Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source
Comparative phylogenomics of the food-borne pathogen Campylobacter jejuni reveals genetic markers predictive of infection source
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DOI：
10.1073/pnas.0503252102
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发表时间：
2005-11-01
影响因子：
11.1
通讯作者：
Wren, BW
中科院分区：
文献类型：
--
作者：
Champion, OL;Gaunt, MW;Wren, BW
空肠弯曲杆菌是全球细菌性胃肠炎的主要原因，但传统的分型方法无法区分导致人类疾病的不同来源的菌株。我们报告使用基因组分型(使用DNA微阵列对微生物进行全基因组比较)与基于贝叶斯的算法相结合来模拟这种主要食源性病原体的系统发育。在这项研究中，对111株空肠弯曲菌进行了基因分型，这些分离株来自与空肠弯曲菌相关的人类分离株(70株)、鸡(17株)、牛(13株)、绵羊(5株)和环境(6株)。根据这些数据，分离株的贝叶斯系统发育显示出两个不同的空地，由贝叶斯概率明确支持(P=1)；一个家畜空地由31/35(88.6%)的家畜分离株组成，另一个“非家畜”空地由其他环境分离株的空地组成。有几个基因被鉴定为家畜林地菌株的特征。最突出的是鞭毛蛋白糖基化位点上的6个基因簇(cj1321~cj1326)，经PCR分析证实，这些基因是另外6个鸡相关菌株的遗传标记。令人惊讶的是，这些研究表明，大多数(39/70，55.7%)人空肠弯曲菌分离株是在非家畜林地发现的，这表明大多数空肠弯曲菌感染可能来自非家畜(也可能是非农业)来源。这项研究提供了对以前未知的空肠弯曲菌感染宿主的洞察，这可能对疾病控制策略有影响。所描述的比较系统基因组学方法提供了一个可靠的方法原型，应该适用于其他微生物。
Campylobacter jejuni is the predominant cause of bacterial gastroenteritis worldwide, but traditional typing methods are unable to discriminate strains from different sources that cause disease in humans. We report the use of genomotyping (whole-genome comparisons of microbes using DNA microarrays) combined with Bayesian-based algorithms to model the phylogeny of this major food-borne pathogen. In this study 111 C. jejuni strains were examined by genomotyping isolates from humans with a spectrum of C. jejuni-associated disease (70 strains), chickens (17 strains), bovines (13 strains), ovines (5 strains), and the environment (6 strains). From these data, the Bayesian phylogeny of the isolates revealed two distinct Glades unequivocally supported by Bayesian probabilities (P = 1); a livestock Glade comprising 31/35 (88.6%) of the livestock isolates and a "nonlivestock" Glade comprising further Glades of environmental isolates. Several genes were identified as characteristic of strains in the livestock Glade. The most prominent was a cluster of six genes (cj1321 to cj1326) within the flagellin glycosylation locus, which were confirmed by PCR analysis as genetic markers in six additional chicken-associated strains. Surprisingly these studies show that the majority (39/70, 55.7%) of C. jejuni human isolates were found in the nonlivestock Glade, suggesting that most C. jejuni infections may be from nonlivestock (and possibly nonagricultural) sources. This study has provided insight into a previously unidentified reservoir of C. jejuni infection that may have implications in disease-control strategies. The comparative phylogenomics approach described provides a robust methodological prototype that should be applicable to other microbes.