Quantifying the Survival of Multiple Salmonella enterica Serovars In Vivo via Massively Parallel Whole-Genome Sequencing To Predict Zoonotic Risk.
Quantifying the Survival of Multiple Salmonella enterica Serovars In Vivo via Massively Parallel Whole-Genome Sequencing To Predict Zoonotic Risk.
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DOI：
10.1128/aem.02262-17
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发表时间：
2018-02-15
影响因子：
4.4
通讯作者：
Stevens MP
中科院分区：
文献类型：
--
作者：
Vohra P;Bugarel M;Turner F;Loneragan GH;Hope JC;Hopkins J;Stevens MP
肠沙门氏菌是一种具有世界重要意义的动物和人畜共患病病原体。存在不同宿主和组织嗜性的沙门氏菌血清型。牛是人类非伤寒沙门氏菌病的重要宿主，受污染的牛外周淋巴结通过碎牛肉进入食物链。不同血清型在牛淋巴系统中生存的相对能力尚不清楚，并限制了控制策略的发展。这个问题是通过开发一种大规模并行的全基因组测序方法来研究体内混合血清型感染而解决的。沙门氏菌血清型在某些基因上存在自然发生的单核苷酸多态(SNPs)，在遗传上有所不同。有人假设，这些SNP可以作为标记，同时识别混合群体中的血清型，并量化群体中每个成员的丰度。使用包含多达11个不同比例的血清型的模拟池在体外验证了该方法的性能。然后将其用于研究口服相同11个血清型的牛体内的血清型存活。所有的血清型都成功地定植了牛的淋巴系统，包括周围的淋巴结节，因此构成了类似的人畜共患病风险。这种方法可以在一只动物身上同时评估多个未经基因改造的菌株的命运。它可能有助于减少研究混合菌株感染所需的动物数量，并有助于测试疫苗和治疗的交叉保护效果。它还有可能应用于拥有共同但多态等位基因的不同细菌物种。虽然一些沙门氏菌血清型更多地是从淋巴结中分离出来的，而不是从牛的粪便和环境中分离出来的，但这些血清型在牛的淋巴系统中生存的相对能力仍然不清楚。发展了一种基于测序的方法，该方法利用测序的沙门氏菌基因组中的可用信息来研究体内混合血清型感染的动力学。该方法的主要优点包括同时鉴定和定量多个菌株，而不需要任何基因修改和最少的动物使用。这种方法可用于疫苗接种试验或流行病学调查，在这些情况下，对混合人群中密切相关的病原体菌株动态的了解可以为人畜共患病风险的预测和干预策略的制定提供信息。
Salmonella enterica is an animal and zoonotic pathogen of worldwide importance. Salmonella serovars that differ in their host and tissue tropisms exist. Cattle are an important reservoir of human nontyphoidal salmonellosis, and contaminated bovine peripheral lymph nodes enter the food chain via ground beef. The relative abilities of different serovars to survive within the bovine lymphatic system are poorly understood and constrain the development of control strategies. This problem was addressed by developing a massively parallel whole-genome sequencing method to study mixed-serovar infections in vivo. Salmonella serovars differ genetically by naturally occurring single nucleotide polymorphisms (SNPs) in certain genes. It was hypothesized that these SNPs could be used as markers to simultaneously identify serovars in mixed populations and quantify the abundance of each member in a population. The performance of the method was validated in vitro using simulated pools containing up to 11 serovars in various proportions. It was then applied to study serovar survival in vivo in cattle challenged orally with the same 11 serovars. All the serovars successfully colonized the bovine lymphatic system, including the peripheral lymph nodes, and thus pose similar risks of zoonosis. This method enables the fates of multiple genetically unmodified strains to be evaluated simultaneously in a single animal. It could be useful in reducing the number of animals required to study mixed-strain infections and in testing the cross-protective efficacy of vaccines and treatments. It also has the potential to be applied to diverse bacterial species which possess shared but polymorphic alleles. IMPORTANCE While some Salmonella serovars are more frequently isolated from lymph nodes rather than the feces and environment of cattle, the relative abilities of serovars to survive within the lymphatic system of cattle remain ill defined. A sequencing-based method which used available information from sequenced Salmonella genomes to study the dynamics of mixed-serovar infections in vivo was developed. The main advantages of the method include the simultaneous identification and quantification of multiple strains without any genetic modification and minimal animal use. This approach could be used in vaccination trials or in epidemiological surveys where an understanding of the dynamics of closely related strains of a pathogen in mixed populations could inform the prediction of zoonotic risk and the development of intervention strategies.