1. College of Veterinary Medicine, Yunnan Agricultural University, Kunming, P.R. China.
2. Department of Gynecology, The Second Affiliated Hospital of Kunming Medical University, Kunming, P.R. China.
3. Yan'an Hospital of Kunming City and Yan'an Hospital Affiliated to Kunming Medical University, Kunming, P.R. China.
4. Second People's Hospital of Yunnan Province and Yunnan Red Cross Hospital, Kunming, P.R. China.
5. College of Marine Science, Shandong University, Weihai, P.R. China.
6. State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China.