Project description:The study aims to identify genes associated with Linezolid resistance. Linezolid resistant strains were compared to a Linezolid sensitive reference strain in the presence of linezolid and absence of linezolid (mock).
Project description:In this study, we investigated the role of efflux pump genes in linezolid resistance. M. tuberculosis H37Rv cultures were exposed to sub-inhibitory concentrations of linezolid (¼ MIC) for 24 hours, and transcriptomic analysis was performed to identify upregulated genes. Of the 120 genes involved in cell wall processes, 9/120 (7.5%) were efflux pump genes, primarily belonging to the ATP-binding cassette (ABC), major facilitator superfamily (MFS), resistance nodulation division (RND), and small multidrug resistance (SMR) families. qRT-PCR, performed at 1/2, 1/4 and 1/8 MIC of linezolid, confirmed the RNA-seq results, showing that 8/9 (88.88%) of the efflux pump genes were upregulated at 1/8 MIC of linezolid, indicating that this concentration is optimal for studying efflux pump activity. These findings not only identify 1/8 MIC as optimum concentration for efflux pump studies after linezolid exposure, they also highlight the significant role of efflux pumps in linezolid resistance, providing potential targets for further research on efflux pumps in clinical isolates of M. tuberculosis.
Project description:Background: Bacterial small regulatory RNAs (sRNAs) have been implicated in important processes including antimicrobial stress response. However, the full extent of sRNA involvement in antimicrobial response in Staphylococcus aureus, an important pathogen, is incompletely understood. We investigated the transcriptional profiles of a linezolid-resistant, livestock-associated methicillin-resistant S. aureus (LA-MRSA) strain ST398 under conditions of linezolid stress. Methods: Cells in mid-exponential growth were subjected to low (8 µg/ml) and high (16 µg/ml) dose linezolid treatments followed by high throughput RNA sequencing. Read mapping and differential expression analysis were performed followed by detection and interrogation of various sRNA and mRNA transcripts. Results: Twenty-three putative regulatory RNA transcripts were expressed under low- and high-dose exposure conditions. Cis-acting regulatory elements, mainly targeting ribosomal biogenesis constituted the majority of transcriptional response with limited antisense and small RNA expression. Conclusions: This is the first study to investigate linezolid-responsive small RNA transcription in LA-MRSA strain ST398 and the first to query regulatory RNAs on a background of linezolid resistance. It provides preliminary insights and a basis for interrogating small RNAs in other strains in the quest to understand drug-responsive regulatory RNAs and identify potential anti-staphylococcal therapeutic candidates.
Project description:Transcriptional profiling of Mycobacterium tuberculosis H37Rv strains comparing control DMSO treated strains with Linezolid treated strains. Goal was to determine the effects of Linezolid against Mycobacterium tuberculosis H37Rv strains. Two-condition experiment,control DMSO treated strains vs. Linezolid treated strains. Biological replicates: 2 control replicates, 2 Linezolid replicates.
