title: New filtration system for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts.
abstract: OBJECTIVE
  To develop a filtration unit for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts ((oo-)cysts) in drinking water.
  
  
  RESULTS
  This unit utilizes a metallic filter and an ultrasound transducer for eluting (oo-)cysts, with a fixed retentate backwash volume; approx. 400 μl. Changes in the viability was evaluated by seeding wild type (oo-)cysts (1 × 10(4)) followed by sonication for 5, 10, 20 or 40 s (five replicates for each period). Flow cytometry analysis showed negligible increase in the mortality of (oo-)cysts exposed to 5-10 s of sonication. Recovery rate was assessed by seeding ColorSeed(™) (10 replicates) into the filter unit followed by air backwash to a glass slide and counting of (oo-)cysts by epifluorescent microscopy. High recovery rates (mean ± SD) were found: 84·9% ± 4·8 for Giardia cysts and 70% ± 6·5 for Cryptosporidium oocysts. DNA of seeded wild type (oo-)cysts (1 × 10(2); 10 replicates) was successfully amplified using real-time PCR.
  
  
  CONCLUSIONS
  The use of a metallic filter, sonication and 'air backwash' were key factors for creating a highly efficient system for recovery of apparently undamaged protozoa.
  
  
  CONCLUSIONS
  This reagent-less system can be used for monitoring of parasite contamination in drinking water.
authors.affiliation: Section for Bacteriology, Pathology and Parasitology, National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark.|Centre for Medical Parasitology, Department of International Health, Immunology, and Microbiology, University of Copenhagen, Copenhagen, Denmark.|Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: M N S
authors.identifier: http://orcid.org/0000-0003-2277-4587
authors.initials: MN
authors.lastname: Al-Sabi
authors.affiliation: Grundfos Management A/S, Bjerringbro, Denmark.
authors.forename: J A
authors.initials: JA
authors.lastname: Gad
authors.affiliation: Section for Immunology and Vaccinology, National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark.
authors.forename: U
authors.initials: U
authors.lastname: Riber
authors.affiliation: Centre for Medical Parasitology, Department of International Health, Immunology, and Microbiology, University of Copenhagen, Copenhagen, Denmark.|Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: J A L
authors.initials: JA
authors.lastname: Kurtzhals
authors.affiliation: Section for Bacteriology, Pathology and Parasitology, National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark.
authors.forename: H L
authors.initials: HL
authors.lastname: Enemark
mesh_terms: D000818:Animals; D003458:Cryptosporidium / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D060766:Drinking Water / Q000469:parasitology*; D005374:Filtration / Q000379:methods*; D005872:Giardia / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D033661:Oocysts / Q000737:chemistry / Q000254:growth & development; D060888:Real-Time Polymerase Chain Reaction; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water
keywords: detection; drinking water; protozoa; rapid methods; waterborne micro-organism