title: Strongyloides stercoralis genotypes in humans in Cambodia.
abstract: Little is known about the genetic variability of the soil-transmitted nematode, Strongyloides stercoralis, in humans. We sequenced portions of the small subunit rDNA (SSU), including the hyper variable regions (HVR) I and IV from S. stercoralis larvae derived from individuals living in a rural setting in Cambodia. We identified three polymorphic positions, including a previously reported one within the HVR I. HVR IV was invariable. Six different SSU alleles existed in our sample. Although different genotypes of S. stercoralis were found in the same individuals, no heterozygous larvae were found. This indicates that there is no or very little interbreeding between the different genotypes. Further studies are needed to examine if this is because sexual reproduction, which is facultative, is rare in our study area's S. stercoralis population or because what is considered to be S. stercoralis today is actually a complex of closely related species or subspecies.
authors: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors: Fabian
authors: F
authors: Schär
authors: Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Tuebingen, Germany.
authors: Li
authors: L
authors: Guo
authors: Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Tuebingen, Germany.
authors: Adrian
authors: A
authors: Streit
authors: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
authors: Virak
authors: V
authors: Khieu
authors: National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
authors: Sinuon
authors: S
authors: Muth
authors: University of Basel, Basel, Switzerland; Medical and Diagnostics Department, Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors: Hanspeter
authors: H
authors: Marti
authors: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland. Electronic address: peter.odermatt@unibas.ch.
authors: Peter
authors: P
authors: Odermatt
mesh_terms: D000818:Animals; D001483:Base Sequence; D002160:Cambodia / Q000453:epidemiology; D018509:DNA, Helminth / Q000235:genetics / Q000378:metabolism; D005260:Female; D005838:Genotype; D006801:Humans; D007814:Larva; D008969:Molecular Sequence Data; D012337:RNA, Ribosomal, 18S / Q000235:genetics / Q000378:metabolism; D017171:Strongyloides stercoralis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D013322:Strongyloidiasis / Q000453:epidemiology / Q000469:parasitology*
chemical_list: D018509:DNA, Helminth; D012337:RNA, Ribosomal, 18S
keywords: Cambodia; Genotype; Human; SSU hyper variable region I/IV; Strongyloides stercoralis