ABSTRACT
The interferon inducing abilities of eleven ethanolic extracts obtained from nine taxons of Polygonum L. genus, were tested in the cell culture of monkey kidney. The extracts from the herb of Polygonum amphibium L. and the rhizome and fruit of Polygonum bistorta L. induced a substance showing an interferon-like activity. Biological activity studies showed that the protective titre (the highest dilution which protected cells by 50% against virus infection) of the interferon-like materials was 1:10-1:15.
Subject(s)
Antiviral Agents/pharmacology , Interferon Inducers/pharmacology , Interferons/pharmacology , Polygonaceae/chemistry , Cell Line , Enterovirus B, Human/drug effects , Humans , Microbial Sensitivity Tests , Plant Extracts/pharmacologyABSTRACT
Washed cells of the cadmium-sensitive Staphylococcus aureus 17810S accumulated 109Cd under anaerobic conditions via the Mn2+ porter down delta psi in 1 or 100 mM phosphate buffer, pH 7; in washed cells of the cadmium-resistant S. aureus 17810R 109Cd accumulation was highly reduced. Nigericin did not stimulate anaerobic Cd2+ accumulation by strain 17810R in 100 mM phosphate buffer, suggesting that delta psi could energize Cd2+ efflux. In 1 mM phosphate buffer nigericin restored Cd2+ accumulation via the Mn2+ porter down delta psi in strain 17810R, indicating involvement of delta pH in Cd2+ extrusion. Increase of phosphate buffer concentration from 1 to 100 mM and addition of energy source at steady-state caused delta psi-dependent Cd2+ efflux from the nigericin-pretreated cells of strain 17810R. This suggests that the Cd2+ efflux system in S. aureus may require energy of both ATP and delta mu H+.
Subject(s)
Cadmium/pharmacology , Staphylococcus aureus/metabolism , Adenosine Triphosphatases/metabolism , Anaerobiosis , Buffers , Cadmium/metabolism , Drug Resistance, Microbial , Kinetics , Staphylococcus aureus/drug effectsABSTRACT
The effect of Cd2+ on aerobic and anaerobic growth was studied in the Cd2+-resistant Staphylococcus aureus 17810R which harbours the cadA and cadB markers on a penicillinase plasmid pII17810. Also the effect of Cd2+ on growth of the plasmidless strain 17810S, sensitive to Cd2+ was investigated. The results indicate that under all growth conditions the Cd2+-resistant S. aureus 17810R is protected against Cd2+ toxicity up to 100 microM Cd2+ by the 2H+/Cd2+ antiporter, the product of the cadA gene. Energetics of growth of both strains under various conditions is also discussed.
Subject(s)
Cadmium/pharmacology , Drug Resistance, Microbial , Staphylococcus aureus/growth & development , Anaerobiosis , Culture Media , Ionophores/pharmacology , Staphylococcus aureus/drug effectsABSTRACT
The effect of Cd2+ on [14C]-glutamate transport energized by endogenous respiration and on glutamate oxidation was studied in the Cd2+-resistant and -sensitive Staphylococcus aureus strains. The results indicate that these processes are protected against 10 microM Cd2+ in the Cd2+ resistant strain 17810R by the 2H+/Cd2+ antiporter encoded by the cadA determinant located on a penicillinase plasmid p II17810. Even at 100 microM Cd2+, glutamate oxidation was only partially inhibited in this organism and this inhibition appeared to be reversible. In the plasmidless variant strain 17810S, which lacks the 2H+/Cd2+ antiporter, both [14C]-glutamate transport and its oxidation was blocked by Cd2+ at 10 or 100 microM. In this strain, Cd2+-mediated inhibition of glutamate oxidation was irreversible. Energetics of glutamate transport in both strains was analyzed.
Subject(s)
Cadmium/pharmacology , Glutamates/metabolism , Plasmids , Staphylococcus aureus/metabolism , Biological Transport , Culture Media , Drug Resistance, Microbial , Glucose/pharmacology , Ionophores/pharmacology , Oxidation-Reduction , Staphylococcus aureus/drug effectsABSTRACT
The aim of the study was to evaluate an influence of Cd++ on 14C-glucose uptake by two strains of S. aureus resistant and sensitive to cadmium in 0.1 M phosphate buffer, pH 7.0. Uptake of this sugar in both strains is an active process in which energy comes from oxidation of endogenous substrates, what was shown in aerobic condition, anaerobic condition at temperatures of 37 degrees C and 4 degrees C, and with p-CMB and CCCP. In the resistant strains Cd++ at 10 microM concentration did not inhibit endogenous respiration, 14C-glucose uptake and its oxidation. This is due to presence of energy-dependent system of 2H+/Cd++ antiport coded by cadA genes located on penicillinase pII17810 plasmid, which eliminated Cd++ from bacterial cell. In the case of plasmid free variant deprived of this system, Cd++ is retained in cytoplasm and blocks endogenous respiration uptake, and oxidation of glucose.
