Dominance of Zoonotic Pathogen Cryptosporidium Meleagridis in Broiler Chickens in Guangdong, China, Reveals Evidence of Cross-Transmission

Abstract

Background Cryptosporidium is one of the most prevalent parasites infecting both birds and mammals. To examine the prevalence of Cryptosporidium species and evaluate the public health significance of domestic chickens in Guangdong Province, Southern China, we analyzed 1001 fecal samples collected from 43 intensive broiler chicken farms from six distinct geographical regions between June 2020 and March 2021. Methods Individual DNAs were subjected to nested PCR-based amplification and sequencing of the small subunit of the nuclear ribosomal RNA gene (SSU rRNA). The 60 kDa glycoprotein gene (pgp60) was performed from all positive SSU rRNA samples to characterise subtypes of C. meleagridis. Results Cryptosporidium infection rates was found to be 13.2%, comprising with infections with C. meleagridis (78/1001, 7.8%), C. baileyi (48/1001, 4.8%) and mixed infections (6/1001, 0.6%). Three subtype families were identified, IIIb, IIIe and IIIg. Six subtypes were identified in broiler chickens, including one novel (IIIgA25G3R1a) and five previously reported (IIIbA23G1R1c, IIIbA24G1R1, IIIbA21G1R1a, IIIeA17G2R1 and IIIeA26G2R1). Within these subtypes, five known subtypes were genetically identical to those identified in humans. Conclusions This is the first report of C. meleagridis in chickens from Guangdong. The frequent occurrence of C. meleagridis in domestic chickens and the common C. meleagridis subtypes identified both in humans and chickens is of public health significance. Our study indicates that broiler chickens represent a potential zoonotic risk for the transmission of Cryptosporidium in this region.

Genetic characterization of Cryptosporidium spp. in Hotan Black Chickens in China reveals two novel subtypes of Cryptosporidium meleagridis

“…In this study, the Hotan Black chickens aged 30-60 days had the highest infection rate by Cryptosporidium (14.5%), followed by those aged <30 days (12.0%), 60-90 days (6.9%) and >90 days (3.4%). In one previous study, chickens aged 61-90 days (17.8%) showed a significantly higher infection rate than chickens <30 d (8.3%), 31-60 days (12.0%) and >90 days (6.8%) of age, which was partially in agreement with the results of our study [22]. Usually, warming of chickens can be completely stopped at the age of >30 days, and they then leave the hotbed for flat-surfaced cages, living at their natural room temperature.…”