Portadores faríngeos de Streptoccocus pneumoniae en dos grupos poblacionales. Ciudad Bolivar, Estado Bolívar, Venezuela

Resumen Introducción Streptococcus pneumoniae es un patógeno para el ser humano que precisa de una previa colonización faríngea para causar enfermedad, cuya morbimortalidad se acentúa en los menores de 6 años y los mayores de 65 años de edad. Objetivo Determinar la prevalencia de portadores faríngeos de Streptococcus pneumoniae en dos grupos poblacionales en Ciudad Bolívar, Estado Bolívar. Metodología Durante los años 2009 a 2010, se evaluaron dos grupos: uno que incluyó a 66 individuos de la tercera edad institucionalizados en el Asilo "San Vicente de Paúl" y Geriátrico "Carlos Fragachan", con una edad promedio de 75 años ± 6 años y otro que abarcó a preescolares y escolares de 2 a 12 años hospitalizados en los Servicios de Pediatría y del área de emergencia del Complejo Hospitalario Universitario "Ruíz y Páez". A cada individuo se le tomó una muestra faríngea, la cual fue procesada según los lineamientos establecidos por la Sociedad Americana de Microbiología. Se estudiaron 80 exudados de origen faríngeo. Resultados En el grupo de los individuos de la tercera edad se identificaron 10 casos (15,15%) de portadores faríngeos de S. pneumoniae. El 70% (n=7) correspondía al género masculino. En todas las edades se diagnosticaron casos, frecuentemente observados en el grupo entre 71 a 80 años de edad (n=4; 40%). El 46,2% de los portadores faríngeos de la tercera edad refirieron antecedentes tabáquicos. Se observaron diferencias estadísticas significativas entre el estado de portador de neumococo y la diabetes mellitus tipo II y estado de vacunación contra la bacteria, En el grupo de los pacientes preescolares y escolares hospitalizados, se aislaron 3 cepas de S. pneumoniae que representó el 3,75% del total. El mayor porcentaje de muestras positivas se obtuvo en el grupo de 2 a 4 años, con predominio del género masculino (2,5%). En el grupo de la población infantil hospitalizada, se observaron diferencias estadísticamente significativas entre el estado de portador y antecedentes personales como asma, resfriado común a repetición, infección urinaria e infección de piel y tejido blando. No estaban vacunados contra el neumococo o solo cumplieron una sola dosis. En ambas investigaciones se determinaron 13 cepas de Streptococcus pneumoniae, las cuales mostraron un perfil de resistencia a la Penicilina, por método del disco de Oxacilina, del 50%; mientras que la totalidad de las cepas aisladas resultaron con alta resistencia a Macrólidos, Clindamicina y Sulfamidas, y sensibles a Vancomicina. Conclusión Se identificó una baja prevalencia de individuos colonizados por Streptococcus pneumoniae, sin embargo, se debe considerar la investigación de colonización faríngea por neumococo como un buen método por ser simple y fácil de obtener muestras bacterianas y poder reflejar la progresión de la resistencia bacteriana en grupos de riesgo.

Abstract Introduction Streptococcus pneumonia is a pathogen for humans that requires a prior pharyngeal colonization to cause disease, whose mortality is accentuated in children 6 years and older than 65 years of age. Objective To assess the prevalence of pharyngeal carriage of S pneumonia in two population groups in Ciudad Bolívar, Bolívar State. Methodology . During the years 2009 and 2010, two groups were evaluated: one which included 66 senior individuals institutionalized in the asylum "San Vicente de Paúl" and the geriatric "Carlos Fragachan", with an average of 75 years ± 6 years age and another that it comprised preschool and school aged 2 to 12 hospitalized in Pediatrics and the area of the University Hospital emergency services "Ruiz and Páez". Each individual took a pharyngeal sample, which was processed according to the guidelines established by the American society for of microbiology. 80 exudates from pharyngeal origin were studied. Results Between elderly individuals 10 cases were identified (15.15%) of S. pneumonia pharyngeal carriers. 70% (n = 7) corresponded to the male gender. In all the ages were diagnosed cases, often observed in the group between 71 to 80 years of age (n = 4; 40%). 46.2% of pharyngeal carriers concerned smoking history. Were observed significant statistical differences between the pneumococcus`s state carrier and type II diabetes mellitus and vaccination´s state against the bacterium, In the group of preschool and school inpatients, 3 strains of S. pneumonia that accounted for 3.75% of the total were isolated. The highest percentage of positive specimens was obtained in the group of 2 to 4 years, with a predominance of the male gender (2.5%). Statistically significant differences were observed in the hospitalized children, between the carrier´s state and personal history as asthma, cold common, urinary tract infection and infection of skin and tissue soft. They were not vaccinated against the pneumococcus or met only a single dose. Both studies identified 13 strains of Streptococcus pneumoniae, which showed a profile of resistance to penicillin, by method of disk Oxacillin, of 50%; While all of the isolates were with high resistance to macrolides and clindamycin, sulfonamides, and sensitive to Vancomycin. Conclusion We identified a low prevalence of individuals colonized by Streptococcus pneumoniae, however should be consider the research of colonization of the pharynx by Pneumococcus as a good method to be simple and easy to obtain bacterial samples and to reflect the progression of bacterial resistance in risk groups.

