Analysis of autofluorescence and expression of key genes pvdD and pvdS in response to environmental stress in human pathogen Pseudomonas aeruginosa

Aims The study investigated the changes in fluorescence of P. aeruginosa under different temperatures, pH values, and osmotic pressures, and analyzed the expression levels of the pigment synthesis enzyme gene (pvdD) and the pigment synthesis σ factor (pvdS) genes in different environments.Materials and methods Using the Image J software, the fluorescence intensity changes of P. aeruginosa colonies under different conditions (including temperature, pH value, and osmotic pressure) were studied and analyzed. The RT-qPCR technique was employed to detect the expression levels of key enzyme genes related to the fluorescence intensity of P. aeruginosa, specifically including the pvdD and pvdS genes.Results The bacterial fluorescence intensity was significantly influenced by the culture environment, lower temperature, acidity, and high osmolality environments all inhibit fluorescence production by P. aeruginosa. Moreover, there was a strong correlation between the fluorescence intensity of the bacteria and the expression level of key genes (pvdD / pvdS).Conclusions This study reveals the potential influence of the in vitro environment on the spontaneous fluorescence of bacteria and provides a mechanistic basis for understanding the potential changes in fluorescence signals under environmental stress conditions.