Longitudinal surveillance of Cryptosporidium spp. in broiler chickens in Xinjiang, northwest China: genetic diversity of Cryptosporidium meleagridis subtypes.

Cryptosporidium spp. are common enteric parasites in humans and animals. Herein, 175 faecal specimens were collected from a broiler farm in Xinjiang, China, including seven repeated samplings at 10-day intervals of broilers aged 10 to 70 days. Cryptosporidium was detected and identified by PCR-RFLP analysis. The overall infection rate of Cryptosporidium in broilers was 23.4% (41/175), with the highest infection rate of 48.0% (12/25) at 40 days of age, and no infection was detected at 10 days of age. Two Cryptosporidium species were confirmed, namely, C. baileyi (3.4%, 6/175) and C. meleagridis (20%, 35/175). In total, 21 of 35 C. meleagridis isolates were successfully subtyped based on the gp60 gene, and one known subtype, IIIgA22G3R1 (n = 1), and three novel subtypes, IIIbA25G1R1 (n = 10), IIIgA24G3R1 (n = 9) and IIIgA25G2R1 (n = 1), were identified. Our findings highlight the genetic diversity of C. meleagridis in Xinjiang and the potential endemic characteristics of the subtypes.