Setor de Patologia Veterinária (SPV), Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal Do Rio Grande Do Sul (UFRGS), Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS, 91540-000, Brazil.
Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva (DMVP), Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Building 63C, Bairro Camobi, Santa Maria, RS, 97105-900, Brazil.
Parasitol Res. 2022 Sep;121(9):2633-2639. doi: 10.1007/s00436-022-07581-w. Epub 2022 Jul 2.
Toxoplasma gondii is a major cause of reproductive losses in small ruminants in several countries. We describe here an outbreak of T. gondii-associated abortion in sheep in Southern Brazil. The flock was comprised of 55 adult sheep, and late-term abortions and stillbirths were detected in 15/36 (41.66%) gestating ewes. Serum samples collected from 45 sheep were tested for T. gondii through indirect immunofluorescence assay; IgM and IgG positive results were detected in 44.44% (20/45) and 86.67% (39/45) of the cases, respectively. Four fetuses and two placentas were pathologically evaluated. Gross changes were restricted to fetal membranes and were characterized by multifocal white areas in the cotyledons. Microscopically, these areas corresponded to necrotic foci affecting the chorionic epithelium accompanied by rare cysts of T. gondii. The main histological change in fetal tissues consisted of well-demarked and sparsely distributed necrotic foci in the central nervous system. Tissue samples from all four fetuses and one placenta had positive PCR results for T. gondii. Restriction fragment length polymorphism (RFLP) genotyping using ten markers (SAG1, 5'-3'SAG2, alt.SAG2, SGA3, BTUB, GRA6, c22-8, c29-2, L358, and PK1) was carried out on one sample, and results were consistent with T. gondii clonal type III (ToxoDB-PCR-RFLP genotype #2, TgCpBr4).
刚地弓形虫是多个国家小反刍动物繁殖损失的主要原因。本研究描述了巴西南部绵羊弓形虫相关流产的暴发情况。该羊群由 55 只成年绵羊组成，在 36 只妊娠母羊中发现了 15 只（41.66%）晚期流产和死胎。采集了 45 只绵羊的血清样本，通过间接免疫荧光试验检测弓形虫；在 44.44%（20/45）和 86.67%（39/45）的病例中分别检测到 IgM 和 IgG 阳性结果。对 4 只胎儿和 2 只胎盘进行了病理评估。大体变化仅限于胎膜，表现为绒毛叶上的多个白色区域。镜下，这些区域对应于影响绒毛膜上皮的坏死灶，伴有罕见的弓形虫囊肿。胎儿组织中的主要组织学变化是中枢神经系统中界限分明且稀疏分布的坏死灶。来自所有 4 只胎儿和 1 只胎盘的组织样本的 PCR 结果均为弓形虫阳性。使用 10 个标记物（SAG1、5'-3'SAG2、alt.SAG2、SGA3、BTUB、GRA6、c22-8、c29-2、L358 和 PK1）对一个样本进行了限制性片段长度多态性（RFLP）基因分型，结果与弓形虫克隆型 III（ToxoDB-PCR-RFLP 基因型 #2，TgCpBr4）一致。
