Experimental anthrax infection in laboratory animals with differing species susceptibility to the causative agent

In guinea pigs and noninbred white mice, infected subcutaneously with anthrax which resulted in their death, characteristic generalized infection with the hematogenic contamination of their organs and the signs of intoxication and shock could be observed. In inbred white rats (Fisher 344) the invasion and dissemination of B. anthracis are relatively slightly pronounced, the phenomena of intoxication and shock being clearly prevalent.     

Cross-reacting antigens of pathogenic Burkholderia and some dangerous causative agents of infectious diseases

Cross-reacting antigens in B. mallei, B. pseudomallei, B. thailandensis, Francisella tularensis, Yersinia pestis and Mycobacterium tuberculosis were studied with the use of immuno- and electrophoretic techniques. The set of antigens was shown to be almost identical in the causative agents of glanders, melioidosis, as well as in B. thailandensis, though in the latter organism 200-kD glycoprotein was absent. The analysis of immuno- and proteinograms demonstrated the presence of cross-reactions in the representatives of the genus Burkholderia with the causative agents of plague, tularemia and tuberculosis, which served as the basis for making the scheme of their antigenic relationships. The use of immunosorption techniques with subsequent analysis of the preparations by means of the SDS polyacryl gel electrophoresis and immunoblotting made it possible to characterize cross-reacting antigens of the pathogenic microorganisms under study, to establish their molecular weights (81-15 kD) and to show that some detected antigens are analogous to B. pseudomallei outer membrane proteins (34 and 30 kD).     

Opportunistic microorganisms: the causative agents of food toxicoinfections and acute intestinal diseases

The analysis of sporadic morbidity due to acute intestinal infections and toxicoinfections caused by potentially pathogenic microorganisms is presented. The hypothesis stating that different pathogenic agents have different levels of pathogenic potential at a given stage of their evolution is proposed. Microorganisms with a low level of pathogenicity potential are characterized by the prevalence of the syndrome of toxicoinfection and by the rarity or absence of the syndrome of an acute intestinal disease. The prevalence of the latter is characteristic of potentially pathogenic microbes with a high level of pathogenicity potential making them similar to complete parasites.     

Specific antigens of the causative agents and their antibodies in the circulating immune complexes in acute dysentery

The level of circulating immune complexes has been determined in 53 patients in the dynamics of the disease. For the first time circulating immune complexes have been found to contain Shigella sonnei K-antigen and Shigella flexneri O-antigen, as well as IgA, IgG and IgM to Shigella. Shigella antigens can be detected from the first week of the disease, and their occurrence does not depend on the level of circulating complexes in patients blood serum.     

HLA DR antigens and susceptibility to insulin-dependent diabetes mellitus.

Two novel analytic methods to evaluate the roles of the HLA alleles of the human major histocompatibility complex in disease predisposition have been formulated and applied to insulin-dependent diabetes mellitus (IDDM). The HLA-DR antigens, as they are presently defined, are shown not to directly predispose individuals to IDDM. This result does not discount the possibility that subdivision of the DR antigens will yield the predisposing agents. In Caucasian populations, after consideration of the predisposing effect of the antigens DR3 and DR4, the protective effect of DR2 in predisposition is demonstrated. Additionally, DR1 and possibly DRw8 exhibit a higher than expected frequency in patients.     

Comparative population study of the etiological role of causative agents of purulent inflammatory diseases and serum antibodies to antigens of opportunistic microorganisms

The comparative study of the relationship between the levels of serum antibodies to the antigens of opportunistic microorganisms of 5 genera (Pseudomonas, Proteus, Staphylococcus, Klebsiella, Escherichia) and the microbial status was carried out. A total of 854 patients from 10 profile departments of a surgical hospital were examined. Population analysis and statistical methods of processing the results of the examination of 353 practically healthy subjects and 268 blood and plasma donors permitted the norms for the levels of specific antimicrobial antibodies (decreased, normal, elevated levels) were established. The constancy coefficients of Pseudomonas, Staphylococcus, Klebsiella, Escherichia and the number of patients with elevated titers of specific serum antibodies were found to be positively correlated (r = +0.47-0.89, p < 0.01). The data thus obtained made it possible to substantiate the importance of population serological investigations for the evaluation of the epidemiological situation in the surgical hospital.     

