Time filter

Source Type

Rossi F.,University of Sao Paulo | Diaz L.,El Bosque University | Diaz L.,University of Houston | Wollam A.,Washington University in St. Louis | And 23 more authors.
New England Journal of Medicine

We report the case of a patient from Brazil with a bloodstream infection caused by a strain of methicillin-resistant Staphylococcus aureus (MRSA) that was susceptible to vancomycin (designated BR-VSSA) but that acquired the vanA gene cluster during antibiotic therapy and became resistant to vancomycin (designated BR-VRSA). Both strains belong to the sequence type (ST) 8 community-associated genetic lineage that carries the staphylococcal chromosomal cassette mec (SCCmec) type IVa and the S. aureus protein A gene (spa) type t292 and are phylogenetically related to MRSA lineage USA300. A conjugative plasmid of 55,706 bp (pBRZ01) carrying the vanA cluster was identified and readily transferred to other staphylococci. The pBRZ01 plasmid harbors DNA sequences that are typical of the plasmid-associated replication genes rep24 or rep21 described in community-associated MRSA strains from Australia (pWBG745). The presence and dissemination of community-associated MRSA containing vanA could become a serious public health concern. Copyright © 2014 Massachusetts Medical Society. Source

Zea D.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Osorio L.,University of Valle
Revista de Salud Publica

Objective The surveillance of dengue cases is essential for defining, implementing and assessing interventions and promptly detecting outbreaks. Municipal health authorities are the key stakeholders guaranteeing surveillance system quality and coverage and are the first users of the information so collected. The present study was aimed at assessing how well the dengue case surveillance system was operating in a municipality in the Valle del Cauca department of Colombia during 2008. Methods The CDC proposed model was used. Emphasis was placed on describing system operation, the available resources, compliance with reports and case adjustment and using information. Interviews were held with health workers. Dengue surveillance system data from the municipality, departmental health authorities and the Valle del Cauca Public Health Laboratory were reviewed. Results Notification coverage was 91.3%. A lack of using surveillance software and delays in notification were identified. Three people were in charge of all public health responsibilities and none of them had had any training or prior knowledge regarding public health surveillance protocols. There had not been any systematic data analysis. Conclusions As in other areas of Colombia, the lack of training, professional profile and other resources as well as a high turnover of public health personnel were the weakest points of the surveillance system in the municipality. Corrective measures for improving the surveillance system have now been implemented in the municipality which was studied. Source

Rodriguez-Pinto D.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Rodriguez-Pinto D.,University of the Americas in Ecuador | Saravia N.G.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | McMahon-Pratt D.,Yale University
BMC Infectious Diseases

Background: An effective adaptive immune response requires activation of specific CD4 T cells. The capacity of B cells to activate CD4 T cells in human cutaneous leishmaniasis caused by Leishmania (Viannia) has not been evaluated.Methods: CD4 T cell activation by B cells of cutaneous leishmaniasis patients was evaluated by culture of PBMCs or purified B cells and CD4 T cells with Leishmania panamensis antigens. CD4 T cell and B cell activation markers were evaluated by flow cytometry and 13 cytokines were measured in supernatants with a bead-based capture assay. The effect of Leishmania antigens on BCR-mediated endocytosis of ovalbumin was evaluated in the Ramos human B cell line by targeting the antigen with anti-IgM-biotin and anti-biotin-ovalbumin-FITC.Results: Culture of PBMCs from cutaneous leishmaniasis patients with Leishmania antigens resulted in upregulation of the activation markers CD25 and CD69 as well as increased frequency of CD25hiCD127- cells among CD4 T cells. Concomitantly, B cells upregulated the costimulatory molecule CD86. These changes were not observed in PBMCs from healthy subjects, indicating participation of Leishmania-specific lymphocytes expanded in vivo. Purified B cells from these patients, when interacting with purified CD4 T cells and Leishmania antigens, were capable of inducing significant increases in CD25 and CD69 expression and CD25hiCD127- frequency in CD4 T cells. These changes were associated with upregulation of CD86 in B cells. Comparison of changes in CD4 T cell activation parameters between PBMC and B cell/CD4 T cell cultures showed no statistically significant differences; further, significant secretion of IFN-γ, TNF-α, IL-6 and IL-13 was induced in both types of cultures. Additionally, culture with Leishmania antigens enhanced BCR-mediated endocytosis of ovalbumin in Ramos human B cells.Conclusions: The capacity of B cells specific for Leishmania antigens in peripheral blood of cutaneous leishmaniasis patients to activate CD4 T cells and induce cytokine secretion is similar to that of all cell populations present in PBMCs. This capacity implicates B cells as a plausible target for modulation of the immune response to Leishmania infection as a therapeutic strategy. © 2014 Rodriguez-Pinto et al.; licensee BioMed Central Ltd. Source

Ocampo C.B.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Mina N.J.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Carabali M.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Alexander N.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | And 2 more authors.
Acta Tropica

Dengue incidence continues to increase globally and, in the absence of an efficacious vaccine, prevention strategies are limited to vector control. It has been suggested that targeting the most productive breeding sites instead of all water-holding containers could be a cost-effective vector control strategy. We sought to identify and continuously control the most productive Aedes (Stegomyia) breeding site in an endemic urban area in Colombia and followed the subsequent incidence of dengue. In the urban area of Guadalajara de Buga, southwestern Colombia, potential breeding sites inside and outside houses were first characterized, and local personnel trained to assess their productivity based on the pupae/person index. Simultaneously, training and monitoring were implemented to improve the dengue case surveillance system. Entomological data and insecticide resistance studies were used to define the targeted intervention. Then, a quasi-experimental design was used to assess the efficacy of the intervention in terms of the positivity index of the targeted and non- targeted breeding sites, and the impact on dengue cases. Street catch basins (storm drains) were the potential breeding site most frequently found containing Aedes immature stages in the baseline (58.3% of 108). Due to the high resistance to temephos (0% mortality after 24. h), the intervention consisted of monthly application of pyriproxyfen in all the street catch basins (n= 4800). A significant decrease in catch basins positivity for Aedes larvae was observed after each monthly treatment (p< 0.001). Over the intervention period, a reduction in the dengue incidence in Buga was observed (rate ratio 0.19, 95% CI 0.12-0.30, p< 0.0001) after adjusting for autocorrelation and controlling with a neighboring town, Palmira, This study highlights the importance of street catch basins as Aedes breeding sites and suggests that their targeted control could help to decrease dengue transmission in such areas. © 2014. Source

Gallego C.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Golenbock D.,University of Massachusetts Medical School | Gomez M.A.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim | Saravia N.G.,Centro Internacional Of Entrenamiento E Investigaciones Medicas Cideim
Infection and Immunity

Toll-like receptors (TLRs) play a central role in macrophage activation and control of parasitic infections. Their contribution to the outcome of Leishmania infection is just beginning to be deciphered. We examined the interaction of Leishmania panamensis with TLRs in the activation of host macrophages. L. panamensis infection resulted in upregulation of TLR1, TLR2, TLR3, and TLR4 expression and induced tumor necrosis factor alpha (TNF-α) secretion by human primary macrophages at comparable levels and kinetics to those of specific TLR ligands. The TLR dependence of the host cell response was substantiated by the absence of TNF-α production in MyD88/TRIF-/- murine bone marrow-derived macrophages and mouse macrophage cell lines in response to promastigotes and amastigotes. Systematic screening of TLR-deficient macrophages revealed that TNF-α production was completely abrogated in TLR4. Source

Discover hidden collaborations