Algorithm for prediction of reconvalescent salmonellosis carriage

Of total of 181 patients with Salmonella infection were examined by clinical and laboratory methods. As many as 124 indices characterizing biological properties of Salmonellae, a large intestine microbiocenosis status, systemic and local immunity, were investigated as well. Among these indices, the most revealing signs were defined to prognosticate the reconvalescent carrier state. Conclusion was made on the prevalence of immune mechanisms in the development of reconvalescent salmonella carriage and on the important role of the ability of a causative agent to inactivate the factors of host innate immunity in this process. Diagnostic prognosis algorithm for Salmonella bacterial carriage was worked out. Clinical testing confirmed its effectiveness.     

The seroresistance of enterobacteria isolated from different sources

395 representatives of the family Enterobacteriaceae, isolated from household and drinking water, from healthy and sick persons, were used as an example to demonstrate that their seroresistance was greatly connected with the type of the source from which these bacteria had been isolated. Experiments showed the phenotypic conversion of Escherichia coli towards an increase in their seroresistance on contact with human blood serum. The study revealed the pleiotropic effect produced by the action of serum on a number of other properties, responsible for survival in a macroorganism (anticomplement and antilysozyme activities, adhesive capacity and hydrophobic properties of the outer surface).     

Comparative analysis of the sensitivity of enterobacteria to bile

The analysis of the sensitivity of 195 enterobacterial cultures to bile revealed that their level of resistance decreased in the following row: Shigella > Salmonella > Klebsiella > Escherichia > Providencia. As shown on a sample of 136 E. coli isolates the level of resistance of these bacteria to bile depended on their isolation source: in E. coli isolated from bile in cholecystitis, from urine in pyelonephritis and from feces in intestinal dysbacteriosis resistance was 1.1-1.3 times higher than in E. coli isolated from the water of open reservoirs, from the feces of healthy persons and from extraintestinal foci of purulent inflammation. The level of sensitivity to bile is regarded as a property making it possible for enterobacteria to colonize biliary tracts and the proximal sections of the digestive tract.     

The properties of Escherichia isolated from the bodies of mice in bacterial translocation after immobilization stress

As revealed in experiments on mice, 6-hour immobilization stress initiates the process of the translocation of intestinal flora to mesenteric lymph nodes and the blood. This process is accompanied by the infection of parenchymatous organs (the liver, the spleen, the kidneys, the lungs) and the increase of the concentration of E. coli in the proximal sections of the digestive tract (the duodenum and the jejunum). As the result of the comparative analysis of the phenotypic signs of bacterial isolates obtained from intestinal and "extraintestinal" E. coli populations, the accumulation of clones with highly pronounced seroresistance and such persistence characteristics as anticomplementary and antilysozume signs, as well as resistance to the bactericidal action of leukocytic cation protein with a molecular weight of 11.0-11.5 kD, has been found to occur in the body (the blood, parenchymatous organs and the small intestine).     

Characteristics of enterobacteria isolated from patients with urogenital pathology

Species composition and a number of persistence characteristics enterobacteria isolated from urine of 42 pregnant and 22 nonpregnant women with pyelonephritis (relapse, remission), from prostatic fluid of 225 males and secretions of cervical canal of 124 women with urogenital pathology (prostatitis, salpingo-oophoritis) were studied. The study revealed that enterobacteria, including Escherichia coli, prevailed in the structure of uromicroflora (66.7-83.3%) and constituted a relatively small proportion among "genital" isolates of microorganisms (19.9-22.2%). Male and female sterility and the presence of enterobacteria in the reproductive tract of patients were found to be directly correlated. Clinical isolates of enterobacteria were shown to possess pronounced seroresistance and the complex of persistence characteristics, including antilysozyme, anti-intercidal and anticomplementary activity.     

Activity catalase and superoxide dismutase of Staphylococcus aureus during its persistence in the body

The dynamics of the level of catalase and superoxidedismutase (SOD) expression by S. aureus isolated in persistent experimental kidney infection is described. A rise in the activity of the staphylococci under study during transition of the infectious process from the alteration to persistence stage. Changes in the expression of SOD and catalase were observed simultaneously with a decrease in hemolytic, fibrinolytic and protease activity, as well as in the presence of more pronounced clumping and an increase in the production of protein A, the antilysozyme and anticomplement activity of staphylococcal clones obtained from kidney tissue. The significance of all above-mentioned phenomena in the persistence of microorganisms is discussed.     

Determination with a microelectrode of membrane potential of giant human erythrocytes obtained by La(3+)-induced fusion

The effect of La3+ on the fusion of erythrocytes of blood stored for a week at +4 degrees C was studied. It was shown that the fusion of erythrocytes begins after one day of storage of blood. The most intensive fusion of erythrocytes was observed on day 4 of blood storage. As a result, giant cells with a size of 100 microns and more arise. The electrical potential of giant cells was measured using a microelectrode and was -6.6 +/- 1.5 mV.     

Properties of Staphylococcus aureus in case of the unfavorable course of burn infection

Clinical and microbiological study of wound discharge from 35 patients demonstrated a relationship between biological properties of S. aureus, the causative agent of burn infection, and the course of the infected burn trauma. The prognostic importance of the antioxidant properties of these staphylococci was established: in cases of the unfavorable course of the burn process they showed essentially greater resistance to peroxinitrite and higher superoxide dismutase activity in comparison with the cultures isolated from patients with uncomplicated wound infection.