Mutations in the kelch propeller domain (K13 propeller) of
parasites from Southeast Asia are associated with reduced susceptibility to artemisinin. We exposed
-cultured stage V gametocytes from ...Cambodian K13 propeller mutant parasites to dihydroartemisinin and evaluated the inhibition of male gamete formation in an
exflagellation inhibition assay (EIA). Gametocytes with the R539T and C580Y K13 propeller alleles were less susceptible to dihydroartemisinin and had significantly higher 50% inhibitory concentrations (IC
s) than did gametocytes with wild-type alleles.
Epidemiological data show a worldwide increase in nontuberculous mycobacteriosis. Although it has been partially attributed to the improvement of microbiological methodologies that has allowed a ...better recovery and identification of nontuberculous mycobacteria (NTM), it is generally accepted that there is a genuine incidence augmentation. The reasons of the increase are likely multifactorial, depending on the nature of the pathogen, the host, and their interaction. Mycobacteria from the Mycobacterium tuberculosis complex has been regarded as pathogenic and NTM as opportunistic and nontransmissible. Nevertheless, few differences have been found in either their phenotypic or genotypic characteristics. The phenomenon of M. tuberculosis adaptation to the human host may be taking place again in NTM as a consequence of human environmental alterations that facilitate the interaction with the pathogen. The current worsening of the immunological status of increasing numbers of individuals, a result of factors such as malnutrition (obesity and diabetes), population aging or the widespread use of immunosuppressive medication, may be allowing the rapid evolution and person-to-person transmission of NTM. It is likely that mycobacteriosis incidence will keep escalating. New measures should be taken to deal with these diseases, including their reportability and the implementation of strain genotyping that would shed light on the NTM dissemination routes from the environment or human hosts.
Bronchiectasis is considered a consequence of the neutrophilic inflammatory response to infection. Mycobacterial infections, mainly from the Mycobacterium avium complex and M. abscessus, have been ...inextricably linked to bronchiectasis development. The most important pathogen that infect patients with bronchiectasis is Pseudomonas aeruginosa, associated with an increased risk of death. Patients with bronchiectasis are often co-infected with P. aeruginosa and M. avium complex, and it was studied whether they interacted in immune cell cultures. Peripheral blood mononuclear cells from healthy volunteers were infected overnight with clinical isolates of mycobacteria, 18 h later co-infected with P. aeruginosa and Pseudomonas multiplication was quantified. Inoculated P. aeruginosa multiply faster when cells were previously infected in vitro with M. avium complex or M. tuberculosis, but not with M. kansasii or M. gordonae, mycobacteria not regularly isolated from patients with bronchiectasis. The interaction between mycobacteria and P. aeruginosa also takes place in the absence of cells, but to a lower degree. Growth of Staphylococcus aureus, less frequently co-isolated with mycobacteria, was not affected by previous infection with mycobacteria. Surprisingly, multiplication of P. aeruginosa in neutrophil cultures did not vary in the presence of mycobacteria. Nevertheless, co-infection of mycobacteria and P. aeruginosa induced the production of IL-1β, a mediator of neutrophilic inflammation. P. aeruginosa stimulation by mycobacteria provides evidence for explaining their common clinical association. Strategies to control mycobacteria may be useful to impair P. aeruginosa colonization.
•M. avium complex and M. tuberculosis co-infected cells promote P. aeruginosa growth.•Peripheral blood mononuclear cells, but not neutrophils, promote growth.•Less pathogenic mycobacteria (e.g. M. gordonae) do not promote growth.•Co-infected cells produce IL-1β, mediator of neutrophilic inflammation.•Observed mycobacteria - P. aeruginosa interaction may have clinical relevance.
Contexto: El café es una bebida popular que se obtiene de la semilla de un arbusto denominado cafeto, esta es molida y tostada para obtener el polvo que se utiliza para la elaboración de la bebida. ...Para su transformación es necesario emplear diferentes tipos de máquinas, lo cual es un nicho de mercado importante para la economía del país. Por lo tanto, se hace necesario identificar oportunidades de mejora en las actividades del proceso que comprende pedido, producción y despacho de las máquinas despulpadoras de café en una empresa colombiana.
Método: A partir del uso de simulación como herramienta, se procede a construir un modelo que represente apropiadamente la realidad de la empresa, iniciando por la delimitación del problema, siguiendo con la identificación de variables clave, la toma de muestras y su análisis estadístico, la construcción de la simulación con sus respectivos procesos de validación y verificación, y finalmente el análisis de resultados, y las posibilidades de aplicación en la empresa en conjunto con conclusiones del proceso.
Resultados: A partir de los escenarios construidos, se recomienda diseñar un área de despacho para acceder a la información de forma rápida y oportuna junto con el desarrollo de un software especializado que permita digitalizar órdenes y remisiones, adicionalmente la planeación de rutas de entrega de pedidos priorizados según las variables clave en el proceso. Con la implantación de las anteriores sugerencias, la cola de máquinas ensambladas y sin ser despachadas se redujo en un 51 % y los despachos de las máquinas despulpadoras de café incrementaron en un 49 % mejorando la satisfacción del cliente.
