Abstract: In June 2022，sows in a large??scale pig farm in Longyan City，Fujian Province were reported ill in succession. The main clinical symptoms include slight swollen knee joints，reluctant to move or even difficulty instanding. In order to find out the causes of the disease，pathological examination was carried out on the diseased pigs. Blood samples were collected for nucleic acid detection of common pathogens and knee joint synovial fluid samples were collected for the isolation of microorganisms. The results showed that no obvious pathological changes were found in the main organs. The nucleic acid detection results of blood samples showed that porcine circovirus type 3（PCV3） was positive and no other major pathogens were detected. Microscopic examination of the microbial culture product of knee joint synovial fluid sample showed that there was yeast ?like fungus. PCR amplification and DNA sequencing of the cultured products showed that the yeast ?like fungus was Candida parapsilosis. Conclusion：This case is a mixed infection of PCV?3 and Candida parapsilosis. According to the literature，this is the first case in the world to report that Candida parapsilosis caused deep knee joint infection in pigs and Candida parapsilosis was successfully isolated from knee joint synovial fluid.

Key words: Sows； Porcine circovirus type 3； Candida parapsilosis； Co?infection

摘要： 2022年6月福建省龙岩市某规模化猪场的母猪陆续发病，临床主要表现为病猪的膝 关节轻微肿大，不愿久站，甚至站立困难。为查明发病原因，对病猪进行病理剖检，并采集血 液和膝关节积液样品，分别用于生猪常见疫病病原体的核酸检测和微生物的分离培养。结果 显示：病理剖检未发现主要脏器的明显病变；血液样品的核酸检测显示，猪圆环病毒3型（Por? cine Circovirus type 3，PCV3）为阳性，未检出其它主要病原体；膝关节积液样品的微生物培养产 物的显微镜镜检结果显示有酵母样真菌，经培养产物的PCR扩增和DNA测序表明：该酵母样 真菌为近平滑假丝酵母菌（Candida parapsilosis）。结论：该病例为猪圆环病毒3型（PCV??3）与近 平滑假丝酵母菌的混合感染。根据文献查询，这是世界首例有关近平滑假丝酵母菌导致生猪 膝关节深部感染并从膝关节积液中成功分离到近平滑假丝酵母菌的报道。

关键词: 母猪； 猪圆环病毒3型； 近平滑假丝酵母菌； 混合感染