Prevalence of intestinal parasites in shelter cats with diarrhea from Colorado, USA, and optimization and application of a qPCR assay for detection of Cyclospora cayetanensis

Abstract

Objectives: The objectives of this study were to optimize a Cyclospora cayetanensis quantitative PCR (qPCR) assay and apply it to feces of cats with diarrhea from a shelter in Colorado, USA to determine whether or not this human parasite was the cause of the diarrhea and thus if it carries zoonotic potential, as well as to assess which other fecal parasites can be found in shelter cats with diarrhea.

Methods: The optimization of a published SYBR Green based qPCR of a fragment of the internal transcribed spacer 2 (ITS-2) gene of C. cayetanensis followed by a melting curve analysis were performed as published. Feces were analyzed using microscopic examination for parasite eggs, cysts and oocysts after using Sheather’s sugar centrifugation. For detection of Cryptosporidium spp. oocysts and Giardia spp. cysts a commercial IFA was used (MERIFLUOR® Cryptosporidium/Giardia, Meridian Biosciences).

Results: Fecal samples from a total of 60 shelter cats with acute diarrhea were evaluated. Enteric parasites were detected in 8 of 60 cats (13.3%) and included Cryptosporidium spp. (6.7%), Giardia spp. (3.3%) and Isospora felis (3.3%). DNA of C. cayetanensis was not amplified from any sample.

Conclusion and relevance: The parasites detected in this study were similar to those in other similar studies and C. cayetanensis was not detected. Since all cats were negative for C. cayetanensis, it is not likely the diarrhea was caused by this parasite, but more research needs to be done to investigate whether C. cayetanensis has the zoonotic potential to infect cats.