The study identifies that upregulated expression of genes involved in DNA replication and repair, such as recA, uvrD, xseB, ssb, mutM, and crc, contributes to levofloxacin heteroresistance in Pseudomonas aeruginosa strains PAS71 and PAS81. Additionally, the expression of genes related to bacterial secretion systems, such as gspD, vgrG1, hcpC, clpV1, and ppkA, is increased in PAS81 under LVX stress.