| Summary: | An accurate method that rapidly detects the number of viable but nonculturable (VBNC) <i>Cronobacter sakazakii</i> was developed by combining propidium bromide with quantitative LAMP (PMA-QLAMP). The <i>gyrB</i> gene was the target for primers design. The optimal PMA treatment conditions were determined to eliminate the DNA amplification of 10<sup>8</sup> CFU/mL of dead <i>C. sakazakii</i> without affecting any viable <i>C. sakazakii</i> DNA amplification. Compared with the DNA of 24 strains of common non-<i>C. sakazakii</i> strains found in raw milk and dairy products, the DNA of only six <i>C. sakazakii</i> strains from different sources was amplified using PMA-QLAMP. The ability of PMA-QLAMP to quantitatively detect non-dead <i>C. sakazakii</i> in a 10% powdered infant formula (PIF) solution was limited to 4.3 × 10<sup>2</sup> CFU/mL and above concentrations. Pasteurizing 10<sup>6</sup> CFU/mL viable <i>C. sakazakii</i> yielded the maximum ratio of the VBNC <i>C. sakazakii</i>. PMA-QLAMP-based detection indicated that, although approximately 13% of 60 samples were positive for viable <i>C. sakazakii,</i> the <i>C. sakazakii</i> titers in these positive samples were low, and none entered the VBNC state under pasteurization. PMA-QLAMP showed potential as a specific and reliable method for detecting VBNC-<i>C. sakazakii</i> in pasteurized raw milk, thereby providing an early warning system that indicates potential contamination of PIF.
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