Global similarity and local differences in Campylobacter jejuni lineages associated with asymptomatic paediatric infection from the Peruvian Amazon

<i>Campylobacter</i> is the leading bacterial cause of gastroenteritis worldwide and despite high incidence in low- to middle-income countries, where infection can be fatal, surveillance is rare and the genotypes responsible for disease have not been identified. The epidemiology of disease is different to the developed world, where infection is mostly associated with consumption of contaminated meat products. Infection is endemic among children and asymptomatic carriage is thought to be common. Widespread malnutrition encourages asymptomatic colonisation stunting childhood growth, leading to poor cognitive and physical development. Here, we sequence the genomes of a collection of <i>C. jejuni</i> isolates sampled from children in the Peruvian Amazon to investigate genetic differences between them and a global reference collection. In addition to common global disease lineages, we identified local genotypes rarely seen before. Asymptomatic isolates were not restricted to specific ecological groups or genotypes and chicken was the primary source of infection. Hidden reservoirs of bacterial diversity can help us understand the genetics underlying differences in the presentation of disease and will inform work to improve infant health globally.<br>

弯曲杆菌（Campylobacter）是全球范围内引发肠胃炎的首要细菌性致病菌。尽管中低收入国家的该病发病率居高不下，且感染可致命，但当地的监测工作极为匮乏，致病相关基因型尚未被鉴定出来。该病的流行病学特征与发达国家存在显著差异：在发达国家，感染多与食用受污染肉制品相关；而在中低收入地区，感染在儿童群体中呈地方性流行，无症状带菌现象被认为十分普遍。广泛存在的营养不良会促进细菌的无症状定植，阻碍儿童生长发育，进而造成认知与躯体发育迟缓。本研究对秘鲁亚马逊地区儿童体内分离得到的空肠弯曲杆菌（Campylobacter jejuni，缩写C. jejuni）菌株集进行基因组测序，以探究其与全球参考菌株集之间的遗传差异。除了常见的全球致病谱系外，本研究还鉴定出此前罕见的本土基因型。无症状分离菌株并未局限于特定生态类群或基因型，鸡肉是主要的感染来源。潜藏的细菌多样性储库有助于我们解析疾病表现差异背后的遗传学机制，也将为全球范围内改善婴幼儿健康的相关工作提供参考。