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Amaral L

Inhibition of quorum sensing and efflux pump system by trifluoromethyl ketone proton pump inhibitors.

BACKGROUND:
One major microbiological problem is the widespread antibiotic resistance. There is an urgent need for new antibiotics and ways to treat multi-drug-resistant infections. Inhibition of bacterial quorum sensing (QS) systems could be an effective alternative in a smuch as they regulate a broad spectrum of cell functions, including, virulence factor production, biofilm organisation and motility. Influx and efflux bacterial systems involved in quorum sensing (QS) are known to depend on the proton motive force (PMF). Thus, a new series of 12 trifluoromethyl ketones (TFs) known to inhibit the PMF, was investigated for effects on the efflux pump of a QS responding bacterium, for its subsequent effect on the response to a QS signal and its direct inhibition of the response to a QS signal.
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Activity of fourteen new hydantoin compounds on the human ABCB1 efflux pump.

BACKGROUND:
Multidrug resistance (MDR) is one of the major concerns in the treatment of cancer and one of the major causes of therapy failure. The overexpression of an ABC transporter, the ABCB1, is often associated with MDR in cancer. Previously it was observed that hydantoin compounds can modulate the activity of the ABCB1 pump.
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The activity of 16 new hydantoin compounds on the intrinsic and overexpressed efflux pump system of Staphylococcus aureus.

AIM:
To evaluate a new series of 16 hydantoin derivatives for activity against the intrinsic and overexpressed efflux pumps of the ATTC 25923 Staphylococcus aureus and the clinical Staphylococcus aureus HPV-107 strain, respectively.
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Potential therapy of multidrug-resistant and extremely drug-resistant tuberculosis with thioridazine.

Multidrug-resistant tuberculosis (MDRTB) infections that continue to increase in frequency globally have progressed to become extremely drug-resistant tuberculosis (XDRTB). The therapeutic problems associated with MDRTB pale in comparison to those for XDRTB where mortality is high.
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Contribution of efflux activity to isoniazid resistance in the Mycobacterium tuberculosis complex.

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.
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Inhibitors of mycobacterial efflux pumps as potential boosters for anti-tubercular drugs.

Tuberculosis is one of the major causes of infection across the world. The emergence of multi-, extensively- and totally drug-resistant strains of Mycobacterium tuberculosis contributes to the lack of therapeutic options available.
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Why and how thioridazine in combination with antibiotics to which the infective strain is resistant will cure totally drug-resistant tuberculosis.

Over a period of 14 years, the authors have studied thioridazine, an old neuroleptic, that has been shown to have in vitro activity against intracellular Mycobacterium tuberculosis, regardless of its antibiotic resistance status, thioridazine cures infected mice of antibiotic-susceptible and multidrug-resistant tuberculosis (TB) infections and, when used in combination with antibiotics used for therapy of TB, renders the organism significantly more susceptible.
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Evidence of significant synergism between antibiotics and the antipsychotic, antimicrobial drug flupenthixol.

Previously, the antipsychotic, non-antibiotic compound flupenthixol dihydrochloride (Fp) was shown to exhibit distinct in vitro antibacterial activity against Gram-positive and Gram-negative bacteria and to significantly protect Swiss albino mice challenged with a known mouse virulent salmonella.
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The in vitro activity of products formed from exposure of chlorpromazine to a 266nm laser beam against species of mycobacteria of human interest

Chlorpromazine (CPZ) was exposed to a 266 nm laser beam for different periods of time ranging from minutes to 24 h. At intervals, the products from irradiation were evaluated by thin-layer chromatography (TLC) and evaluated for their activity against mycobacteria of human interest (Mycobacterium tuberculosis, M. avium, M. intracellulare and their corresponding reference strains or clinical isolates).
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