Prevalence and molecular characterization of Cryptosporidium and Giardia species and genotypes in sheep in Maryland
Prevalence and molecular characterization of Cryptosporidium and Giardia species and genotypes in sheep in Maryland
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DOI：
10.1016/j.vetpar.2007.01.010
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发表时间：
2007-05-15
影响因子：
2.6
通讯作者：
Fayer, Ronald
中科院分区：
文献类型：
--
作者：
Santin, Monica;Trout, James M.;Fayer, Ronald
在英国和澳大利亚，绵羊被认为是感染人类的隐孢子虫和贾第鞭毛虫的来源，但在北美没有进行过这样的研究。因此，在马里兰州的一个农场进行了一项研究，以调查这些寄生虫在绵羊中的流行情况。从32只妊娠母羊分娩后1、2和3天以及出生后7、14和21天的每只羔羊中收集粪便。隐孢子虫卵囊和贾第鞭毛虫包囊的存在下，通过免疫荧光显微镜和PCR/基因序列分析确定。PCR始终比显微镜更敏感。通过PCR检测，绵羊和羔羊隐孢子虫感染率分别为25%和77.4%。隐孢子虫有3个种/基因型：C. parvum，一种新的C.牛样基因型和鹿隐孢子虫基因型。隐孢子虫和鹿的基因型已在世界范围内报告的人类感染。小说C。牛样基因型为首次报道。绵羊和羔羊的贾第虫患病率分别为12%和4%。大多数感染是非人畜共患病的组合E;然而，一只母羊感染了人畜共患病组合A。仅对2只感染C. parvum和1只感染G.十二指肠是集合A表明这些人畜共患病率低。然而，人畜共患病的鹿基因型的高患病率表明，绵羊应被视为这种人类病原体的潜在环境来源。(c)2007年由Elsevier B. V.出版。
In the United Kingdom and Australia sheep have been implicated as sources of Cryptosporidium and Giardia that infect humans, but no such studies have been conducted in North America. Therefore, a study was undertaken to investigate the prevalence of these parasites in sheep on a farm in Maryland. Feces were collected from 32 pregnant ewes 1, 2, and 3 days after parturition and from each of their lambs 7, 14, and 21 days after birth. The presence of Cryptosporidium oocysts and Giardia cysts was determined by both immunofluorescence microscopy and PCR/gene sequence analysis. PCR was consistently more sensitive than microscopy. The prevalence, by PCR, of Cryptosporidium in ewes and lambs was 25 and 77.4%, respectively. Three species/genotypes of Cryptosporidium were identified: C. parvum, a novel C. bovis-like genotype, and Cryptosporidium cervine genotype. Cryptosporidium parvum and the cervine genotype have been reported worldwide in human infections. The novel C. bovis-like genotype is reported here for the first time. The prevalence of Giardia in ewes and lambs was 12 and 4%, respectively. Most infections were Assemblage E which is not zoonotic; however, one ewe was infected with zoonotic Assemblage A. The identification of only two lambs infected with C. parvum and one ewe infected with G. duodenal is Assemblage A suggests a low prevalence of these zoonoses. However, the high prevalence of the zoonotic cervine genotype indicates that sheep should be considered a potential environmental source of this human pathogen. (c) 2007 Published by Elsevier B.V.