Brown Phillip, Lee Sangmi, Elhanafi Driss, Tham Wilhelm, Danielsson-Tham Marie-Louise, Lopez-Valladares Gloria, Chen Yi, Ivanova Mirena, Leekitcharoenphon Pimlapas, Kathariou Sophia
Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA.
Department of Food and Nutrition, Chungbuk National University, Chengju 28644, Chungbuk, Republic of Korea.
Microorganisms. 2023 Mar 8;11(3):699. doi: 10.3390/microorganisms11030699.
is a Gram-positive pathogen responsible for the severe foodborne disease listeriosis. A chromosomal hotspot between and has been noted to harbor diverse restriction modification (RM) systems. Here, we analyzed 872 genomes to better understand the prevalence and types of RM systems in this region, designated the immigration control region (ICR). Type I, II, III and IV RM systems were found in 86.1% of strains inside the ICR and in 22.5% of strains flanking the ICR. ICR content was completely conserved within the same multilocus sequence typing-based sequence type (ST), but the same RM system could be identified in diverse STs. The intra-ST conservation of ICR content suggests that this region may drive the emergence of new STs and promote clone stability. Sau3AI-like, LmoJ2 and LmoJ3 type II RM systems as well as type I EcoKI-like, and type IV AspBHI-like and -like systems accounted for all RM systems in the ICR. A Sau3AI-like type II RM system with specificity for GATC was harbored in the ICR of many STs, including all strains of the ancient, ubiquitous ST1. The extreme paucity of GATC recognition sites in lytic phages may reflect ancient adaptation of these phages to preempt resistance associated with the widely distributed Sau3AI-like systems. These findings indicate that the ICR has a high propensity for RM systems which are intraclonaly conserved and may impact bacteriophage susceptibility as well as ST emergence and stability.
是一种革兰氏阳性病原体，可导致严重的食源性疾病李斯特菌病。已注意到在[具体区域1]和[具体区域2]之间的一个染色体热点区域含有多种限制修饰（RM）系统。在这里，我们分析了872个[具体菌名]基因组，以更好地了解该区域（指定为移民控制区域，ICR）中RM系统的流行情况和类型。在ICR内部86.1%的菌株以及ICR侧翼22.5%的菌株中发现了I型、II型、III型和IV型RM系统。ICR内容物在基于多位点序列分型的相同序列类型（ST）内完全保守，但在不同的ST中可以鉴定出相同的RM系统。ICR内容物在ST内的保守性表明该区域可能推动新ST的出现并促进克隆稳定性。Sau3AI样、LmoJ2和LmoJ3 II型RM系统以及I型EcoKI样、IV型AspBHI样和[具体类型]系统占ICR中所有RM系统。许多ST的ICR中都含有对GATC具有特异性的Sau3AI样II型RM系统，包括古老的、普遍存在 ST1的所有菌株。裂解性噬菌体中GATC识别位点的极度稀少可能反映了这些噬菌体为了预先阻止与广泛分布的Sau3AI样系统相关的抗性而进行的古老适应。这些发现表明，ICR具有很高的RM系统倾向，这些系统在克隆内保守，可能会影响噬菌体易感性以及ST的出现和稳定性。
