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PubMed1994

[The comparative characteristics of the immunogenic and immunomodulating activity of different antigenic preparations of the causative agent of Q fever Coxiella burnetii].

The immunogenicity of the Coxiella burnetii corpuscle antigen and two its components, obtained after the treatment with chloroform-methanol or extraction by trichloroacetic acid, was investigated. All the studied antigens were highly immunogenic. A strong correlation was discovered between the immunogenic and immunomodulating properties of the C. burnetii antigens. Cells of the mononuclear phagocytic system are the targets for stimulating action of the studied antigens. A cyclic increase of antibacterial activity and oxygen-dependent metabolism of the peritoneal cells was noted, in addition to the increase of the natural splenocyte cytotoxicity caused by the action of these antigens. The role of cytokines in rising the activity of peritoneal cells and splenocytes, caused by immunization of mice with the above antigenic substances, is discussed.

Adjuvants, Immunologic↗

PubMed1991

Analysis of proteins and lipopolysaccharides from Chinese isolates of Coxiella burnetii with monoclonal antibodies.

Four Coxiella burnetii isolates in China and two reference strains were compared by SDS-PAGE and immunoblotting. The SDS-PAGE profiles of whole cells and LPS of Chinese isolates Qiyi, Xinqiao, and YS-8 were found closely related to Henzerling strain, and different from the Grita strain. In immunoblot assay of LPS and proteinase K-digested whole rickettsiae minor differences were seen in polysaccharide structure among the Chinese isolates by phase I monoclonal antibody. The present results suggest that the strains reported here may be divided into three groups according to the polysaccharide structure: Xinqiao and Henzerling strains (1), YS-8 and Grita (2), and Qiyi (3).

Antibodies, Monoclonal↗

PubMed1998

Genotypic and phenotypic characterization of two Swedish isolates and two prototypic strains of Coxiella burnetii.

Two Swedish isolates of Coxiella burnetii and the two prototype strains of the species, Nine Mile and Priscilla, were characterized with regard to their multiplication and cytopathic effect on BGM cells and by PCR-based amplification of repetitive element DNA and the C. burnetii-specific plasmids QpH1 and QpRS. Moreover, 1330 bp of each 16S rRNA gene were sequence-determined. All four strains multiplied at virtually the same rate and displayed the same type of vacuoles in the BGM cells. Genetic homogeneity was observed inasmuch as the 16S rDNA sequences were identical and the strains showed identical PCR amplification patterns using primers specific to enterobacterial repetitive intragenic consensus DNA sequences. The two Swedish strains and the Priscilla strain also showed identical patterns after PCR amplification of repetitive extragenic palindromic DNA sequences, whereas the Nine Mile strain demonstrated a similar, but not identical pattern. Thus, the investigated strains demonstrated very similar phenotypic and genotypic characteristics. This finding is discussed in view of the very rare occurrence of domestic Q fever in Sweden.

Animals↗

PubMed2000

Diagnosis of quinolone-resistant Coxiella burnetii strains by PCR-RFLP.

A total of 12 strains of Coxiella burnetii (8 Greek isolates from acute Q-fever patients, two reference strains-Nine Mile and Q212-and two pefloxacin-resistant laboratory strains) were examined for the presence of point mutations in the quinolone resistance determining region (QRDR) of gyrA gene by direct DNA sequencing of the polymerase chain reaction (PCR)-amplified fragments. The gene sequences of all eight Greek isolates and the two reference strains Nine Mile and Q212 [minimal inhibitory concentration (MIC)</= 4 microg/ml] were identical. Direct DNA sequencing of the in vitro-selected resistant strains (MICs to pefloxacin, 8-32 microg/ml) revealed a transition (G-->A) at the corresponding codon 87 of E. coli. This mutation lead to the substitution of Glu (codon GAG) by Lys (codon AAG ). Restriction maps of amplified gyrA gene sequences were determined by GCG Wisconsin PACKAGE, and the MnlI restriction enzyme was found to cut only the sensitive strains sequences and not the resistant ones. The present PCR-RFLP analysis has proved to be a simple, rapid, and useful method for the detection of Coxiella burnetii and, at the same time, for the diagnosis of quinolone-resistant Coxiella burnetii strains.

