Antunes Maria Inês, Lima Miguel Saraiva, Stilwell George, Romeiras Maria Inês, Fragoso Luís, Madeira de Carvalho Luís Manuel
CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal.
Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal.
Pathogens. 2022 Dec 1;11(12):1457. doi: 10.3390/pathogens11121457.
Infections caused by gastrointestinal parasites have been described worldwide as one of the most important issues impacting small ruminant production. The systematic administration of anthelmintic (AH) drugs without following good practice principles has led to an increase in anthelmintic resistance (AR). There is scarce information regarding AH efficacy in small ruminants in Portugal. This study aimed to characterize by in vivo methods the presence and level of AR in four farms in the region of Lisbon and Tagus Valley. All four farms kept small herds in extensive management systems and used different deworming protocols. The active substances used were fenbendazole and a combination of mebendazole plus closantel in a dosage according to the manufacturers' instructions. On day 0 (T0), fecal samples were collected from all study animals, and animals in the treatment group (n = 40) were dewormed with the AH previously chosen by the assistant veterinarian. Animals in the control group (n = 30) did not receive any AH drug. The fecal sample collection was repeated on day 15 (T15), and the control group was treated. Egg counts were performed using the McMaster method for the eggs per gram (EPG), and AR was evaluated by the fecal egg count reduction test (FECRT) with a 95% confidence level (CL). The results from this experiment indicated that the four farms presented AR with two farms to fenbendazole (FECRT of 48% and 85%) and two farms to mebendazole plus closantel (FECRT of 66% and 79%). These results indicate that the gastrointestinal parasites of the four studied Portuguese farms are resistant to benzimidazoles, which suggests an increase in AR regarding nematodes in small ruminant production systems in Portugal.
胃肠道寄生虫引起的感染在全球范围内被认为是影响小反刍动物生产的最重要问题之一。不遵循良好实践原则而系统地施用驱虫药（AH）导致了驱虫抗药性（AR）的增加。关于葡萄牙小反刍动物中AH疗效的信息很少。本研究旨在通过体内方法表征里斯本和塔霍河谷地区四个农场中AR的存在情况和水平。所有四个农场都在粗放管理系统中饲养小群动物，并使用了不同的驱虫方案。使用的活性物质是芬苯达唑以及甲苯咪唑加氯氰碘柳胺的组合，剂量按照制造商的说明。在第0天（T0），从所有研究动物中采集粪便样本，治疗组（n = 40）的动物用助理兽医预先选择的AH进行驱虫。对照组（n = 30）的动物未接受任何AH药物。在第15天（T15）重复采集粪便样本，并对对照组进行治疗。使用麦克马斯特方法对每克粪便中的虫卵（EPG）进行计数，并通过粪便虫卵计数减少试验（FECRT）在95%置信水平（CL）下评估AR。该实验结果表明，四个农场均存在AR，其中两个农场对芬苯达唑有抗性（FECRT分别为48%和85%），两个农场对甲苯咪唑加氯氰碘柳胺有抗性（FECRT分别为66%和79%）。这些结果表明，所研究的四个葡萄牙农场的胃肠道寄生虫对苯并咪唑类药物具有抗性，这表明葡萄牙小反刍动物生产系统中线虫的AR有所增加。
