TY - JOUR
T1 - Genetic variations in the beta-tubulin gene and the internal transcribed spacer 2 region of Trichuris species from man and baboons
AU - Hansen, Tina Vicky Alstrup
AU - Thamsborg, Stig Milan
AU - Olsen, Annette
AU - Prichard, Roger K.
AU - Nejsum, Peter
PY - 2013
Y1 - 2013
N2 - Background: The whipworm Trichuris trichiura has been estimated to infect 604 - 795 million people worldwide. The current control strategy against trichuriasis using the benzimidazoles (BZs) albendazole (400 mg) or mebendazole (500 mg) as single-dose treatment is not satisfactory. The occurrence of single nucleotide polymorphisms (SNPs) in codons 167, 198 or 200 of the beta-tubulin gene has been reported to convey BZ-resistance in intestinal nematodes of veterinary importance. It was hypothesised that the low susceptibility of T. trichiura to BZ could be due to a natural occurrence of such SNPs. The aim of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal transcribed spacer 2 region (ITS2). Methods. Nucleotide sequences of the beta-tubulin gene were generated by PCR using degenerate primers, specific primers and DNA from worms and eggs of T. trichiura and worms of Trichuris spp. from baboons. The ITS2 region was amplified using adult Trichuris spp. from baboons. PCR products were sequenced and analysed. The beta-tubulin fragments were studied for SNPs in codons 167, 198 or 200 and the ITS2 amplicons were compared with GenBank records of T. trichiura. Results: No SNPs in codons 167, 198 or 200 were identified in any of the analysed Trichuris spp. from humans and baboons. Based on the ITS2 region, the similarity between Trichuris spp. from baboons and GenBank records of T. trichiura was found to be 98 - 99%. Conclusions: Single nucleotide polymorphisms in codon 167, 198 and 200, known to confer BZ-resistance in other nematodes, were absent in the studied material. This study does not provide data that could explain previous reports of poor BZ treatment efficacy in terms of polymorphism in these codons of beta-tubulin. Based on a fragment of the beta-tubulin gene and the ITS2 region sequenced, it was found that T. trichiura from humans and Trichuris spp. isolated from baboons are closely related and may be the same species.
AB - Background: The whipworm Trichuris trichiura has been estimated to infect 604 - 795 million people worldwide. The current control strategy against trichuriasis using the benzimidazoles (BZs) albendazole (400 mg) or mebendazole (500 mg) as single-dose treatment is not satisfactory. The occurrence of single nucleotide polymorphisms (SNPs) in codons 167, 198 or 200 of the beta-tubulin gene has been reported to convey BZ-resistance in intestinal nematodes of veterinary importance. It was hypothesised that the low susceptibility of T. trichiura to BZ could be due to a natural occurrence of such SNPs. The aim of this study was to investigate whether these SNPs were present in the beta-tubulin gene of Trichuris spp. from humans and baboons. As a secondary objective, the degree of identity between T. trichiura from humans and Trichuris spp. from baboons was evaluated based on the beta-tubulin gene and the internal transcribed spacer 2 region (ITS2). Methods. Nucleotide sequences of the beta-tubulin gene were generated by PCR using degenerate primers, specific primers and DNA from worms and eggs of T. trichiura and worms of Trichuris spp. from baboons. The ITS2 region was amplified using adult Trichuris spp. from baboons. PCR products were sequenced and analysed. The beta-tubulin fragments were studied for SNPs in codons 167, 198 or 200 and the ITS2 amplicons were compared with GenBank records of T. trichiura. Results: No SNPs in codons 167, 198 or 200 were identified in any of the analysed Trichuris spp. from humans and baboons. Based on the ITS2 region, the similarity between Trichuris spp. from baboons and GenBank records of T. trichiura was found to be 98 - 99%. Conclusions: Single nucleotide polymorphisms in codon 167, 198 and 200, known to confer BZ-resistance in other nematodes, were absent in the studied material. This study does not provide data that could explain previous reports of poor BZ treatment efficacy in terms of polymorphism in these codons of beta-tubulin. Based on a fragment of the beta-tubulin gene and the ITS2 region sequenced, it was found that T. trichiura from humans and Trichuris spp. isolated from baboons are closely related and may be the same species.
U2 - 10.1186/1756-3305-6-236
DO - 10.1186/1756-3305-6-236
M3 - Journal article
C2 - 23938038
SN - 1756-3305
VL - 6
JO - Parasites & Vectors
JF - Parasites & Vectors
M1 - 236
ER -