Abstract：
Giardia duodenalis (syn. G. intestinalis or G. lamblia) is a parasitic protozoan that infects the upper intestinal tract of a broad range of hosts, including humans and domestic animals. Thus, it has raised concerns about the public health risk due to companion animals. Recently, with the improvement of living standards and increasing contacts between pets and humans, the zoonotic transmission of Giardia has dramatically increased. From a genetic point of view, G. duodenalis should be viewed as a complex species that includes eight different species-specific genetic assemblages. The laboratory diagnosis is mainly based on the finding of microscopic cysts in stool samples by coprological examination. Other methods include the detection of antigens, immunoassays or PCR protocols, which allow the identification of Giardia assemblages. The study aimed to compare the performance of Direct Fluorescence Antibody test (DFA), zinc sulfate flotation technique (ZnSO4), rapid diagnostic test (RDT), end-point PCR amplification (PCR) for the detection of Giardia and to identify the concerning assemblages in a canine population from Central Italy. Direct fluorescence antibody test is the reference standard for laboratory diagnosis of Giardia in fecal samples from dogs, despite the microscopic examination after flotation remains the most useful method in many veterinary diagnostic centers. The present findings demonstrate the high performance of DFA and ZnSO4 in detecting Giardia, while RDT may be useful as alternative or complementary method to the DFA and ZnSO4. PCR performance was low, but it allowed determining Giardia B zoonotic assemblage in 25% of the PCR-positive specimens (15 out of 60), while the remaining PCR-positive isolates belonged to the dog-specific assemblage C. The 26% prevalence of G. duodenalis detected by DFA in owned dogs and the identification of potentially zoonotic assemblages underline the potential risk for public health and indicate frequent cross-species transmission of the parasite between humans and dogs.
摘要：
十二指肠贾第鞭毛虫（syn。G.intelinalis或G.lamblia）是一种寄生原生动物，可感染多种宿主的上肠道，包括人类和家畜。因此，它引起了人们对伴侣动物造成的公共卫生风险的担忧。最近,随着生活水平的提高和宠物与人类接触的增加，贾第虫的人畜共患传播急剧增加。从基因的角度来看,十二指肠G.应该被视为一个复杂的物种，包括八个不同的物种特异性遗传组合。实验室诊断主要基于通过联合检查在粪便样本中发现微小囊肿。其他方法包括检测抗原，免疫测定或PCR方案，可以识别贾第虫组合。该研究旨在比较直接荧光抗体测试(DFA)的性能，硫酸锌浮选技术(ZnSO4),快速诊断测试（RDT），终点PCR扩增（PCR）用于检测贾第鞭毛虫并鉴定来自意大利中部的犬种群中的相关组合。直接荧光抗体测试是实验室诊断犬粪便样本中贾第虫的参考标准，尽管浮选后的显微镜检查仍然是许多兽医诊断中心最有用的方法。本发现证明了DFA和ZnSO4在检测贾第虫中的高性能，而RDT可用作DFA和ZnSO4的替代或补充方法。PCR性能较低，但它允许在25％的PCR阳性标本中确定贾第虫B人畜共患病组合（60个中的15个），而其余的PCR阳性分离株属于狗特异性组合C。DFA在自己的狗中检测到26％的十二指肠G。以及潜在的人畜共患组合的鉴定，突显了公共健康的潜在风险，并表明寄生虫在人和狗之间频繁的跨物种传播。
