Coulliette Angela D, Huffman Debra E, Slifko Theresa R, Rose Joan B
Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
J Parasitol. 2006 Feb;92(1):58-62. doi: 10.1645/GE-534R.1.
Cryptosporidium parvum has become the focus of numerous studies on waterborne disease and transmission in response to outbreaks endangering populations worldwide. The Foci Detection Method-Most Probable Number Assay (FDM-MPN) is an in vitro cell culture method that has been developed and used to determine the quantity of infectious C. parvum oocysts. This research evaluated 2 vendor's producing oocysts, Sterling Parasitology Laboratory (SPL) and Pleasant Hill Farms (PHF) (now known as Bunch Grass Farms as of 12/03), classified as young (<30 days) and aged (>165 days), for comparison of treatments (bleach, antibiotic, no treatment) before cell culture, as well as an age study, to determine any lot-to-lot differences and vendor differences regarding the rate of decline in infectivity. Bleach treatment (0.525%) appeared to be the optimum method for the FDM-MPN with regards to maximum infectivity, efficient disinfection, with no visible antagonistic affects on the C. parvum oocysts. The age study revealed that lot-to-lot variability within each vendor stayed within 1 log10 difference, while the rates of decline in infectivity measured until 107 and 120 days of age when stored at 4 C for SPL and PHF were -0.016 and -0.014 log10 infectious oocysts/day, respectively. These results provide insight regarding C. parvum oocyst viability in a fecal population, as well as useful knowledge for further methods development.
微小隐孢子虫已成为众多关于水源性疾病及其传播研究的焦点，这是为应对危及全球人口的疫情爆发。病灶检测方法——最可能数法（FDM-MPN）是一种体外细胞培养方法，已被开发并用于确定感染性微小隐孢子虫卵囊的数量。本研究评估了两家供应商生产的卵囊，即斯特林寄生虫学实验室（SPL）和宜人山农场（PHF）（截至12/03，现称为束草农场），将其分为年轻（<30天）和老化（>165天）两类，用于比较细胞培养前的处理方式（漂白剂、抗生素、不处理），以及进行一项老化研究，以确定不同批次之间以及供应商之间在感染性下降速率方面的差异。就最大感染性、高效消毒而言，且对微小隐孢子虫卵囊无明显拮抗作用，漂白剂处理（0.525%）似乎是FDM-MPN的最佳方法。老化研究表明，每个供应商内部不同批次之间的变异性保持在1个对数10的差异范围内，而对于SPL和PHF，在4℃储存至107天和120天时，感染性下降速率分别为-0.016和-0.014个对数10感染性卵囊/天。这些结果为微小隐孢子虫卵囊在粪便群体中的活力提供了见解，也为进一步的方法开发提供了有用的知识。
