valves, aorta, and pulmonary artery, mainly within macrophages, neutrophils, and endothelial cells. C. burnetii-specific IgG antibodies were detected 150 days after infection but not in the early phase of infection. Cardiac valves were devoid of C. burnetii antigen and without residual lesions at 150 days. These findings offer the possibility for further studies on the pathogenesis of C. burnetii-associated valvular endocarditis and show that acute strains of C. burnetii can cause endocarditis as a part of a disseminated infection in the immunocompromised host.

Animals↗

PubMed1994

Protective immunity induced by 67 K outer membrane protein of phase I Coxiella burnetii in mice and guinea pigs.

A 67 K outer membrane protein (OMP) isolated from phase I Coxiella burnetii QiYi strain was purified with monoclonal antibodies (MoAb) coupled to CNBr-Sepharose 4B. Chemical analyses of the 67 K protein showed that it contained seventeen kinds of amino acids and no LPS. The immunogenicity and protectivity of the 67 K protein against C. burnetii was evaluated in mice and guinea pigs by in vitro lymphocyte proliferation assay, delayed-type skin test, antibody conversion rate, and immunization and challenge tests. Intraperitoneal injection of the 67 K protein resulted in antibody production against phase I and II whole cell antigens. The anti-67 K antibody conversion rate was found to be 100% in mice and guinea pigs as well. Lymphocytes were responses in vitro to specific antigen. In addition, delayed-type hypersensitivity appeared two weeks after immunization with the 67 K protein. Moreover, 100% of mice and guinea pigs inoculated with the 67 K protein were protected against a challenge with 10(3) ID50 virulent C. burnetii. In conclusion, these results demonstrate that the 67 K OMP elicits in vivo and in vitro both B cell-mediated and T cell-mediated immunity in mice and guinea pigs. Thus the 67 K protein is a candidate for an effective subunit vaccine against Q fever.

Animals↗

PubMed1994

Isolation of Coxiella burnetii and of an unknown rickettsial organism from Ixodes ricinus ticks collected in Austria.

Two strains of Coxiella burnetii and two strains of an unidentified rickettsial organism were isolated for the first time from Ixodes ricinus ticks collected in the Alpine region of Tirol, Austria. The C. burnetii strains belong to the group of agents causing acute forms of Q fever. The other two strains of isolated rickettsial agent share some antigenic epitopes with C. burnetii and R. prowazekii but they differ from them by their high sensitivity to freezing and refreezing and by poor multiplication in yolk sacs of chick embryos. There is at present no evidence that these organisms cause human illness and no ecological information is available. We suggest they may be some new species of rickettsiae or rickettsia-like organisms.

Animals↗

PubMed1997

Relationship between pathogenicity of Coxiella burnetii isolates and gene sequences of the macrophage infectivity potentiator (Cbmip) and sensor-like protein (qrsA).

Coxiella burnetii, the Q fever agent, is an obligate intracellular bacterium and survival in phagolysosomes is an important virulence factor. The present study was performed to determine the relationship between its pathogenicity and genes related to its survival in macrophages, i.e. macrophage infectivity potentiator and Q fever agent regulatory sensor-like protein. The sequence similarity was more than 99% among Japanese, European and American strains, and no relationship was found between pathogenicity in guinea pigs and these genes.

Bacterial Proteins↗

PubMed1998

Direct identification of Coxiella burnetii plasmids in human sera by nested PCR.

Nested PCR assays were used for the direct identification of Coxiella burnetii plasmids in human sera. A total of 81 serum samples from 81 patients with Q fever were tested by nested PCR with four sets of primers. The first set of primers was used to detect the genomic sequences. The second set of primers was used to detect the conserved sequences of the plasmids. Another two sets of primers were used to identify the QpH1 and QpRS plasmids. QpH1 and QpRS plasmid-specific sequences were identified in 40 (49.4%) and 24 (29.6%) of the serum samples, respectively. Both of the QpH1 and QpRS plasmid-specific sequences were detected in 5 (8.6%) of the serum samples but were not found in 12 (20.7%) of the serum samples. Furthermore, all of the 23 acute-phase serum samples were positive for the QpH1 plasmid and negative for the QpRS plasmid. Nested PCR with plasmid-specific primers appears to be a useful method for the direct typing of C. burnetii plasmids in human sera.

Acute Disease↗

PubMed1991

Analysis of Coxiella burnetii isolates in cell culture and the expression of parasite-specific antigens on the host membrane surface.

Coxiella burnetii isolates may be classified into several groups based on plasmid character. These groups may also be correlated with disease syndrome--chronic or short-term acute. L929 mouse fibroblast cells were exposed, independently, to two members of the three major C. burnetii groups, and their growth/morphological characteristics analysed by light and electron microscopy, including High Voltage Electron Microscopy. The fates of the isolates were followed. Two acute isolates [Nine Mile (RSA 493) and Henzerling (RSA 331), QpH1-type plasmids] and two chronic isolates (S Q217 and L Q216, plasmidless) readily infected L929 cells in static culture. Priscilla (Q177) and F (Q228) isolates (QpRS-type plasmid, and implicated in causing chronic Q fever) took longer to infect cells, and, unlike the members of the other two groups, gradually disappeared when shifted to suspension culture. Cells infected with Q177 and Q228 exhibited a higher degree of vacuolation than cells infected with the other isolates. Parasite-specific antigens on the surfaces of the host cells were analysed by immunofluorescence/flow cytometry. The acute and plasmidless isolates caused the display of significantly more C. burnetii-specific antigen on the host cell membrane than the two QpRS plasmid-containing isolates. This host cell model system clearly reveals biological differences among the C. burnetii groups.

Animals↗