School of Veterinary and Biomedical Sciences, Murdoch University, Western Australia, 6150, Australia.
Vet Parasitol. 2012 Mar 23;184(2-4):298-308. doi: 10.1016/j.vetpar.2011.08.016. Epub 2011 Aug 16.
On two separate sampling occasions, faecal samples were collected from lambs (2-5 months of age) grazing pasture on two separate sheep farms in southern Western Australia. Live weight, body condition score (BCS), faecal consistency score (FCS) and faecal dry matter percentage (DM%) were measured. Faecal samples were screened by PCR for Cryptosporidium (18S rRNA, actin and 60 kDa glycoprotein [gp60] loci), Giardia duodenalis (glutamate dehydrogenase [gdh] and β-giardin) and patent strongylid nematode infections (ITS-2 nuclear ribosomal DNA for Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus spp. Chabertia ovina and Oesophagostomum spp.). Faecal worm egg counts (WECs) were performed using a modified McMaster WEC technique. The WECs were adjusted for FCS and transformed using log(10)(adjusted WEC+25) prior to statistical analyses. Cryptosporidium, Giardia and Trichostrongylus spp. detected by PCR were associated with an increased risk of non-pelleted faeces (FCS ≥ 3.0) for both flocks. Cryptosporidium-positive lambs were 2.8-11.6 times more likely to have non-pelleted faeces and Giardia-positive lambs were 2.4-14.0 times more likely to have non-pelleted faeces compared to lambs negative for each respective parasite. Lambs positive for both Cryptosporidium and Giardia were 2.9-11.8 times more likely to have non-pelleted faeces than lambs positive for only one or neither of these parasites. Mixed internal parasite infections were found to have greater impacts on FCS and BCS than single infections. A higher number of internal parasites detected per lamb was associated with lower BCS and more loose faeces. The relationship between parasite detection and live weight or growth rate were inconsistent for both flocks. Adjusted WEC was correlated with FCS and faecal DM% for one flock only, although little or no correlation was found with live weight and growth rate for both flocks. Cryptosporidium ubiquitum and Cryptosporidium parvum were the most prevalent Cryptosporidium species isolated in the two flocks. Giardia assemblage E was the most commonly isolated genotype assemblage from both flocks, while assemblage A was isolated almost as frequently as assemblage E in the one flock. One flock was a potential source of zoonotic Cryptosporidium and the other flock was a potential source of zoonotic Giardia.
在两个不同的采样时间，从放牧在西澳大利亚南部两个不同的绵羊养殖场的羔羊（2-5 月龄）中采集粪便样本。测量活重、身体状况评分（BCS）、粪便稠度评分（FCS）和粪便干物质百分比（DM%）。通过 PCR 筛查粪便样本以检测隐孢子虫（18S rRNA、肌动蛋白和 60 kDa 糖蛋白[gp60]基因座）、贾第虫（谷氨酸脱氢酶[gdh]和β-微管蛋白）和专利强旋毛虫感染（ITS-2 核核糖体 DNA 用于捻转血矛线虫、奥斯特拉西亚线虫、毛圆线虫和食道线虫）。使用改良的麦克马斯特 WEC 技术进行粪便蠕虫卵计数（WEC）。在进行统计分析之前，根据 FCS 调整 WEC，并使用 log(10)(调整后的 WEC+25)进行转换。在两个羊群中，PCR 检测到的隐孢子虫、贾第虫和毛圆线虫与非颗粒状粪便（FCS≥3.0）的风险增加有关。隐孢子虫阳性羔羊发生非颗粒状粪便的可能性是隐孢子虫阴性羔羊的 2.8-11.6 倍，贾第虫阳性羔羊发生非颗粒状粪便的可能性是贾第虫阴性羔羊的 2.4-14.0 倍。同时感染隐孢子虫和贾第虫的羔羊发生非颗粒状粪便的可能性是仅感染一种或两种寄生虫的羔羊的 2.9-11.8 倍。混合的内部寄生虫感染比单一感染对 FCS 和 BCS 的影响更大。每只羔羊检测到的寄生虫数量越多，BCS 越低，粪便越松散。两个羊群的寄生虫检测与活重或生长率之间的关系不一致。一个羊群的调整后的 WEC 与 FCS 和粪便 DM%相关，但两个羊群的活重和生长率几乎没有相关性。在两个羊群中，最常见的隐孢子虫物种是微小隐孢子虫和微小隐孢子虫。贾第虫组 E 是从两个羊群中分离出来的最常见的基因型组，而在一个羊群中，组 A 几乎与组 E 一样常见。一个羊群是人类隐孢子虫的潜在来源，另一个羊群是人类贾第虫的潜在来源。
