An investigation of the role of FTL_1711 in erythrocyte invasion by Francisella tularensis.

Francisella tularensis is a pathogenic intracellular bacterium and the causative agent of the zoonotic disease tularemia. The CDC classifies F. tularensis as a Tier 1 select agent due to its potential for misuse as a biological weapon, given its low infectious dose and capacity to produce a fatal pneumonic infection. Furthermore, naturally occurring subspecies of F. tularensis are known to cause numerous human infections through exposure to various blood-sucking arthropods and contaminated animal hosts. Prior research conducted in our laboratory has demonstrated that FTL_1199 serves as a putative transcriptional regulator necessary for erythrocyte invasion. Comprehensive transcriptome analysis has further elucidated that FTL_1711 is an open reading frame regulated by FTL_1199. We hypothesize that FTL_1711 plays a role in erythrocyte invasion by F. tularensis. In pursuit of this objective, we will generate a deletion mutant of FTL_1711. During this process, DNA flanking FTL_1711 will be cloned into the unstable plasmid, pJH1. After integration into the F. tularensis chromosome by homologous recombination, the merodiploid will be resolved by introducing pGUTS. This plasmid encodes an enzyme that will force a double-stranded break near the target gene, facilitating the deletion of FTL_1711. Upon confirmation of this mutagenesis, we will evaluate the ability of the mutant strain to invade erythrocytes, thereby revealing the significance of FTL_1711 in red blood cell invasion.