Incidence, genetic characterization and phylogenetic analysis of Cryptosporidium species infecting domestic pigeons (Columba livia domestica) in Egypt.

The current investigation was performed to study the incidence, morphological characters and molecular identification of Cryptosporidium species infecting domestic pigeons in the Giza governorate, Egypt. The incidence of Cryptosporidium spp. by modified Ziehl-Neelsen stain technique was 12 % and 14 % of the examined intestinal and bursal samples respectively. Seasonal incidence showed that winter had the highest rate (15.38 % and 21.74 %) while the lowest one was in autumn (7.95 % and 8.33 %) of the intestinal and bursal samples respectively. Two forms of Cryptosporidium spp. were detected. The small oocysts had average size (4.6 ± 0.63 × 4.44 ± 0.76 μm) while the large one had average size (5.64 ± 0.39 × 5.57 ± 0.41 μm). The PCR products of Cryptosporidium spp. were analyzed using two pairs of primers. The analysis revealed that the amplicons of the 18S rRNA region had 830 bp and 760 bp. Sequencing and phylogenetic analysis of the amplified products indicated that the species under investigation were C. meleagridis and C. baileyi with accession numbers OR631411 and OR631417, respectively. To our knowledge, the identification and genetic characterization of C. meleagridis and C. baileyi within the genus Cryptosporidium infecting domestic pigeons is reported for the first time in Egypt.