Learn More
BACKGROUND Membrane permeability is the first step involved in resistance of bacteria to an antibiotic. The number and activity of efflux pumps and outer membrane proteins that constitute porins play major roles in the definition of intrinsic resistance in Gram-negative bacteria that is altered under antibiotic exposure. METHODOLOGY/PRINCIPAL FINDINGS(More)
The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these(More)
The phenothiazines chlorpromazine (CPZ) and thioridazine (TZ) have equal in vitro activities against antibiotic-sensitive and -resistant Mycobacterium tuberculosis. These compounds have not been used as anti-M. tuberculosis agents because their in vitro activities take place at concentrations which are beyond those that are clinically achievable. In(More)
Promethazine has been recognised as an effective antiplasmid agent in cultures containing a single bacterial species such as Escherichia coli, Yersinia enterocolitica, Staphylococcus aureus and Agrobacterium tumefaciens. The objective of this study was to examine the effect of heterogenity of the microbial flora on plasmid elimination by promethazine in a(More)
Resistance to isoniazid (INH), one of the main drugs used in tuberculosis (TB) therapy, is mostly due to chromosomal mutations in target genes. However, approximately 20-30% of INH resistant Mycobacterium tuberculosis isolates do not have mutations in any of the genes associated with INH resistance. This suggests that other mechanism(s) may be involved,(More)
Chemoresistance presents a general health problem concerning the therapy of infectious disease and cancer. In this context, the worldwide dissemination of "multidrugresistant" (MDR) pathogens has severely reduced the efficacy of our antimicrobial weapons and dramatically increased the frequency of therapeutic failure. Because MDR bacterial infections(More)
BACKGROUND Human monocyte-derived macrophages that have little killing activity of their own kill intracellular Staphylococcus aureus when cultured in the presence of inhibitors of calcium and potassium efflux pumps. The aim of this study was to evaluate the effect of inhibitors such as ouabain, reserpine and verapamil in the killing activity of macrophages(More)
Diclofenac sodium (Dc), an anti-inflammatory agent, has remarkable inhibitory action both against drug-sensitive and drug-resistant clinical isolates of various Gram-positive and Gram-negative bacteria. The aim of this study was to determine the ability of Dc to protect mice from a virulent Salmonella infection. Dc injected at 1.5 microg/g and 3.0 microg/g(More)
The effect of thioridazine (TZ) was studied on the killing activity of human peripheral blood monocyte derived macrophages (HPBMDM) and of human macrophage cell line THP-1 at extracellular concentrations below those achievable clinically. These macrophages have nominal killing activity against bacteria and therefore, would not influence any activity that(More)
The worldwide dissemination of «multi-drug resistant» (MDR) pathogens has severely reduced the efficacy of our antibiotic arsenal and increased the frequency of therapeutic failure. MDR bacteria over-express efflux pumps and this active mechanism can extrude all classes of antibiotics from the cell. It is necessary to clearly decipher the genetic,(More)