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Instituto de Higiene e Medicina Tropical

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In vivo

Non-antibiotics reverse resistance of bacteria to antibiotics.

BACKGROUND: Most clinical isolates that exhibit a multi-drug resistant phenotype owe that resistance to over-expressed efflux pumps. Compounds that are efflux pump inhibitors (EPIs) reduce or reverse resistance to antibiotics to which the bacterial strain is initially resistant. We have evaluated non-antibiotics to reduce resistance of commonly encountered bacterial pathogens to antibiotics. MATERIALS AND METHODS: […]
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Identification of efflux pump-mediated multidrug-resistant bacteria by the ethidium bromide-agar cartwheel method.

BACKGROUND/AIM:
Bacterial multidrug resistance may be mediated by the overexpression of efflux pumps. Conventional evaluation of efflux activity using efflux pump substrates, such as ethidium bromide, requires specialised instrumentation. The agar-based method, previously reported, has been modified to evaluate as many as twelve bacterial strains and has been termed the ethidium bromide-agar cartwheel method.
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Immune reactivity to dengue and Aedes albopictus mosquitoes in the population from Macao, China, before dengue occurrence.

A serological survey was conducted in Macao, China, in 753 individuals, with the objective of looking for antibodies to the mosquito, Aedes albopictus (Skuse 1894) (Diptera: Culicidae), and to dengue, before the occurrence of any autochthonous dengue cases.
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Phenothiazines, bacterial efflux pumps and targeting the macrophage for enhanced killing of intracellular XDRTB

Phenothiazines have their primary effects on the plasma membrane of prokaryotes and eukaryotes. Among the components of the prokaryotic plasma membrane affected are efflux pumps, their energy sources, energy providing enzymes such as ATPases, and genes that regulate and code for permeability aspects of the bacterium.
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Competition between substrates of the efflux pump system of Salmonella enteritidis.

AIM:
To determine whether tetracycline competes with ethidium bromide (EB), used as substrate of efflux pumps, for extrusion by the efflux pump system of Salmonella enteritidis NCTC 13349 reference strain.
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Immune reactivity to dengue and Aedes albopictus mosquitoes in the population from Macao, China, before dengue occurrence.

A serological survey was conducted in Macao, China, in 753 individuals, with the objective of looking for antibodies to the mosquito, Aedes albopictus (Skuse 1894) (Diptera: Culicidae), and to dengue, before the occurrence of any autochthonous dengue cases.
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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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