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PubMed1989

Susceptibility of Coxiella burnetii to pefloxacin and ofloxacin in ovo and in persistently infected L929 cells.

The relative lack of efficacy of the antibiotic treatment of chronic Q fever endocarditis justifies the further evaluation of the susceptibility of Coxiella burnetii to the modern quinolone antibiotics. We evaluated the efficacies of pefloxacin and ofloxacin in controlling the Nine Mile isolate of C. burnetii by using an embryonated egg assay and persistently infected L929 cells in culture. Pefloxacin was effective in controlling the intracellular parasite at a concentration of 50 micrograms per egg and 1 microgram/ml in cultures of infected cells. Ofloxacin was effective at a concentration of 25 micrograms per egg and 0.5 microgram/ml in infected-cell cultures. In light of the fact that the concentrations of antibiotics used fall within physiological ranges used in humans, ofloxacin and pefloxacin may be useful in the clinical management of chronic Q fever, for which, to date, results have been poor.

Animals↗
PubMed1990

The immune response to phase I and phase II Coxiella burnetii antigens as measured by western immunoblotting.

To determine the utility of Western immunoblotting in distinguishing chronic Q fever from acute Q fever, we first examined serum samples from individuals who had no antibodies to Coxiella burnetii by either the indirect immunofluorescence antibody test or by the enzyme-linked immunosorbent assay. In these subjects, the IgG fraction in low dilutions of serum (1:8, 1:16) reacted with as many as 10 proteins in phase I and phase II antigens. This number of reacting bands seen in Western blots was reduced by using serum in a dilution of 1:1024. In contrast, IgA antibodies were uncommon even at low dilutions. Likewise, IgA antibodies were infrequently observed in patients with acute Q fever. However, in chronic Q fever there were many IgA antibodies to phase I and phase II proteins. Antibodies to phase I proteins were more common than those to phase II proteins. Several antigenic protein bands were recognized only by serum from chronic Q fever patients. Three of these antigens had molecular masses of, respectively, 50 kDa, 80 kDa, and 160 kDa. Serial serum samples from patients with chronic Q fever revealed that the number of antigens recognized by the IgA fraction decreased after the initiation of antibiotic therapy. The decline was faster for antibodies to phase II proteins. We conclude that immunoblotting is useful in the diagnosis of chronic Q fever.

Acute Disease↗
PubMed1985

Shedding of Coxiella burnetii in milk by Nigerian dairy and dual purposes cows.

Fresh milk from dairy cows kept at semi-intensive husbandry in governmental and institutional farms and dual purpose Fulani nomadic husbandry around Zaria, Nigeria were screened for Coxiella burnetii using the mouse inoculation test. Of the 20 herds from both management systems tested, 16(80.0%) contained dairy cows shedding C. burnetii in their milk. Of a total of 169 cows tested, 41(24.3%) were shedders. Eighteen (22.0%) of 82 cows kept under semi-intensive and 23(26.4%) of 87 cows kept under Fulani nomadic systems were shedding C. burnetii. The difference in frequency of shedding C. burnetii between both system was not statistically significant (P greater than 0.05, X2). Of the 88 dairy cows serologically tested for C. burnetii agglutinins by the capillary agglutination test (C.A.T), 48(54.5%) were sero-positive and 40(45.5%) were seronegative. Among Q-fever sero-positive cows, 11(22.9%) were shedders and 37(77.1%) were not shedding C. burnetii in their milk. Of the sero-negative cows, 6(15.0%) and 34(85.0%) were shedders and non-shedders, respectively. With milk from Fulani nomadic cows predominantly taken raw or made into unheated fermented milk products, the health risk to the consumers of such products cannot be over-emphasized.

Animal Husbandry↗
PubMed1978

Experimental Coxiella burnetii infection of guinea pigs and mice.

The susceptibility of five inbred strains of mice, designated DBA/1J, DBA/2J, C57BL/6J, Balf/CJ, and AKR/J, as well as outbred Hartley and Moen-Chase guinea pigs to infection with Coxiella burnetii by several routes was studied. The DBA/2J mice were more susceptible to infection and had higher mortality rates than other strains of mice. Guinea pigs were more susceptible to infection than mice. Lesions observed in the infected animals were similar to those previously described in man and experimentally infected animals.

Aerosols↗
PubMed1984

Coxiella burnetii antibodies in some Nigerian dairy cows and their suckling calves.

