Population structure among mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Colombia.

BACKGROUND: Phylogeographic composition of M. tuberculosis populations reveals associations between lineages and human populations that might have implications for the development of strategies to control the disease. In Latin America, lineage 4 or the Euro-American, is predominant with considerable variations among and within countries. In Colombia, although few studies from specific localities have revealed differences in M. tuberculosis populations, there are still areas of the country where this information is lacking, as is a comparison of Colombian isolates with those from the rest of the world. PRINCIPAL FINDINGS: A total of 414 M. tuberculosis isolates from adult pulmonary tuberculosis cases from three Colombian states were studied. Isolates were genotyped using IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, and 24-locus Mycobacterial interspersed repetitive units variable number tandem repeats (MIRU-VNTRs). SIT42 (LAM9) and SIT62 (H1) represented 53.3% of isolates, followed by 8.21% SIT50 (H3), 5.07% SIT53 (T1), and 3.14% SIT727 (H1). Composite spoligotyping and 24-locus MIRU- VNTR minimum spanning tree analysis suggest a recent expansion of SIT42 and SIT62 evolved originally from SIT53 (T1). The proportion of Haarlem sublineage (44.3%) was significantly higher than that in neighboring countries. Associations were found between M. tuberculosis MDR and SIT45 (H1), as well as HIV-positive serology with SIT727 (H1) and SIT53 (T1). CONCLUSIONS: This study showed the population structure of M. tuberculosis in several regions from Colombia with a dominance of the LAM and Haarlem sublineages, particularly in two major urban settings (Medellín and Cali). Dominant spoligotypes were LAM9 (SIT 42) and Haarlem (SIT62). The proportion of the Haarlem sublineage was higher in Colombia compared to that in neighboring countries, suggesting particular conditions of co-evolution with the corresponding human population that favor the success of this sublineage.

Tuberculosis among homeless population from Medellín, Colombia: associated mental disorders and socio-demographic characteristics.

Homeless people are highly susceptible to tuberculosis. It has been suggested that this population have high rates of mental disorders associated with tuberculosis. We assessed tuberculosis incidence, its transmission patterns and association with socio-demographic factors and mental disorders in Colombian homeless people. Prospective study which socio-demographic characteristics and mental disorders were assessed through interviews. Sputa from patients with respiratory symptoms were processed and clinical isolates analyzed by IS6110-RFLP. Multivariate analysis performed by logistic regression model. From 426 homeless studied, tuberculosis incidence found was 7.9 %. 44 % of isolates were clustering. It was found high risk of having tuberculosis associated with income from drugs trade (OR: 3.40 [95 % CI: 1.28-9.05]), dysthymia (OR: 2.54 [95 % CI: 1.10-5.86]) and receiving food from other homeless (OR: 2.47 [95 % CI: 1.16-5.25]). Tuberculosis incidence and degree of transmission are high in homeless studied. Implementing programs to better control tuberculosis among homeless population must consider socio-demographic factors and mental disorders associated with the disease.

Genomic signatures of the haarlem lineage of Mycobacterium tuberculosis: implications of strain genetic variation in drug and vaccine development.

Tuberculosis is the world's leading cause of death due to a single infectious agent, and efforts aimed at its control require a better understanding of host, environmental, and bacterial factors that govern disease outcome. Growing evidence indicates that certain Mycobacterium tuberculosis strains of distinct phylogeographic lineages elicit unique immunopathological events. However, identifying the genetic basis of these phenotypic peculiarities has proven difficult. Here we report the presence of six large sequence polymorphisms which, together with two single-nucleotide changes previously described by our group, consistently differentiate Haarlem strains from the remaining M. tuberculosis lineages. The six newly found Haarlem-specific genetic events are four deletions, which altogether involve more than 13 kb, and two intragenic insertions of the element IS6110. The absence of the genes involved in these polymorphisms could have an important physiological impact on Haarlem strains, i.e., by affecting key genes, such as Rv1354c and cyp121, which have been recently proposed as plausible drug targets. These lineage-specific polymorphisms can serve as genetic markers for the rapid PCR identification of Haarlem strains, providing a useful tool for strain surveillance and molecular epidemiology studies. Strain variability such as that described here underscores the need for the definition of a core set of essential genes in M. tuberculosis that are ubiquitously present in all circulating lineages, as a requirement in the development of effective antituberculosis drugs and vaccines.

