Mutations in the hemolytic-phospholipase C operon result in decreased virulence of Pseudomonas aeruginosa PAO1 grown under phosphate-limiting conditions

• DOI: 10.1128/iai.57.5.1369-1373.1989
• Publication Date: 2020-01-03T13:19:32Z
• Authors: R M Ostroff; B Wretlind; M L Vasil
• Keywords: 0301 basic medicine; DNA Mutational Analysis; Restriction Mapping; Phosphates; Blotting, Southern; Hemolysin Proteins; Mice; 03 medical and health sciences; Gene Expression Regulation; Type C Phospholipases; Operon; Pseudomonas aeruginosa; Animals; Pseudomonas Infections; Cloning, Molecular; Burns

The phospholipase C (PLC) operon of Pseudomonas aeruginosa consists plcS, which encodes a heat-labile secreted hemolysin, and two in-phase, overlapping genes, plcR1 plcR2, may encode Pi-regulatory genes. A 2.8-kilobase-pair deletion mutation in this was constructed, tetracycline resistance (Tcr) cartridge replaced the deleted sequences. mutant strain PAO1 obtained through recombination between flanking regions mutated cloned PLC homologous chromosomal regions. its replacement by Tcr confirmed Southern hybridization. strain, SR, is nonhemolytic. However, it retains activity when measured on synthetic substrate. second R, contains plcR This more hemolytic produces enzymatic than PAO1. virulence both these mutants compared with that mouse burn model infection. When mice were infected cultures grown high-Pi medium, there 10-fold increase 50% lethal dose In contrast, inoculum originated from low-Pi cultures, 200- to 10,000-fold over