Viability of preserved Cryptosporidium baileyi oocysts

  • Surl, Chan-Gu (Department of Veterinary Medicine, College of Veterinary Medicine, Chonbuk National University) ;
  • Kim, Se-Min (Department of Veterinary Medicine, College of Veterinary Medicine, Chonbuk National University) ;
  • Kim, Hyeon-Cheol (Department of Parasitology, College of Animal Resources Sciences, Kangwon National University)
  • Published : 2003.12.01

Abstract

The present study was undertaken to determine the viability and infectivity of oocysts of Cryptosporidium baileyi that had been stored from 1 to 40 months at $4^{\circ}C$ preserved in 2.5% potassium dichromate solution. Oocysts of C. baileyi were purified from the feces of experimentally infected chickens using discontinuous sucrose gradients. Subsequently, the purified oocysts were suspended in 2.5% potassium dichromate solution at a concentration of $1{\;}{\times}10^7$ organism/ml, and their viabilities were assessed by nucleic acid staining, histologic examination, and infectivity to 2-day-old chickens. All chickens inoculated with oocysts that had been stored for 1-18 months developed patent infections, while chickens infected with older oocysts remained uninfected. Between 5.8% and 82.2% of the oocysts, stored at $4^{\circ}C$ in 2.5% potassium dichromate solution, were found to be viable, as determined by nucleic acid staining. Parasite colonization in the bursa of Fabricius was detected in the microvillus border of bursal epithelium. The finding that C. baileyi oocysts remain infective to chickens for at least 18 months offers important time-saving advantages to investigators who frequently require large numbers of oocysts.

Keywords

References

  1. Arrowood MJ, Sterling CR (1987) Isolation of Cryptosporidium oocysts and sporozoites using discontinuous sucrose and isopycnic Percoll gradients. J Parasitol 73: 314-319.
  2. Belosevic M, Guy RA, Taghi-Kilani R, et al. (1997) Nucleic acid stains as indicators of Cryptosporidium parvum oocyst viability. Int J Parasitol 27: 787-798.
  3. Fayer R, Speer, CA, Dubey JP (1990) General biology of Cryptosporidium. In Dubey, J.P., Speer, C.A. and Fayer, R. (Eds.), Cryptosporidiosis of Man and Animals, pp 1-30. CRC Press, Boca Raton, FL.
  4. Kim HC, Healey MC (2001) Infectivity of Cryptosporidium parvum oocysts following cryopreservation. J Parasitol 87: 1191-1194.
  5. Lorenzo-Lorenzo MJ, Ares-Mazas ME, Villacorta-Martinez de Maturana I, Duran-Oreiro D. (1993) Effect of ultraviolet disinfection of drinking water on the viability of Cryptosporidium parvum oocysts. J Parasitol 79: 67-70.
  6. Mosier DA, Oberst RD (2000) Cryptosporidiosis. A global challenge. Ann N Y Acad Sci 916: 102-111.
  7. Rhee JK, Kim HC, Park BK (1997) Effects of Cryptosporidium baileyi infection on the bursa of Fabricius in chickens. Korean J Parasitol 35: 181-187.
  8. Rhee JK, Park BK (1996) Survival of Cryptosporidium muris (strain MCR) oocysts under cryopreservation. Korean J Parasitol 34: 155-157.
  9. Rhee JK, Seu YS, Park BK (1991) Isolation and identification of Cryptosporidium from various animals in Korea. III. Identification of Cryptosporidium baileyi from Korean chicken. Korean J Parasitol 29: 315-324.
  10. Robertson LJ, Campbell AT, Smith HV (1992) Survival of Cryptosporidium parvum oocysts under various environmental pressures. Appl Environ Microbiol 58: 3494-3500.
  11. Sherwood D, Angus KW, Snodgrass DR, Tzipori S (1982) Experimental cryptosporidiosis in laboratory mice. Infect Immun 38: 471-475.
  12. Sreter T, Hornok S, Varga I, Beksi L, Szell Z. (1997) Attempts to immunize chickens against Cryptosporidium baileyi with C. parvum oocyst and ParacoxTM vaccine. Folia Parasitol (Praha) 44: 77-80.
  13. Sreter T, Varga I (2000) Cryptosporidiosis in birds. A review. Vet Parasitol 87: 261-279.
  14. Yang S, Healey MC, Du C (1996) Infectivity of preserved Cryptosporidium parvum oocysts for immunosuppressed adult mice. FEMS Immunol Med Microbiol 13: 141-145.
  15. Yang S, Benson SK, Du C, Healey MC (2000) Infection of immunosuppressed C57BL/6N adult mice with a single oocyst of a Cryptosporidium parvum. J Parasitol 86: 884-887.