DYNAMIC REGULATION OF EXTRACELLULAR ADENOSINE TRIPHOSPHATE IN Serratia marcescens.

TUTTOBENE, MARISEL R.; SCHACHTER, J; ALVAREZ, CL; GARCÍA VÉSCOVI, E.; SCHWARZBAUM, PS

Córdoba

Congreso; XVII Congreso Argentino de Microbiología General; 2022

SAMIGE

Serratia marcescens is a highly ubiquitous Gram-negative enteric bacterium that can be isolated frommost abiotic environmental sources, as well as from plants, insects, and nematodes. In the clinicalsetting, S. marcescens is the cause of urinary tract, respiratory, wound, ocular, cardiac, bloodstream,and surgical infections, mostly affecting intensive care unit patients. In 2017, the World HealthOrganization declared S. marcescens, along with other Enterobacteriaceae, a priority research targetto develop alternative antimicrobial strategies given the high frequency of clinical isolates resistant tocarbapenems. In our previous work, we have demonstrated that S. marcescens is able to beinternalized by nonphagocytic cells. We showed that, once inside the cell, Serratia is able to inhabitand proliferate inside large membrane-bound compartments. These vesicles exhibit autophagic-likefeatures, as they acquire markers typically recruited throughout the progression of autophagosomebiogenesis in the antibacterial process. Serratia maneuvers the normal progression of host cell traffic,and this contributes to explaining the potential for Serratia to establish infection and persist in thehost. In addition, ShlA, a pore-forming toxin, is responsible for inducing autophagy in nonphagocyticCHO epithelial cells, previous to the internalization process. In this study we seek to analyze the roleof extracellular ATP (eATP), on Serratia dependent autophagy of CHO cells, a mammalian cell model.The CHO cell possesses two families of nucleotide receptors, metabotropic (P2Y) and ionotropic (P2X),with various subtypes displaying high affinity for eATP. Preincubation of CHO cells with an excess of