Immunodetection and N-terminal sequencing of DNA replication proteins of bacteriophage BFK20 - lytic phage of Brevibacterium flavum.

Phages are excellent models for studying the mechanism of DNA replication in prokaryotes. Identification of phage proteins involved in phage DNA replication is the first prerequisite for elucidation of the phage replication module. We focused on replication proteins gp41 (a putative helicase from SF2 superfamily), gp43 (a RepA-like protein), and gp44 (a putative DNA polymerase A) of phage BFK20 grown in Brevibacterium flavum.

Effects of LPS, lipid A and polysaccharide from adapted strains of Escherichia coli on human leucocyte activity.

Polysaccharide and lipid A are responsible for the wide-ranging pharmacological activity of bacterial lipopolysaccharides (LPS). The alterations in LPS structure result in various effects on different functions of the target cells. The effects of LPS substructures, the polysaccharide (P) and lipid A (L) from E.

Adaptive changes in fatty acids of E. coli strains exposed to a quaternary ammonium salt and an amine oxide.

Resistant strains of Escherichia coli were obtained by stepwise cultivation in media with increasing concentration of antimicrobially active 1-(methyldodecyl)dimethylamine oxide and 1-(methyldodecyl)trimethylammonium bromide. Adaptive changes were determined in the fatty-acid (FA) composition in an isolated lipopolysaccharide sample from the outer membrane of these strains. The composition of this FA mixture from adapted strains was compared with that of FA from a sensitive strain.

[Anticomplement activity of Mahonia aquifolium bisbenzylisoquinoline alkaloids and berberine extract].

Crude extracts obtained from the stem bark of Mahonia aquifolium have been investigated as to the chemical composition and anticomplementary activity. The results show that their anticomplementary activity is mainly due to the alkaloid components. Especially the BBI alkaloid fraction and berberine showed a strong inhibitory effect on CH50 total hemolytic complement assay.

Comparative study of disintegrated cells influence of Staphylococcus aureus, Escherichia coli and Candida albicans on human and mouse immune mechanisms.

The study presents comparison of immunomodulatory effects of Staphylococcus aureus, Escherichia coli and Candida albicans disintegrated cells on selected immune mechanisms of human and mouse leukocytes. We measured their phagocytic activity, phagocytic index and microbicidal activity against Staphylococcus aureus, Escherichia coli and Candida albicans cells as well as peroxidase and lysozyme activities of human and mouse leukocytes. Our results revealed predominantly inhibitory effect of disintegrated microorganisms on nonspecific immune functions of human leukocytes, but mainly stimulatory effect on mouse leukocytes monitored immune functions.