Cellular Interaction Potential of Clinical Corynebacterium Striatum Isolates With Human Pneumocytes

<title>Abstract</title> <p> Healthcare-Associated Infections (HAIs) represent a major epidemiological concern in both public health and hospital care settings. Currently, several studies have associated different <italic>Corynebacterium</italic> species with these infections, particularly among patients admitted to intensive care units (ICUs) and those using invasive medical devices, with <italic>Corynebacterium striatum</italic> being the species most frequently reported. This study aimed to elucidate the interaction of <italic>C. striatum</italic> strains isolated from severe invasive infections in patients hospitalized at a tertiary care hospital in the city of Rio de Janeiro, Brazil. Bacterial isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Cell interaction profiles were evaluated using bacterial adherence, invasion, intracellular internalization, and viable cell quantification assays. The results demonstrated that all isolates exhibited distinct patterns of cellular adherence. Furthermore, all tested isolates were able to survive in the presence of A549 human pneumocytes and persist within the intracellular environment for up to 24 hours, although with varying intensities. Among them, <italic>C. striatum</italic> strains 1961BR-RJ and 2351BR-RJ displayed the most prolonged interaction profile. Overall, the findings of this study expand the current knowledge regarding the pathogenicity of <italic>C. striatum</italic> by demonstrating that these clinical isolates are capable of adhering to and surviving within human pneumocytes. </p>