α-Toxin Effect on Behavior.

Polymicrobial infections are more challenging to treat and are recognized as responsible for significant morbidity and mortality. It has been demonstrated that multiple Gram-negative organisms take advantage of the effects of α-toxin on mucosal host defense, resulting in proliferation and dissemination of the co-infecting pathogens. Through phenotypic approaches, we observed a decrease in the motility of A118 after exposure to cell-free conditioned media (CFCM) of strains, USA300 and LS1. However, the motility of A118 was increased after exposure to the CFCM of strains USA300 Δ and LSI Δ. Hemolytic activity was seen in A118, in the presence of CFCM of LS1. Further, A118 showed an increase in biofilm formation and antibiotic resistance to tetracycline, in the presence of CFCM of USA300. Transcriptomic analysis of A118, with the addition of CFCM from USA300, was carried out to study response to released molecules. The RNA-seq data analysis showed a total of 463 differentially expressed genes, associated with a wide variety of functions, such as biofilm formation, virulence, and antibiotic susceptibility, among others. The present results showed that can sense and respond to molecules secreted by . These findings demonstrate that may perceive and respond to changes in its environment; specifically, when in the presence of CFCM from .