Swings in gene expression from copiotropic to oligotrophic lifestyle in a facultatively oligotrophic strain of Klebsiella pneumoniae by Whole genome transcriptomic analysis Klebsiella pneumoniae Transcriptome or Gene expression. Klebsiella pneumoniae strain:PB12

Primary objective of this study is to understand the molecular mechanism of oligotrophy. Klebsiella pneumoniae although being a respiratory pathogen, the other sites of infection reported include urinary tract, digestivetract, surgical wound sites etc. The invasiveness of infection takes place generally via contaminated respiratory support equipment and urinary catheters or via other surgical/non surgical equipments. Interestingly, they are omnipresent. The model strain K.pneumoniae PB12, described in this study, isolated from river water possessing oligotrophic characteristics, was resistant to multipleantibiotics as well as resistant to human serum. PB12 can grow in an environment without nutrient-luxury. Whole genome transcriptomic responses of PB 12 to high and low nutrient medium was compared to reveal the regulation of gene expressions inrelation to surface attachment, secretion, iron-chelation and transport, multidrug resistance, and two-component signaling system thatmight influence their adaptability to colonize diverse infection sites. The most highly up-regulated iron-transport genes in oligotrophic condition were afeABCD. Significant downregulation of dhaR, uhpA, evgS, basR, zraR, cusR, barA, sdiA, uvrY, and phoQ genes; and upregulation of six novel genes of two-component signal transduction system (phosho-relay) under oligotrophic condition.