Appreciating that cytotoxin-producing K. oxytoca is the etiologic agent of antibiotic-associated hemorrhagic colitis (AAHC) [29–31], we further evaluated the toxigenic properties of an isolate from the index NEC case using bacterial culture supernatants in cleaved caspase-3 and enterocyte apoptosis assays. This evidence concerns the gene CASP3 and necrotizing enterocolitis.