UK Cryptosporidium Reference Unit, NPHS Microbiology Swansea, Singleton Hospital, Swansea SA2 8QA, UK.
J Water Health. 2010 Jun;8(2):311-25. doi: 10.2166/wh.2009.185. Epub 2009 Nov 9.
As part of investigations into the cause of a waterborne outbreak of Cryptosporidium hominis infection linked to a mains water supply, surface waters and wastewater treatment plants were tested for Cryptosporidium spp. Oocyst counts in base flow surface water samples ranged from nil to 29 per 10 l. Oocyst counts in effluent from a community wastewater treatment plant were up to 63 fold higher and breakout from one septic tank five logs higher. There were no peak (storm) flow events during the investigation. C. hominis, four named genotypes (cervine, muskrat II, rat, W19) and six new small subunit ribosomal RNA gene sequences were identified. Four of the new sequences were closely related to Cryptosporidium muskrat genotype I, one was closely related to the fox genotype and one to Cryptosporidium canis. C. hominis was found extensively in the catchment, but only at sites contaminated by wastewater, and in the treated water supply to the affected area. All were gp60 subtype IbA10G2, the outbreak subtype. Multiple routes of contamination of the reservoir were identified, resulting in persistent detection of low numbers of oocysts in the final water. This work demonstrates the utility of genotyping Cryptosporidium isolates in environmental samples during outbreak investigations.
作为调查起因于水源的隐孢子虫属人感染的一部分，对地表水和废水处理厂进行了检测，以检测隐孢子虫属。基础流量地表水样本中的卵囊计数从零到每 10 升 29 个。社区废水处理厂的废水中的卵囊计数高了 63 倍，一个化粪池的卵囊计数高了 5 个对数级。在调查期间没有出现峰值（风暴）流量事件。鉴定出了隐孢子虫属人、四个命名基因型（鹿型、麝香鼠 II 型、鼠型、W19 型）和六个新的小亚基核糖体 RNA 基因序列。其中四个新序列与隐孢子虫属麝香鼠基因型 I 密切相关，一个与狐狸基因型密切相关，一个与犬隐孢子虫属密切相关。隐孢子虫属人在集水区广泛存在，但仅在受废水污染的地点和受影响地区的处理供水水源中发现。所有都是 gp60 亚型 IbA10G2，即暴发亚型。确定了多种污染水库的途径，导致最终水中持续检测到低数量的卵囊。这项工作证明了在暴发调查期间对环境样本中的隐孢子虫属分离物进行基因分型的实用性。
