Acinetobacter baumannii Fatty Acid Desaturases Facilitate Survival in Distinct Environments

RNA sequencing transcriptomics was performed on a highly multidrug resistant A. baumannii strain belonging to international clone I, AB5075_UW and a transposon insertion inactivated mutant of ABUW_1103 (DesT1), which encodes for a TetR family regulator. Transcriptomics revealed that DesT1 might function as a global regulator controlling expression of various genes involved in fatty acid metabolism and transport and a range of outer membrane proteins. Genes encoding acyl-CoA desaturase and ferredoxin reductase were found to be significantly upregulated when DesT1 regulator was inactivated. Aerobic desaturases are known to play an important role in maintaining membrane homeostasis. Global transcriptomic profiles of the regulator mutant and the parental A. baumannii strain were compared. The parental and mutant cells were grown to mid exponential phase at 37°C, with shaking. Cell pellets were harvested and the total RNA was extracted from three biological replicates. Ribosomal RNA was depleted using Ribozero magnetic kit (Bacteria) (Illumina, Inc., USA) and the cDNA library was generated using Truseq stranded RNA preparation kit (Illumina, Inc., USA). RNA libraries were prepared for sequencing using standard Illumina protocols. The processed data columns correspond to the samples as below: Parental AB5075_Rep1 = WT1.rpkm_1 Parental AB5075_Rep2 = WT2.rpkm_1 Parental AB5075_Rep3 = WT3.rpkm_1 ABUW_1103-112:T26_Rep1 = M1.rpkm_1 ABUW_1103-112:T26_Rep2 = M2.rpkm_1 ABUW_1103-112:T26_Rep3 = M3.rpkm_1