Tarbiat B, Jansson D S, Tydén E, Höglund J
Department of Biomedical Sciences and Veterinary Public Health,Section for Parasitology,Swedish University of Agricultural Sciences (SLU),P.O. Box 7036 SE-750 07,Uppsala,Sweden.
Department of Animal Health and Antimicrobial Strategies,National Veterinary Institute (SVA),SE-751 89 Uppsala,Sweden.
Parasitology. 2017 Sep;144(10):1338-1345. doi: 10.1017/S0031182017000531. Epub 2017 May 18.
Susceptability of Ascaridia galli to benzimidazole (BZ) was investigated using faecal egg count reduction test (FECRT), in ovo larval development test (LDT) and genetic markers (mutations at codons 167, 198 and 200 of β-tubulin gene). Six flocks (F1-F6) of a commercial laying hen farm with different number of exposure to BZ were recruited. The FECR was calculated by analyzing individual faeces (F1, F2, F4 and F5) before and 10 days after treatment. The LDT was performed on parasite eggs from pooled samples from F1 to F6 and LC50 and LC99 were calculated. DNA was extracted from 120 worms and sequenced for β-tubulin gene. In all flocks, the FECRs were above 95% (lower CI above 90%). No significant difference was observed (p > 0·05) among obtained LC50 (F1/F4 and F2/F5 vs F3/F6) in the LDT. However, LC50 and LC99 were higher than suggested values for declaration of resistance in other nematode species. No variation was observed in codon positions involved in BZ resistance. Overall, our results indicated lack of evidence of resistance to BZ in A. galli. More research is needed to confirm these results and to further optimize the existing tools for detection and monitoring of anthelmintic resistance in A. galli.
采用粪便虫卵计数减少试验（FECRT）、卵内幼虫发育试验（LDT）和遗传标记（β-微管蛋白基因第167、198和200位密码子的突变）研究了鸡蛔虫对苯并咪唑（BZ）的敏感性。招募了一个商业蛋鸡场的六个鸡群（F1 - F6），它们接触BZ的次数不同。通过分析治疗前和治疗后10天的个体粪便（F1、F2、F4和F5）来计算FECR。对来自F1至F6混合样本的寄生虫卵进行LDT，并计算LC50和LC99。从120条虫体中提取DNA并对β-微管蛋白基因进行测序。在所有鸡群中，FECR均高于95%（下限置信区间高于90%）。在LDT中，所获得的LC50（F1/F4和F2/F5与F3/F6相比）之间未观察到显著差异（p > 0·05）。然而，LC50和LC99高于其他线虫物种抗药性声明的建议值。在与BZ抗性相关的密码子位置未观察到变异。总体而言，我们的结果表明没有证据表明鸡蛔虫对BZ产生抗性。需要更多研究来证实这些结果，并进一步优化现有的鸡蛔虫抗寄生虫药物抗性检测和监测工具。
