Neonatal-Mouse Infectivity of Intact Cryptosporidium parvum Oocysts Isolated after Optimized In Vitro Excystation

L. Hou, X. Li, L. Dunbar, R. Moeller, B. Palermo, Edward R Atwill

Research output: Contribution to journalArticle

16 Scopus citations


We reexamined the finding of Neumann et al. (10) that intact Cryptosporidium parvum oocysts obtained after in vitro excystation were infectious for neonatal CD-1 mice. We used both established excystation protocols and our own protocol that maximized excystation (2). Although intact oocysts isolated after any of three protocols were infectious for neonatal CD-1 mice, the infectivity of intact oocysts isolated with our optimized excystation protocol was significantly lower than the infectivity of intact oocysts isolated after established protocols or from fresh oocysts. Excystation should not be considered a valid measure of C. parvum viability, given that it is biologically implausible for oocysts to be nonviable and yet infectious.

Original languageEnglish (US)
Pages (from-to)642-646
Number of pages5
JournalApplied and Environmental Microbiology
Issue number1
StatePublished - Jan 2004


ASJC Scopus subject areas

  • Environmental Science(all)
  • Biotechnology
  • Microbiology

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