Ma Jiawen, Feng Yaoyu, Hu Yue, Villegas Eric N, Xiao Lihua
State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China E-mail:
National Exposure Research Laboratory, US Environmental Protection Agency, Cincinnati, OH 45268, USA.
J Water Health. 2016 Jun;14(3):411-23. doi: 10.2166/wh.2016.192.
Cryptosporidiosis, giardiasis, and microsporidiosis are important waterborne diseases. In the standard for wastewater treatment plant (WWTP) effluents in China and other countries, the fecal coliform count is the only microbial indicator, raising concerns about the potential for pathogen transmission through WWTP effluent reuse. In this study, we collected 50 effluent samples (30 L/sample) from three municipal WWTPs in Shanghai, China, and analyzed for Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi by microscopy and/or polymerase chain reaction (PCR). Moreover, propidium monoazide (PMA)-PCR was used to assess the viability of oocysts/cysts. The microscopy and PCR-positive rates for Cryptosporidium spp. were 62% and 40%, respectively. The occurrence rates of G. duodenalis were 96% by microscopy and 92-100% by PCR analysis of three genetic loci. Furthermore, E. bieneusi was detected in 70% (35/50) of samples by PCR. Altogether, 10 Cryptosporidium species or genotypes, two G. duodenalis genotypes, and 11 E. bieneusi genotypes were found, most of which were human-pathogenic. The chlorine dioxide disinfection employed in WWTP1 and WWTP3 failed to inactivate the residual pathogens; 93% of the samples from WWTP1 and 83% from WWTP3 did not meet the national standard on fecal coliform levels. Thus, urban WWTP effluents often contain residual waterborne human pathogens.
隐孢子虫病、贾第虫病和微孢子虫病是重要的水源性疾病。在中国和其他国家的污水处理厂（WWTP）出水标准中，粪大肠菌群数是唯一的微生物指标，这引发了人们对通过污水处理厂出水回用传播病原体可能性的担忧。在本研究中，我们从中国上海的三个城市污水处理厂收集了50个出水样本（30升/样本），并通过显微镜检查和/或聚合酶链反应（PCR）分析隐孢子虫属、十二指肠贾第虫和微小隐孢子虫。此外，单叠氮丙锭（PMA）-PCR用于评估卵囊/包囊的活力。隐孢子虫属的显微镜检查和PCR阳性率分别为62%和40%。十二指肠贾第虫的检出率通过显微镜检查为96%，通过对三个基因位点的PCR分析为92%-100%。此外，通过PCR在70%（35/50）的样本中检测到微小隐孢子虫。总共发现了10种隐孢子虫物种或基因型、2种十二指肠贾第虫基因型和11种微小隐孢子虫基因型，其中大多数是人类致病性的。污水处理厂1和污水处理厂3采用的二氧化氯消毒未能灭活残留病原体；污水处理厂1的93%的样本和污水处理厂3的83%的样本不符合粪大肠菌群水平的国家标准。因此，城市污水处理厂出水通常含有残留的水源性人类病原体。
