Prevalence, Diversity, and Virulence of Campylobacter Carried by Migratory Birds at Four Major Habitats in China

species, especially and , are the main zoonotic bacteria causing human gastroenteritis. A variety of species has been reported in wild birds, posing a potential avian-human transmission pathway. Currently, there has been little surveillance data on carriage in migratory birds in China. In the current work, fresh fecal droppings from individual migratory birds were collected at four bird wintering/stopover sites in China from May 2020 to March 2021. Nucleic acid was extracted and tested for with PCR-based methods. Overall, 73.8% (329/446) of the samples were positive for demonstrating location and bird host specificity. Further speciation revealed the presence of , , , , and an uncharacterized species, which all harbored a variety of virulence factors. Phylogenetic analysis performed on concatenated 16S rRNA- - genes elucidated their genetic relationship, demonstrating both inter- and intra-species diversity. The wide distribution and high diversity of spp. detected in migratory birds in China indicated potential transmission across territories. The existence of virulence factors in all of these species highlighted their public health importance and the necessity of monitoring and controlling and other pathogens carried by migratory birds.