Buncic S, Avery S M
Meat Industry Research Institute of New Zealand (Inc.), Hamilton, New Zealand.
Lett Appl Microbiol. 1996 Jul;23(1):18-22. doi: 10.1111/j.1472-765x.1996.tb00020.x.
Three haemolytic, pathogenic strains of Listeria monocytogenes (a reference strain, a food-derived strain and a human strain) were held at 4 degrees C for 4 weeks in phosphate-buffered saline pH 5.5 or 7.0, with and without 0.2% potassium sorbate or 0.3% sodium acetate. The number of viable cells did not change significantly during this storage. Pathogenicity of non-growing L. monocytogenes cells for 14-d-old chick embryos was determined before and after storage. Storage at 4 degrees C resulted in decreased pathogenicity, but effects were strain-, pH-and substrate-dependent. After 4 weeks storage at 4 degrees C non-growing bacterial cells were transferred to Brain Heart Infusion broth and growth characteristics were determined during incubation at 37 degrees C. Strains that showed decreased pathogenicity had significantly longer lag phases at 37 degrees C than strains that maintained pathogenicity. It is concluded that decreased pathogenicity of L. monocytogenes stored without growth at 4 degrees C for 4 weeks and subsequent long lag phase at 37 degrees C are correlated.
将三株溶血性单核细胞增生李斯特菌致病菌株（一株参考菌株、一株食品源菌株和一株人体菌株）于4℃在pH值为5.5或7.0的磷酸盐缓冲盐水中保存4周，保存时添加或不添加0.2%山梨酸钾或0.3%醋酸钠。在此保存期间，活菌数没有显著变化。在保存前后测定了处于非生长状态的单核细胞增生李斯特菌细胞对14日龄鸡胚的致病性。4℃保存导致致病性降低，但影响因菌株、pH值和底物而异。在4℃保存4周后，将处于非生长状态的细菌细胞转移至脑心浸液肉汤中，并在37℃培养期间测定生长特性。致病性降低的菌株在37℃时的延迟期明显长于保持致病性的菌株。得出的结论是，4℃无生长状态下保存4周的单核细胞增生李斯特菌致病性降低以及随后在37℃出现长延迟期这两者之间存在相关性。