Expression of NAT2 in immune system cells and the relation of NAT2 gene polymorphisms in the anti-tuberculosis therapy in Mexican mestizo population.

Arylamine N-acetyltransferase 2 (NAT2) metabolizes isoniazid (INH) and Single Nucleotide Polymorphisms (SNP) responsible for its activity has been reported. The aim of this study in the Mexican mestizo population was to evaluate NAT2 expression at the protein level in immune cells, as well as the distribution and frequency of six NAT2 SNPs and their association with anti-TB therapy, by measuring the plasma levels of INH and Acetyl-INH (AcINH). We performed genotyping assays of NAT2 SNPs in 40 TB patients and 121 healthy volunteers by real-time PCR. A method for detecting NAT2 in immune cells using flow cytometry was developed. Plasma concentrations of INH and AcINH were obtained by HPLC in TB patients and the Metabolic Ratio (MR) was calculated. The phenotypes obtained in the healthy volunteers were as follows; 18.87 % of subjects had the rapid acetylator phenotype, 45.45 % had the intermediate phenotype and 39.66 % exhibited the slow acetylator phenotype. In the TB patient group, 35 % of patients had the rapid acetylator phenotype, 32.5 % were intermediate and 32.5 % showed the slow acetylator phenotype. A higher expression level of NAT2 in innate immune cells from TB patients compared to those from healthy volunteers was detected (P < 0.013). In TB patients the MR showed a bimodal distribution with an antimode of 0.7, which was used as a threshold value for acetylator classification. A high correspondence between the rapid and slow acetylator phenotype with MR was demonstrated. In conclusion, the 282C>T, 341T>C, 481C>T, 590G>A, 803A>G, 857G>A SNPs of NAT2 gene provides accurate for prediction of the acetylator phenotype in Mexican mestizo population. A statistical difference was found in frequency of rapid metabolizer phenotype, which was higher in TB patients. In addition, the expression of NAT2 protein in immune cells can lead to further studies related to its functional role in the innate immune response against M. tuberculosis and other xenobiotics metabolized by this enzyme.

The innate immune response to Entamoeba histolytica lipopeptidophosphoglycan is mediated by toll-like receptors 2 and 4.

Entamoeba histolytica is a human pathogen that may invade the intestinal mucosa, causing amoebic colitis or hepatic abscesses when the trophozoites travel through the portal circulation to the liver. Lipopeptidophosphoglycan (LPPG) is a molecular pattern of E. histolytica recognized by the human immune system. Here we report that LPPG is exposed on the cell surface of E. histolytica trophozoites, and is recognized by the host through toll-like receptor (TLR) 2 and TLR4. Correspondingly, human embryonic kidney (HEK)-293 cells were rendered LPPG responsive through overexpression of TLR2 or TLR4/MD2. Moreover, co-expression of CD14 enhanced LPPG signal transmission through TLR2 and TLR4. The interaction of LPPG with TLR2 and TLR4 resulted in activation of NF-kappaB and release of interleukin (IL)-10, IL-12p40, tumour necrosis factor (TNF)-alpha, and IL-8 from human monocytes. Consistent with these findings, responsiveness of mouse macrophages lacking TLR2 expression (TLR2-/-) or functional TLR4 (TLR4d/d) to E. histolytica LPPG challenge was impaired while double deficient macrophages were unresponsive. In contrast to wild-type control and TLR2-/- animals succumbing to lethal shock syndrome, TLR4d/d mice were resistant to systemic LPPG challenge-induced pathology.