Abstract：
BACKGROUND: Toxoplasma is an obligate intracellular protozoan that causes an important zoonotic disease with a worldwide distribution. Felids are the definitive hosts of this parasite, while virtually all warm-blooded animals, including birds, serve as intermediate hosts. Four ring-tailed lemurs (Lemur catta) in the Taipei Zoo died of acute Toxoplasma infection in June 2019. Since then, Toxoplasma has occasionally been identified in this Zoo during necropsy of dead animals and PCR of animal blood samples. Therefore, a general survey of Toxoplasma infection in animals in the Zoo seems to be needed.
RESULTS: An indirect multispecies ELISA was used for the first time to screen for Toxoplasma infection in 326 serum samples collected from 75 species of animals. The infection rate of Toxoplasma was 27% (88/326). A commercial latex agglutination (LAT) assay was used to re-examine the samples with doubtful and uncertain ELISA results (151 samples from 42 species). The infection rate increased to 36.2% (118/326), and the indirect multispecies ELISA appeared to be applicable to 31 of 75 species animals included in this study. Nested PCR assays targeting the dense granule protein 7 (GRA7) gene and B1 gene were also used to detect Toxoplasma in DNA samples extracted from 10 liver or blood specimens from 8 animals. GRA7 gene fragments were amplified from 8 samples from 7 animals, while B1 gene fragments were amplified from only 4 samples from 4 animals. From the B1 nested PCR and the sequence data of GRA7 fragments amplified from infectious specimens, the animals in the Zoo were speculated to have been infected by at least three different Toxoplasma variants.
CONCLUSIONS: According to the serological investigation, we speculated that over one-third (36.2%) of animals in Taipei Zoo presented the infection of Toxoplasma, and the indirect multispecies ELISA we used can be applied to detect Toxoplasma infection in 31 animal species included in this study. Sequence analysis revealed that at least three Toxoplasma variants were infecting the animals of Taipei Zoo.
RESULTS: An indirect multispecies ELISA was used for the first time to screen for Toxoplasma infection in 326 serum samples collected from 75 species of animals. The infection rate of Toxoplasma was 27% (88/326). A commercial latex agglutination (LAT) assay was used to re-examine the samples with doubtful and uncertain ELISA results (151 samples from 42 species). The infection rate increased to 36.2% (118/326), and the indirect multispecies ELISA appeared to be applicable to 31 of 75 species animals included in this study. Nested PCR assays targeting the dense granule protein 7 (GRA7) gene and B1 gene were also used to detect Toxoplasma in DNA samples extracted from 10 liver or blood specimens from 8 animals. GRA7 gene fragments were amplified from 8 samples from 7 animals, while B1 gene fragments were amplified from only 4 samples from 4 animals. From the B1 nested PCR and the sequence data of GRA7 fragments amplified from infectious specimens, the animals in the Zoo were speculated to have been infected by at least three different Toxoplasma variants.
CONCLUSIONS: According to the serological investigation, we speculated that over one-third (36.2%) of animals in Taipei Zoo presented the infection of Toxoplasma, and the indirect multispecies ELISA we used can be applied to detect Toxoplasma infection in 31 animal species included in this study. Sequence analysis revealed that at least three Toxoplasma variants were infecting the animals of Taipei Zoo.
摘要：
背景：弓形虫是一种专性细胞内原生动物，可引起重要的人畜共患疾病，分布于全球。Felids是这种寄生虫的确定宿主,虽然几乎所有的温血动物，包括鸟类,作为中间主机。台北动物园的四只环尾狐猴（Lemurcatta）于2019年6月死于急性弓形虫感染。从那以后,在对死亡动物进行尸检和对动物血液样本进行PCR的过程中，偶尔会在该动物园中发现弓形虫。因此,似乎需要对动物园中动物的弓形虫感染进行一般调查。
结果：首次使用间接多物种ELISA在从75种动物收集的326份血清样品中筛查弓形虫感染。弓形虫感染率为27%(88/326)。使用商业乳胶凝集（LAT）测定法重新检查ELISA结果可疑且不确定的样品（来自42个物种的151个样品）。感染率上升至36.2%(118/326),间接多物种ELISA似乎适用于本研究中包括的75种动物中的31种。还使用靶向致密颗粒蛋白7(GRA7)基因和B1基因的巢式PCR测定来检测从10只动物的肝脏或血液样本中提取的DNA样品中的弓形虫。从7只动物的8个样本中扩增GRA7基因片段，而B1基因片段仅从4只动物的4个样品中扩增。从B1巢式PCR和从感染标本中扩增的GRA7片段的序列数据，据推测，动物园中的动物感染了至少三种不同的弓形虫变体。
结论：根据血清学调查，我们推测台北动物园超过三分之一(36.2%)的动物感染弓形虫，我们使用的间接多物种ELISA可用于检测本研究中包括的31种动物的弓形虫感染。序列分析显示，至少有三种弓形虫变体感染了台北动物园的动物。
结果：首次使用间接多物种ELISA在从75种动物收集的326份血清样品中筛查弓形虫感染。弓形虫感染率为27%(88/326)。使用商业乳胶凝集（LAT）测定法重新检查ELISA结果可疑且不确定的样品（来自42个物种的151个样品）。感染率上升至36.2%(118/326),间接多物种ELISA似乎适用于本研究中包括的75种动物中的31种。还使用靶向致密颗粒蛋白7(GRA7)基因和B1基因的巢式PCR测定来检测从10只动物的肝脏或血液样本中提取的DNA样品中的弓形虫。从7只动物的8个样本中扩增GRA7基因片段，而B1基因片段仅从4只动物的4个样品中扩增。从B1巢式PCR和从感染标本中扩增的GRA7片段的序列数据，据推测，动物园中的动物感染了至少三种不同的弓形虫变体。
结论：根据血清学调查，我们推测台北动物园超过三分之一(36.2%)的动物感染弓形虫，我们使用的间接多物种ELISA可用于检测本研究中包括的31种动物的弓形虫感染。序列分析显示，至少有三种弓形虫变体感染了台北动物园的动物。
