title: Toxoplasma tachyzoites from cell culture are more appropriate in some situations.
abstract: BACKGROUND
  Laboratories traditionally culture toxoplasma tachyzoites in animals for testing and experimental use. This article considers why available cell culture methods are not used more often.
  
  
  OBJECTIVE
  To compare HeLa cell culture and animal culture for production of toxoplasma tachyzoites.
  
  
  METHODS
  In 2000 HeLa culture replaced animal culture for continuous production of toxoplasma tachyzoites in the Scottish Toxoplasma Reference Laboratory. The performance of animal culture (1994-1998) was compared with HeLa culture (2004-2008). A PubMed search was carried out for 1998 and 2008 to assess the culture methods used in laboratories.
  
  
  RESULTS
  Animal culture was able to produce higher yields of tachyzoites (10(9) from a cotton rat peritoneal harvest compared to 10(7) from a 75 cm(2) cell culture flask) but significantly more HeLa cultures were successful (93% versus 84%; p=0.025). There was no difference in the quality of tachyzoites from animal and HeLa cultures as demonstrated by the high levels of success in the dye test. HeLa culture offered significant advantages in flexibility and control. A review of the literature showed no significant change in the method of culture used in laboratories between 1998 and 2008 (p=0.36).
  
  
  CONCLUSIONS
  The availability of cell culture methods and the increasingly stringent regulations on the use of animals have not resulted in a decline in the use of animal culture. Animals are necessary for certain experiments but many studies could use cell-culture-derived parasites.
authors.affiliation: Scottish Toxoplasma Reference Laboratory, Microbiology Department, Raigmore Hospital, Inverness IV2 3UJ, UK. jean.chatterton@nhs.net
authors.forename: Jean M W
authors.initials: JM
authors.lastname: Chatterton
authors.forename: Susan
authors.initials: S
authors.lastname: McDonagh
authors.forename: Darrel O
authors.initials: DO
authors.lastname: Ho-Yen
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D010274:Parasitology / Q000379:methods; D016205:Sigmodontinae; D014122:Toxoplasma / Q000254:growth & development* / Q000302:isolation & purification