Rouffaer Lieze Oscar, Strubbe Diederik, Teyssier Aimeric, Salleh Hudin Noraine, Van den Abeele Anne-Marie, Cox Ivo, Haesendonck Roel, Delmée Michel, Haesebrouck Freddy, Pasmans Frank, Lens Luc, Martel An
Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Department of Biology (Terrestrial Ecology Unit), Faculty of Sciences, Ghent University, Ghent, Belgium.
PLoS One. 2017 Dec 27;12(12):e0189509. doi: 10.1371/journal.pone.0189509. eCollection 2017.
Urbanization strongly affects biodiversity, altering natural communities and often leading to a reduced species richness. Yet, despite its increasingly recognized importance, how urbanization impacts on the health of individual animals, wildlife populations and on disease ecology remains poorly understood. To test whether, and how, urbanization-driven ecosystem alterations influence pathogen dynamics and avian health, we use house sparrows (Passer domesticus) and Yersinia spp. (pathogenic for passerines) as a case study. Sparrows are granivorous urban exploiters, whose western European populations have declined over the past decades, especially in highly urbanized areas. We sampled 329 house sparrows originating from 36 populations along an urbanization gradient across Flanders (Belgium), and used isolation combined with 'matrix-assisted laser desorption ionization- time of flight mass spectrometry' (MALDI-TOF MS) and PCR methods for detecting the presence of different Yersinia species. Yersinia spp. were recovered from 57.43% of the sampled house sparrows, of which 4.06%, 53.30% and 69.54% were identified as Y. pseudotuberculosis, Y. enterocolitica and other Yersinia species, respectively. Presence of Yersinia was related to the degree of urbanization, average daily temperatures and the community of granivorous birds present at sparrow capture locations. Body condition of suburban house sparrows was found to be higher compared to urban and rural house sparrows, but no relationships between sparrows' body condition and presence of Yersinia spp. were found. We conclude that two determinants of pathogen infection dynamics, body condition and pathogen occurrence, vary along an urbanization gradient, potentially mediating the impact of urbanization on avian health.
城市化对生物多样性有强烈影响，改变自然群落，常常导致物种丰富度降低。然而，尽管其重要性日益得到认可，但城市化如何影响个体动物健康、野生动物种群以及疾病生态学仍知之甚少。为了测试城市化驱动的生态系统变化是否以及如何影响病原体动态和鸟类健康，我们以家麻雀（Passer domesticus）和耶尔森菌属（对雀形目鸟类致病）为例进行研究。麻雀是食谷性城市开拓者，其西欧种群在过去几十年中有所减少，尤其是在高度城市化地区。我们沿着比利时弗拉芒地区的城市化梯度，从36个种群中采集了329只家麻雀样本，并采用分离结合“基质辅助激光解吸电离飞行时间质谱法”（MALDI - TOF MS）和聚合酶链反应（PCR）方法来检测不同耶尔森菌属的存在情况。从57.43%的家麻雀样本中检测到了耶尔森菌属，其中分别有4.06%、53.30%和69.54%被鉴定为假结核耶尔森菌、小肠结肠炎耶尔森菌和其他耶尔森菌属。耶尔森菌的存在与城市化程度、平均日气温以及麻雀捕获地点的食谷性鸟类群落有关。结果发现，与城市和农村家麻雀相比，郊区家麻雀的身体状况更好，但未发现麻雀身体状况与耶尔森菌属存在之间的关系。我们得出结论，病原体感染动态的两个决定因素，即身体状况和病原体出现情况，沿着城市化梯度变化，这可能介导了城市化对鸟类健康的影响。
