Project description:The goal of this RNA-Seq study was to determine Acinetobacter baumannii's transcriptiional response to sub-MIC concentrations of benzalkonium chloride in Acinetobacter baumannii. This RNA-seq data was then utilized to aide in the determination of the sub-MIC mechanism of action for benzalkonium chloride.
Project description:The goal of this Tn-Seq study was to determine important determinants of Acinetobacter baumannii tolerance of sub-MIC concentrations of benzalkonium chloride. This Tn-seq data was then utilized to aide in the determination of the sub-MIC mechanism of action for benzalkonium chloride.
Project description:A major reservoir for spread of the emerging pathogen Acinetobacter baumannii is hopsital surfaces, where bacteria persist in a desiccated state. To identify gene products influencing desiccation survival, a transposon sequencing (Tn-seq) screen was performed. Using this approach, we identified genes both positively and negatively impacting the desiccation tolerance of A. baumannii.
Project description:In recent years, the Gram-negative bacterium Acinetobacter baumannii has garnered considerable attention for its unprecedented capacity to rapidly develop resistance to antibacterial therapeutics. This is coupled with the seemingly epidemic emergence of new hyper-virulent strains. Although strain-specific differences for A. baumannii isolates have been well described, these studies have primarily focused on proteinaceous factors. At present, only limited publications have investigated the presence and role of small regulatory RNA (sRNA) transcripts. Herein, we perform such an analysis, describing the RNA-seq-based identification of 78 A. baumannii sRNAs in the AB5075 background. Together with six previously identified elements, we include each of these in a new genome annotation file, which will serve as a tool to investigate regulatory events in this organism. Our work reveals that the sRNAs display high expression, accounting for >50 % of the 20 most strongly expressed genes. Through conservation analysis we identified six classes of similar sRNAs, with one found to be particularly abundant and homologous to regulatory, C4 antisense RNAs found in bacteriophages. These elements appear to be processed from larger transcripts in an analogous manner to the phage C4 molecule and are putatively controlled by two further sRNAs that are strongly antisense to them. Collectively, this study offers a detailed view of the sRNA content of A. baumannii, exposing sequence and structural conservation amongst these elements, and provides novel insight into the potential evolution, and role, of these understudied regulatory molecules. This study is based on the annotation of novel sRNAs on basis of an Acinetobacter baumannii RNA sequencing dataset. Each sample was generated by pooling three independent biological replicate RNA preps
Project description:Acinetobacter baumannii is a Gram-negative pathogen that has emerged as one of the most troublesome pathogens for health care institutions globally. Bacterial quorum sensing (QS) is a process of cell-to-cell communication that relies on the production, secretion and detection of autoinducer (AI) signals to share information about cell density and regulate gene expression accordingly. The molecular and genetic basis of Acinetobacter baumannii virulence remains poorly understood. Therefore, the contribution of the abaI/abaR quorum sensing system to growth characteristics, morphology, biofilm formation, resistance, motility and virulence of Acinetobacter baumannii was studied in detail. RNA-seq analysis indicated that genes involved in various aspects of energy production and conversion, Valine, leucine and isoleucine degradation and lipid transport and metabolism are associated with bacterial pathogenicity. Our work provides a new insight into abaI/abaR quorum sensing system effects pathogenicity in A. baumannii. We propose that targeting the AHL synthase enzyme abaI could provide an effective strategy for attenuating virulence. On the contrary, interdicting the autoinducer synthase–receptor abaR elicits unpredictable consequences, which may lead to enhanced bacterial virulence.
Project description:RNA sequencing was carried out by ARK genomics, Edinburgh on an Illumina HiSeq platform to compare gene expression in Acinetobacter baumannii strain AYE and an adeRS deletion mutant in this strain.
