DeBrock Spencer, Cohen Emily, Balasubramanian Sujata, Marra Peter P, Hamer Sarah A
Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA.
Schubot Center for Avian Health, Department of Veterianry Pathobiology, Texas A&M University, USA.
Int J Parasitol Parasites Wildl. 2021 Apr 1;15:12-21. doi: 10.1016/j.ijppaw.2021.03.013. eCollection 2021 Aug.
Animal movements, especially avian migration, can be a mechanism for the large-scale dispersal and geographic range expansion of parasites. The host-parasite relationships among birds during migration have yet to be fully explored. We characterized the haemosporidian parasite lineages in passerines during spring migration on the Texas coast of the Gulf of Mexico, and identified associations among wintering origin (US, Central America, South America) and foraging height (canopy, understory, ground) and infection status. We examined 743 samples representing 52 species of 10 families over six years, 2014-2019. We used PCR and DNA sequencing of the haemosporidian cytB gene from avian blood samples to determine infection status with the genera and and characterize the lineages of blood parasites. We found an overall haemosporidian infection prevalence of 48.4% among neotropical migrant and Texas wintering birds. Among families, Icterids had the highest prevalence (75%, 24 individuals, 4 species sampled) whereas Parulids had the lowest prevalence (38.4%, 177 individuals, 18 species sampled). Among infected birds, spp. infections were more common than spp. infections in species that winter in Central America compared to those that winter in the US or South America. Similarly, among infected birds, spp. infections were more common than spp. infections in species that forage on the ground or in the understory compared to those that forage in the canopy. Infected birds harbored 65 different haemosporidian lineages (71% ; 29% ) of which 17 lineages have never previously been reported and six lineages were documented for the first time in North America, having been previously detected only in Central or South America. These data are consistent with the premise that intercontinental parasite dispersal may be facilitated by passerine birds. Future studies focused on surveillance, the probability of establishment of parasite lineages, and the use of individual bird tracking methods to understand infection dispersion over time will allow a more comprehensive understanding of changing avian host-haemosporidian relationships.
动物的移动，尤其是鸟类的迁徙，可能是寄生虫进行大规模传播和地理范围扩张的一种机制。鸟类在迁徙过程中的宿主 - 寄生虫关系尚未得到充分探索。我们对墨西哥湾得克萨斯海岸春季迁徙期间雀形目鸟类中的血孢子虫寄生虫谱系进行了特征描述，并确定了越冬地来源（美国、中美洲、南美洲）、觅食高度（树冠层、林下植被、地面）与感染状况之间的关联。在2014年至2019年的六年时间里，我们检测了代表10个科52种鸟类的743个样本。我们使用来自鸟类血液样本的血孢子虫细胞色素B基因进行PCR和DNA测序，以确定感染状况并对血寄生虫的谱系进行特征描述。我们发现新热带地区迁徙鸟类和得克萨斯越冬鸟类的血孢子虫总体感染率为48.4%。在各个科中，拟鹂科的感染率最高（75%，24只个体，4个采样物种），而森莺科的感染率最低（38.4%，177只个体，18个采样物种）。在受感染的鸟类中，与在美国或南美洲越冬的物种相比，在中美洲越冬的物种感染疟原虫属的情况比感染血疟原虫属更为常见。同样，在受感染的鸟类中，与在树冠层觅食的物种相比，在地面或林下植被觅食的物种感染疟原虫属的情况比感染血疟原虫属更为常见。受感染的鸟类携带了65种不同的血孢子虫谱系（71%为疟原虫属；29%为血疟原虫属），其中17种谱系此前从未被报道过，有6种谱系在北美洲首次被记录，之前仅在中美洲或南美洲被检测到。这些数据与雀形目鸟类可能促进洲际寄生虫传播这一前提相符。未来聚焦于监测、寄生虫谱系建立概率以及使用个体鸟类追踪方法来了解感染随时间扩散情况的研究，将有助于更全面地理解不断变化的鸟类宿主 - 血孢子虫关系。
