ABSTRACT
Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Subject(s)
Animals , Humans , Ancylostoma/genetics , Ancylostomiasis/diagnosis , Base Sequence , DNA, Intergenic/genetics , DNA, Protozoan/genetics , DNA, Ribosomal Spacer/genetics , Diagnosis, Differential , Molecular Sequence Data , Necator americanus/genetics , Phylogeny , Polymerase Chain Reaction/methods , Sequence Alignment , Trichostrongylosis/diagnosis , Trichostrongylus/geneticsABSTRACT
Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Subject(s)
Animals , Humans , Ancylostoma/genetics , Ancylostomiasis/diagnosis , Base Sequence , DNA, Intergenic/genetics , DNA, Protozoan/genetics , DNA, Ribosomal Spacer/genetics , Diagnosis, Differential , Molecular Sequence Data , Necator americanus/genetics , Phylogeny , Polymerase Chain Reaction/methods , Sequence Alignment , Trichostrongylosis/diagnosis , Trichostrongylus/geneticsABSTRACT
In experimental crosses between A. tubaeform and A caninum the worms failed to produce progeny in dual-strain combinations. Even though these two strains did not fail to copulate. Egg production was observed only in identical single-strain combinations. This supports the assumption that the two species are genetically separate and valid.