Batista Leandro Farias, Oliveira Laura Lúcia Dos Santos, Silva Fredson Vieira E, Lima Walter Dos Santos, Pereira Cíntia Aparecida de Jesus, Rocha Raul Herberth Freitas, Santos Izadora Souza, Dias Júnior José Alisson, Alves Cleison Augusto
Departamento de Ciências Agrárias, Universidade Estadual de Montes Claros (UNIMONTES), Av. Reinaldo Viana, s/n, São Vicente, 39.448-524 Janaúba, MG, Brazil.
Departamento de Ciências Agrárias, Universidade Estadual de Montes Claros (UNIMONTES), Av. Reinaldo Viana, s/n, São Vicente, 39.448-524 Janaúba, MG, Brazil.
Vet Parasitol Reg Stud Reports. 2023 Jan;37:100821. doi: 10.1016/j.vprsr.2022.100821. Epub 2022 Dec 16.
Anthelmintic efficacy was evaluated among sheep that had become naturally infected with gastrointestinal nematodes in 17 flocks located in the semiarid region of Minas Gerais, Brazil. Feces were collected individually from 1021 hairy sheep to determine the number of eggs per gram of feces (EPG) and for coprocultures to identify nematode genera the nematodes. Only the animals that presented EPG counts greater than or equal to 200 were included in the study (totaling 381 sheep). The animals were divided into three treatment groups: albendazole, ivermectin and levamisole. Fourteen days after the administration of anthelmintics, fecal samples were taken from all animals. In each flock, the pre-treatment and post-treatment arithmetic mean EPG were used to calculate the efficacy (FECR) for each of the treatment groups and the lower 95% confidence limit. Data were analyzed with the "eggCounts 2.3" package in RStudio, using a Bayesian model for paired design. The anthelmintics were classified as being efficacious (when the FECR was both equal to or above 95% and the lower 95% confidence limit was equal to or above 90%) or as encountering anthelmintic resistance (when the FECR was below 95% and the lower 95% confidence limit was below 90%) or inconclusive (when none of the other criteria were fulfilled). Albendazole and ivermectin were not effective in any of the flocks. Levamisole was effective against gastrointestinal nematodes in 25% of the flocks studied. Haemonchus, Trichostrongylus and Oesophagostomum genera were identified in this study in a semiarid region of Minas Gerais, Brazil. The genus Haemonchus was the most prevalent, followed by Trichostrongylus and Oesophagostomum. After anthelmintic treatment, the most prevalent genus was Haemonchus, followed by Trichostrongylus; the genus Oesophagostomum was not detected. The highest percentage of Haemonchus larvae was observed after treatment with ivermectin, followed by albendazole and levamisole. This study revealed the existence of gastrointestinal nematodes in sheep that present multiple resistance to all three main classes of anthelmintic drugs.
在巴西米纳斯吉拉斯州半干旱地区的17个羊群中，对自然感染胃肠道线虫的绵羊进行了驱虫效果评估。从1021只毛用绵羊中分别采集粪便，以确定每克粪便中的虫卵数（EPG），并进行粪便培养以鉴定线虫种类。只有EPG计数大于或等于200的动物才被纳入研究（共计381只绵羊）。这些动物被分为三个治疗组：阿苯达唑、伊维菌素和左旋咪唑。在施用驱虫药14天后，从所有动物身上采集粪便样本。在每个羊群中，使用治疗前和治疗后的算术平均EPG来计算每个治疗组的疗效（FECR）和较低的95%置信限。使用RStudio中的“eggCounts 2.3”软件包，采用配对设计的贝叶斯模型对数据进行分析。驱虫药被分类为有效（当FECR等于或高于95%且较低的95%置信限等于或高于90%时）、遇到驱虫药抗性（当FECR低于95%且较低的95%置信限低于90%时）或不确定（当不满足其他任何标准时）。阿苯达唑和伊维菌素在任何一个羊群中都无效。左旋咪唑在25%的研究羊群中对胃肠道线虫有效。在巴西米纳斯吉拉斯州的一个半干旱地区的这项研究中，鉴定出了血矛线虫属、毛圆线虫属和食道口线虫属。血矛线虫属最为普遍，其次是毛圆线虫属和食道口线虫属。驱虫治疗后，最普遍的属是血矛线虫属，其次是毛圆线虫属；未检测到食道口线虫属。伊维菌素治疗后观察到血矛线虫幼虫的百分比最高，其次是阿苯达唑和左旋咪唑。这项研究揭示了绵羊胃肠道线虫的存在，这些线虫对所有三种主要类别的驱虫药都具有多重抗性。
