[Seroimmunologic monitoring of microorganisms of Rickettsia and Bartonella species microorganisms in the Moscow region].

Serological study of 788 blood sera, taken from residents of the Moscow region was conducted using antigens of microorganisms of the genera Rickettsia and Bartonella. The first group under examination consisted of 355 patients with diagnosed diseases of nonreckettsial nature. The second group includes 433 healthy adults working at a meat processing and packing factory.

[The laboratory diagnosis of rickettsioses].

Difficulties in the clinical diagnosis of rickettsiosis and related illnesses made it necessary to develop and improve its methods (immunoferment analysis, nondirect methods of fluorescent antibodies and polimerase chain reaction). Detailed recommendations for diagnosis of Q-fever by the level and growth of antibodies of IgG and IgA subclasses.

[The need for a review of the procedure for the preventive vaccination of researchers working with Rickettsia prowazekii].

The analysis of the results of prolonged observations on the prophylactic immunization of employees working with R. prowazekii is presented. The necessity of the differentiated approach to the determination of the immunization schedule and the choice of vaccine is shown.

Biological and genetic characterization of Rickettsia sibirica strains isolated in the endemic area of the north Asian tick typhus.

Restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction-amplified gene fragments was used to characterize 24 isolates of spotted fever group rickettsiae previously identified as Rickettsia sibirica from their serologic properties. These strains were obtained in Russia between 1946 and 1991 from humans and different species of Ixodid ticks. The RFLP analysis was performed using amplified DNA products obtained with a genus-specific primer pair derived from the R.

Genomic study of Rickettsia akari by pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis of SmaI-, EagI-, and BssHII-digested DNA was used to perform restriction fragment length polymorphism analysis of Rickettsia akari strains isolated from humans, rodents, and mites in the United States and Ukraine. Although some differences in biological and serological characteristics were present between strains, the genomic studies demonstrated a high degree of intraspecies homogeneity of R. akari isolates.

Genomic and proteinic characterization of strain S, a rickettsia isolated from Rhipicephalus sanguineus ticks in Armenia.

Strain S, a spotted fever group (SFG) rickettsia isolated from Rhipicephalus sanguineus ticks collected in Armenia, was identified. Microimmunofluorescence, sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis and Western immunoblotting, PCR and then restriction fragment length polymorphism analysis, pulsed-field gel electrophoresis, and 16S rRNA gene sequencing were used to compare strain S with reference isolates. Strain S was found to possess proteinic, antigenic, and genomic patterns which were unique among SFG rickettsiae.

Interaction of Rickettsia prowazekii strains of different virulence with white rat macrophages.

The growth of mildly pathogenic strain E, its virulent revertant EVir, and prototype virulent strain Breinl of Rickettsia prowazekii in peritoneal macrophage cultures of outbread white rats (WR) was evaluated by light microscopy and bioassay in chick embryos (CE). Macrophage cultures infected with strain E were characteristic by limited number of infected cells, poor or moderate accumulation of rickettsiae in individual cells, poor or nil spread of infectious process during first 7 days of infection, and the death of rickettsiae in cultures as determined by the bioassay in CE. Moreover, rickettsiae were not determined in 20.

Serologic response to rickettsial antigens in patients with Astrakhan fever.

Astrakhan fever is a new spotted fever group (SFG) rickettsiosis. Sera of patients with Astrakhan fever have been examined by microimmunofluorescence and western immunoblotting to determine the serologic responses to the Astrakhan strain and to R. conorii M-1 strain and the Israelian isolate of SFG rickettsiae.

Studies of Rickettsia prowazekii antigens in immunoblotting with specific sera of infected white mice.

Five strains of Rickettsia prowazekii different in origin, biological and genetic properties were compared in protein and LPS patterns by the polyacrylamide gel electrophoresis and in antigenic properties by immunoblotting with specific sera of infected white mice. Three virulent strains Breinl, G and Katsinjan had identical protein patterns and differed from isogenic pair of strains E and EVir in the electrophoretic properties of 29-30 kDa proteins. Silver-strained LPS patterns were different in five compared strains.

Genotypic characterization of rickettsiae by DNA probes generated from Rickettsia prowazekii DNA.

Southern blot analysis of HindIII-cleaved rickettsial DNA was used for genotypic characterization of the typhus group (TG) species (R. prowazekii, R. typhi, R.

Genotypic and biological characteristics of non-identified strain of spotted fever group rickettsiae isolated in Crimea.

A strain of rickettsiae, designated Crimea-108, was isolated from ticks Dermacentor marginatus in the Crimea in 1977. Its immunobiological characteristics involve low pathogenicity for experimental animals, moderate infectivity for chick embryos, and antigenic relatedness to spotted fever group (SFG) rickettsiae (R. sibirica, R.

