Haemonchus contortus β-tubulin isotype 1 gene F200Y and F167Y SNPs are both selected by ivermectin and oxfendazole treatments with differing impacts on anthelmintic resistance

Background and Aim: Haemonchus contortus is one of the major trichostrongyloid nematodes affecting small ruminant production worldwide, especially in tropical and subtropical regions. Adult H. contortus suck the blood from the host abomasum leading to anemia and often death in heavily infected animals. The mainstay of parasitic control is an anthelmintic drug, but long-term drug use may cause drug resistance. The aim of this study was to examine benzimidazole resistance in H. contortus of goats from different regions in Thailand by detecting the frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene. Materials and Methods: A total of 121 H. contortus adults were obtained from 31 naturally infected out of 37 slaughtered goats from city abattoirs in five regions of Thailand. The frequency of the F200Y polymorphism in the β-tubulin isotype 1 gene was detected following the allele-specific polymerase chain reaction protocol. Results: The overall genotype frequencies in Thailand were homozygous resistant (RR: 24%), heterozygous (SR: 44.6%), and homozygous susceptible (SS: 31.4%). The allele frequencies were resistant allele (R: 46%) and susceptible allele (S: 54%). The R allele frequency and the RR genotype varied from 30% to 65% and 0% to 43.9%, respectively. The frequency of R alleles was significantly higher in the southern region (0.65) as compared to northern (0.30, p=0.001), western (0.38, p=0.04), and central regions (0.30, p=0.03). The RR genotype was also significantly higher in the southern region (43.9%) versus the northern (0 %, p=0.001), western (11.8%, p=0.012), and central regions (17.4%, p=0.001). Conclusion: This is the first study of the detection of single-nucleotide polymorphisms in codon 200 of the β-tubulin isotype 1 gene of H. contortus from goats in Thailand. These findings are essential and imply that an integrated approach is needed for issues such as drug treatment, farm management, prevention, and control strategies. This is of interest to farmers, veterinarians, and the department of livestock.

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High levels of benzimidazole resistance and β-tubulin isotype 1 SNP F167Y in Haemonchus contortus populations from Ceará State, Brazil

Small Ruminant Research ◽

10.1016/j.smallrumres.2016.11.023 ◽

2017 ◽

Vol 146 ◽

pp. 48-52 ◽

Cited By ~ 6

Author(s):

Jessica Maria Leite dos Santos ◽

Jomar Patrício Monteiro ◽

Wesley Lyeverton Correia Ribeiro ◽

Iara Tersia Freitas Macedo ◽

José Vilemar de Araújo Filho ◽

...

Keyword(s):

Haemonchus Contortus ◽

Benzimidazole Resistance ◽

Tubulin Isotype ◽

Β Tubulin

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Molecular detection of benzimidazole resistance in Haemonchus contortus using real-time PCR and pyrosequencing

Parasitology ◽

10.1017/s003118200800543x ◽

2009 ◽

Vol 136 (3) ◽

pp. 349-358 ◽

Cited By ~ 84

Author(s):

G. von SAMSON-HIMMELSTJERNA ◽

T. K. WALSH ◽

A. A. DONNAN ◽

S. CARRIÈRE ◽

F. JACKSON ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Haemonchus Contortus ◽

Anthelmintic Resistance ◽

Allele Frequencies ◽

Detection Methods ◽

Resistance Testing ◽

Β Tubulin

SUMMARYBenzimidazoles (BZ) are widely used to treat parasitic nematode infections of humans and animals, but resistance is widespread in veterinary parasites. Several polymorphisms in β-tubulin genes have been associated with BZ-resistance. In the present study, we investigated β-tubulin isotype 1 sequences of 18 Haemonchus contortus isolates with varying levels of resistance to thiabendazole. The only polymorphism whose frequency was significantly increased in the resistant isolates was TTC to TAC at codon 200. Real-time PCR (using DNA from 100 third-stage larvae, L3s) and pyrosequencing (from DNA from 1000–10 000 L3s) were used to measure allele frequencies at codon 200 of these isolates, producing similar results; drug sensitivity decreased with increasing TAC frequency. Pyrosequencing was also used to measure allele frequencies at positions 167 and 198. We showed that such measurements are sufficient to assess the BZ-resistance status of most H. contortus isolates. The concordance between real-time PCR and pyrosequencing results carried out in different laboratories indicated that these tools are suitable for the routine diagnosis of BZ-resistance in H. contortus. The molecular methods were more sensitive than the ‘egg hatch test’, and less time-consuming than current in vivo- or in vitro-anthelmintic resistance detection methods. Thus, they provide a realistic option for routine molecular resistance testing on farms.

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Analisis Sekuen Gen Tubulin-β Isotipe 1 Cacing Haemonchus contortus Isolat Resisten terhadap Benzimidazole pada Domba di Indonesia

Jurnal AgroBiogen ◽

10.21082/jbio.v4n2.2008.p45-50 ◽

2016 ◽

Vol 4 (2) ◽

pp. 45

Author(s):

Dyah Haryuningtyas ◽

Wayan T. Artama

Keyword(s):

Anthelmintic Resistance ◽

Stop Codon ◽

Small Ruminants ◽

Gastrointestinal Nematodes ◽

Single Mutation ◽

Coding Region ◽

West Java ◽

Central Java ◽

Tubulin Isotype ◽

Β Tubulin

Benzimidazole (BZ) resistance to gastrointestinal nematodes in small ruminants (sheep and goat) has become a significant problem worldwide. Evidences of anthelmintic resistance to albendazole in Indonesia has been reported from some government owned farms in West Java, Central Java, and Yogyakarta. Previous study on the sheep parasite H. contortus had shown that the BZ resistance was related to selection for individuals in a population possesing a spesific β-tubulin isotype 1 gene. The study is aimed to determine mutation on coding region of central part of β-tubulin isotype 1 gene of H. contortus resistant strain from Indonesia. Seven H. contortus worms were isolated from four BZ resistant sheep from two government farms (SPTD Trijaya, Kuningan, West Java, and UPTD Pelayanan Kesehatan Hewan, Bantul, Yogyakarta), and from a BZ susceptible sheep from Cicurug, Sukabumi, West Java. DNA was extracted individually from female H. contortus worms. A fragment of 520 bp β-tubulin isotype 1 gene exon 3, 4, 5 was amplified using the PCR technique and then sequenced. The results showed that a single mutation occurred in codon 200 (from phenilalanine to tyrosine) had caused benzimidazole resistance in H. contortus from SPTD Trijaya, Kuningan, West Java. Mutation in β-tubulin isotype 1 gene of H. contortus from UPTD Pelayanan Kesehatan Hewan, Yogyakarta, occurred in codon 198 (from glutamate to glycine), codon 201 (from cystein to stop codon), and codon 202 (from isoleucyne to stop codon).

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