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:We performed RNAseq for gene expression analysis for six strains of Acinetobacter Baumannii isolated from blood samples (defined as strains 1, 2, 3, 4 and 6) of patients hospitalized at the University Hospital \\"San Giovanni di Dio e Ruggi d'Aragona\\" (Salerno, Italy)
Project description:Two Acinetobacter baumannii strains with low susceptibility to fosmidomycin and two reference with high susceptibility to fosmidomycin were DNA-sequenced to investigate the genomic determinants of fosmidomycin resistance.
Project description:We worked with microarrys analysis in presence of 3-oxo-C12-HSL molecule to analyze the profile of the genes implicated in the Quorum Quenching network in A.baumannii clinical strains. Interestingly, only 13 genes were overexpressed under 3-oxo-C12-HSL molecule being the most level a gene which encodes an Alpha/beta hydrolase enzyme (5.01). The 46.15% of the genes overexpressed were implicated in the synthesis of the acyl-homoserine lactones (AHLs).
Project description:Acinetobacter baumannii A1S_1874 gene encodes as a LysR-type transcriptional regulator. LysR family regulators known to regulate biofilm formation, antibiotic resistance, and the expression of diverse genes in other Gram-negative bacteria. However, A1S-1874 has never been characterized in Acinetobacter baumannii, and the studies about the regulon of A1S-1874 are not discovered. In this study we revealed that A1S_1874 differentially regulates at least 302 genes including the csu pilus operon, N-acylhomoserine lactone synthese gene, A1S_0112-A1S_0118 operon, type 1v secretion system related genes that are involved in biofilm formation, surface motility, adherence, quorum sensing and virulence. Overall, our data suggests that A1S-1874 is a key regulator of Acinetobacter baumannii biofilm formation and gene expression.
Project description:We report the transcriptional expression from wild type, a ponA mutant, and lipooligosaccharide-deficient A. baumannii in order to understand the cellular changes after inactivation of lipid A biosynthesis. Among all strains, genes in the Localization Of Lipoprotein (Lol) transport pathway were upregulated. This study provides a framework to understand how some Acinetobacter baumannii strains can survive without lipid A and lipopolysaccharide/lipooligosaccharide.
Project description:We analyzed the extracellular proteome of colistin-resistant Korean Acinetobacter baumannii (KAB) strains to identify proteome profiles that can be used to characterize extensively drug-resistant KAB strains.
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.
