圈养珍稀鹤类长疟原虫流行情况研究

Investigation on Prevalence of Plasmodium elongatum in Captive Rare Cranes

2017—2021年,收集5家饲养单位12种圈养珍稀鹤类的284份样品进行血孢子虫病的流行调查。采用血孢子虫细胞色素b(Cyt b)基因套式PCR检测和Blast序列比对,结果显示:血孢子虫基因序列与已知长疟原虫(Plasmodium elongatum)DENVID02进化支匹配度达到100%;结合虫体形态学,确定该寄生虫所属类群为长疟原虫。长疟原虫在黑颈鹤(Grus nigricollis)、白鹤(Leucogeranus leucogeranus)、丹顶鹤(Grus japonensis)、白头鹤(G.monacha)、灰鹤(G.grus)和白枕鹤(Antigone vipio)6种鹤类中被检出,检出率为8.45%(24/284)。此外,感染长疟原虫DENVID02进化支的鹤类个体未出现明显的临床症状,所有感染个体均未采取防治措施。在跟踪监测中,发现病原体在鹤类体内消失或呈跨年度携带现象,推测鹤类可能对长疟原虫DENVID02具有先天抵抗力。

To investigate the prevalence of Haemosporidia,the present study collected 284 samples from 12 species of captive rare cranes in five crane breeding bases from 2017 to 2021.Using nested PCR of the cytochrome b(Cyt b)gene and Blast sequence alignment,the results showed that the sequence of the Haemoproteus parasites was 100%similarity in comparison with Plasmodium elongatum(lineage DENVID02)by Blast.Combined with the morphology of the parasite,it was determined that the parasite belongs to P.elongatum.P.elongatum(lineage DENVID02)was detected in the six crane species,including black-necked crane(Grus nigricollis),Siberian crane(Leucogeranus leucogeranus),red crowned crane(Grus japonensis),hooded crane(G.monacha),common crane(G.grus),and white-naped crane(Antigone vipio),with a total detection rate of 8.45%(24/284).In addition,the infected crane individuals did not show obvious clinical symptoms,and no treatment measures for the parasites were taken.In the follow-up monitoring,P.elongatum disappeared in one year or two years.All these indicated that the above cranes had innate resistance to the parasite.