Salmonellosis is a leading bacterial cause of foodborne illness, and numerous Salmonella enterica serovars have been responsible for foodborne outbreaks. In the United States outbreaks are often linked to poultry and poultry‐related products. The prevalence of Salmonella serovar Infantis has been increasing in poultry processing facilities over the past few years and in 2018 was identified as the causative agent for a large multistate outbreak linked to raw chicken. CRISPR‐typing is a subtyping approach based on PCR and the sequencing of two Salmonella loci, CRISPR1 and CRISPR2. CRISPR‐typing was used to interrogate 138 recent (2018–2019) isolates and genomes of ser. Infantis. Results show that the CRISPR elements are remarkably conserved in this serovar. The most conserved spacers, and those also unique to ser. Infantis, were used as targets to develop a ser. Infantis‐specific qPCR assay. This assay was able to detect ser. Infantis in mixed serovar cultures of Salmonella, down to 0·1% of the population, highlighting the utility of this molecular approach in improving surveillance sensitivity for this important food safety pathogen.

中文翻译：

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肠道沙门氏菌婴儿血清中的保守 CRISPR 阵列可作为 qPCR 靶标检测混合血清型群体中的婴儿

沙门氏菌病是食源性疾病的主要细菌病因，许多肠道沙门氏菌血清型是食源性疾病爆发的原因。在美国，爆发通常与家禽和家禽相关产品有关。过去几年，家禽加工设施中婴儿沙门氏菌血清型的流行率一直在增加，2018 年被确定为与生鸡肉相关的多州大规模爆发的病原体。CRISPR 分型是一种基于 PCR 和两个沙门氏菌基因座 CRISPR1 和 CRISPR2 测序的亚型分型方法。CRISPR 分型用于询问 138 个最近（2018-2019 年）分离株和 ser 的基因组。婴儿。结果表明，CRISPR 元件在该血清型中显着保守。最保守的间隔区，以及那些也是 ser 独有的间隔区。婴儿，被用作开发系列的目标。婴儿特异性 qPCR 检测。该测定能够检测ser。沙门氏菌混合血清型培养物中的婴儿，低至人口的 0·1%，突出了这种分子方法在提高对这一重要食品安全病原体的监测敏感性方面的效用。