Brauge Thomas, Chalivat Eglantine, Leleu Guylaine, Colas Anthony, Midelet Graziella
Sanitary Safety of Aquatic Origin Food Unit (SANAQUA), Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 62200 Boulogne-sur-Mer, France.
Member of the EU Reference Laboratory for Listeria monocytogenes, Laboratory for Food Safety, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 94700 Maisons-Alfort, France.
FEMS Microbiol Lett. 2025 Jan 10;372. doi: 10.1093/femsle/fnaf048.
This study assessed the impact of six disinfectant-neutralizing buffers on Listeria monocytogenes adhering to stainless steel surfaces treated with quaternary ammonium or hydrogen peroxide-based disinfectants. The goal was to evaluate potential stressors induced by these buffers during sampling, minimizing false negatives in food industry surface monitoring. Neutralizing buffers are essential in preserving bacterial viability during sample transport by counteracting residual disinfectants. Listeria monocytogenes populations were quantified immediately after sampling and after 24-h incubation at 8°C, simulating transport conditions. While neutralizing buffers had minimal impact on untreated adherent cells, they significantly reduced mortality in disinfectant-treated cells. However, most buffers failed to preserve viable culturable (VC) populations after disinfection, instead promoting viable but non-culturable (VBNC) states. Notably, prolonged incubation in the Sponge neutralizer facilitated VC population recovery, likely through VBNC resuscitation or VC growth. In contrast, other buffers inhibited recovery, suggesting detrimental effects on stressed cells due to their chemical composition. These findings underscore the importance of selecting appropriate neutralizing buffers in L. monocytogenes detection, influencing food safety surveillance and risk assessment protocols.
本研究评估了六种消毒中和缓冲液对粘附在经季铵盐或过氧化氢基消毒剂处理的不锈钢表面上的单核细胞增生李斯特菌的影响。目的是评估这些缓冲液在采样过程中诱导的潜在应激源，尽量减少食品工业表面监测中的假阴性。中和缓冲液通过中和残留消毒剂，在样品运输过程中保持细菌活力方面至关重要。在采样后以及在8°C下孵育24小时后（模拟运输条件），对单核细胞增生李斯特菌的数量进行了定量。虽然中和缓冲液对未处理的粘附细胞影响最小，但它们显著降低了经消毒剂处理的细胞的死亡率。然而，大多数缓冲液在消毒后未能保持存活可培养（VC）菌群，反而促进了活的但不可培养（VBNC）状态。值得注意的是，在海绵中和剂中长时间孵育促进了VC菌群的恢复，这可能是通过VBNC复苏或VC生长实现的。相比之下，其他缓冲液抑制了恢复，表明由于其化学成分对受应激细胞有有害影响。这些发现强调了在单核细胞增生李斯特菌检测中选择合适的中和缓冲液的重要性，这会影响食品安全监测和风险评估方案。