Systematic interpretation of molecular beacon polymerase chain reaction for identifying rpoB mutations in Mycobacterium tuberculosis isolates with mixed resistant and susceptible bacteria.

Detection of multidrug-resistant tuberculosis (MDR-TB), a frequent cause of treatment failure, takes 2 or more weeks to identify by culture. Rifampicin (RIF) resistance is a hallmark of MDR-TB, and detection of mutations in the rpoB gene of Mycobacterium tuberculosis using molecular beacon probes with real-time quantitative polymerase chain reaction (qPCR) is a novel approach that takes

Mutations in DNA repair genes are associated with the Haarlem lineage of Mycobacterium tuberculosis independently of their antibiotic resistance.

The analysis of the DNA repair genes ogt and ung was carried out in 117 Mycobacterium tuberculosis clinical isolates from Argentina and Colombia in order to explore correlation between mutations in these genes and multi-drug resistance. With the exception of two Beijing family isolates, the rest of the strains harbored either two wild-type or two mutant alleles with identical single nucleotide polymorphisms (SNPs) in each gene (ogt44 and ung501). These ogt44 and ung501 mutations were not associated with multi-drug resistance and occurred simultaneously in circulating Haarlem genotype M. tuberculosis strains. We therefore propose the use of these markers as tools in phylogenetic and epidemiologic studies.

Estreptococo beta hemolítico de los grupos A, B, C, D, F, G en 157 niños con amigdalitis aguda en Medellín, Colombia / Beta hemolitic streptococci group A, B, C, D, F, G in 157 children with acute amigdalitis in Medellin, Colombia

En 157 niños de 2 a 12 años de edad con faringoamigdalitis aguda (FAA), encontramos 85 (54.1 por ciento) con EBH y 66 (42 por ciento) con EBHA. Diecinueve (12.1 por ciento) eran de grupos diferentes al A, siendo el principal el B con 12 casos (7.6 por ciento). Esto ha coincidido con un aislamiento más frecuente de este grupo en orina y con mayor colonización de madres y recién nacidos

Neumonia por mycoplasma pneumoniae en 107 niños de Medellín

Se revisaron las historias de 107 niños con infección respiratoria aguda (IRA) baja que tenían una IgM positiva para Mycoplasma pneumoniae. La edad más afectada fue la de 2 a 6 años (58 por ciento). El tiempo de evolución antes de la consulta fue de 1 a 180 días, con un promedio de 10.7 días. El motivo de consulta más frecuente fue tos (95.3 por ciento), tos prolongada en el 22.45 por ciento, seguida de fiebre (73.5 por ciento), expectoración y rinitis (32.7 por ciento) respectivamente. Al examen se encontró: Sibilancias (67.3 por ciento), estertores crepitantes (30.8 por ciento) fiebre (37 por ciento), faringitis (15.9 por ciento), otitis (13.1 por ciento) y sinusitis (12 por ciento). El hallazgo radiológico más frecuente fue atrapamiento de aire (21.8 por ciento) derrame pleural abacteriano. La proteína C reactiva fue de < 4 mg por ciento en el 70.8 por ciento. El tratamiento fue a base de macrólidos, principalmente claritromicina (72-6 por ciento), broncodilatadores (40 por ciento) y estos asociados a esteroides en el 25.8 por ciento de los casos

Enfermedad ácido péptica asociada a helicobacter pylori en niños

Ciento diecinueve niños de uno a 14 años que consultaron por síntomas sugestivos de enfermedad ácido péptica (EAP) fueron estudiados con endoscopia y biopsia. Presentaron gastritis antral 73.1 por ciento, duodenitis 10.08 por ciento, úlcera duodenal 4.2 por ciento, úlcera gástrica 1.6 por ciento y esofagitis 0.8 por ciento. Cincuenta y un pacientes fueron positivos para H.pylori. Tanto el grupo positivo como el negativo tuvieron sintomatología similar, pero la úlcera duodenal se asoció significativamente a H.pylori. Veintinueve (87.8 por ciento) de 33 niños positivos mejoraron clínicamente con diferentes combinaciones de amoxacilina, metronidazol, bismuto y antiácidos y antagonistas H2. Veinticinco (95 por ciento) de 26 negativos mejoraron con antiácidos y antagonistas H2