Ascariasis in people and pigs: new inferences from DNA analysis of worm populations.
ABSTRACT Ascaris is a large parasitic roundworm (nematode) of the small intestine of humans and pigs. These roundworms cause the socioeconomically important disease, ascariasis. For the past 20 years, molecular markers have been used in studies on Ascaris and ascariasis, and added valuable information to the understanding of these roundworms. Here, we provide a review of these studies on human and pig roundworms. We begin with a summary of studies using molecular phenotypic markers to compare Ascaris from humans and pigs, followed by a synopsis of comparisons using genetic markers. We then draw forth inferences in the aspects of host affiliation and infection success, transmission between and among humans and pigs, evolutionary history of Ascaris. We also highlight additional topics such as mating dynamics, diagnostics, and paleoparasitology where molecular epidemiological approaches have been utilized.
Article: Genetic characterisation and molecular epidemiology of Ascaris spp. from humans and pigs in Brazil.[show abstract] [hide abstract]
ABSTRACT: The molecular epidemiology of Ascaris spp. of human and pig origin has been studied as a means to assess the potential of pigs as reservoirs for human ascariasis. In this study, human (H) and pig (P) Ascaris spp. haplotypes from two Brazilian regions were characterised based on two mitochondrial genes, nad1 and cox1. The results show six haplotypes of the cox1 gene, with two haplotypes (H9P9 and P3) corresponding to haplotypes previously characterised in China. Because P3 was found in humans in this study, it was designated as H14P3. Furthermore, five new Ascaris spp. nad1 haplotypes from humans (H12-H16) and five from pigs (P16-P20) were observed, with one being highly frequent and present in both hosts, here designated as H12P17. Phylogenetic and network analysis demonstrated that the molecular epidemiology of Ascaris spp. in Brazil is driven by the globally distributed haplotypes cox1 H14P3 and nad1H12P17. In conclusion, in this study genetic characterisation of Ascaris spp. showed that humans and pigs share common haplotypes that are also present in two widely separated geographical regions of Brazil.Transactions of the Royal Society of Tropical Medicine and Hygiene 08/2012; 106(10):604-12. · 2.16 Impact Factor