Korean J Parasitol.  2003 Dec;41(4):197-201. 10.3347/kjp.2003.41.4.197.

Viability of preserved Cryptosporidium baileyi oocysts

• Surl CG
• Kim SM
• Kim HC

• KMID: 662759
• DOI: http://doi.org/10.3347/kjp.2003.41.4.197

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 degrees 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 x 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 degrees 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.

Keyword

Cryptosporidium baileyi; chicken; viability

MeSH Terms

Animals
Bursa of Fabricius/parasitology
Chickens/*parasitology
Coloring Agents
Cryptosporidiosis/parasitology/pathology/*veterinary
Cryptosporidium/drug effects/*growth & development/pathogenicity
Feces/parasitology
Oocysts/drug effects/*growth & development/pathogenicity
*Organic Chemicals
*Potassium Dichromate/pharmacology
Poultry Diseases/parasitology/pathology
Preservation, Biological/*methods
Staining and Labeling