Dairy cows and their suckling calves kept at institutional and governmental farms under semi-intensive husbandry and dual purpose Fulani nomadic herds with extensive management system around Zaria, Nigeria were screened for antibodies against Coxiella burnetii using the capillary agglutination test (CAT). An antibody prevalence of 59.8% detected among 306 dairy cows under both management systems was significantly (P less than 0.01, X2) higher than was found among their suckling calves where 41.0% of 205 calves tested were seropositive. At institutional herds, 61.4% of 176 dairy cows, 47.3% of 110 suckling calves and 43.2% of 44 milk samples contained antibodies to C. burnetii. However, within Fulani nomadic herds, 57.7% of 130, 33.7% of 95 and 62.5% of 40, dairy cows, suckling calves and milk samples respectively, were positive for C. burnetii antibodies. Antibody titres of seropositive cows were similar for both systems as 82 (62.7%) of 122 tested sera had titres of 1:64 or above. It is concluded that milkborne C. burnetii infections could be a health hazard to consumers of raw or unpasteurized milk in this environment, based on high prevalence rates and titres, as some cows could be shedding the organism. The role of management practice in the transmission of C. burnetii is also discussed.

Animal Population Groups↗
PubMed1990

Identification and cloning of a 27-kDa Coxiella burnetii immunoreactive protein.

Patients with acute Q fever develop Coxiella burnetii-specific antibody, and chronic disease patients often develop extremely high levels of C. burnetii-specific antibody. Antibody-reactive LPS has been well characterized, but only a few immunoreactive proteins have been identified. An immunoreactive ca. 62-kDa protein has been cloned, sequenced, and shown to be related to an Escherichia coli heat-shock protein. A ca. 27-kDa immunoreactive outer membrane protein(s) has also been identified. We have begun characterizing C. burnetii immunoreactive proteins by gene-cloning methods. A gene bank of total C. burnetii Nine Mile phase 1 (acute strain) DNA was created using the lambda vector EMBL3. This bank was screened for plaques which reacted with E. coli-pre-absorbed rabbit antisera specific for purified, Nine Mile C. burnetii whole cells. Twenty-three immunoreactive plaques were identified from a screening of 3000 plaques. Twenty-two plaques produced a ca. 60-65-kDa immunoreactive protein. One plaque produced a ca. 27-kDa immunoreactive protein, as well as a ca. 60-65-kDa immunoreactive protein. Phage extracts of this plaque were used to enrich the antisera to produce a ca. 27-kDa-specific antisera. This enriched sera reacted with a ca. 27-kDa protein in all C. burnetii isolates tested, comprising isolates from both chronic and acute strains. The DNA contained in the immunoreactive clone was C. burnetii-specific, as shown by DNA hybridization. We are currently subcloning the ca. 27-kDa protein-coding region for sequencing to determine if this gene encodes the previously identified ca. 27-kDa immunodominant protein. This protein may ultimately have both diagnostic and vaccinogenic potential.

Antigens, Bacterial↗
PubMed1991

Erythromycin and the treatment of Coxiella burnetii pneumonia.

Erythromycin is commonly used for the empirical treatment of community-acquired pneumonia, but there is some concern about its usefulness when Q fever is suspected because of in-vitro studies showing a lack of efficacy against Coxiella burnetii. This study was undertaken to assess the clinical value of the antibiotic in this setting. Nineteen patients with Q fever pneumonia treated with a variety of antibiotics considered ineffective against C. burnetii, were reviewed. Eleven patients who received erythromycin had a rapid clinical improvement and each became afebrile by the fourth day of treatment. However, only two of eight patients who received other antibiotics improved (both of them had been treated with beta-lactams). Both groups were comparable regarding to age and previous duration and severity of disease. Those patients who did not respond to other antibiotics improved promptly after erythromycin was started. This study suggests that erythromycin is an adequate treatment for Q fever pneumonia.

Adolescent↗
PubMed1977

Analysis of antibody response and immunoglobulins in sera of rabbits and guinea pigs immunized with Coxiella burnetii.

