Nascimento Lauricia S, Evaristo Anna M C F, Oliveira Glauber M B, Ferreira Matheus S, Silva Déborah L R, Azevedo Sergio S, Yamamoto Sandra M, Araújo Márcia M, Horta Mauricio C
Federal University of Vale do São Francisco (Univasf), Campus Ciências Agrárias, Rodovia BR 407, km 12, Lote 543, Projeto de Irrigação Senador Nilo Coelho s/n, Petrolina, PE, 56300-990, Brazil.
Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, SP, 05508-270, Brazil.
Trop Anim Health Prod. 2021 Apr 17;53(2):267. doi: 10.1007/s11250-021-02647-w.
This study aimed to determine the AR of gastrointestinal nematodes (GIN) to commercial drugs in sheep flocks naturally infected, grazing in irrigated (IA) and dry (DA) areas of the semiarid region in northeastern Brazil. Fecal egg count reduction tests (FECRT) were performed at 10 farms. From each flock, 36 adult sheep were selected and divided into five groups (G1 (0.08% ivermectin), G2 (10% albendazole), G3 (5% levamisole), G4 (1% moxidectin), G5 (10% closantel) and one control group, G6). All the commercial drugs were found to reduce the number of eggs per gram of feces (EPG). Resistance to ivermectin (37.1%), albendazole (52.1%), and levamisole (52.0%) was detected at all the farms, but nematodes proved to be susceptible to moxidectin (87.9%) and closantel (83.9%). The overall average efficacy of the commercial drugs was significantly higher (P < 0.05) in DA (49.2%), where moxidectin (90.4%) showed high effectiveness. The presence of the parasite Haemonchus contortus predominated at all the farms. The variables irrigated area (P = 0.002), intensive breeding (P = 0.018), uncovered enclosures (P = 0.05), cultivated (P = 0.043) and native/cultivated (P = 0.007) pastures, and rotational grazing (P = 0.013) were significantly associated with GIN infection; irrigated area (P = 0.009), semi-intensive breeding (P = 0.05), rotational grazing (P = 0.045), cultivated (P = 0.021) and native/cultivated (P = 0.04) pastures, and estimated weighing of animals (P = 0.002) were significantly associated with AR. Therefore, improved management practices and strategic deworming must be implemented to prevent the development of AR.
本研究旨在确定巴西东北部半干旱地区灌溉区（IA）和干旱区（DA）自然感染的羊群中胃肠道线虫（GIN）对市售药物的抗药性。在10个农场进行了粪便虫卵计数减少试验（FECRT）。从每个羊群中挑选36只成年绵羊，分为五组（G1（0.08%伊维菌素）、G2（10%阿苯达唑）、G3（5%左旋咪唑）、G4（1%莫西菌素）、G5（10%氯氰碘柳胺））和一个对照组G6。所有市售药物均能减少每克粪便中的虫卵数（EPG）。在所有农场均检测到对伊维菌素（37.1%）、阿苯达唑（52.1%）和左旋咪唑（52.0%）的抗药性，但线虫对莫西菌素（87.9%）和氯氰碘柳胺（83.9%）敏感。市售药物的总体平均疗效在干旱区（49.2%）显著更高（P<0.05），其中莫西菌素（90.4%）显示出高效。所有农场均以捻转血矛线虫寄生虫为主。灌溉区（P = 0.002）、集约化养殖（P = 0.018）、露天围栏（P = 0.05）、耕地（P = 0.043）以及天然/耕地（P = 0.007）牧场和轮牧（P = 0.013）等变量与胃肠道线虫感染显著相关；灌溉区（P = 0.009）、半集约化养殖（P = 0.05）、轮牧（P = 0.045）、耕地（P = 0.021）以及天然/耕地（P = 0.04）牧场和动物估计体重（P = 0.002）与抗药性显著相关。因此，必须实施改进的管理措施和战略驱虫以防止抗药性的发展。
