Modulatory effects of sub-MIC concentrations silver nanoparticles on virulence factor gene expression in Staphylococcus aureus

IF 1 Q4 GENETICS & HEREDITY

Gene Reports Pub Date : 2024-09-16 DOI:10.1016/j.genrep.2024.102034

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引用次数: 0

Abstract

Background

Silver nanoparticles (AgNPs) exhibit a dose-dependent anti-bacterial effect, and it was aimed in this study to investigate the impact of sub-minimum inhibitory concentration (MIC) doses of AgNPs on the expression of virulence genes in Staphylococcus aureus (S. aureus).

Methods

Minimum inhibitory concentration (MIC) values for AgNPs were determined for 183 S. aureus isolates. Gene expression was assessed in 14 isolates with sea and seb genes treated with AgNPs at a sub-MIC dose of 1 μg/ml. Accordingly, these strains were exposed to 1 μg/ml doses of AgNPs, and gene expression levels of sea, seb, and agr were assessed using quantitative RT-PCR after 4- and 12-hour post-AgNPs inoculation at 37 °C. The impact of AgNPs on the virulence factors of S. aureus was investigated over different time points, focusing on methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates.

Results

Analysis revealed significant reductions in gene expression levels of seb and agr after 4 h post-AgNPs treatment in the MSSA group (p < 0.05), with further decreases observed at 12 h for sea, seb, and agr genes (p < 0.0001). MRSA isolates exhibited significant declines in sea and agr gene expression levels at both time points (p < 0.0001). However, no significant changes were observed in seb gene expression among MRSA isolates. Fold-change analysis indicated time-dependent effects of AgNP treatment on gene expression, highlighting substantial alterations in gene expression levels over time, particularly in seb and agr genes.

Conclusion

These results show that sub-MIC levels of AgNPs greatly decrease the gene expression of important virulence factors in MSSA and MRSA strains, indicating their promise as treatments for S. aureus infections, particularly at 12 h post-treatment. The differential response between MSSA and MRSA isolates highlights the importance of strain variation in antimicrobial strategies.

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亚中微子浓度银纳米粒子对金黄色葡萄球菌毒力因子基因表达的调节作用

背景银纳米粒子（AgNPs）具有剂量依赖性抗菌效果，本研究旨在探讨次最低抑菌浓度（MIC）剂量的 AgNPs 对金黄色葡萄球菌（S. aureus）毒力基因表达的影响。方法确定了 183 个金黄色葡萄球菌分离物的 AgNPs 最低抑菌浓度（MIC）值。对 14 个带有 sea 和 seb 基因的分离菌株进行了基因表达评估，AgNPs 的亚 MIC 剂量为 1 μg/ml。因此，将这些菌株暴露于 1 μg/ml 剂量的 AgNPs 中，在 37 °C 下接种 AgNPs 4 小时和 12 小时后，使用定量 RT-PCR 对 sea、seb 和 agr 的基因表达水平进行评估。研究了 AgNPs 在不同时间点对金黄色葡萄球菌毒力因子的影响，重点是甲氧西林敏感金黄色葡萄球菌（MSSA）和甲氧西林耐药金黄色葡萄球菌（MRSA）分离物。结果分析表明，AgNPs 处理后 4 小时，MSSA 组的 seb 和 agr 基因表达水平明显下降（p < 0.05），12 小时后，sea、seb 和 agr 基因表达水平进一步下降（p < 0.0001）。MRSA 分离物在两个时间点的 sea 和 agr 基因表达水平都出现了显著下降（p < 0.0001）。然而，在 MRSA 分离物中未观察到 seb 基因表达的明显变化。折叠变化分析表明，AgNP 处理对基因表达的影响具有时间依赖性，突显出基因表达水平随时间的推移发生了重大变化，尤其是 seb 和 agr 基因。MSSA 和 MRSA 分离物之间的不同反应凸显了菌株变异在抗菌策略中的重要性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Gene Reports Biochemistry, Genetics and Molecular Biology-Genetics

CiteScore

3.30

自引率

7.70%

发文量

246

审稿时长

49 days

期刊介绍： Gene Reports publishes papers that focus on the regulation, expression, function and evolution of genes in all biological contexts, including all prokaryotic and eukaryotic organisms, as well as viruses. Gene Reports strives to be a very diverse journal and topics in all fields will be considered for publication. Although not limited to the following, some general topics include: DNA Organization, Replication & Evolution -Focus on genomic DNA (chromosomal organization, comparative genomics, DNA replication, DNA repair, mobile DNA, mitochondrial DNA, chloroplast DNA). Expression & Function - Focus on functional RNAs (microRNAs, tRNAs, rRNAs, mRNA splicing, alternative polyadenylation) Regulation - Focus on processes that mediate gene-read out (epigenetics, chromatin, histone code, transcription, translation, protein degradation). Cell Signaling - Focus on mechanisms that control information flow into the nucleus to control gene expression (kinase and phosphatase pathways controlled by extra-cellular ligands, Wnt, Notch, TGFbeta/BMPs, FGFs, IGFs etc.) Profiling of gene expression and genetic variation - Focus on high throughput approaches (e.g., DeepSeq, ChIP-Seq, Affymetrix microarrays, proteomics) that define gene regulatory circuitry, molecular pathways and protein/protein networks. Genetics - Focus on development in model organisms (e.g., mouse, frog, fruit fly, worm), human genetic variation, population genetics, as well as agricultural and veterinary genetics. Molecular Pathology & Regenerative Medicine - Focus on the deregulation of molecular processes in human diseases and mechanisms supporting regeneration of tissues through pluripotent or multipotent stem cells.