title: Molecular surveillance of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi by genotyping and subtyping parasites in wastewater.
abstract: BACKGROUND
  Despite their wide occurrence, cryptosporidiosis and giardiasis are considered neglected diseases by the World Health Organization. The epidemiology of these diseases and microsporidiosis in humans in developing countries is poorly understood. The high concentration of pathogens in raw sewage makes the characterization of the transmission of these pathogens simple through the genotype and subtype analysis of a small number of samples.
  
  
  RESULTS
  The distribution of genotypes and subtypes of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in 386 samples of combined sewer systems from Shanghai, Nanjing and Wuhan and the sewer system in Qingdao in China was determined using PCR-sequencing tools. Eimeria spp. were also genotyped to assess the contribution of domestic animals to Cryptosporidium spp., G. duodenalis, and E. bieneusi in wastewater. The high occurrence of Cryptosporidium spp. (56.2%), G. duodenalis (82.6%), E. bieneusi (87.6%), and Eimeria/Cyclospora (80.3%) made the source attribution possible. As expected, several human-pathogenic species/genotypes, including Cryptosporidium hominis, Cryptosporidium meleagridis, G. duodenalis sub-assemblage A-II, and E. bieneusi genotype D, were the dominant parasites in wastewater. In addition to humans, the common presence of Cryptosporidium spp. and Eimeria spp. from rodents indicated that rodents might have contributed to the occurrence of E. bieneusi genotype D in samples. Likewise, the finding of Eimeria spp. and Cryptosporidium baileyi from birds indicated that C. meleagridis might be of both human and bird origins.
  
  
  CONCLUSIONS
  The distribution of Cryptosporidium species, G. duodenalis genotypes and subtypes, and E. bieneusi genotypes in urban wastewater indicates that anthroponotic transmission appeared to be important in epidemiology of cryptosporidiosis, giardiasis, and microsporidiosis in the study areas. The finding of different distributions of subtypes between Shanghai and Wuhan was indicative of possible differences in the source of C. hominis among different areas in China.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Lihua
authors.initials: L
authors.lastname: Xiao
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Shuming
authors.initials: S
authors.lastname: Zhao
authors.forename: Xukun
authors.initials: X
authors.lastname: Zhao
authors.forename: Liping
authors.initials: L
authors.lastname: Duan
authors.forename: Meijin
authors.initials: M
authors.lastname: Guo
authors.forename: Lili
authors.initials: L
authors.lastname: Liu
authors.forename: Yaoyu
authors.initials: Y
authors.lastname: Feng
mesh_terms: D000818:Animals; D044822:Biodiversity; D001717:Birds; D002681:China; D003458:Cryptosporidium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D021744:Cyclospora / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004539:Eimeria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D021862:Enterocytozoon / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005838:Genotype; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012377:Rodentia; D017422:Sequence Analysis, DNA; D062065:Wastewater / Q000469:parasitology*
chemical_list: D004271:DNA, Fungal; D016054:DNA, Protozoan; D062065:Wastewater