HLA class II polymorphisms and susceptibility to recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is characterised by multiple laryngeal papillomas. Left untreated, the lesions enlarge, spread, and endanger the airway. Medical treatments are unsatisfactory, and repeated surgery remains the mainstay of therapy. RRP is caused by human papillomavirus (HPV) infection. However, since oral HPV infection is common and RRP is rare, other host and/or viral factors may contribute to pathogenesis. In an attempt to identify such factors, we have investigated 60 patients. The patients were HLA class I, II, and tumor necrosis factor TNF typed by sequence-specific primer PCR, and the results compared to those for 554 healthy controls by using Fisher's exact test. Peripheral blood mononuclear cell proliferative responses of 25 controls and 10 patients to HPV-11 L1 virus-like particles (VLP) were compared. Short-term VLP-specific T-cell lines were established, and recognition of L1 was analyzed. Finally, the L1 open reading frames of HPV isolates from four patients were sequenced. Susceptibility to RRP was associated with HLA DRB1*0301 (33 of 60 patients versus 136 of 554 controls, P < 0.0001). The three most severely affected patients were homozygous for this allele. A range of T-cell proliferative responses to HPV-11 VLP were observed in DRB1*0301-positive healthy donors which were comparable to those in DRB1*0301-negative controls. Individuals with juvenile-onset RRP also mounted a range of VLP responses, and their magnitude was negatively correlated with the clinical staging score (P = 0.012 by the Spearman rank correlation). DRB1*0301-positive patients who responded to L1 recognized the same epitope as did matched controls and produced similar cytokines. Sequencing of clinical isolates excluded the possibility that nonresponsiveness was the result of mutation(s) in L1.     

Mechanism of the transmission of the causative agents of infectious diseases

Another interpretation, differing from the commonly acknowledged one, of the transfer mechanism is presented. The factors transporting pathogens in the body are the integral part of the transfer mechanism. They ensure the interrelation of the infectious and epidemic processes. In typical contact infections these factors function integrally as the transfer mechanism consisting of two components. This is the sum total of environment and internal factors, specific for a given pathogenic species. These factors ensure the travel of the pathogens from an infected body to a new one. From this viewpoint, the source of infection cannot be an independent element of the infectious process. It is only a transfer factor. The localization of the pathogen, constituting just one of the stages of its travel route in the body, cannot determine the specificity of the transfer mechanism. Its specificity depends on the properties of the pathogen.     

Use of the toxin-tissue receptor reaction for detecting toxic substances of the causative agents of acute intestinal diseases

The possibility of using erythrocytic ganglioside diagnostic reagents (EGDR) for the detection of V. cholerae, E. coli and S. typhimurium enterotoxins in the passive hemagglutination (PHA) test has been shown. Museum strains and cultures isolated from patients with acute intestinal diseases were tested for the presence of enterotoxins. Cell-free extracts were studied by biological methods and by serological titration in the PHA test with the use of EGDR. The diagnostic reagent was found to interact only with those enterotoxins whose specific receptors were gangliosides GM1.     

The HLA system antigens in delayed sexual development

Frequency distribution of HLA antigens of A and B loci was examined in 138 adolescent boys aged 14-18 with delayed sexual development (DSD) of stages I-III, residing in the north-eastern region of Ukraine. Increase of A28- and B40-antigens and haplotypes A1-B40, A28-B40, A10-B40 determination frequencies was established. There were revealed positive and negative correlation between some of HLA antigens and DSD. Relative and attributive risks of DSD formation were calculated.     

Etiology of purulent septic diseases and the antibiotic resistance of the isolated causative agents

Among the causative agents of purulent septic diseases in the surgical hospital, 25 microbial species were isolated; of these, the prevailing species were Staphylococcus aureus (19.86 +/- 1.07%), Escherichia coli (16.5 +/- 0.99%) and Pseudomonas aeruginosa (10.06 +/- 0.8%). From environmental objects in the hospital 14 microbial species were isolated, among them bacteria of the genus Enterobacter (27 +/- 1.7%), E. coli (19.07 +/- 1.48%), S. aureus (14.7 +/- 1.31%), Klebsiella pneumoniae (13.73 +/- 1.31%), P. aeruginosa (7.33 +/- 0.98%). During 3 years of observation the isolation rate of K. pneumoniae from different environmental objects was found to increase threefold to 24.7 +/- 2.7%. The results of the study of the microbial picture in surgical hospitals, as well as the antibiotic resistance of circulating causative agents, should be borne in mind while taking epidemic control measures.     

Blood antigens in the AB0 system and susceptibility of humans to diphtheria

The analysis of a large number of diphtheria cases (1326) at the peak of diphtheria morbidity in Russia (1993-1994) revealed that the intensity of antidiphtheria antitoxic immunity was age-dependent with a sharp immunodeficiency in the population aged 35 years and older. As adaptive capacity of the organism decreases, the positive associative links between immunity to diphtheria and the AB0 blood groups become evident. Populations with phenotype B (III) had the largest diphtheria immune stratum at the age of 35 years and over as compared to 3 other phenotypes. The genotypic analysis of serological data may be of practical importance for the detection of the degree of predisposition of humans to infectious diseases.