Comparison of virulence for guinea pigs and mice of different Coxiella burnetii phase I strains.

Virulence of four Coxiella burnettii phase I strains associated with acute (Nine Mile and Luga strains) and chronic (S and Priscilla strains) forms of Q fever, respectively, for outbred guinea pigs and inbred BALB/c mice was compared. In guinea pigs exposed to infectious aerosol, virulence of the strains Nine Mile, Luga and S was similar, because they all caused lethal infection and high febrile reaction (FR). By contrast, exposure to similar doses of the strain Priscilla resulted in the non-lethal infection manifested only by low, dispersed and protracted FR during a 20 day-period of observation.

[Clinical and serologic study of Czecho-Slovak citizens working in developing countries from the aspect of risk of infection with Coxiella burnetii].

In the years 1984-1988 we observed, besides the routine examinations of history, clinical state, and laboratory tests, also the presence of antibodies to Coxiella burnetii antigens by means of microagglutination reaction (MAR). The examinations were performed in our citizens returning to Czecho-Slovakia from a long termed business stay in the developing countries. Antibodies to C.

Immunoblot analysis of antibody response in mice infected with Coxiella burnetii phase I.

Mouse sera collected from day 4 to day 133 postinfection (p.i.) with phase I Coxiella burnetii strain Nine Mile were analysed by immunoblotting with phase I C.

Control of rickettsial diseases.

Prevention of rickettsial infections is aimed at individual control and epidemic measures (especially in epidemic typhus), vector and rodent control, milk pasteurization (in Q fever), chemoprophylaxis and immunoprophylaxis. In vector and rodent control, the main obstacle is the rise in resistance to insecticides and rodenticides. For this reason in vector control, apart from insecticides, enhancement of the natural immunity acquired by animals in response to tick infestation and vaccination with concealed tick antigens as well as the use of hormones, chemosterilants and genetic manipulation can also be considered.

Cell-mediated immune response to Coxiella burnetii antigens in Q fever convalescents and vaccinees.

Cellular immunity against phase I and II Coxiella burnetii antigens was evaluated by the lymphocyte blast transformation test in a) Q fever convalescents; b) persons immunized with a chemovaccine against Q fever; and c) control persons. The first two groups consisted of workers in a ricketsiology department. Of the 9 convalescents, all (100%) were positive against phase I antigen and 4 (44.

The ability of mononuclear cells to coagulate blood in response to Coxiella burnetii.

Endocarditis is a rather frequent complication of Q fever caused by Coxiella burnetii. We examined the ability of phase I (virulent) or phase II (avirulent) C. burnetii to coagulate blood in the presence of human blood mononuclear cells in vitro.

Comparison of protein and lipopolysaccharide patterns of several Coxiella burnetii strains in phase I.

Electrophoresis in polyacrylamide gel gradients in the presence of sodium dodecyl sulphate revealed at least 18 identical protein bands in eight strains of Coxiella burnetii. By staining with Coomassie Brilliant Blue R-250 it was possible to visualize clearly at least 40 proteins. The protein pattern showed the greatest variability in the region from 27 to 18.

Chemical composition of phase I Coxiella burnetii soluble antigen prepared by trichloroacetic acid extraction.

Optimal conditions of extraction (time and temperature) by trichloroacetic acid of soluble antigen from phase I Coxiella burnetii (TCAE), possessing protective properties and used as a chemovaccine against Q fever in men, were studied. Extracts prepared under various conditions were analysed for their polysaccharide, protein and phosphorus contents. Forty-five min of extraction at 0 degrees C were sufficient to obtain a soluble antigen reacting in immunodiffusion with hyperimmune rabbit antiserum.

[Differences in sensitivity of passive hemagglutination and passive hemolysis reactions in serological diagnosis of rickettsial infections].

We compared the sensitivity of indirect hemagglutination and indirect hemolysis tests by detection of antibodies in sera of man, rabbits and sheep after infection with R. slovaca, R. sibirica and C.

Q fever in Spain: acute and chronic cases, 1981-1985.

Two hundred forty-nine cases of Q fever were documented at the laboratories of the Centro Nacional de Microbiología, Virología e Inmunología Sanitarias (CNMVIS) during the 5-year period 1981-1985. Two hundred thirty-four cases corresponded to acute infections, mostly sporadic but including two epidemics. The clinical presentation was respiratory in 74% of the cases and febrile in 18%.

