Development of a Visual Assay for Detection of Viable Cronobacter sakazakii Using RT-PSR and Hydroxynaphthol Blue Indicator

<i>Cronobacter sakazakii</i> is a foodborne pathogen in powdered infant formula, which poses a significant risk to susceptible populations such as infants and the elderly. This study aims to develop a visual detection method for viable <i>C. sakazakii</i> using the reverse transcription-polymerase spiral reaction and hydroxynaphthol blue indicator. Under the optimized conditions, the detection process could be completed within 55 min with low equipment dependence. It was evaluated to have high specificity and sensitivity with the detection limit low to 1.2 × 10¹ CFU/mL. The assay also showed 100% accuracy in artificially contaminated samples.