Gastric Infection by <i>Cronobacter sakazakii</i> : An <i>In Vitro</i> Insight

Cronobacter sakazakii , an opportunistic foodborne pathogen associated with powdered infant formula, causes severe neonatal infections, yet its interaction with gastric epithelial cells remains poorly characterized. Here, we conducted a preliminary in vitro study to evaluate early host–pathogen responses of C. sakazakii in AGS gastric epithelial cells. AGS cells were exposed to C. sakazakii ATCC 29544 at a multiplicity of infection of 100 for 2 h, and cytotoxicity and transcriptional responses were assessed by viability assay, gentamicin protection assay, and reverse transcription-quantitative polymerase chain reaction. Infection significantly reduced AGS cell viability and increased expression of bacterial virulence-associated genes ( ompA and hfq ) and host inflammatory genes ( IL-8 and NF-ƙB ) compared with mock-infected controls ( p &lt; 0.001). Gentamicin-protected recovery was consistent with bacterial entry into AGS cells, although confirmatory imaging-based analyses were not performed. These findings indicate that C. sakazakii (ATCC 29544) can elicit early cytotoxic and pro-inflammatory responses in AGS gastric epithelial cells under in vitro conditions, supporting the need for confirmatory studies in more physiologically relevant gastric study models.