Proteinic and genomic identification of spotted fever group rickettsiae isolated in the former USSR.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), restriction fragment length polymorphism of polymerase chain reaction-amplified genes (RFLP-PCR), and pulsed-field gel electrophoresis (PFGE) were used to identify 25 isolates of spotted fever group rickettsia collected in the former USSR. Six Rickettsia akari isolates which were identical to the MK reference strain from the American Type Culture Collection were found. Also, 14 isolates were found to be Rickettsia sibirica and identical to reference strain 246.

[Genotypic characteristics of Rickettsia sibirica strains].

Six Rickettsia sibirica strains isolated in Siberia and Far East (Primorje) from various sources (patient, ticks D. nuttali, D. silvarum, H.

Protein antigens of genetically related Rickettsia prowazekii strains with different virulence.

The protein antigens of two distinct lines of genetically related strains, namely the nonpathogenic strain E and its virulent revertant EVir and of the standard virulent strain Breinl were compared in SDS-PAGE and immunoblot assay using typhus patient sera and immune rabbit sera. No differences in the polypeptide pattern as detected in SDS-PAGE were found between strain E and EVir; the Breinl strain differed in a 30 kD protein. The high immunogenicity of the protein antigens of E, EVir and Breinl strains was demonstrated by immunoblot assay with human sera, which did not show any differences between the strains studied.

Restriction fragment length polymorphism of the DNA of typhus group rickettsiae.

The DNA of 10 strains of Rickettsia prowazekii, 5 strains of Rickettsia typhi and 1 strain of Rickettsia canada was investigated by restriction fragment length polymorphism analysis. Interspecies differences were characterized by a great number of noncomigrating bands. Using the endonuclease HindIII and PstI fragments comigration as a quantitative criterion, genetic similarity coefficient was calculated for the pair Rickettsia prowazekii/Rickettsia typhi-32.

[Serological demonstration of the detection of tick-borne rickettsial disease in Astrakhan Province].

Starting from 1978, noncontagious febrile diseases of unclear etiology, accompanied by pronounced headache, roseolous-papular eruptions, prolonged convalescence period, are registered in May-September in Astrakhan Province. These diseases can be effectively treated with chrolamphenicol. In 11 out of 12 sera obtained from such patients the complement fixation test with the antigens of rickettsiae causing tick-borne spotted fever, epidemic typhus, as well as Coxiella burnetii antigen, revealed the presence of antibodies (in 8 sera) only to the antigens of rickettsiae causing tick-borne spotted fever (R.

Properties in culture and persistence in cotton rats of the Rickettsia prowazekii vaccine strain E and its mutants.

Cultural properties and the capacity for persistence were studied in spontaneous erythromycin-resistant (E errSM), in induced erythromycin-resistant (E errI) mutants and in a virulent revertant (E Vir) of the vaccine strain E, as compared with parent vaccine strain E and standard virulent strain Breinl of Rickettsia prowazekii. Cultural properties of the strains were found to differ in passages in chick embryos (CE) and cultures of FL cells. Multiplication indices in CE of mutant E errI were significantly lower than those of other strains (E, E errSM, E Vir, Breinl).

[The rickettsial genome studied by DNA restriction analysis].

The restriction analysis of 6 Rickettsia prowazekii strains with the use of 8 restrictases (Cfr13I, EcoRI, HindIII, MSpI, MvaI, PstI, XhoI, BamHI) has been carried out. In the presence of considerable homology in the restriction pictures of DNA in these strains some differences in 1-2 fragments within the range of 8,000-20,000 nucleotide pairs have been established. The strains under study have been divided into two groups according to the character of differences in their restrictograms: the group of virulent typing strain Breinl (Breinl, G.

Restriction endonuclease analysis of the DNA of Rickettsia prowazekii vaccine strain E and its revertant.

The DNA of Rickettsia prowazekii vaccine strain E was analysed by restriction analysis with 17 endonucleases in comparison with its virulent revertant - Evir and the virulent reference strain Breinl. The DNA of cloned and uncloned strains showed identical restriction endonuclease patterns. In spite of stable differences in virulence, strains E and Evir displayed a totally identical DNA cleavage pattern indicating the absence of marked structural differences between their genomes.

Methods for purification of Rickettsia prowazekii separated from the host tissue: a step-by-step comparison.

Two methods for purification of Rickettsia prowazekii strains E, E Vir, and Breinl grown in chick embryo yolk sacs are described. These methods combine either differential centrifugation or sucrose mix, centrifugation through sucrose cushion, 10 mmol/l MgCl2 treatment, filtration through a glass filter AP-20 and 2 cycles of verografin discontinuous density gradient centrifugation. The purification procedure including sucrose mix allowed to recover about 38-42% biologically active rickettsiae, a yield which was by 10% higher than that obtained by the method beginning at differential centrifugation.