Light modulates important pathogenic determinants and virulence in Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus ESKAPE pathogens

TUTTOBENE, MARISEL ROMINA; PEREZ JORGELINA; PAVESI, ESTEFANIA; BIANCOTTI, DAIANA; CRIBB, PAMELA; ALTILIO, MATÍAS; GRAMAJO, HUGO; RAMÍREZ, MARÍA SOLEDAD; DIACOVICH, LAUTARO; MUSSI, MARÍA ALEJANDRA

JOURNAL OF BACTERIOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2021

0021-9193

Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that Staphylococcus aureus, Acinetobacter baumannii and Pseudomonas aeruginosa, (ESKAPE) priority pathogens, which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens, light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility, and growth under iron-deprived conditions are modulated by light in S. aureus. Light also regulates persistence, metabolism, and the ability to kill competitors in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, although the response isnot the same in the different species; virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) are involved in virulence modulation by light in A. baumannii. Overall, this fundamental knowledge highlights the potential use of light to control pathogen virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration.