SPD_1629是一种尿嘧啶转运蛋白,对肺炎球菌在体内的适应性和发病机制至关重要。

IF 3.5 3区 医学 Q3 IMMUNOLOGY
Microbial pathogenesis Pub Date : 2025-11-01 Epub Date: 2025-08-06 DOI:10.1016/j.micpath.2025.107974
Ajay Kumar, Shabnam Shabnam, Sachin Kushwaha, Devinder Sehgal
{"title":"SPD_1629是一种尿嘧啶转运蛋白,对肺炎球菌在体内的适应性和发病机制至关重要。","authors":"Ajay Kumar, Shabnam Shabnam, Sachin Kushwaha, Devinder Sehgal","doi":"10.1016/j.micpath.2025.107974","DOIUrl":null,"url":null,"abstract":"<p><p>Streptococcus pneumoniae (pneumococcus), a major human pathogen, causes pneumonia, bacteraemia and meningitis. Unlike free-living bacteria such as Escherichia coli, pathogenic bacteria like S. pneumoniae possess incomplete metabolic pathways and depend on host-derived nutrients. While nucleotide metabolism is essential for bacterial proliferation, how S. pneumoniae takes up uracil is still not well understood. Identifying uracil transporters is important, as they may serve as targets for novel antimicrobial strategies. In this study, we functionally characterized a uracil transporter using the toxic uracil analog 5-fluorouracil (5-FU). In vitro assays showed dose-dependent inhibition of bacterial growth by 5-FU, which was reversed by excess uracil, suggesting the presence of a specific uracil transporter. Bioinformatic analysis identified SPD_0267, SPD_1141 and SPD_1629 as candidates. A mutant lacking SPD_1629 (D39Δspd_1629) showed partial resistance to 5-FU, while deletion of SPD_0267 or SPD_1141 had no effect. The growth of the triple mutant D39Δspd_0267Δspd_1141Δspd_1629 mirrored that of D39Δspd_1629. Unlike in rich medium, D39Δspd_1629 mutant failed to grow in uracil-sufficient chemically defined medium. Radiolabeled [<sup>3</sup>H]-uracil uptake assays validated the transporter's specificity for uracil. In vivo, D39Δspd_1629 displayed significantly reduced bacterial loads in the lungs, blood and spleen of infected mice. Competitive index assays further revealed a severe fitness defect relative to the wildtype. spd_1629 deletion also reduced capsular polysaccharide levels, correlating with attenuated virulence in a mouse model of pneumonia and sepsis. These findings establish SPD_1629 as the principal uracil transporter in S. pneumoniae, and highlight its critical role in virulence and in vivo fitness.</p>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":" ","pages":"107974"},"PeriodicalIF":3.5000,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"SPD_1629 is a uracil transporter and is crucial for pneumococcal fitness and pathogenesis in vivo.\",\"authors\":\"Ajay Kumar, Shabnam Shabnam, Sachin Kushwaha, Devinder Sehgal\",\"doi\":\"10.1016/j.micpath.2025.107974\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Streptococcus pneumoniae (pneumococcus), a major human pathogen, causes pneumonia, bacteraemia and meningitis. Unlike free-living bacteria such as Escherichia coli, pathogenic bacteria like S. pneumoniae possess incomplete metabolic pathways and depend on host-derived nutrients. While nucleotide metabolism is essential for bacterial proliferation, how S. pneumoniae takes up uracil is still not well understood. Identifying uracil transporters is important, as they may serve as targets for novel antimicrobial strategies. In this study, we functionally characterized a uracil transporter using the toxic uracil analog 5-fluorouracil (5-FU). In vitro assays showed dose-dependent inhibition of bacterial growth by 5-FU, which was reversed by excess uracil, suggesting the presence of a specific uracil transporter. Bioinformatic analysis identified SPD_0267, SPD_1141 and SPD_1629 as candidates. A mutant lacking SPD_1629 (D39Δspd_1629) showed partial resistance to 5-FU, while deletion of SPD_0267 or SPD_1141 had no effect. The growth of the triple mutant D39Δspd_0267Δspd_1141Δspd_1629 mirrored that of D39Δspd_1629. Unlike in rich medium, D39Δspd_1629 mutant failed to grow in uracil-sufficient chemically defined medium. Radiolabeled [<sup>3</sup>H]-uracil uptake assays validated the transporter's specificity for uracil. In vivo, D39Δspd_1629 displayed significantly reduced bacterial loads in the lungs, blood and spleen of infected mice. Competitive index assays further revealed a severe fitness defect relative to the wildtype. spd_1629 deletion also reduced capsular polysaccharide levels, correlating with attenuated virulence in a mouse model of pneumonia and sepsis. These findings establish SPD_1629 as the principal uracil transporter in S. pneumoniae, and highlight its critical role in virulence and in vivo fitness.</p>\",\"PeriodicalId\":18599,\"journal\":{\"name\":\"Microbial pathogenesis\",\"volume\":\" \",\"pages\":\"107974\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2025-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microbial pathogenesis\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1016/j.micpath.2025.107974\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/8/6 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"IMMUNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microbial pathogenesis","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.micpath.2025.107974","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/8/6 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0

