From multidrug-resistant to extensively drug-resistant tuberculosis in Lisbon, Portugal: The stepwise mode of resistance acquisition

The development and transmission of extensively drug-resistant (XDR) tuberculosis (TB) constitutes a serious threat to the effective control of TB in several countries. Here, in an attempt to further elucidate the dynamics of the acquisition of resistance to second-line drugs and investigate an eventual role for eis promoter mutations in aminoglycoside resistance, we have studied a set of multidrug-resistant (MDR)/XDR-TB isolates circulating in Lisbon, Portugal.
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Ion channel blockers as antimicrobial agents, efflux inhibitors, and enhancers of macrophage killing activity against drug resistant mycobacterium tuberculosis

Given the ability of M. tuberculosis to survive as an intracellular pathogen and its propensity to develop resistance to the existing antituberculosis drugs, its treatment requires new approaches. Here the antimycobacterial properties of verapamil, thioridazine, chlorpromazine, flupenthixol and haloperidol were investigated against a panel of drug resistant M. tuberculosis strains, both in vitro and on human-infected macrophages.
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High-level resistance to isoniazid and ethionamide in multidrug-resistant Mycobacterium tuberculosis of the Lisboa family is associated with inhA double mutations

The purpose of this study was to determine the levels of isoniazid and ethionamide resistance and to identify associated mutations in endemic multidrug-resistant (MDR) strains of Mycobacterium tuberculosis from the Lisbon metropolitan area, Portugal.
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Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus.

BACKGROUND:
Antimicrobial resistance mediated by efflux systems is still poorly characterized in Staphylococcus aureus, despite the description of several efflux pumps (EPs) for this bacterium. In this work we used several methodologies to characterize the efflux activity of 52 S. aureus isolates resistant to ciprofloxacin collected in a hospital in Lisbon, Portugal, in order to understand the role played by these systems in the resistance to fluoroquinolones.
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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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From multidrug-resistant to extensively drug-resistant tuberculosis in Lisbon, Portugal: The stepwise mode of resistance acquisition

Ion channel blockers as antimicrobial agents, efflux inhibitors, and enhancers of macrophage killing activity against drug resistant mycobacterium tuberculosis

High-level resistance to isoniazid and ethionamide in multidrug-resistant Mycobacterium tuberculosis of the Lisboa family is associated with inhA double mutations

Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus.

Contribution of efflux activity to isoniazid resistance in the Mycobacterium tuberculosis complex.

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