Amino Acid Sequence↗

PubMed1995

Entry and survival of Leishmania amazonensis amastigotes within phagolysosome-like vacuoles that shelter Coxiella burnetii in Chinese hamster ovary cells.

Coxiella burnetii, a rickettsia, and Leishmania amazonensis, a protozoan flagellate, lodge in their host cells within large phagolysosome-like vacuoles. In the present study, C. burnetii-infected Vero or CHO cells were superinfected with L. amazonensis amastigotes to determine if these parasites can home to and survive within heterologous vacuoles. Six hours after superinfection, Leishmania amastigotes were located almost exclusively within large Coxiella-containing vacuoles. Thereafter, the numbers of parasites in the vacuoles increased at the same rate as those in cells infected with L. amazonensis alone. Furthermore, in cultures shifted to 25 degrees C, some of the amastigotes transformed into promastigote-like forms that moved their flagella within the adoptive vacuoles. Thus, L. amazonensis amastigotes not only entered Coxiella vacuoles, most likely by fusion of donor and recipient vacuoles, but temporarily survived, differentiated, and replicated therein. This appears to be the first account of the temporary cohabitation of two living pathogens within the same vacuole in a mammalian cell.

Animals↗

PubMed2002

Shedding of Coxiella burnetii in ewes in two pregnancies following an episode of Coxiella abortion in a sheep flock.

Coxiella burnetii infection in pregnant sheep typically causes abortion or the birth of weak lambs. Two C. burnetii-related abortions in a group of 34 pregnant ewes were reported at their first lambing in our research institute. The seroprevalence of C. burnetii infection and bacteria shedding were investigated using an ELISA and PCR, respectively, during the course of two subsequent pregnancies. None of the ewes examined seroconverted from negative to positive at the time of the second and the third parturition and most of the ewes that were seropositive at the abortion episode remained positive throughout the investigation. The two successive pregnancies resulted in the birth of healthy lambs without PCR evidence of Coxiella infection from placenta and vaginal swabs taken postpartum. PCR assay performed on vaginal swabs taken from all animals 1, 5 or 12 days after the second lambing were also negative for Coxiella. However, one ewe that had previously experienced C. burnetii shedding at the first lambing excreted the bacteria in the genital tract after the third parturition. The bacteria could not be detected by PCR in milk and faecal samples taken up to 12 days after both parturitions.

Abortion, Veterinary↗

PubMed2006

Short report: seroprevalence of human infection by Coxiella burnetii in Barcelona (northeast of Spain).

Coxiella burnetii is the causal agent of Q fever, a worldwide-distributed zoonosis, which is endemic in Spain. C. burnetii has an extensive reservoir, including farm animals and pets. The aim of this study was to determine the seroprevalence of C. burnetii in humans in Vallés Occidental (Barcelona, northeast of Spain) and its possible related risk factors. The prevalence of phase II antibodies from 216 subjects was determined by indirect immunofluorescence assay (IFA). Age, sex, living place, occupation, and contact with animals were surveyed. A 15.3% seroprevalence was found (> or = 1/40), and 8.8% of samples had titers > or = 1/80. Seropositive cases were significantly higher in patients > 44 years of age. No statistically significant correlation was found between seropositivity and the remaining variables studied. Therefore, infection by C. burnetii seems to be endemic in our region, with a prevalence ranging from 9% to 15%, depending on the titers that are to be considered significant.

Adolescent↗

PubMed2005

Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection.