摘要

肺炎链球菌(肺炎球菌)是一种主要的人类病原体,可引起肺炎、菌血症和脑膜炎。与大肠杆菌等自由生活的细菌不同,肺炎链球菌等致病菌具有不完整的代谢途径,并依赖于宿主来源的营养物质。虽然核苷酸代谢对细菌增殖至关重要,但肺炎链球菌如何吸收尿嘧啶仍未得到很好的理解。确定尿嘧啶转运体是很重要的,因为它们可以作为新的抗菌策略的靶点。在这项研究中,我们使用有毒的尿嘧啶类似物5-氟尿嘧啶(5-FU)对尿嘧啶转运体进行了功能表征。体外实验显示5-FU对细菌生长的抑制呈剂量依赖性,过量的尿嘧啶可以逆转这种抑制,这表明存在一种特定的尿嘧啶转运体。生物信息学分析鉴定出候选候选SPD_0267、SPD_1141和SPD_1629。缺失SPD_1629的突变体(D39Δspd_1629)对5-FU表现出部分抗性,而缺失SPD_0267或SPD_1141则没有影响。三重突变体D39Δspd_0267Δspd_1141Δspd_1629的生长反映了D39Δspd_1629的生长。不像在富培养基中,D39Δspd_1629突变体不能在尿嘧啶充足的化学定义培养基中生长。放射性标记[3H]-尿嘧啶摄取试验证实了转运体对尿嘧啶的特异性。在体内,D39Δspd_1629在感染小鼠的肺、血液和脾脏中显示出显著减少的细菌负荷。竞争指数分析进一步揭示了相对于野生型的严重适应度缺陷。Spd_1629缺失也降低了荚膜多糖水平,与肺炎和脓毒症小鼠模型的毒性减弱有关。这些发现证实了SPD_1629是肺炎链球菌的主要尿嘧啶转运蛋白,并强调了其在毒力和体内适应性中的关键作用。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
SPD_1629 is a uracil transporter and is crucial for pneumococcal fitness and pathogenesis in vivo.

Streptococcus pneumoniae (pneumococcus), a major human pathogen, causes pneumonia, bacteraemia and meningitis. Unlike free-living bacteria such as Escherichia coli, pathogenic bacteria like S. pneumoniae possess incomplete metabolic pathways and depend on host-derived nutrients. While nucleotide metabolism is essential for bacterial proliferation, how S. pneumoniae takes up uracil is still not well understood. Identifying uracil transporters is important, as they may serve as targets for novel antimicrobial strategies. In this study, we functionally characterized a uracil transporter using the toxic uracil analog 5-fluorouracil (5-FU). In vitro assays showed dose-dependent inhibition of bacterial growth by 5-FU, which was reversed by excess uracil, suggesting the presence of a specific uracil transporter. Bioinformatic analysis identified SPD_0267, SPD_1141 and SPD_1629 as candidates. A mutant lacking SPD_1629 (D39Δspd_1629) showed partial resistance to 5-FU, while deletion of SPD_0267 or SPD_1141 had no effect. The growth of the triple mutant D39Δspd_0267Δspd_1141Δspd_1629 mirrored that of D39Δspd_1629. Unlike in rich medium, D39Δspd_1629 mutant failed to grow in uracil-sufficient chemically defined medium. Radiolabeled [3H]-uracil uptake assays validated the transporter's specificity for uracil. In vivo, D39Δspd_1629 displayed significantly reduced bacterial loads in the lungs, blood and spleen of infected mice. Competitive index assays further revealed a severe fitness defect relative to the wildtype. spd_1629 deletion also reduced capsular polysaccharide levels, correlating with attenuated virulence in a mouse model of pneumonia and sepsis. These findings establish SPD_1629 as the principal uracil transporter in S. pneumoniae, and highlight its critical role in virulence and in vivo fitness.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
Microbial pathogenesis
Microbial pathogenesis 医学-免疫学
CiteScore
7.40
自引率
2.60%
发文量
472
审稿时长
56 days
期刊介绍: Microbial Pathogenesis publishes original contributions and reviews about the molecular and cellular mechanisms of infectious diseases. It covers microbiology, host-pathogen interaction and immunology related to infectious agents, including bacteria, fungi, viruses and protozoa. It also accepts papers in the field of clinical microbiology, with the exception of case reports. Research Areas Include: -Pathogenesis -Virulence factors -Host susceptibility or resistance -Immune mechanisms -Identification, cloning and sequencing of relevant genes -Genetic studies -Viruses, prokaryotic organisms and protozoa -Microbiota -Systems biology related to infectious diseases -Targets for vaccine design (pre-clinical studies)
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信