Conclusiones: La inversión necesaria para implementar el escenario de solución representa retornos a mediano plazo, lo cual, junto con la satisfacción del cliente, permite hacer competitiva a la empresa. Se propone hacer un estudio de la logística de despacho de los pedidos, dado que esta parte del problema se evidencia, pero no se puede resolver mediante simulación.
The increasing worldwide incidence of mycobacteriosis and the need to achieve improved clinical management makes nontuberculous mycobacteria (NTM) genotyping a useful tool. However, because of ...technical difficulties, medium size microbiology laboratories do not attempt to compare the genetic patterns that each of their isolates present. We have aimed to optimize a genotyping method with a reduced hands-on experimental time and that requires few technical resources. A strategy based on the Amplified Fragment Length Polymorphism (AFLP) methodology was developed using two rare-cutters enzymes (
Sac
I and
Bgl
II). One out of seven primers was sequentially used in each amplification reaction that was analyzed by agarose gel electrophoresis. This approach makes it possible the timely genotyping of a moderate number of strains and its characterization without the need of image analysis software. We have genotyped 28
Mycobacterium intracellulare
and 4 M
. abscessus
. Clinical researchers are encouraged to routinely genotype their NTM isolates.
The elderly account for a disproportionate share of all tuberculosis cases, and the population ageing may not fully explain this phenomenon. We have performed in vitro infection experiments to ...investigate whether there is an immunological basis for the apparent susceptibility of elders to tuberculosis. In our infection model,
Mycobacterium tuberculosis
induces a higher production of interleukin (IL)-6 and reactive oxygen species in macrophages from elders than from younger adults. This response did not prevent, however, an increased multiplication of
M. tuberculosis
in macrophages from elders as compared with the growth observed within cells from adults. By performing a factorial experiment, we have found that IFN-γ, but not IL-1β, IL-6 or TNF-α, stimulate the macrophages to restrict the multiplication of the bacterium in macrophages from elders. Although monocytes from elders seem to be in a higher level of activation, we present evidences that protein tyrosine phosphorylation response induced by
M. tuberculosis
is stronger in monocytes from adults than from elders. Using a protein array that detects 71 tyrosine phosphorylated kinases, we identified Pyk2 as the only kinase that displayed a difference of intensity larger than 50 % in adults than in elders. Furthermore, monocytes from elders that were incubated in the presence of tyrosine kinase inhibitors (genistein and PP2) allowed a higher level of bacterial multiplication. These observations may help to explain the susceptibility of elders to tuberculosis. An unexpected result was that both genistein and its negative control, daidzein, abundant soy isoflavones, promoted intracellular mycobacterial growth.
Abstract We have investigated the role of CXCL7 in the immune response of human phagocytes against the intracellular bacteria Mycobacterium tuberculosis and Legionella pneumophila . We have observed ...that polymorphonuclear neutrophil (PMN) chemotaxis induced by the supernatants of infected monocyte derived macrophages (MDM) may be attributed to CXCL8 rather than CXCL7, although both chemokines are present in large quantities. We have also found that CXCL7 is present not only in the supernatants of MDM, but also in the supernatants of PMN of some, but not all, individuals. Western blot analysis revealed that, in both MDM and PMN supernatants appeared two bands with molecular weights consistent with the platelet basic protein (PBP) and the neutrophil activating protein-2 (NAP-2) sizes. Regarding the influence on infected cells, recombinant NAP-2 enhanced the antimicrobial activity of IFNγ activated MDM against L. pneumophila , but not against M. tuberculosis . In addition, U937 cells transfected with a NAP-2 construct inhibited the intracellular multiplication of L. pneumophila , supporting its role in the modulation of the antimicrobial activity. Finally, U937 cells transfected with the NAP-2 construct showed an adherence that was dramatically enhanced when the substrate was fibronectin. We conclude that human phagocytes produce CXCL7 variants that may have a significant influence on the immune response against bacterial pathogens.
Plasmodium falciparum Standard Membrane Feeding Assay (PfSMFA) is the current gold standard mosquito based confirmatory transmission blocking (TrB) assay for human malaria. However, owing to its ...complexity only selected gametocytocidal molecules are progressed into SMFA. Predictive tools for evaluation of TrB behavior of compounds in SMFA would be extremely beneficial, but lack of substantially large data sets from many mosquito feeds preempts the ability to perform correlations between outcomes from in vitro assays and SMFA. Here, a total of 44 different anti-malarial compounds were screened for inhibitory effect on male gamete formation in exflagellation inhibition assay (EIA) and the same drug-treated parasites were fed to mosquitoes in SMFA. Regression analysis was performed between outcomes of the two assays and regression models were applied to a randomly selected validation set of four compounds indicating no overfitting and good predictive power. In addition, the pIC50 for 11 different compounds obtained in the EIA was also correlated with pIC50's in SMFA. Resulting regression models provided pIC50 predictions in SMFA with reasonably good accuracy thereby demonstrating the use of a simple in vitro assay to predict TrB of molecules in a complex mosquito based assay.
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