OBJECTIVE: To examine whether Coxiella burnetii (C. burnetii) is involved in chronic fatigue syndrome (CFS), we administered tetracycline antibiotics to subjects with CFS, and followed changes in clinical symptoms, PCR findings, and C. burnetii antibody titers. PATIENTS AND METHODS: The subjects were 8 patients with CFS and 213 with nonspecific complaints such as chronic fatigue and low-grade fever for several months or longer but not meeting the diagnostic criteria for CFS. All were examined for C. burnetii infection by nested PCR and the indirect immunofluorescence test (IF). RESULTS: Four CFS patients (the CFS group) and 54 controls [the post-Q fever fatigue syndrome (QFS) group] positive for C. burnetii were treated mainly with minocycline or doxycycline (100 mg/day) for 3 months. After treatment, all 58 patients tested negative for C. burnetii infection. In the CFS group, no significant difference was noted between the mean pre- and post-treatment temperatures or headache scores. Similarly, there was no significant improvement in performance status (PS) scores. In the QFS group, however, mean temperatures and headache scores were significantly decreased after treatment (p<0.001). PS scores were also improved. CONCLUSION: These results suggest the possibility of direct involvement of C. burnetii in the pathological state of CFS to be low, despite the C. burnetii infection rate being high in CFS patients. This is a pilot study and further larger investigations are necessary to confirm our preliminary results.

Adolescent↗

PubMedDate not supplied

[Definitive ability of Stamp-staining, antigen-ELISA, PCR and cell culture for the detection of Coxiella burnetii].

Many assays are used for the detection of the aetiological agent of Q fever, Coxiella burnetii, i.e. staining according to the method of Stamp, capture ELISA, PCR or isolation by cell culture. In this study the results of these four assays are compared for their sensitivity and specificity. Staining smears according to the method of Stamp gave many false positive or false negative results. The capture ELISA seems to be a very sensitive assay for the detection of Coxiella burnetii but it has a lack in specificity. It is a useful test system for the screening of large scales of samples. Positive ELISA results should be confirmed by PCR, a very sensitive and specific method for the detection of Coxiella burnetii but more time consumptive than the ELISA. Isolation of the agent using cell cultures was not completely satisfactory because of its lack in sensitivity. Therefore it should only be used in special cases.

Animals↗

PubMed1998

Q fever in the Greek island of Crete: detection, isolation, and molecular identification of eight strains of Coxiella burnetii from clinical samples.

Over a period of 6 years (1989 to 1995), serum samples from 3,300 patients suspected to be infected by Coxiella burnetii were assayed for the presence of antibodies against antigen phase II of the microorganism by the indirect immunofluorescence antibody technique (IFAT). One hundred fifty-two cases were recorded, and blood samples from 17 patients were cultured for the isolation of the pathogen. By a centrifugation shell vial technique, eight strains were isolated from patients suffering from acute Q fever. The microorganism was detected in the cultures by IFAT, by Gimenez staining, and by the cytopathogenic effect on Vero and human embryonic lung (HEL) cells. PCR followed by restriction fragment length polymorphism analysis was used to confirm the diagnosis and identify the Coxiella burnetii strains within the cell cultures as well as to compare them with reference strains. In order to avoid time-consuming cultures, to achieve direct detection of Coxiella burnetii in clinical samples (blood, buffy coat, etc.), and to increase the specificity and sensitivity of the detection, nested PCR was performed. The first step of DNA extraction was performed with the QIAamp blood kit 250. For the second step of the PCR assays, the conditions of temperature and times of recycling were properly modified, and the microorganism was detected within 4 h. Our study demonstrates that Q fever is an endemic disease in Crete and that the diagnosis of Coxiella burnetii infection can be rapidly achieved by the detection of the microorganism in buffy coat samples by nested PCR. Although the presenting symptoms of the disease in this study differed from those in other studies, the Cretan strains do not differ genotypically from the reference strains (Nine Mile and Q212).

Animals↗

PubMed1994

Is plasmid based differentiation of Coxiella burnetii in 'acute' and 'chronic' isolates still valid?

