Toloza Johana E Hernández, Xu Ye, Mendum Tom A, Siedler Bianca Sica, Casey Rosalyn, Wu Huihai, Williams Kerstin, Hingley-Wilson Suzanne, McFadden Johnjoe
Department of Microbial Sciences, School of Biosciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
Bioinformatics Facility, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
Sci Rep. 2025 Jul 1;15(1):21746. doi: 10.1038/s41598-025-04038-9.
In 2023, Mycobacterium tuberculosis (Mtb) caused 10.6 million new tuberculosis cases and 1.3 million deaths. The WHO proscribed treatment is not always successful, even when strains were sensitive to the antibiotics.as clinical Mtb populations contain phenotypically tolerant subpopulations, termed persisters. Here a Mtb transposon library was challenged with rifampicin (RIF) and streptomycin (STM) under conditions designed to identify genes that modulate persister frequency. Mutants with reduced survival in RIF were predominantly in genes associated with membrane integrity e.g. arabinogalactan assembly genes cpsA/lytR/Psr, whilst for STM, reduced survival was associated with toxin/antitoxin genes. Some mutations enhanced survival. For RIF these included the methyl citrate cycle genes prpC, prpD and prpR, and the trkA-C K uptake system genes ceoB and Rv2690, and for STM, the resistance associated gene, gidB, and anion-transport genes Rv3679c and Rv3680c. Few genes overlapped the RIF and STM selections, demonstrating that survival mechanisms were antibiotic-specific. Directed deletions of ΔprpD and ΔfadE5 confirmed their predicted enhanced and reduced RIF fitness respectively. The study identified genes that modulate not only persister frequency but also resistance and tolerance, and demonstrates that the mechanisms that produce these phenotypes are diverse and antibiotic-specific.
2023年，结核分枝杆菌（Mtb）导致1060万例新发结核病病例和130万人死亡。即使菌株对抗生素敏感，世界卫生组织规定的治疗方法也并非总是成功的。因为临床Mtb群体中含有表型耐受的亚群，称为持留菌。在此，一个Mtb转座子文库在旨在鉴定调节持留菌频率的基因的条件下，用利福平（RIF）和链霉素（STM）进行了挑战。在RIF中存活率降低的突变体主要存在于与膜完整性相关的基因中，例如阿拉伯半乳聚糖组装基因cpsA/lytR/Psr，而对于STM，存活率降低与毒素/抗毒素基因有关。一些突变提高了存活率。对于RIF，这些基因包括甲基柠檬酸循环基因prpC、prpD和prpR，以及trkA-C钾摄取系统基因ceoB和Rv2690，对于STM，包括抗性相关基因gidB以及阴离子转运基因Rv3679c和Rv3680c。很少有基因在RIF和STM选择中重叠，这表明存活机制是抗生素特异性的。ΔprpD和ΔfadE5的定向缺失分别证实了它们预测的RIF适应性增强和降低。该研究鉴定了不仅调节持留菌频率，还调节抗性和耐受性的基因，并表明产生这些表型的机制是多样的且具有抗生素特异性。
