Brook Emily J, Anthony Hart C, French Nigel P, Christley Robert M
Department of Veterinary Clinical Science, University of Liverpool, Neston, UK.
Vet J. 2009 Mar;179(3):378-82. doi: 10.1016/j.tvjl.2007.10.023. Epub 2008 Feb 20.
Samples of Cryptosporidium spp., collected in a cross-sectional study of calves (median age 26 days) from 41 farms in Cheshire, UK, underwent molecular typing. The aim was to determine naturally occurring species/genotypes and to investigate transmission pathways within a local area. Of 60 positive samples, 54 were sequenced at an 18S rRNA locus and 51 were typed at a GP60 locus. C. parvum was identified in 50 samples, three cases were C. bovis and one was Cryptosporidium deer-like genotype. Six GP60 subgenotypes were identified. One subgenotype (IIaA15G2R1) was highly prevalent throughout the study area. A single subgenotype was identified on 20/22 farms. Two subgenotypes were found on 2/22 farms. The spatial scan statistic detected a cluster of subgenotype IIaA15G2R1 comprising seven farms. This suggests local transmission of the parasite between farms. As most of the isolates detected were the potentially zoonotic C. parvum allele IIa, intervention strategies should be considered to reduce the threat to public health. Biosecurity measures may reduce transmission between farms and result in lower levels of environmental contamination.
在英国柴郡对41个农场的犊牛（中位年龄26天）进行的一项横断面研究中收集的隐孢子虫属样本进行了分子分型。目的是确定自然存在的物种/基因型，并调查当地的传播途径。在60个阳性样本中，54个在18S rRNA基因座进行了测序，51个在GP60基因座进行了分型。在50个样本中鉴定出微小隐孢子虫，3例为牛隐孢子虫，1例为隐孢子虫鹿样基因型。鉴定出6种GP60亚型。一种亚型（IIaA15G2R1）在整个研究区域高度流行。在22个农场中的20个农场鉴定出单一亚型。在22个农场中的2个农场发现了两种亚型。空间扫描统计检测到一个由7个农场组成的IIaA15G2R1亚型集群。这表明该寄生虫在农场之间存在本地传播。由于检测到的大多数分离株是具有潜在人畜共患病的微小隐孢子虫等位基因IIa，应考虑采取干预策略以减少对公共卫生的威胁。生物安全措施可能会减少农场之间的传播，并降低环境污染水平。
