Characteristics of Factors of Protozoa Blastocystis hominis Persistence.

Persistence activity manifested in the expression of anti-lysozyme, anti-lactoferrin, and antihistone factors promoting inactivation of natural anti-infection resistance factors in the body was revealed in Blastocystis hominis protozoa. Activities of these factors were ranged. The frequency of these factors in clinical isolates of blastocyst decreased in the following order: anti-lactoferrin activity (84.5±3.7%)→anti-lysozyme activity (64.8±5.7%)→anti-histone activity (48.1±2.3%). In healthy humans, the corresponding parameters were 7.3±1.3, 5.3±0.9, and 3.3±0.4%, respectively (p<0.05). It was shown that the studied activities in highly virulent blastocysts were higher than in groups of medium-, low-, and avirulent protozoa.

The Use of Atomic Force Microscopy for Cytomorphological Analysis of Bacterial Infection Agents.

Cytomorphological signs of bacterial infection agents were studied by atomic force microscopy. Analysis of the elastic mechanical characteristics of Staphylococcus spp. from the skin of patients with chronic dermatoses showed lower elasticity of S. aureus cell membrane in comparison with that of transitory flora representatives. Significant differences in characteristics of cell membrane relief and presence of fimA pathogenicity factor were detected in E. coli isolated from the reproductive tract mucosa of clinically healthy women and patients with inflammatory urogenital infections.

The Use of Cell Elastography to Study the Biomechanical Properties of Bacillus subtilis.

The cytometric, elastic, and adhesion properties of Bacillus subtilis at different terms of culturing were studied. The cytometric parameters of bacterial cells increased by day 6 in culture and decreased at later terms. Analysis of membrane rigidity showed that parameters describing bacterial elastic properties underwent waveform changes: the decrease in bacterial elasticity (from day 1 to 6) was followed by its increase on day 12 in culture. Analysis of adhesion activity showed that this parameter increased during the first 6 days and than decreased at later stages culturing.

A comparison of phylogenetic group, virulence factors and antibiotic resistance in Russian and Norwegian isolates of Escherichia coli from urinary tract infection.

Isolates of Escherichia coli from 31 Norwegian and 31 Russian females with significant bacteruria who presented with clinical signs of urinary tract infection (UTI) were tested for antimicrobial sensitivity, the presence of virulence genes, phylogroup distribution and clonal affinity. Twenty isolates, representing the full clonal diversity of a collection of 138 intestinal isolates of E. coli from healthy Norwegian females, served as a reference group. Russian UTI isolates belonged more often to phylogroup A and possessed fewer virulence genes than did Norwegian isolates. UTI isolates of E. coli were genetically heterogeneous and had a high degree of antimicrobial sensitivity.

[An experimental model of enteric klebsiellosis]. / Eksperimental'naia model' kishechnogo klebsielleza.

Acute enteric infection was reproduced in rabbits, used as an experimental model, receiving Aspergillus flavus metabolites with food for 15 days and inoculated rectally with enterotoxigenic strain Klebsiella pneumoniae K24 6723. Pathomorphological study revealed the penetration of Klebsiella into microplicate cells of the intestinal epithelium, the proliferation of bacteria in the lamina propria and in the cupolas of Peyer's patches, as well as in phagolysosomes of leukocytes and macrophages. The lesion of the mucous membrane in both large and small intestine, accompanied by the hyperplasia of lymphoid follicles, was noted. As a rule, surface epithelium was dystrophically changed and peeled off into the lumen of the intestine. The specificity of such lesion was confirmed by the detection of Klebsiella in Coons' direct immunofluorescence test. The experimental model confirmed the role of a decrease in immunological protective reactions of the body, caused the action of A.flavus metabolites, in the development of the infectious process, initiated by opportunistic enterobacteria.

[Possible use of exclusive ghosts of autologous erythrocytes for directed transport of antibiotics]. / O vozmozhnosti ispol'zovaniia zamknutykh tenei autologichnykh eritrotsitov dlia napravlennogo transporta antibiotikov.

Incorporation of rubomycin into exclusive shades of erythrocytes amounted to 7.1 per cent, that of tetracyclines to 6.9-8.9 per cent. Determination of stability of the erythrocyte containers showed that leakage of the antibiotics proceeded during the first 30 minutes of incubation at 37 degrees C when titrated with the Hanks solution. It varied with respect to different antibiotics. With the use of blood serum for titration stability of the erythrocyte containers probably increased. After incubation for 30 minutes only traces of the tetracycline derivatives were detected in the supernatant liquid while rubomycin was not detectable at all. Therefore, the study showed that the exclusive shades of autologous erythrocytes may be in principle used for transport of water-soluble antibiotics.