Björkman C, Lindström L, Oweson C, Ahola H, Troell K, Axén C
Department of Clinical Sciences,Swedish University of Agricultural Sciences,P.O. Box 7054,SE-750 07 Uppsala,Sweden.
Department of Virology,Immunobiology and Parasitology,National Veterinary Institute,SE-751 89 Uppsala,Sweden.
Parasitology. 2015 Jul;142(8):1108-14. doi: 10.1017/S0031182015000426. Epub 2015 Apr 22.
A study was carried out to investigate how common Cryptosporidium infections are in beef calves in Swedish suckler herds and to explore which species and subtypes that occur. We further aimed at identifying factors associated with shedding of Cryptosporidium oocysts in this type of calf management. The study was conducted in two regions in Sweden and included 30 herds. Faecal samples were collected from calves younger than 3 months. A brief clinical examination was done and a questionnaire was used to collect data on management routines. Faeces were cleaned and concentrated and oocysts identified by epifuorescence microscopy. Cryptosporidium positive samples were analyzed at the 18S rRNA and GP60 genes to determine species and Cryptosporidium parvum subtype, respectively. Logistic regression was used to identify factors associated with infection. Oocysts were detected in 122 (36.7%) calves from 29 (97%) herds, at 400 to 2.4 × 107 OPG. The youngest positive calves were only 1 and 2 days old. There was no association between age and Cryptosporidium infection. Cryptosporidium bovis, Cryptosporidium ryanae, C. parvum and Cryptosporidium ubiquitum were identified, with C. bovis being the major species. Two C. parvum subtypes, IIaA16G1R1 and IIdA27G1 were identified. Routines for cleaning calf pens and number of cows in calving pens were associated with infection.
开展了一项研究，以调查瑞典奶牛场肉牛犊中隐孢子虫感染的普遍程度，并探究出现的种类和亚型。我们还旨在确定在这种犊牛管理类型中与隐孢子虫卵囊排出相关的因素。该研究在瑞典的两个地区进行，包括30个牛群。从3个月以下的犊牛采集粪便样本。进行了简要的临床检查，并使用问卷收集管理常规数据。粪便经过清洗和浓缩，通过落射荧光显微镜鉴定卵囊。对隐孢子虫阳性样本分别在18S rRNA和GP60基因上进行分析，以确定种类和微小隐孢子虫亚型。使用逻辑回归来确定与感染相关的因素。在来自29个（97%）牛群的122头（36.7%）犊牛中检测到卵囊，每克粪便含卵囊数为400至2.4×10⁷个。最小的阳性犊牛仅1天和2天大。年龄与隐孢子虫感染之间没有关联。鉴定出了牛隐孢子虫、雷氏隐孢子虫、微小隐孢子虫和泛在隐孢子虫，其中牛隐孢子虫是主要种类。鉴定出了两种微小隐孢子虫亚型，即IIaA16G1R1和IIdA27G1。犊牛栏的清洁常规和产犊栏中的奶牛数量与感染有关。
