Detection of Sarcocystis parasites in retail beef:: A regional survey combining histological and genetic detection methods
Detection of Sarcocystis parasites in retail beef:: A regional survey combining histological and genetic detection methods
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DOI：
10.4315/0362-028x-71.10.2144
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发表时间：
2008-10-01
影响因子：
2
通讯作者：
Rosenthal, Benjamin M.
中科院分区：
文献类型：
--
作者：
Pritt, Bobbi;Trainer, Thomas;Rosenthal, Benjamin M.
肉孢子虫寄生原生生物是在食用未煮熟的、充满胞囊的肉类时获得的。虽然牛肉中都有人肉孢子虫和克氏肉孢子虫包囊，但只有人肉孢子虫对人类是致病的。在这项研究中，我们使用组织学方法和新的分子技术来确定肉孢子虫的地区性流行和鉴定。在零售牛肉方面。在110份标本中，60份支持用聚合酶链式反应扩增寄生虫rRNA。所有41个测序代表都被鉴定为克鲁兹链霉菌。为了比较检测方法，组织学和聚合酶链式反应平行检测了48个样本，分别有16个和26个样本呈阳性。5例组织切片阳性的标本经聚合酶链式反应均未扩增。15个PCR阳性的样本在最初的组织切片上没有发现肉瘤，但从这些样本的额外切片中发现了另外12个样本的肉瘤。结合组织学切片和聚合酶链式反应，在48份标本中检出31份阳性标本。我们没有发现人类病原体人链球菌的证据，并确认牛的病原体克氏链球菌在该地区样本中高度流行。聚合酶链式反应可提高肉孢子虫的检测灵敏度。并有助于提高诊断精度。
Sarcocystis spp. are parasitic protists acquired when undercooked, cyst-laden meat is consumed. While both Sarcocystis hominis and S. cruzi encyst in beef, only S. hominis is pathogenic to humans. In this study, we used histological methods and novel molecular techniques to determine the regional prevalence and identity of Sarcocystis spp. in retail beef. Of 110 samples, 60 supported amplification of parasite rRNA by PCR. All 41 sequenced representatives were identified as S. cruzi. To compare detection methods, 48 samples were then examined in parallel by histology and PCR, and 16 and 26 samples, respectively, were positive. Five samples positive by initial histologic sections were not amplified by PCR. Fifteen PCR-positive samples did not contain sarcocysts on initial histologic section, but additional sections from these samples revealed sarcocysts in an additional 12 samples. When combined, histology with additional sections and PCR detected 31 positive specimens of the 48 total specimens. We found no evidence of human pathogen S. hominis and confirm that cattle pathogen S. cruzi is highly prevalent in this regional sample. PCR assays may increase the detection sensitivity of Sarcocystis spp. and contribute diagnostic precision.