Serological examination of human and animal sera from six countries of three continents for the presence of rickettsial antibodies.

Forty samples each of human sera collected in Guinea Bissau, Cape Verde, El Salvador and Iran, and animal sera (goat and cattle from Sri Lanka and sheep from Tanzania) were examined for the presence of antibodies to typhus group (TG) rickettsiae, spotted fever group (SFG) rickettsiae and Coxiella burnetii by enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody (IFA) test. Of human sera tested, a higher proportion of positive sera were found with ELISA and IFA test for TG, SFG rickettsiae and C. burnetii in El Salvador (42.5 vs 20.0%, 40.0 vs 32.5%, and 27.5 vs 27.5%, respectively) and in Iran (25.0 vs 15.0%, 45.0 vs 27.5%, and 27.5 vs 25.0%, respectively), than in Guinea Bissau and Cape Verde, where they were less than 20.0% except for antibodies to SFG rickettsiae in Guinea Bissau (25.0% with ELISA and 20.0% with IFA test). While all animal sera were negative for the presence of antibodies to TG rickettsiae, a high proportion of sera from Sri Lanka reacted in ELISA and IFA test with SFG rickettsiae and C. burnetii (37.5 vs 20.0% and 27.5 vs 25.0% for goat sera, and 40.0 vs 30.0%, and 17.5 vs 15.0% for cattle sera, respectively). The results obtained indicate that the studied rickettsial diseases can be spread in given territories and may pose a public health problem requiring greater attention than has been paid so far. The suitability of ELISA and IFA test for serological survey of rickettsial antibodies is discussed.

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.

Immunochemical and antigenic characterization of Coxiella burnetii strains isolated in Europe and Mongolia.

SDS-PAGE, immunoblotting and serological methods such as microimmunofluorescence (MIF) test and ELISA were used to compare protein and lipopolysaccharide (LPS) profiles and antigenicity of 12 Coxiella burnetii strains isolated mostly from ticks in Europe and Mongolia with three reference C. burnetii strains originating from USA, namely Nine Mile from tick, Priscilla from goat placenta and S from human heart valve. Among strains from Europe and Mongolia, no significant differences in protein and LPS profiles were observed, irrespective of their origin, i.e. the country and source of isolation. The LPS profiles of these strains appeared to be more related to those of Nine Mile strain associated with acute Q fever, than to those of strains S and Priscilla associated with chronic Q fever. In immunoblots all strains isolated from Slovakia and Poland reacted more expressively with rabbit serum against Nine Mile than with serum against Priscilla strain. In the MIF test and ELISA there were no substantial differences in antibody-binding capacity between the reference and newly isolated C. burnetii strains, except for strain Priscilla reacting with homologous serum in lower antigenic concentration than other strains under study. However, in the MIF test much higher antigenic concentrations of each C. burnetii strain was required to detect antibodies in the Priscilla serum than in the Nine Mile, Luga and S sera.

Susceptibility of some species of rodents to rickettsiae.

The present study was designed to test the susceptibility of free-living rodents, viz Apodemus flavicollis, Microtus arvalis, Clethrionomys glareolus, Mus musculus, and outbred white mice from Dobrá Voda farm, CSFR, to Coxiella burnetii, rickettsiae of the spotted fever group (Rickettsia sibirica, R. conorii, R. slovaca and R. akari) and rickettsiae of typhus group (R. typhi and R. prowazekii) by various routes of administration. The highest levels of antibodies to C. burnetii were found in A. flavicollis and M. arvalis inoculated intraperitoneally and intracerebrally. Antibodies to C. burnetii exerted peak levels between days 13 and 16 in contrast to white mice which showed maximum levels on day 28. When 10(0.5) and 10(0.05) EID50/0.25 ml of C. burnetii was administered intraperitoneally to A. flavicollis, M. arvalis and white mice, the agent was detected only in organs of wild animals. In addition to spleen, the bone marrow appeared as a predilective tissue for the detection of this agent. R. akari at a dose of 10(4.5) EID50/0.25 ml caused overt illness and death in rodents. Antibody levels to R. sibirica and R. conorii were dependent on dosage, route of inoculation and duration of infection, but were not dependent on animal species. Antibodies to R. slovaca and R. akari were dependent on dosage, infection duration and animal species but were not dependent on the route of infection. For R. conorii, R. sibirica and R. slovaca a sharp increase of antibody levels with high titres on days 4-6 and peak levels about day 11 post intraperitoneal infection was characteristic. Antibody level to R. akari increased up to day 21. Spotted fever group rickettsiae in rodents inoculated intraperitoneally were observed in various organs, particularly in tunica vaginalis and spleen at days 2-8 post infection. R. typhi at a dose of 10(4.3) EID50/0.25 ml inoculated intracerebrally or intraperitoneally killed white mice and inoculated intraperitoneally killed C. glareolus and M. musculus. The antibody response of white mice to intraperitoneal, subcutaneous or intranasal inoculation of this rickettsia was low and no antibody was detected following peroral administration. M. musculus did not develop antibodies after intracerebral, intranasal, subcutaneous or peroral inoculation of R. typhi. The target organs for this rickettsia were the spleen and tunica vaginalis. R. prowazekii inoculated intraperitoneally into white mice at a dose of 10(6.5) EID50/0.25 ml and at a dose of 10(4.5) EID50 into C. glareolus was fatal for these rodents.(ABSTRACT TRUNCATED AT 400 WORDS)

Extensive examination of different tick species for infestation with Coxiella burnetii in Slovakia.

