Assessing the population structure of trematode Metagonimus suifunensis using three mitochondrial markers.

In this work, for the first time, the genetic variability of the Metagonimus suifunensis population in the Russian southern Far East was estimated based on the full-length sequences of the nad1 gene of mitochondrial DNA. In addition, for a sample of the same size, the sequences of cox1 and cytb genes, previously used for population studies for M. suifunensis, were reanalysed. Three markers were combined to a common sequence, and the obtained data were studied. Despite the higher level of variability, nad1 and cox1 mtDNA genes did not reveal subdivisions within the population. The combined dataset made it possible to determine that the sample from the Odyr River was the centre of the species' range formation and clarified the continental migration route of the parasite from south to north. According to the data obtained, it was presumed that piscivorous birds participate in the life cycle of the parasite. The subdivision within population revealed that using all three mitochondrial markers is consistent with the features of differentiation within populations of related species, but the reasons for its formation remain unclear due to the insufficient amount of data and the use of different markers in studies of different species.

Bight of Benin: a Maternal Perspective of Four Beninese Populations and their Genetic Implications on the American Populations of African Ancestry.

The understanding of the first movements of the ancestral populations within the African continent is still unclear, particularly in West Africa, due to several factors that have shaped the African genetic pool across time. To improve the genetic representativeness of the Beninese population and to better understand the patterns of human settlement inside West Africa and the dynamics of peopling of the Democratic Republic of Benin, we analyzed the maternal genetic variation of 193 Beninese individuals belonging to Bariba, Berba, Dendi, and Fon populations. Results support the oral traditions indicating that the western neighbouring populations have been the ancestors of the first Beninese populations, and the extant genetic structure of the Beninese populations is most likely the result of admixture between populations from neighbouring countries and native people. The present findings highlight how the Beninese populations contributed to the gene pool of the extant populations of some American populations of African ancestry. This strengthens the hypothesis that the Bight of Benin was not only an assembly point for the slave trade during the Trans-Atlantic Slave Trade but also an important slave trapping area.

Human fascioliasis emergence in southern Asia: Complete nuclear rDNA spacer and mtDNA gene sequences prove Indian patient infection related to fluke hybridization in northeastern India and Bangladesh.

Fascioliasis is a snail-borne zoonotic disease with impact on the development of human subjects and communities. It is caused by two liver-infecting fasciolid trematode species, the globally-distributed Fasciola hepatica and the Africa/Asia-restricted but more pathogenic, larger F. gigantica. Fasciola gigantica is the cause of endemicity in livestock throughout the warm lowlands from Pakistan to southeastern Asia since old times. Human fascioliasis is emerging in this region at present, with an increase of patient reports. Complete sequences of rDNA ITS-1 and ITS-2 spacers and mtDNA nad1 and cox1 genes were obtained from fasciolid eggs found in the endoscopic bile aspirate from a patient of Arunachal Pradesh, northeastern India. Egg measurements, pronounced ITS heterozygosity, and pure F. gigantica mtDNA haplotypes demonstrate an infection by a recent F. gigantica-like hybrid. Sequence identities and similarities with the same DNA markers found in livestock from Bangladesh prove the human-infecting fasciolid to present identical ITSs and nad1 haplotypes and only one silent transversion in cox1 when compared to a widely-spread combined haplotype in animals. In northeastern India and Bangladesh, human fascioliasis emergence appears linked to increasing livestock prevalences due to: ruminant importation from other countries because of the increasing demand of rapidly growing human populations; numerous livestock movements, including transborder corridors, due to the uncontrolled small-scale household farming practices; and man-made introduction of F. hepatica with imported livestock into an area originally endemic for F. gigantica leading to frequent hybridization. Sequences, phylogenetic trees, and networks indicate that the origins of intermediate/hybrid fasciolids and factors underlying human infection risk differ in eastern and western South Asia. The emergence scenario in southern China and Vietnam resembles the aforementioned of northeastern India and Bangladesh, whereas in Pakistan it is linked to increasing monsoon rainfall within climate change combined with an impact of an extensive irrigation system. Past human-guided movements of pack animals along the western Grand Trunk Road and the eastern Tea-Horse Road explain the F. gigantica mtDNA results obtained. Physicians should be aware about these emerging scenarios, clinical pictures, diagnostic techniques and treatment. Government authorities must appropriately warn health professionals, ensure drug availability and improve livestock control.

Identification and genomic characterization of influenza viruses with different origin in Mexican pigs.

Swine influenza is a worldwide disease, which causes damage to the respiratory system of pigs. The H1N1 and H3N2 subtypes circulate mainly in the swine population of Mexico. There is evidence that new subtypes of influenza virus have evolved genetically and have been rearranged with human viruses and from other species; therefore, the aim of our study was to identify and characterize the genetic changes that have been generated in the different subtypes of the swine influenza virus in Mexican pigs. By sequencing and analyzing phylogenetically the eight segments that form the virus genome, the following subtypes were identified: H1N1, H3N2, H1N2 and H5N2; of which, a H1N1 subtype had a high genetic relationship with the human influenza virus. In addition, a H1N2 subtype related to the porcine H1N2 virus reported in the United States was identified, as well as, two other viruses of avian origin from the H5N2 subtype. Particularly for the H5N2 subtype, this is the first time that its presence has been reported in Mexican pigs. The analysis of these sequences demonstrates that in the swine population of Mexico, circulate viruses that have suffered punctual-specific mutations and rearrangements of their proteins with different subtypes, which have successfully adapted to the Mexican swine population.