Rabbit and guinea pig sera and their immunoglobulin fractions (IgM and IgG) were examined by complement-fixation (CF), microagglutination (MA), opsonization-phagocytosis (OP) and serum protection (SP) tests at intervals after immunization with live phase I and phase II Coxiella burnetii suspensions. In general, MA antibodies, but also decreased, earlier than CF antibodies. The anamnestic immune response was higher with lower primary doses. Both phase II and phase I CF and MA antibodies as well as phase I opsonins and protective antibodies were found in either immunoglobulin fraction depending on post-immunization intervals. At later intervals and especially after the second immunizing dose the levels of protective antibodies in whole sera, but mainly in the IgG fractions, showed a better agreement with those of phase I opsonins rather than of phase I CF and MA antibodies.

Agglutination Tests↗
PubMed1983

Dermal granulomatous hypersensitivity in Q fever: comparative studies of the granulomatous potential of whole cells of Coxiella burnetii phase I and subfractions.

Dermal granulomatous reactivity to Q fever antigens in guinea pigs has been described as a model for vaccine reactions seen in previously sensitized humans. This model has now been applied to study the ability of subfractions of Coxiella burnetii to produce granulomas. Q fever organisms in phase I, trichloroacetic acid-soluble and -insoluble fractions, and the extract and residue of chloroform-methanol extraction were tested for their relative ability to elicit and immunize for dermal granulomatous reactions and specific lymphocyte proliferative responses in guinea pigs. The results suggest that a determinant(s) causing granulomas can be removed by chloroform-methanol extraction of phase I whole cells. The chloroform-methanol residue elicited strong delayed-type hypersensitivity without subsequent granuloma formation. The chloroform-methanol residue appears to possess a determinant(s) for lymphocyte stimulation equivalent to that of whole phase I organisms.

Animals↗
PubMed1986

Synthesis of three 3-C-hydroxymethylpentoses with the D-ribo-, D-xylo- and L-lyxo-configurations. Identification of the latter with a monosaccharide isolated from phase I Coxiella burnetii lipopolysaccharide.

Three 3-C-hydroxymethylpentoses with the D-ribo-, D-xylo and L-lyxo-configurations, were synthesised via nitromethane addition for the first two and 1,3-dithiane addition for the last one, to appropriate 3-ulose derivatives. 3-C-Hydroxy-methyl-L-lyxose is identical with a monosaccharide component previously isolated from hydrolysates of the phase I Coxiella burnetii lipopolysaccharide.

Chromatography, Gas↗
PubMed1998

Coxiella burnetii infection of aneurysms or vascular grafts: report of seven cases and review.

The most frequent clinical presentation of chronic Q fever is endocarditis, although infections of aneurysms and vascular prostheses have also been described. We report seven new cases of Coxiella burnetii infection of aneurysms or vascular grafts. We also review the literature and compare our cases with the six previously reported cases. This study demonstrated the lack of specific symptoms associated with this disease. Moreover, prospectively, in an attempt to reevaluate the incidence of Q fever-associated vascular infection, we systematically searched for C. burnetii infections in 163 patients with aortic aneurysms or vascular grafts who underwent vascular surgery. Microbiological testing included standard culture, Q fever serology, cell culture, and polymerase chain reaction amplification of C. burnetii DNA from biopsy specimens of aneurysms or vascular grafts. A microorganism was isolated from 25 patients, including C. burnetii in two cases; both of these patients had serological titers consistent with chronic Q fever. Both patients had nonspecific clinical features, and thus their infections would have probably remained undiagnosed without our systematic testing. Therefore, since the incidence of C. burnetii vascular infection is probably underestimated, we suggest that C. burnetii serology be routinely carried out in cases of unexplained febrile illness, pain, or weight loss in patients with a history of underlying vascular disease.

Adult↗
PubMed1979

Prevalence of Coxiella burnetii infection among humans and domestic animals of Rajasthan State, India.

A total number of 1806 sera comprising 1049 humans and 757 animals from four ecologically different areas of Rajasthan State were tested to determine the prevalence of complement-fixing (CF) antibodies to Coxiella burnetii (C burnett). Of the 1049 human and 757 animal sera tested, antibodies to C. burnetii were detected in 195 sera (18.6 per cent) and 187 sera (24.7 per cent), respectively. Among humans, the prevalence of infection with C. burnetii was highest in the desert area of Barmer district and the hilly area of Bundi district, viz 64.5 per cent and 28.2 per cent, respectively. It was slightly lower in the semi-arid and the arid zones of the State, viz Sirohi (20 per cent) and Jalore (13.7 per cent), whereas the irrigated areas of Kota and Jaipur had the lowest prevalence, 9.9 and 8.4 per cent, respectively. Among animals, the highest prevalence was detected in sheep (39.6 per cent), followed by cattle (29.9 per cent) and goats (18.6 per cent).

