title: [Study of the mechanisms of levomycetin inactivation by the palgue causative agent and Escherichia coli with episomal and chromosomal resistance. The enzymatic acetylation of levomycetin].
abstract: One of the mechanisms of levomycetin inactivation, i.e. enzymatic acetylation of the plague causative agent and Coli bacteria with chromosomic and episomic type of resistance was studied. It was shown that resistance to levomycetin in the recombinants of the plague microbe and Coli bacteria stipulated by one and the same R-factor was associated with their capacity for the antibiotic inactivation mainly with the help of levomycetinacetyltransferase. At the same time the enzyme activity in the mutants was very low and in the cells of Y. pestis and E. coli sensitive to the antibiotic it was absent. Levomycetinacetyltransferase is to somee extent soluble, still a singificant amount of it is connected with the structures of the bacterial cells and in particular with the cytoplasmic membranes. Comparison of the activity of levomycetinacetyltransferase as dependent on the incubation time, substrate concentration, pH and thermal treatment provided determination of quantitative differences in the properties of the enzyme of Y. petis and E. coli with episomic multiple drug resistance. However, under the experimental conditions transfer of R-factor from one host to the other induced no qualitative changes in the mechanism of levomycetin inactivation.
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000378:metabolism; D002474:Cell-Free System / Q000187:drug effects; D002701:Chloramphenicol / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002876:Chromosomes, Bacterial / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology; D010957:Plasmids / Q000187:drug effects; D011815:R Factors / Q000187:drug effects; D011995:Recombination, Genetic / Q000187:drug effects; D013997:Time Factors; D015010:Yersinia pestis / Q000187:drug effects* / Q000201:enzymology
chemical_list: D002701:Chloramphenicol; D000123:Acetyltransferases
vernacular_title: Izuchenie mekhanizmov inaktivatsii levomitsetina vozbuditelem chumy i kishechnoĭ palochkoĭ pri épisomnoĭ i khromosomnoĭ rezistentnosti. Enzimaticheskoe atsetilirovanie levomitsetina