Lim Yvonne A L, Lai Monica M, Mahdy Mohammed A K, Mat Naim H R, Smith Huw V
Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Environ Res. 2009 Oct;109(7):857-9. doi: 10.1016/j.envres.2009.07.007. Epub 2009 Aug 6.
We used a combined microscopy-molecular approach to determine the occurrence and identities of waterborne Giardia sp. cysts isolated from 18 separate, 10l grab samples collected from a Malaysian zoo. Microscopy revealed that 17 of 18 samples were Giardia cyst positive with concentrations ranging from 1 to 120 cysts/l. Nine (52.9%) of the 17 cyst positive samples produced amplicons of which 7 (77.8%) could be sequenced. Giardia duodenalis assemblage A (6 of 7) and assemblage B (1 of 7), both infectious to humans, were identified at all sampling sites at the zoo. The presence of human infectious cysts raises public health issues, and their occurrence, abundance and sources should be investigated further. In this zoo setting, our data highlight the importance of incorporating environmental sampling (monitoring) in addition to routine faecal examinations to determine veterinary and public health risks, and water monitoring should be considered for inclusion as a separate element in hazard analysis, as it often has a historical (accumulative) connotation.
我们采用了显微镜检查与分子生物学相结合的方法，来确定从马来西亚一家动物园采集的18份独立的10升抓取水样中分离出的水源性贾第虫属囊肿的存在情况及种类。显微镜检查显示，18份样本中有17份贾第虫囊肿呈阳性，浓度范围为每升1至120个囊肿。17份囊肿阳性样本中有9份（52.9%）产生了扩增子，其中7份（77.8%）能够进行测序。在动物园的所有采样点均鉴定出了对人类具有感染性的十二指肠贾第虫A群（7份中的6份）和B群（7份中的1份）。人类感染性囊肿的存在引发了公共卫生问题，其发生情况、丰度及来源应进一步调查。在该动物园环境中，我们的数据凸显了除常规粪便检查外纳入环境采样（监测）以确定兽医和公共卫生风险的重要性，并且水监测应被视为危害分析中的一个单独要素纳入其中，因为它往往具有历史（累积）内涵。