Animals↗
PubMed1998

NMR study of virenose and dihydrohydroxystreptose isolated from Coxiella burnetii phase I lipopolysaccharide.

A lipopolysaccharide (LPS) isolated from Coxiella burnettii in virulent phase I contains in its O-polysaccharide chain two unusual sugars, virenose (6-deoxy-3-C-methylgulose) and dihydrohydroxystreptose [3-C-(hydroxymethyl)lyxose]. The sugars were isolated from LPS I, after acid hydrolysis and removal of lipid A, by a combination of HPLC and preparative paper chromatography. Their enantiomeric forms and ring conformations were established from optical rotation and NMR data. Two-dimensional COSY, HSQC, and HMBC as well as one- and two-dimensional NOEs were used to assign all proton and carbon signals in both monosaccharides. Virenose was found to be the D-gulo enantiomer with the 4C1 ring conformation and dihydrohydroxystreptose was shown to be the L-lyxo enantiomer also with the 4C1 conformation. The latter sugar was reported [S. Schramek, J. Radziejewska-Lebrecht, and H. Mayer, Eur. J. Biochem., 148 (1985) 455-461] to be present in LPS I in a furanose form, and it appears that a furanose to pyranose tautomerization took place in the course of the isolation procedure.

Carbohydrate Conformation↗
PubMed1983

Rickettsial antibody prevalence in southern Israel: IgG antibodies to Coxiella burnetii, Rickettsia typhi, and spotted fever group rickettsiae among urban- and rural-dwelling and Bedouin women.

A retrospective serological survey was carried out using sera obtained from women at childbirth in the southern desert region of Israel to determine exposure experience to three rickettsial agents: Coxiella burnetii, Rickettsia typhi, and spotted fever group rickettsiae. Using the indirect fluorescent antibody method for determining IgG antibodies, it was found that about 40% of all sera examined demonstrated antibodies to one or more rickettsiae. Bedouin women appeared to be at greater risk of having antibodies to C. burnetii and spotted fever group rickettsiae than did Jewish residents of Beersheba, agricultural settlements, and development towns. The residents of development towns appeared to be at lower risk of developing antibodies to spotted fever group rickettsiae than did other populations sampled. Possible reasons for these differences are discussed.

Antibodies, Bacterial↗
PubMed2005

Immunization experiments with recombinant Coxiella burnetii proteins in a murine infection model.

Previous attempts to develop Q fever vaccines were less successful in that the vaccines caused unacceptable side effects or failed to be protective. In this study, we tested the efficacy of a mixture of eight recombinant Coxiella burnetii (C. b.) proteins in sublethal challenge infections with mice. Eight potential C. b. virulence genes (Omp, Pmm, HspB, Fbp, Orf410, Crc, CbMip, and MucZ) were overexpressed in E. coli as his-tagged fusion proteins and partially purified. All recombinant proteins but rPmm proved to be antigenic in BALB/c mice when administered as protein mixtures. For efficacy testing, mice were immunized with an adjuvanted mixture of the eight recombinant proteins and subsequently challenged intraperitoneally with the C. b. isolate Nine Mile RSA493 (1.8 x 10(8) C. b.). Only animals vaccinated with the licensed Q fever vaccine Q-Vax (vaccination control) exhibited milder symptoms and minor gain of spleen and liver weights. In summary, clinical examinations and dissection of mice immunized with the eight recombinant C. b. proteins did not indicate a protective immune response after test infection.

Animals↗
PubMed1998

Prevalence of Coxiella burnetii infections among North Dakota sheep producers.

A case of Q fever in a sheep producer was detected by a surveillance system in North Dakota in 1993, when Q fever was not reportable. This is the first officially documented case in the state. To estimate the prevalence of Coxiella burnetii infection and identify associated risk factors, we conducted a study covering the whole state. A total of 17 cases were identified among 496 sheep producers, their family members, and hired helpers. The number of sheep raised was a good predictor of C. burnetii infection. Lambing outdoors and frequent physical contacts with sheep during lambing were associated with a higher risk, but petting dogs was correlated with a lower risk. We conclude that C. burnetii infection is prevalent among sheep producers in North Dakota. As the result, Q fever became a reportable disease in North Dakota.

Adult↗