Abstract：
Cryptosporidium is an important gastrointestinal parasite that can cause mild to severe diarrhea in various vertebrates, including humans and domestic animals. Infection is prevalent in dairy cattle, particularly calves, resulting in diarrhea and increased mortality with significant production losses. However, the prevalence and identity of Cryptosporidium spp. in cattle in Heilongjiang Province is still poorly known. Our study aimed to investigate the prevalence and species and subtype distribution of Cryptosporidium in cattle in the region. In addition, we evaluated the zoonotic potential of Cryptosporidium isolates and assessed possible transmission routes and health effects of this organism. We collected 909 fecal samples from five different farms in Heilongjiang Province between August and September 2022. The samples underwent Cryptosporidium detection by nested PCR and small subunit (SSU) rRNA gene sequence analysis. Four Cryptosporidium species were identified, including C. parvum, C. bovis, C. ryanae, and C. andersoni, with an overall prevalence of 4.4% (40/909). Based on sequence analysis of the 60 kDa glycoprotein gene of C. parvum and C. bovis, three subtypes of C. parvum were identified, namely two previously known subtypes (IIdA19G1 and IIdA20G1), and one novel subtype (IIdA24G2). Two distinct subtype families were identified in C. bovis (XXVId and XXVIe). The high diversity of Cryptosporidium in dairy cattle and the emergence of a novel subtype of C. parvum in Heilongjiang Province suggest that dairy cattle may serve as a significant source of zoonotic cryptosporidiosis infection in this region.
摘要：
隐孢子虫是一种重要的胃肠道寄生虫，可在各种脊椎动物中引起轻度至重度腹泻，包括人类和家畜。感染在奶牛中很普遍，尤其是小牛,导致腹泻和死亡率增加，生产损失显著。然而,隐孢子虫的患病率和身份。在黑龙江省的牛中仍然鲜为人知。我们的研究旨在调查该地区牛中隐孢子虫的患病率，种类和亚型分布。此外,我们评估了隐孢子虫分离株的人畜共患潜能,并评估了该生物可能的传播途径和对健康的影响.我们在2022年8月至9月期间从黑龙江省五个不同的农场收集了909份粪便样本。通过巢式PCR和小亚基（SSU）rRNA基因序列分析对样品进行了隐孢子虫检测。确定了四种隐孢子虫，包括C.parvum,C.牛，C.ryanae,还有C.Andersoni,总体患病率为4.4%(40/909)。基于对C.parvum和C.bovis的60kDa糖蛋白基因的序列分析，确定了C.parvum的三种亚型，即两个先前已知的亚型（IIdA19G1和IIdA20G1），和一个新的亚型（IIdA24G2）。在牛梭菌中鉴定了两个不同的亚型家族(XXVId和XXVIe)。奶牛隐孢子虫的高度多样性和黑龙江省小孢子虫新亚型的出现表明，奶牛可能是该地区人畜共患隐孢子虫病感染的重要来源。
