Ultrastructural study of chitosan effects on Klebsiella and staphylococci.

Antibacterial effect of chitosan on the morphofunctional organization of clinical strains of Klebsiella pneumoniae and Staphylococcus aureus was studied by transmission electron microscopy. Chitosan promoted aggregation of bacterial cells and disorganization of bacterial cell wall and cytoplasmic membrane, which leads to the release of bacterial contents into the environment. These structural changes result in bacterial death.

[Antibacterial effects of water-soluble low-molecular-weight chitosans on different microorganisms].

Low-molecular-weight chitosans with a viscosity-average molecular weight (Mv) of 5 to 27 kDa and equal degree of deacetylation (DD, 85%) were highly active against Pseudomonas aureofaciens, Enterobacter agglomerans, Bacillus subtilis, and Bifidobacterium bifidum 791, causing death of 80 to 100% of cells. An exception to this tendency was Escherichia coli, for which the rate of cell death, induced by the 5-kDa chitosan, was 38%. The antibacterial effect was manifested as early as 10 min after incubation of 12-kDa chitosan with B.

[Search for biological remedies for fungi of the Candida genus].

51 bacterial strains were studied with a view to find out anticandidial activity; of these, 15 strains were found to have activity, more on less expressed with respect to fungi of the genus Candida. In most cases the anticandidial activity of an antagonist strain was manifested to a similar degree against several Candida strains. The preliminary analysis of antifungal substances produced by microbial strains makes it possible to suggest their antibiotic nature.

[The pathogenesis and treatment of infectious-toxic shock].

The kallikrein-kinin and coagulation systems of the blood and histamine were examined in 56 patients with infectious-toxic shock. Severe shock was characterized by high histaminemia, excessive activation of prekallikrein along with low compensatory activity of kallikrein and histamine inhibitors. Changes of the coagulograms evidence manifestations of the PIC-syndrome.