A first insight into tuberculosis transmission at the border of Ecuador and Colombia: a retrospective study of the population structure of Mycobacterium tuberculosis in Esmeraldas province.

Objective: Tuberculosis (TB) is a major public health concern in Ecuador and Colombia, considering that both countries are high-burden TB settings. Molecular epidemiology is crucial to understand the transmission dynamics of Mycobacterium tuberculosis complex (MTBC) and to identify active transmission clusters of regional importance. Methods: We studied the potential transmission of TB between Colombia and Ecuador through the analysis of the population structure of MTBC lineages circulating in the Ecuadorian province of Esmeraldas at the border with Colombia. A total of 105 MTBC strains were characterized by 24-loci MIRU-VNTR and spoligotyping. Results: MTBC lineage 4 is only present in Esmeraldas; no MTBC strains belonging to Lineage 2-sublineage Beijing were found despite its presence in other provinces of Ecuador and, in Colombia. Genotyping results revealed a high degree of diversity for MTBC in Esmeraldas: Neither active transmission clusters within this province nor including MTBC strains from Colombia or other provinces of Ecuador were found. Conclusion: Our data suggest that tuberculosis dynamics in this rural and isolated area may be not related to highly transmitted strains but could be influenced by other health determinants that favor TB relapse such as poverty and poor health system access. Further studies including a larger number of MTBC strains from Esmeraldas are necessary to test this hypothesis.

Population structure of Mycobacterium tuberculosis in El Oro: A first insight into Ecuador-Peru tuberculosis transmission.

BACKGROUND: Tuberculosis (TB) is a major public health concern in Ecuador and Peru, both settings of high burden of drug resistance TB. Molecular epidemiology tools are important to understand the transmission dynamics of Mycobacterium tuberculosis Complex (MTBC) and to track active transmission clusters of regional importance. This study is the first to address the transmission of TB between Peru and Ecuador through the population structure of MTBC lineages circulating in the Ecuadorian border province of "El Oro". METHODS: A total number of 56 MTBC strains from this province for years 2012-2015 were included in the study and analyzed by 24-loci MIRU-VNTR and spoligotyping. RESULTS: Genotyping revealed a high degree of diversity for MTBC in "El Oro", without active transmission clusters. MTBC L4 was predominant, with less than 2% of strains belonging to MTBC L2-Beijing. CONCLUSIONS: These results may suggest that TB dynamics in this rural and semi-urban area would not be linked to highly transmitted strains like MTBC L2-Beijing from Peru, but related to TB relapse; although further studies with larger MTBC cultures collection from recent years are needed. Nevertheless, we recommend to reinforce TB surveillance programs in remote rural settings and border regions in Ecuador.

Systematics and biogeography of the genus Scaria Bolívar, 1887 (Orthoptera: Tetrigidae: Batrachideinae).

The Amazon rainforest is the world's most extensive tropical rainforest, holding a considerable ecological and taxonomic diversity. Speciation in this region arises from multiple factors, such as topography, climate fluctuations, oceanic transgression, vegetation and the delimitation of zones circumscribed by sub-basins within the greater Amazon basin. Different scenarios have been proposed to better understand the diversification of Amazonian taxa, whether by Pleistocene refugia or by areas of endemism.                The genus Scaria is distributed mostly in Amazonia, with a single species that ranges from the Tumbes-Chocó-Magdalena ecoregion well into Central America all the way to southern Nicaragua. Eight species are currently recognized, with three additional described here as new: Scaria rafaeli sp. nov., S. jonasi sp. nov. and S. granti sp. nov., and the status of S. laeta stat. resurr. is revalidated. Two new combinations are established: S. verutum comb. nov. (formerly placed in Rehnidium Grant, 1956) and Batrachidea brevis comb. nov. (formerly placed in Scaria). New synonym is proposed: Batrachidea brevis (Hancock, 1909) = Batrachidea inermis Hebard, 1923 syn. nov. Lectotypes and paralectotypes were selected for S. laeta, S. maculata and S. lineata, as well as the neotypes for S. hamata and S. boliviana. An updated key to species of Scaria is also provided.                A cladistic analysis for 15 species was performed (12 in the inner group and 3 in the outer group) with 40 morphological characters, confirming the monophyly of Scaria. A biogeographical analysis of dispersion-vicariance indicates that the origin of the genus was probably in the Inambari endemism center as the only reconstruction of the resulting ancestral distribution, five dispersions and three vicariance events being postulated. These suggest that both types of events are equally important in the current configuration of the distribution in Scaria. Vicariance events arise mostly by isolation of the species because of the uplift of the Andes and the dispersion events comprise four waves originating from the ancestral range into central and east Amazonia.

Outlining the Ancestry Landscape of Colombian Admixed Populations.

The ancestry of the Colombian population comprises a large number of well differentiated Native communities belonging to diverse linguistic groups. In the late fifteenth century, a process of admixture was initiated with the arrival of the Europeans, and several years later, Africans also became part of the Colombian population. Therefore, the genepool of the current Colombian population results from the admixture of Native Americans, Europeans and Africans. This admixture occurred differently in each region of the country, producing a clearly stratified population. Considering the importance of population substructure in both clinical and forensic genetics, we sought to investigate and compare patterns of genetic ancestry in Colombia by studying samples from Native and non-Native populations living in its 5 continental regions: the Andes, Caribe, Amazonia, Orinoquía, and Pacific regions. For this purpose, 46 AIM-Indels were genotyped in 761 non-related individuals from current populations. Previously published genotype data from 214 Colombian Natives from five communities were used for population comparisons. Significant differences were observed between Native and non-Native populations, among non-Native populations from different regions and among Native populations from different ethnic groups. The Pacific was the region with the highest African ancestry, Amazonia harboured the highest Native ancestry and the Andean and Orinoquían regions showed the highest proportion of European ancestry. The Andean region was further sub-divided into 6 sub-regions: North East, Central West, Central East, West, South West and South East. Among these regions, the South West region showed a significantly lower European admixture than the other regions. Hardy-Weinberg equilibrium and variance values of ancestry among individuals within populations showed a potential stratification of the Pacific population.