Between 1987-1989 almost 7000 adult Ixodes ricinus, Dermacentor reticulatus, Dermacentor marginatus, Haemaphysalis concinna, Haemaphysalis punctata and Haemaphysalis inermis ticks collected in all 38 districts of Slovakia were screened for the presence of Coxiella burnettii. The proportion of ticks containing C. burnetii as indicated by the haemocyte test was less than 3%. Attempts to recover C. burnetii by inoculation of yolk sacs of embryonated hen eggs from pools of 1-6 specimens of haemocyte test positive ticks resulted in the isolation of 10 rickettsial strains. Six strains were recovered from I. ricinus, the remaining ones from single pools of D. reticulatus, D. marginatus. H. concinna and H. inermis ticks. In addition to the previous recovery of C. burnetii from H. punctata ticks, the agent was thus isolated from all important ticks living in Slovakia. The agent was found in tick habitats regardless of the latitude and altitude in the entire country. These results are not consistent with the negligible number of Q fever cases occurring in past years in Slovakia.

[The effect of serial passage of Coxiella burnetii in chick embryos on pathogen phase variability]. / Vliianie kratnosti passirovaniia koksiella berneta na kurinykh émbrionakh na fazovuiu izmenchivost' vozbuditelia.

Coxiella burnetii has been investigated in different egg passages (EP-17, 163). Coxiella in EP 163 was completely eliminated from the suspension during the purification but not that in EP 17. It means that the coxiella of the two EP with a seroreaction of phase II are different, and phase II positivity of EP 17 can't be the result of presence of two populations in the suspension or of one mutation during the multiplication in yolk sacs but of a change on the surface of C. burnetii.

Diagnosis of endocarditis in acute Q-fever by immunofluorescence serology.

The authors compared two groups of 20 patients suffering from Q fever using microimmunofluorescence (micro IF) serology. One group had endocarditis and the other conventional symptoms of acute Q fever but no endocarditis. Determination of the levels of antibodies against the two phases of rickettsiae in each of the three immunoglobulin classes (IgG, IgM and IgA), allowed to determine the type of infection using a single serum sample. Patients having IgA class antiphase I antibodies at a level equal to/or higher than 1:25 as well as those whose antibody levels fulfilled the conditions for the equation (IgG anti-phase I greater than or equal to IgG anti-phase II) + (IgA anti-phase I greater than or equal to IgA anti-phase II) were suffering from endocarditis. The positive predictive value of these tests was 100% and 94.1%, respectively.

[Study of the reactivity and immunogenicity of a combined vaccine against abortion due to coxiellosis and chlamydiosis in sheep]. / Sledovanie reaktogénnosti a imunogénnosti kombinovanej vakcíny proti koxielóze a chlamýdiovému potratu oviec.

Reactogenicity was studied in a combined vaccine against Q-fever and chlamydia-induced abortion in ewes; the vaccine consisted of a mixture of purified corpuscles of Chlamydia psittaci (100 micrograms) and Coxiella burnetii (50 micrograms). The immunogenicity of the combined vaccine, evaluated by the number of positive serums after vaccination and by the average geometric titre of antibodies, was the same as that of the vaccine separate constituents as to the antibodies to C. burnetii, but somewhat higher in the case of antibodies to Chlamydia psittaci. When studied on a smaller number of ewes, the combined vaccine had an optimum immunogenicity in the cases of the prevalence of Chlamydia psittaci over C. burnetii in the vaccine.

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.

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.

First report of an infection with Rickettsia slovaca.

A description was given of an infection with Rickettsia slovaca following a tick bite. The clinical picture was that of an acute meningoencephalitis. Its etiology was confirmed serologically by an increase in complement-fixating antibodies, from negative values to diagnostically significant titers. There were febrile relapses and a prolonged persistence of neurasthenic disorders.

Suitability of Coxiella burnetii strains for preparation of phase II artificial diagnostic antigen for microagglutination test.

Sensitivity in the microagglutination (MA) test of artificial (prepared by potassium periodate treatment) phase II Coxiella burnetii antigens depended on the C. burnetii strain used and the number of its chick embryo yolk sac passages.

Rickettsiae of the spotted fever group in Hungary.

Rickettsiae were detected by haemocyte test in 7.2% of Dermacentor marginatus and 4.7% of D. reticulatus ticks collected in Hungary. Six strains of rickettsiae were isolated from positive specimens. These rickettsiae according to CFR are closely related, probably identical with R. slovaca and they represent the first rickettsiae of the Spotted Fever group found in that country.