Coxiella burnetii antigens for detection of Q fever antibodies by ELISA in human sera.

Different concentrations of chemically-treated (by potassium periodate oxidation or mild acid hydrolysis) purified phase I Coxiella burnetii (C.b.) corpuscles and natural (untreated) purified phase I and phase II C.

Antigenicity of chloroform-methanol-treated Coxiella burnetii preparations.

Phase I Coxiella burnetii (C.b.) cells untreated (Cb I) or treated with chloroform-methanol (CM) mixture (Cb I-CM) were compared as to their capacity to induce antibodies in laboratory animals and cattle, their ability to elicit delayed type hypersensitivity (DTH) reaction in mice and rabbits and protective effect in mice.

Diagnosis and control of rickettsial diseases.

Common isolation procedures on chick embryos and laboratory animals are not of great importance for routine diagnosis of rickettsioses. Detection of rickettsiae in skin lesions by immunofluorescence technique allows early diagnosis of Rocky Mountain spotted fever (RMSF). Broad spectrum of methods is at disposal for serological diagnosis of rickettsial diseases.

Rickettsiae in the Sumava region.

Antibodies were detected to C oxiella burnetii, Rickettsia slovaca and Chlamydia psittaci in the blood of small terrestrial mammals, larger wild and domestic animals and humans in the southern part of the Protected Landscape Area of the Sumava region between 1977 and 1982. The data obtained have contributed to the safe development of livestock raising in this region.

Changing of antigenic, imumnogenic and chemical properties of a Coxiella burnetii strain during chick embryo yolk sac passaging.

Coxiella burnetii (C.b.) strain 48 after an increasing number of chick embryo yolk sac (CEYS) passages had lost at egg passages (EP) 15--20 its antigenic, immunogenic and chemical properties typical of phase I.

The value of skin test in Q fever convalescents and vaccinees as indicator of antigen exposure and inducer of antibody recall.

The skin test (ST) with Q fever chemovaccine revealed more positive reactors than the serological examination by microagglutination (MA) test among humans, who had suffered from Q fever one to eleven years ago or who had been vaccinated with Q fever chemovaccine from three months to four years ago. When examining the sera harvested either at skin-testing or two weeks thereafter by MA test, seroconversion or rise in antibody titres were found to both main Coxiella burnetii (C. b.

Isolation of Chlamydia trachomatis from urethral scrapings of men.

Two strains of Chlamydia were isolated in McCoy cell cultures and hens' yolk sacs from urethral scrapings of men suffering from "nonspecific" urethritis. Their identification as Chlamydia trachomatis was based on cytoplasmic inclusions staining with iodine and on indirect immunofluorescence with anti-LGV serum. Both tests were performed in McCoy cells.

Different antigenic properties of lipopolysaccharides isolated from Coxiella burnetii in phase I and pure phase II.

Lipopolysaccharides (LPSs) isolated from Coxiella burnetii cells in phase I and pure phase II behaved as antigens reacting in serological tests (passive haemolysis, passive haemolysis inhibition, complement-fixation, immunoprecipitation) with sera of rabbits immunized with C. burnetii strains in the corresponding phase. No cross-reactions were observed between LPSs isolated from C.

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.

Immunogenicity and reactogenicity of a Q fever chemovaccine in persons professionally exposed to Q fever in Czechoslovakia.

An immunization trial carried out on 1310 persons professionally exposed to Q fever confirmed the suitability of a chemovaccine for field use. Its immunogenicity and reactogenicity differed in three groups of subjects who differed in their previous experience of Q fever and who were given different lots of the vaccine. There was some correlation between reactogenicity of the vaccine and pre-immunization positivity in the microagglutination and skin tests as indicators of a previous exposure.

Suitability of the microagglutination test for detection of post-infection and post-vaccination Q fever antibodies in human sera.

Serological examination by the microagglutination (MA) and complement-fixation (CF) tests of human sera collected before and after vaccination with Q fever chemovaccine revealed a higher sensitivity of the MA test for detecting both pre-vaccination antibodies reflecting a previous exposure to Q fever and post-vaccination antibodies reflecting vaccine immunogenicity. In persons serologically positive before vaccination the level of post-vaccination MA antibody response was indirectly proportional to the titres of prevaccination MA antibodies.