Reinoso-Pérez María Teresa, Dhondt Keila V, Sydenstricker Agnes V, Heylen Dieter, Dhondt André A
Department of Natural Resources Cornell University Ithaca New York.
Laboratory of Ornithology Cornell University Ithaca New York.
Ecol Evol. 2020 Apr 29;10(12):5801-5814. doi: 10.1002/ece3.6318. eCollection 2020 Jun.
Hosts are typically coinfected by multiple parasite species whose interactions might be synergetic or antagonistic, producing unpredictable physiological and pathological impacts on the host. This study shows the interaction between spp. and spp. in birds experimentally infected or not infected with .In 1994, the bacterium jumped from poultry to wild birds in which it caused a major epidemic in North America. Birds infected with . show conjunctivitis as well as increased levels of corticosterone.Malaria and other haemosporidia are widespread in birds, and chronic infections become apparent with the detectable presence of the parasite in peripheral blood in response to elevated levels of natural or experimental corticosterone levels.Knowing the immunosuppressive effect of corticosterone on the avian immune system, we tested the hypothesis that chronic infections of spp. and spp. in house finches would respond to experimental inoculation with as corticosterone levels are known to increase following inoculation. spp. infection intensity increased within days of inoculation as shown both by the appearance of infected erythrocytes and by the increase in the number and the intensity of positive PCR tests. spp. infection intensity increased when spp. infection intensity increased, but not in response to inoculation. spp. and spp. seemed to compete in the host as shown by a negative correlation between the changes in their PCR score when both pathogens were present in the same individual.Host responses to coinfection with multiple pathogens measured by the hematocrit and white blood cell count depended on the haemosporidian community composition. Host investment in the leukocyte response was higher in the single-haemosporidia-infected groups when birds were infected with .A trade-off was observed between the immune control of the chronic infection ( spp. spp.) and the immune response to the novel bacterial infection ().
宿主通常会被多种寄生虫物种共同感染，这些寄生虫之间的相互作用可能是协同的或拮抗的，会对宿主产生不可预测的生理和病理影响。本研究展示了在实验性感染或未感染[某种病原体]的鸟类中，[两种寄生虫物种名称]之间的相互作用。1994年，[某种细菌名称]从家禽传播到野生鸟类，在北美引发了一场重大疫情。感染[该细菌名称]的鸟类会出现结膜炎以及皮质酮水平升高。疟疾和其他血孢子虫在鸟类中广泛存在，随着外周血中可检测到寄生虫，慢性感染会因自然或实验性皮质酮水平升高而显现出来。鉴于已知皮质酮对鸟类免疫系统具有免疫抑制作用，我们测试了这样一个假设：家朱雀体内[两种寄生虫物种名称]的慢性感染会对实验性接种[某种病原体]产生反应，因为接种后皮质酮水平会升高。接种[某种病原体]后数天内，[一种寄生虫物种名称]的感染强度增加，这可通过感染红细胞的出现以及阳性PCR检测数量和强度的增加来表明。当[一种寄生虫物种名称]的感染强度增加时，[另一种寄生虫物种名称]的感染强度也会增加，但并非对接种[某种病原体]的反应。当两种病原体存在于同一个体中时，它们的PCR评分变化呈负相关，这表明[两种寄生虫物种名称]似乎在宿主体内相互竞争。通过血细胞比容和白细胞计数衡量的宿主对多种病原体共同感染的反应取决于血孢子虫群落组成。当鸟类感染[某种病原体]时，单血孢子虫感染组对白细胞反应的宿主投入更高。在慢性感染（[两种寄生虫物种名称]）的免疫控制与对新型细菌感染（[某种病原体]）的免疫反应之间观察到了一种权衡。
