Mycobacterium leprae's evolution and environmental adaptation.

Leprosy is an ancient disease caused by the acid-fast bacillus Mycobacterium leprae, also known as Hansen's bacillus. M. leprae is an obligate intracellular microorganism with a marked Schwann cell tropism and is the only human pathogen capable of invading the superficial peripheral nerves.

Screening food-borne and zoonotic pathogens associated with livestock practices in the Sumapaz region, Cundinamarca, Colombia.

Hazardous practices regarding antibiotics misuse, unsanitary milking procedures, and the commercial sales of raw milk and unpasteurized dairy products are currently being practiced by livestock farmers in the Sumapaz region (Colombia). The purpose of this study was to screen for food-borne and zoonotic pathogens associated with local livestock practices. We evaluated 1098 cows from 46 livestock farms in the Sumapaz region that were selected by random.

The ATPase activity of the mycobacterial plasma membrane is inhibited by the LL37-analogous peptide LLAP.

The emergence of multidrug-resistant Mycobacterium tuberculosis strains has led to the development of new antituberculous agents. In this context, antimicrobial targeting proteins to the cell membrane are interesting due to the avoidance of the plasma membrane permeation. Through this study, the antimicrobial activity, cellular toxicity, as well as the effect on the mycobacterial cell membrane ATPase activity of a cathelicidin-analogous peptide were assessed.

In silico identification and characterization of the ion transport specificity for P-type ATPases in the Mycobacterium tuberculosis complex.

Background: P-type ATPases hydrolyze ATP and release energy that is used in the transport of ions against electrochemical gradients across plasma membranes, making these proteins essential for cell viability. Currently, the distribution and function of these ion transporters in mycobacteria are poorly understood.

Results: In this study, probabilistic profiles were constructed based on hidden Markov models to identify and classify P-type ATPases in the Mycobacterium tuberculosis complex (MTBC) according to the type of ion transported across the plasma membrane.

Identification of potential biomarkers to distinguish Mycobacterium colombiense from other mycobacterial species.

Mycobacterium avium complex (MAC) consists of 9 species of slow-growing mycobacteria with differing degrees of pathogenicity, host preference and environmental distribution. Mycobacterium colombiense is a novel member of MAC that is responsible for disseminated infections in HIV-infected patients in Colombia and lymphadenopathy cases in Europe. At present, methods to easily differentiate novel members of MAC are lacking.

Effect of antimicrobial peptides on ATPase activity and proton pumping in plasma membrane vesicles obtained from mycobacteria.

The potential usefulness of antimicrobial peptides (AMPs) as antimycobacterial compounds has not been extensively explored. Although a myriad of studies on AMPs from different sources have been done, some of its mechanisms of action are still unknown. Maganins are of particular interest since they do not lyse non-dividing mammalian cells.

Electrochemical monitoring of the metabolic activity of mycobacteria in culture.

Mycobacterial metabolic activity is typically measured using time-consuming manual methods based on nutrient consumption, nucleic acid synthesis or reduction of tetrazolium salts. In this study, we propose much simpler electrochemical methods for continuous monitoring of the metabolic activity of mycobacteria in culture. Chronoamperometry and chronopotentiometry were used to detect metabolic activity of both slow-growing and fast-growing mycobacteria using a potentiostat with 2D-electrochemical cell.

Detection and diversity evaluation of tetracycline resistance genes in grassland-based production systems in Colombia, South america.

Grassland-based production systems use ∼26% of land surface on earth. However, there are no evaluations of these systems as a source of antibiotic pollution. This study was conducted to evaluate the presence, diversity, and distribution of tetracycline resistance genes in the grasslands of the Colombian Andes, where administration of antibiotics to animals is limited to treat disease and growth promoters are not included in animals' diet.

The virulence-associated two-component PhoP-PhoR system controls the biosynthesis of polyketide-derived lipids in Mycobacterium tuberculosis.

Two-component regulatory signal transduction systems are important elements of the adaptative response of prokaryotes to a variety of environmental stimuli. Disruption of PhoP-PhoR in Mycobacterium tuberculosis dramatically attenuates virulence, implying that this system directly and/or indirectly coordinates the expression of important virulence factors whose identity remains to be established. Interestingly, in knockingout the PhoP-PhoR two-component system in M.