This study confirms that there are significant geographical differences in the distribution of resistance-related mutations and suggests that an increased understanding of such differences in the specific distribution of resistance conferring mutations is crucial for development of new, generally applicable, molecular tools for rapid diagnosis of drug-resistant TB. The fact that a narrower distribution of mutations in high MDR-TB prevalence settings was seen suggests that much of the problems in these settings can be a result of an ongoing transmission of certain MDR-TB strains.

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BackgroundTuberculosis persists as a public health problem in Honduras. A better knowledge of the molecular characteristics of Mycobacterium tuberculosis strains will contribute to understand the transmission dynamics of the disease within the country. The aim of this study was to provide an insight of the genetic biodiversity of M. tuberculosis clinical isolates collected in Honduras between 1994 and 2002. Genotyping was performed using spoligotyping and RFLP. The spoligotypes obtained were compared with the SITVIT2 proprietary database of the Pasteur Institute of Guadeloupe.ResultsSpoligotyping grouped 84% of the isolates into 27 clusters (2 to 43 strains per cluster). Of the 44 shared international types (SITs) identified among the Honduran stains, 8 SITs were newly identified either within the present study or after match with an orphan type previously identified in the SITVIT2 database. In addition, 16 patterns corresponded to orphan, previously unreported isolates.The Latin American Mediterranean (LAM) lineage was the most common in this study; 55% of the strains belonged to this family. Other genotypes found were Haarlem (16%), T (16%), X-clade (6%), Unknown signature (5%) and S (1%). Only one Beijing strain was identified (0.5%).We observed a high degree of diversity after characterizing the 43 isolates belonging to the main spoligotyping cluster (SIT 33, LAM3) with IS6110-RFLP. A total of 35 different RFLP-fingerprints were detected, of which 6 patterns corresponded to the same number of clusters comprising 14 strains.ConclusionsThe findings obtained in this study show that tuberculosis transmission in Honduras is due to modern M. tuberculosis lineages with high level of biodiversity.

BackgroundA better understanding of the quality of cellular immune responses directed against molecularly defined targets will guide the development of TB diagnostics and identification of molecularly defined, clinically relevant M.tb vaccine candidates.MethodsRecombinant proteins (n = 8) and peptide pools (n = 14) from M. tuberculosis (M.tb) targets were used to compare cellular immune responses defined by IFN-γ and IL-17 production using a Whole Blood Assay (WBA) in a cohort of 148 individuals, i.e. patients with TB + (n = 38), TB- individuals with other pulmonary diseases (n = 81) and individuals exposed to TB without evidence of clinical TB (health care workers, n = 29).ResultsM.tb antigens Rv2958c (glycosyltransferase), Rv2962c (mycolyltransferase), Rv1886c (Ag85B), Rv3804c (Ag85A), and the PPE family member Rv3347c were frequently recognized, defined by IFN-γ production, in blood from healthy individuals exposed to M.tb (health care workers). A different recognition pattern was found for IL-17 production in blood from M.tb exposed individuals responding to TB10.4 (Rv0288), Ag85B (Rv1886c) and the PPE family members Rv0978c and Rv1917c.ConclusionsThe pattern of immune target recognition is different in regard to IFN-γ and IL-17 production to defined molecular M.tb targets in PBMCs from individuals frequently exposed to M.tb. The data represent the first mapping of cellular immune responses against M.tb targets in TB patients from Honduras.

RESUMEN El objetivo de esta investigación es determinar la resistencia antimicrobiana delStaphylococcus aureus en dos hospitales de Tegucigalpa. Para lograrlo se siguió una metodología de estudio descriptivo, transversal. Se recolectaron todas las muestras de Staphylococcus aureus aisladas de pacientes, de los laboratorios de dos hospitales, durante un periodo de 5 meses, en cada institución; las que se trasladaron al Laboratorio de Bacteriología de la Escuela de Microbiología de la UNAH; para el estudio de sensibilidad antibiótica y la identificación de los SARM, mediante el método de Kirby-Bauer y según normas establecidas por el Clinical and Laboratory Standards Institute (CLSI); para los que se usaron diferentes antibióticos.También se realizó la determinación de la concentración inhibitoria mínima (CIM) a OX usando E-test y la determinación de la producción de PBP2a, por el método de aglutinación en látex. Los datos fueron analizados con estadística descriptiva con el paquete estadístico EPI-INFO, versión 3.5.1. para Windows.Se obtuvieron 90 aislamientos de S. aureus del laboratorio del Hospital Escuela y 106 de S. aureus en el laboratorio del IHSS. La mayoría de las bacterias aisladas provenían de exudados, los cuales presentaron resistencia a diferentes antibióticos y ninguna bacteria aislada presentó resistencia a Vancomicina. La resistencia a Oxacilina o SARM fue de un 14.3 % (IC95 % = 9.7 a 20 Conclusions: compared to other countries data, we found a very low MRSA prevalence and absence of vancomicin resistance in our study.