Improvement of the method for the indication of the causative agent of anthrax

A combined method for the indication of the causative agent of anthrax (Bacillus anthracis), including the preparation of the material to be tested, the exposure of the magneto-imunosorbent in the sample, cultivation in selective medium, DNA extraction with subsequent testing in the polymerase chain reaction with primers to genes cap, pag and chromosomal sequence Ba813, the registration and interpretation of results, has been developed. All determinations, including the preparation of samples, last not more than 6 hours. The indication of B. anthracis by the proposed method makes it possible not only to confirm its presence in the sample Under test, but also to evaluate its epidemic potential.     

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.     

Capsule formation in the causative agent of glanders

Electron-microscopic and electron-cytochemical method were used to indicate the capability of Pseudomonas mallei (str. N 10230) to produce extracellular slime during the agent growth on the meat-peptone agar. In case of guinea pigs infection the agent forms a capsule that defends the pathogen from phagocytosis.     

Protein phosphorylation in the causative agent of plague

The phenomenon of the reversible phosphorylation of proteins has been discovered in Y. pestis cells. Eight proteins with a molecular weight of 30-80 kilodaltons have been found capable of phosphorylation. The intensity of phosphorylation has been found to be influenced by the temperature of cultivation and the composition of the incubation medium. This newly found phenomenon of the chemical modification of proteins is supposed to play a certain role in the organization of rapid responses of the cell to changes in the environment.     

Circulation of the causative agent of diphtheria in immune collectives

Prolonged observations on the spread of toxigenic C. diphtheriae carriership, made during a school year in 12 groups of immune children (3809 children), showed that the penetration of diphtherial infection could give rise to the outbreak of bacterial carriership, its level being as high as 20.9-35.1% of the total number of children in the group. The spread of bacterial carriership occurred during the first months after the penetration of the infection, achieving its peak, then followed the subsidence of the infection in the focus. Though some children in the group persistently released C. diphtheriae, almost no new cases of carriership were registered in spring. The highest spread of carriership (55.6-73%) was revealed in the first forms of boarding schools despite a higher level of antitoxic immunity in these children. Cases of the spontaneous cessation of carriership were observed. The spread and subsidence of carriership were determined by the presence or absence of a susceptible contingent. Tests on guinea pigs, carried out in the course of this study to determine the toxigenicity of C. diphtheriae, showed its variability.     

Proteomics analysis of the causative agent of typhoid fever

Typhoid fever is a potentially fatal disease caused by the bacterial pathogen Salmonella enterica serotype Typhi ( S. typhi). S. typhi infection is a complex process that involves numerous bacterially encoded virulence determinants, and these are thought to confer both stringent human host specificity and a high mortality rate. In the present study, we used a liquid chromatography-mass spectrometry (LC-MS)-based proteomics strategy to investigate the proteome of logarithmic, stationary phase, and low pH/low magnesium (MgM) S. typhi cultures. This represents the first large-scale comprehensive characterization of the S. typhi proteome. Our analysis identified a total of 2066 S. typhi proteins. In an effort to identify putative S. typhi-specific virulence factors, we then compared our S. typhi results to those obtained in a previously published study of the S. typhimurium proteome under similar conditions ( Adkins, J. N. et al. Mol. Cell. Proteomics 2006, 5, 1450-1461 ). Comparative proteomics analysis of S. typhi strain Ty2 and S. typhimurium strain LT2 revealed a subset of highly expressed proteins unique to S. typhi that were exclusively detected under conditions that are thought to mimic the infective state in macrophage cells. These proteins included CdtB, HlyE, and gene products of t0142, t1108, t1109, t1476, and t1602. The differential expression of T1108, T1476, and HlyE was confirmed by Western blot analysis. When our observations are taken together with the current literature, they suggest that this subset of proteins may play a role in S. typhi pathogenesis and human host specificity.     

The glycolipids of the causative agent of tularemia]

Up to 10 glycolipids were detected in F. tularensis with the use of thin-layer chromatographic techniques. These glycolipids were slime antigens of F. tularensis membrane. Attenuated F. tularensis strains were found to have defects in their glycolipid composition: in the vaccine strain glycolipid 8 was replaced by more polar lipid 8-a; the avirulent strain had only two glycolipids, and one of them was not typical for virulent strains. Considering that glycolipids differed from entero-bacterial Vi-antigen in their physical-chemical and biological properties, the suggestion was made that the use of the symbol "Vi" to denote the surface substances of F. tularensis should be abolished.     

Sensitivity of the causative agent of tularemia to antibiotics

Sensitivity of the tularemia causative agent of different geographical races to antibiotics such as streptomycin, tetracycline, gentamicin, rifampicin (20 strains), ampicillin, polymyxin M, erythromycin, oleandomycin (361 strains) and lincomycin (294 strains) was studied. High sensitivity of the tularemi a microbe to streptomycin, tetracycline, rifampicin (MIC of 10 gamma/ml), gentamicin (MIC of 1 gamma/ml) and resistance to 50 gamma of ampicillin and 1000 gamma/ml of polymyxin M were found. Combined use of 50 gamma of ampicillin and 100 gamma/ml of polymyxin M added to the nutrient medium for growth inhibition of the foreign flora on isolation of the tularemia causative agent from the infected material including stable laboratory animal carcases was recommended. Marked differences in sensitivity of the strains of different geographical races to the macrolides and lincomycin were observed. The strains of the non-Arctic and Central Asiatic races were of low resistance to the above drugs (the MIC of erythromycin, oleandomycin and lincomycin were 10--50, 50--400 and 25--100 gamma/ml respectively. Within the holarctic race 40 per cent were low resistant and 60 per cent were highly resistant to these drugs. The above drugs should not be used for treatment of tularemia cases.     

Geographical variability of the causative agent of zoonotic cutaneous leishmaniasis

A study of the phenetics of the zoonotic cutaneous leishmaniasis agent in Uzbekistan and subzone of southern and northern deserts has made it possible to separate a northern population (or a group of populations) of the agent. It differs from the southern population (or southern ones) in having smaller sizes of the amastigote stage, greater abundance of parasites in cutaneous affections of gerbils, milder progress of leishmaniasis in white mice and great gerbils. This population can be called priaral, i.e. belonging to the subzone of northern deserts of the Turan lowland.