Abstract:
Wild animals in general, birds in particular, play a key role in transporting ticks and propagating tick-borne pathogens. Several studies have confirmed the infection of birds with Anaplasma phagocytophilum, with overall prevalence varying widely from country to country and/or study to study. This zoonotic bacterium, transmitted mainly by ticks of the genus Ixodes, is responsible for granulocytic anaplasmosis in humans (HGA) and domestic animals (cats, dogs, horses). The disease is also called tick-borne fever (TBF) in ruminants. Extremely rare in the USA, TBF is very common in Europe, where it causes economic losses in livestock. Conversely, HGA is well established in the USA whereas only a few less severe cases have been observed in Europe. Current typing techniques support the existence of multiple variants with differences in virulence/pathogenicity and tropism for certain tick and host species. However, epidemiological cycles remain difficult to characterize in Europe. Several studies describe a cycle apparently involving only birds in Europe, but no such study has been conducted in mainland France. Our objectives were to search for A. phagocytophilum in passerine birds in the Ile-de-France region and to explore their diversity using groEL and ankA gene typing and multilocus sequence typing (MLST). Various tissues (spleen, liver, and skin) were collected from cadavers of 680 passerines between March and December 2021. The presence of A. phagocytophilum was detected by qPCR Taqman targeting the msp2 gene. Three blackbirds (Turdus merula) were found positive, representing detection rates of 0.4 % in all birds tested and 3.3 % in blackbirds. The higher frequency of detection in blackbirds could be at least partially explained by their lifestyle, as they feed on the ground. Analysis of the results of groEL and ankA typing and MLST from positive blackbirds support the hypothesis that the avian A. phagocytophilum strains in Ile-de-France are distinct from those found in mammals, and that they form their own cluster in Europe.
摘要:
一般的野生动物,尤其是鸟类,在运输蜱和传播蜱传病原体中起关键作用。几项研究证实了鸟类感染了吞噬菌体,总体患病率因国家和/或研究而异。这种人畜共患细菌,主要通过Ixodes属的蜱传播,负责人类(HGA)和家畜(猫,狗,马)。该疾病在反刍动物中也被称为蜱传发热(TBF)。在美国极为罕见,TBF在欧洲很常见,造成牲畜经济损失的地方。相反,HGA在美国已经确立,而在欧洲仅观察到少数不太严重的病例。当前的分型技术支持存在多种变体,这些变体在某些蜱和宿主物种的毒力/致病性和向性方面存在差异。然而,在欧洲,流行病学周期仍然难以表征。几项研究描述了一个周期,显然只涉及欧洲的鸟类,但是在法国大陆还没有进行过这样的研究。我们的目标是在法兰西岛地区的雀形目鸟类中寻找A.吞噬细胞,并使用groEL和ankA基因分型和多位点序列分型(MLST)探索其多样性。各种组织(脾脏,肝脏,和皮肤)是在2021年3月至12月之间从680个雀形目的尸体中收集的。通过靶向msp2基因的qPCRTaqman检测吞噬细胞的存在。发现三只黑鸟(Turdusmerula)呈阳性,在所有测试的禽鸟中,检出率为0.4%,在黑鸟中,检出率为3.3%。黑鸟的较高检测频率至少可以部分解释为它们的生活方式,当他们在地面上进食时。对阳性黑鸟的groEL和ankA分型和MLST结果的分析支持以下假设:法兰西岛的禽类A.吞噬细胞菌株与哺乳动物中发现的菌株不同,他们在欧洲形成了自己的集群。