Ten human Coxiella burnetii isolates from french patients with acute hepatitis or chronic endocarditis were characterized according to their polymorphism in DNA restriction patterns and differentiated by plasmid-specific PCR. The aim of this investigation was to clarify if the present classification of so called 'acute' and 'chronic' Coxiella burnetii isolates--based on plasmid profile of a so far limited number of partly ancient isolates--could be confirmed with lately isolated organisms of this agent. The data obtained in this investigation indicate that this classification based on C. burnetii plasmid content is no longer justified.

Acute Disease↗

PubMed1997

Plasmid-homologous sequences in the chromosome of plasmidless Coxiella burnetii Scurry Q217.

Chromosomal DNA from Coxiella burnetii Scurry Q217 was screened for the presence of plasmid-homologous sequences. Total DNA from Scurry Q217 was digested with NotI, and the resulting DNA fragments were separated by contour-clamped homogeneous electric field pulsed-field gel electrophoresis (CHEF-PFGE). Following hybridization with biotin-labeled QpH1 plasmid as a probe, two DNA fragments of 40 and 170 kb were identified as targets. These fragments were cloned, and subclones containing QpH1-homologous sequences were completely sequenced. The physical mapping of DNA fragments was achieved by PCR with primers derived from adjacent fragments, and a total of 18,360 bp was sequenced. Within the QpH1-homologous region spanning 16,624 bp, homology was as high as 99%. Deletions were identified within EcoRI fragments A(H)-C(H)-K(H)-B(H) (13,490 bp) and J(H)-G(H)-E(H)-L+-D(H) (6,509 bp) and in fragment A(H) alone (619 bp). An insertion of 744 bp was identified within the JDc region of Scurry Q217. A search for putative coding regions identified a total of 17 open reading frames (ORFs). Compared to plasmid QpH1, 6 ORFs were identical, 5 ORFs were different in size, 6 ORFs were newly generated, and 25 ORFs were lost. It was found that plasmid-homologous sequences in Scurry Q217 were of chromosomal origin.

Base Composition↗

PubMed1985

Correlation of plasmid type and disease caused by Coxiella burnetii.

The obligate intracellular bacterium Coxiella burnetii is the etiological agent of acute Q-fever and chronic endocarditis in humans and of several zoonotic infections. The DNA from a variety of these disease isolates was compared for homology to the plasmid QpH1, found in the Nine Mile strain. Three patterns of homology were found in these isolates, i.e., one pattern identical to that of QpH1, one common to several endocarditis isolates and goat abortion isolates, and one common to the remaining group of endocarditis isolates. Plasmid DNA from the endocarditis-abortion isolate group, designated QpRS, was mapped by restriction enzyme analysis and compared with QpH1. These data show that QpRS was 2 to 3 kilobase pairs larger, contained DNA not found in QpH1, but was not generated from QpH1 by a single insertional event. Isolation of plasmid DNA from the second endocarditis group of isolates was not successful and may indicate that the plasmid has integrated into the chromosome. This analysis provides the first clear evidence that differences exist between C. burnetii isolates which cause various diseases, indicating that different C. burnetii strains may have unique virulence characteristics.

Animals↗

PubMed2000

[Coxiella burnetii endocarditis: long-term clinical course in 20 patients].

