Molecular Epidemiology ofAscarisInfection Among Pigs in Iowa

Abstract

Ascaris is a large roundworm parasite that infects humans and pigs throughout the world. Molecular markers have been used to study parasite transmission in Ascaris-endemic and -nonendemic regions of the world. In the United States, ascariasis still persists in commercial swine and has been designated a neglected disease of poverty in humans. However, relatively few data are available for evaluation of zoonotic transmission. In the present study, we obtained adult worms from abattoirs and characterized each worm on the basis of the gene encoding nuclear internal transcribed sequence (ITS) and mitochondrial cox1 Restriction fragment-length polymorphism analysis of ITS revealed swine, human, and hybrid genotypes. cox1 sequences were compared to all complete sequences available in GenBank, and haplotype analysis demonstrated 92 haplotypes worldwide. Sequences from the parasites in this study represented 10 haplotypes, including 6 new haplotypes that have not been previously described. Our results indicate that anthropozoonotic transmission has occurred in the past, resulting in the presence of human genotypes in pigs and supporting further investigation of zoonotic Ascaris transmission in the United States.

Molecular evidence of hybridization between pig and human Ascaris indicates an interbred species complex infecting humans

“…Importantly, our nuclear genome SNP analysis suggests that the 68 Kenyan Ascaris are distributed across multiple clades in a phylogeny based on the nuclear genomes. Overall, data from our study and other studies are consistent with a pattern where hybrid genotypes in Ascaris populations were observed ( Betson et al, 2014 ; Cavallero et al, 2013 ; Criscione et al, 2007 ; Jesudoss Chelladurai et al, 2017 ). Our study represents one of the most detailed accounts of mito-nuclear discordance in nematodes echoing patterns seen in another human nematode: Onchocerca volvulus ( Choi et al, 2017 ).…”

Evolutionary and genotypic analyses of global porcine epidemic diarrhea virus strains

“…KX883635) hosted by Ascaris suum (Supporting information Table S1) (Shi et al, 2016), a large roundworm in pigs, thus providing novel insight into the possible epidemiology of PEDV infection. Indeed, parasites have long been regarded as a harmful factor to the pig industry as sources for a variety of infectious agents (Jesudoss Chelladurai et al, 2017). For example, Metastrongylus larvae are considered a reservoir for various porcine viral pathogens, primarily swine fever virus and swine flu virus (Sen, Kelley, Underdahl, & Young, 1961).…”

Genetic diversity of Ascaris spp. infecting humans and pigs in distinct Brazilian regions, as revealed by mitochondrial DNA

“…Interestingly, it has been found in all Brazilian localities studied to date (this study and previous studies by [21] and [20]). This haplotype is widespread in four continents–Asia, Africa, the Americas, and Europe–mainly in human samples [33,35,38]. Furthermore, Ascaris sp.…”