Tatarenkov Andrey, Muñoz-Gutiérrez Iván, Vargas Isabel, Behnsen Judith, Mota-Bravo Luis
School of Biological Sciences, University of California, Irvine, CA 92697, USA.
Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, IL 60612, USA.
Microorganisms. 2024 Jun 28;12(7):1321. doi: 10.3390/microorganisms12071321.
is a leading cause of urinary tract infections and a common commensal of the gastrointestinal tract. Our recent study (JB) showed that strain BL95 employs a novel contact-dependent killing system against enteric bacteria in the mouse gut and in vitro. To uncover the genetic determinants of this system, we performed whole-genome sequencing of BL95 and compared it with 98 complete genomes of . BL95 carries 56 coding sequences (CDSs) not found in other . Over half of these unique genes are located on a novel integrative conjugative element (ICE) named ICE, inserted in tRNA-Phe and exclusive to BL95. ICE has integration, conjugation, and DNA replication modules nearly identical to ICE (common in ), but ICE of BL95 carries two unique operons for -a phenazine biosynthesis and a contact-dependent growth inhibition (CDI) system. ICE is absent in the (AR_0156) closest to BL95 and it is present in the genomes of several from mouse intestines, indicating its recent horizontal mobilization. BL95 shares over 100 genes of five different secretion systems with other , mostly poorly studied, making a large pool of candidate genes for the contact-dependent growth inhibition.
是尿路感染的主要原因，也是胃肠道常见的共生菌。我们最近的研究（JB）表明，菌株BL95在小鼠肠道和体外对肠道细菌采用了一种新型的接触依赖性杀伤系统。为了揭示该系统的遗传决定因素，我们对BL95进行了全基因组测序，并将其与98个完整基因组进行了比较。BL95携带56个在其他中未发现的编码序列（CDS）。这些独特基因的一半以上位于一个名为ICE的新型整合接合元件上，该元件插入tRNA-Phe且为BL95所特有。ICE具有与ICE（中常见）几乎相同的整合、接合和DNA复制模块，但BL95的ICE携带两个独特的操纵子——一个用于吩嗪生物合成，一个用于接触依赖性生长抑制（CDI）系统。与BL95最接近的（AR_0156）中不存在ICE，而在几只小鼠肠道中的基因组中存在ICE，这表明它最近发生了水平转移。BL95与其他共享五个不同分泌系统的100多个基因，其中大多数研究较少，这为接触依赖性生长抑制提供了大量候选基因。
