ABSTRACT
The study dealth with effects of cationic detergents miramistin (alkylamidopropyldimethylbenzylammonium chloride), catamine AB (alkyldimethylbenzylammonium chloride) and the anionic compound sodium dodecyl sulphate (SDS) on the elimination from E. coli cells of plasmids determining the Hly, Ent and, indirectly, Col, F, and R markers of pathogenicity as well as their transfer upon conjugation. At subbacteriostatic concentrations, miramistin and catamine AB were found to suppress the transfer of Hly, Ent, F, and R plasmids during conjugation when applied to the donor, recipient or added to the conjugation medium without, however, eliminating plasmids. This is due to the disruption by detergents of F, J pili and other surface cell structures resulting in diminished ability to conjugate. Anionic SDS eliminated F and R plasmids without affecting Hly, Ent and Col.
Subject(s)
Detergents/pharmacology , Escherichia coli/drug effects , Plasmids/drug effects , Surface-Active Agents/pharmacology , Benzalkonium Compounds/pharmacology , Conjugation, Genetic/drug effects , Escherichia coli/genetics , Quaternary Ammonium Compounds/pharmacology , Sodium Dodecyl Sulfate/pharmacologyABSTRACT
The effect on microorganisms of electromagnetic and magnetic fields (EMF, MF), the frequency and intensity of which were similar to natural ones, was studied. They were found to influence the physiology of bacteria. Changes in the rate of proliferation of microbes, in their susceptibility to antibiotic the frequency of formation of recombinants and partial diploids during conjugation of colibacterium were observed during cultivation in these fields.
Subject(s)
Ecology , Electromagnetic Fields , Electromagnetic Phenomena , Magnetics , Bacillus anthracis/physiology , Cell Division , Escherichia coli/physiology , Klebsiella pneumoniae/physiology , Microbial Sensitivity Tests , Salmonella typhimurium/physiology , Shigella sonnei/physiology , Staphylococcus aureus/physiologyABSTRACT
Hly plasmide of wild type and its derepressive (by transmission) mutant communicated to the E. coli cells an increased resistance to the action of ultraviolet rays. Hly plasmide failed to compensate the defects associated with the excision and postreplicative DNA reparation or the reparative DNA synthesis. Hly plasmide increased the resistance to the ultraviolet light in the lon--mutant in which the ultraviolet irradiation disturbed the process of cell division. It is supposed that the resistance to the ultraviolet light connected with Hly plasmide was caused by the influence of the plasmide on some stages of cell division following the ultraviolet irradiation.