INTRODUCTION AND OBJECTIVES: Coxiella burnetii is a causative agent of increasingly frequent subacute infective endocarditis, and is associated with elevated morbimortality. Our aim in the present study was to assess the clinical, serological and therapeutic long-term evolution of 20 patients with Coxiella burnetii endocarditis. METHODS: Twenty patients (13 male and 7 female, age 42 +/- 10 years) admitted between 1982 and 1996 were retrospectively studied. All of them fulfilled the Duke criteria modified by Raoult for Q fever endocarditis. RESULTS: Endocarditis involved prosthetic and native valves in 14 and 6 patients, respectively. All patients except one received antibiotic treatment. Patients treated with doxycycline in monotherapy showed worse evolution than those treated with doxycycline in combination with other antibiotics. Valve replacement was performed in 15 patients, due to prosthetic dysfunction in most of them. The overall mortality was 40% (8 patients). At follow-up of 74 months (range 19-156) (mean 74 +/- 47) all patients showed persistent high levels of phase I antibodies. At follow-up of 15 to 65 months (32 +/- 30) antibiotic treatment was suspended in five patients because they were asymptomatic and without microbiologic findings of valvular endocarditis. CONCLUSIONS: Q fever endocarditis was associated with severe complications, which often required valve replacement. All patients showed persistent high serological titers of Coxiella burnetii endocarditis without other signs of active infection. This finding raises the issue of suspending antibiotic treatment in patients with negative microbiologic findings and questions the persistence of abnormal serology as a monitor of treatment efficacy.

Adult↗

PubMed1980

Genome size of the rickettsia Coxiella burnetii.

The genome size of Coxiella burnetii Nine Mile strain was determined by the method of initial rate of deoxyribonucleic acid renaturation. The mean value obtained was 1.04 X 10(9) daltons.

Base Composition↗

PubMed1993

Coxiella burnetii infection among subjects infected with HIV type 1 in the Central African Republic.

Sixty-six sera from HIV-1-seropositive adult African subjects and 49 sera from HIV-seronegative age and sex matched healthy African controls living in Bangui, Central African Republic, were screened for Coxiella burnetii antibody by an indirect immunofluorescent antibody test. 16.7% of HIV-infected patients and 16.3% of the HIV-negative controls had positive IgG titres, with no significant difference between the two groups. Two of the seven HIV-infected patients seropositive for Coxiella burnetii for whom clinical data was available had a medical history compatible with symptomatic Q fever. These findings indicate that there is a high degree of exposure to Coxiella burnetii infection in Bangui. In individuals co-infected with HIV and Coxiella burnetii, cellular immunosuppression could favour symptomatic Q fever. Physicians should be aware of the possibility of symptomatic Coxiella burnetii infection among HIV-infected people, particularly in endemic regions for both infections such as in sub-saharan Africa.

AIDS-Related Opportunistic Infections↗

PubMed1983

Studies of the antigenic structure of Coxiella burnetii.

The antigenic structure of Coxiella burnetii (C.b.) was studied by absorption of human and animal immune sera with C.b. organisms in the natural phase II (NPh II) or with artificial phase II (ArPh II) organisms prepared by their treatment with KIO4. It was found that immune sera absorbed with one type of phase II organisms still reacted with the antigen of another type of phase II organisms as demonstrated in both microagglutination (MA) and complement-fixation (CF) tests.

Agglutination Tests↗

PubMed1984

Active transport of proline by Coxiella burnetii.

The obligate intracellular rickettsia, Coxiella burnetii, was shown to possess an energy dependent proline transport system which displayed a high degree of specificity and was highly dependent on pH. Transport was maximal at pH 3.0 to 4.5, a pH range approximately that of the host cell phagolysosome where the agent replicates. Transport was inhibited by the uncouplers carbonyl cyanide m-chlorophenylhydrazone and dinitrophenol, but not by sodium arsenite. In the presence of glutamate, a preferred energy source, proline uptake was enhanced more than two-fold. This enhancement of proline uptake was greatly decreased in the presence of sodium arsenite. The addition of glutamate decreased the apparent Km for proline transport from 45 microM to 15 microM, with the Vmax increasing from 3.6 pmol s-1 (mg dry wt)-1 to 4.8 pmol s-1 (mg dry wt)-1. Two proline analogues, furoic acid and azetidine-2-carboxylic acid, were effective inhibitors of proline transport. D-Proline, 4-hydroxyproline, glycine and proline amide inhibited transport minimally, while no inhibition was seen with succinate, pyruvate or glutamate.

2,4-Dinitrophenol↗