空肠弯曲菌是世界范围内细菌性胃肠炎的主要原因,主要通过食用受污染的家禽来感染人类。空肠杆菌在野鸟的肠道中很常见,并显示出与特定鸟类不同的菌株特异性关联。这与农场动物形成对比,其中几种基因型共存。目前尚不清楚限制此类专业菌株的宿主物种之间传播的障碍是否与环境因素有关,例如宿主物种之间的接触。细菌在环境中生存,等。,或者更确切地说,是对特定宿主肠道环境的特异性适应。我们比较了来自鸣叫鹅口疮(ST-1304复合物)和野鸭(ST-995)的两种宿主特异性空肠杆菌的体内定植动力学,和野生宿主中来自鸡(ST-21复合体)的通才菌株,野鸭(Anasplatyrhynchos)。在18天的感染实验中,鸣叫鹅口疮菌株仅显示出微弱的定殖作用,并在10天后从所有鸟类中清除,而绿头鸭和鸡肉品种都保持稳定。当相同的鸟类与野鸭株共同感染前4天给予鸡毒株时,它迅速被后者击败。相比之下,当野鸭菌株在与鸡菌株共感染前4天给予时,野鸭株仍然存在,鸡肉株的扩张被推迟。我们的结果表明,空肠弯曲菌在野鸭定殖能力方面的菌株特异性差异,可能与宿主起源有关。这种差异可能解释了在野鸟的空肠弯曲杆菌中观察到的宿主关联模式。
Campylobacter jejuni is the primary cause of bacterial gastroenteritis worldwide, infecting humans mostly through consumption of contaminated poultry. C. jejuni is common in the gut of wild birds, and shows distinct strain-specific association to particular bird species. This contrasts with farm animals, in which several genotypes co-exist. It is unclear if the barriers restricting transmission between host species of such specialist strains are related to environmental factors such as contact between host species, bacterial survival in the environment, etc., or rather to strain specific adaptation to the intestinal environment of specific hosts. We compared colonization dynamics in vivo between two host-specific C. jejuni from a song thrush (ST-1304 complex) and a mallard (ST-995), and a generalist strain from chicken (ST-21 complex) in a wild host, the mallard (Anas platyrhynchos). In 18-days infection experiments, the song thrush strain showed only weak colonization and was cleared from all birds after 10 days, whereas both mallard and chicken strains remained stable. When the chicken strain was given 4 days prior to co-infection of the same birds with a mallard strain, it was rapidly outcompeted by the latter. In contrast, when the mallard strain was given 4 days prior to co-infection with the chicken strain, the mallard strain remained and expansion of the chicken strain was delayed. Our results suggest strain-specific differences in the ability of C. jejuni to colonize mallards, likely associated with host origin. This difference might explain observed host association patterns in C. jejuni from wild birds.