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The antibacterial and antiparasitic activities of free oleanolic acid and its glucosides and glucuronides isolated from marigold (Calendula officinalis) were investigated. The MIC of oleanolic acid and the effect on bacterial growth were estimated by A600 measurements. Oleanolic acid's influence on bacterial survival and the ability to induce autolysis were(More)
The plant pentacyclic triterpenoids, oleanolic and ursolic acids, inhibit the growth and survival of many bacteria, particularly Gram-positive species, including pathogenic ones. The effect of these compounds on the facultative human pathogen Listeria monocytogenes was examined. Both acids affected cell morphology and enhanced autolysis of the bacterial(More)
Studies on new antibacterial therapeutics and strategies are currently being conducted in many microbiological, pharmaceutical and biochemical laboratories. The antibacterial activity of plant-derived compounds as well as silver and gold nanoparticles is the subject of this minireview. The application of photodynamic therapy is also discussed.
Antibiotic resistance among bacterial pathogens is a serious problem for human and veterinary medicine, which necessitates the development of novel therapeutics and antimicrobial strategies. Some plant-derived compounds, e.g. pentacyclic triterpenoids such as oleanolic acid (OA) and ursolic acid (UA), have potential as a new class of antibacterial agents as(More)
The frequency of spontaneous as well as induced reversions of auxotrophic mutations in Escherichia coli AB1157 and its DeltadnaK and DeltadnaKdnaJ derivatives was estimated. The obtained results demonstrate that both mutants tested are characterized by elevated frequency of spontaneous reversions compared to their AB1157 parent. In contrast, the frequency(More)
In the environment horizontal DNA transfer between various bacterial species and genera takes place by transformation, transduction, but mainly by conjugation. Conjugation is responsible for the spread of genes coding for antibiotic resistance and xenobiotic degradation. Transfer events are reported in animal, rhizosphere and phylloplane ecosystems and in(More)
Escherichia coli null dnaJ and dnaKdnaJ mutants were defective in the biosynthesis and secretion of several enzymes. The synthesis of beta-galactosidase induced in delta dnaJ and delta dnaKdnaJ mutants was abolished at 42 degrees C and significantly decreased at 30 and 37 degrees C. The activity of alkaline phosphatase in the periplasm in both mutant(More)
The effect of mutations indnaK anddnaJ genes on the expression of two operons that are part of cysteine regulon was determined usingEscherichia coli strains harboringcysPTWA::lacZ andcysJIH::lacZ fusions. NulldnaJ, anddnaKdnaJ mutants were impaired in β-galactosidase expression from both fusions. Effecient complementation of this defect by wild-type alleles(More)
The role of two chaperone proteins, DnaK and the cooperating factor DnaJ, in Escherichia coli antibiotic susceptibility to three antibiotics (a beta-lactam, chloramphenicol, tetracycline) has been studied. It was found that null dnaJ and dnaKdnaJ mutants are impaired in the functions leading to antibiotic susceptibility. The secretion of beta-lactamase to(More)