OBJECTIVES Therapy of AIDS patients infected with Mycobacterium avium is problematic due to its intrinsic resistance to antibiotics. We have characterized the efflux pump activity of M. avium wild-type strain through an automated fluorometric method and correlated it with intrinsic resistance to antibiotics. METHODS M. avium ATCC 25291(T) and Mycobacterium smegmatis mc(2)155 were evaluated fo...

The solution complexes of ethidium bromide with nine different deoxydinucleotides and the four self-complementary ribodinucleoside monophosphates as well as mixtures of complementary and noncomplementary deoxydinucleotides were studied as models for the binding of the drug to DNA and RNA. Ethidium bromide forms the strongest complexes with pdCdG and CpG and shows a definite preference for inter...

Ethidium bromide intercalation strongly effects the circular dichroism spectrum of DNA in the region of 230-300 mu, in a complex manner. In this report we present a study that quantitizes the relationships of the circular dichroism spectrum in the region of 230-300 mu and the ethidium bromide induced optical activity centered around 308 mu. We present evidence of two hidden cooperative bands th...

The proliferative activity of human neoplasms may be an important determinant for therapeutic management. The advent of automated flow-through systems measuring cellular DNA content by means of fluorescence has considerably facilitated the analysis of cellular kinetics. Using a pulse cytophotometer ICP-11 (Phywe Co., Göttingen, Germany), three different fluorescent staining techniques for DNA h...

( a ) S. cerevisiae was grown for 24 h in the presence of various octenidine concentrations and in the absence (0) or presence ( m ) of ethidium bromide (10 pglml) and assayed for petite mutants. Growth conditions and petite assay were as described by Meyer & Whittaker 161. ( 6 ) S. cerevisiue was grown in the presence of ethidium bromide (10 pglml). Octenidine (0.5 pg/ml) was added after 1 h (...

OBJECTIVES By adapting an antibiotic-susceptible Staphylococcus aureus strain to increasing concentrations of ethidium bromide, a known substrate of efflux pumps (EPs), and by phenotypically and genotypically analysing the resulting progeny, we characterized the molecular mechanisms of S. aureus adaptation to ethidium bromide. METHODS S. aureus ATCC 25923 was grown in increasing concentration...

An ethidium bromide-resistant mutant (EB8) derived from a Marburg strain of Bacillus subtilis was found to be conditionally resistant to 10 mug of ethidium bromide per ml. Expression of resistance is complete only during vegetative growth at incubation temperatures above 30 C in complex medium or minimal medium supplemented with Casamino Acids. Strain EB8 is cross-resistant to acriflavine and p...