Short communication: Preliminary investigation into the effect of freezing and a cryopreservant on the recovery of mastitis pathogens from ewe milk.
Short communication: Preliminary investigation into the effect of freezing and a cryopreservant on the recovery of mastitis pathogens from ewe milk.
复制标题
简短的交流：冷冻和低温保存剂对从母乳中回收乳腺炎病原体的影响的初步研究。
作者：
E. M. Smith;E. Monaghan;S. Huntley;L. Green
本研究的目的是调查细菌的复苏，从母羊牛奶冷冻4或8周后，添加和不添加甘油作为冷冻保存剂。共选择了50个具有已知细菌种类范围的乳房半乳样本，储存并在5个处理组中进行分析：时间零点;在有和没有甘油的情况下冷冻4周;在有和没有甘油的情况下冷冻8周。在冷冻后研究的所有细菌种属中观察到较低的回收率。含有低于100 cfu/mL的样品来自体细胞计数较低的母羊，冷冻后细菌学阴性的可能性大于高于此阈值的样品。甘油的加入增加了冷冻后革兰氏阴性菌的回收率，尽管这需要进一步研究才能得出有力的结论。对革兰氏阳性种属的影响不一致。我们的结论是，虽然甘油的加入有一个小的有益影响，从冷冻羊奶细菌检测的灵敏度，灵敏度是最高的新鲜牛奶的文化。
The objective of this study was to investigate the recovery of bacteria from ewe milk after freezing for 4 or 8 wk with and without the addition of glycerol as a cryopreservant. A total of 50 udder-half milk samples with a known range of bacterial species were selected, stored, and analyzed in 5 treatment groups: time zero; frozen for 4 wk with, and without, glycerol; and frozen for 8 wk with, and without, glycerol. A lower recovery was observed in all bacterial species studied after freezing. Samples containing fewer than 100 cfu/mL came from ewes with a lower somatic cell count and were more likely to be bacteriologically negative after freezing than those above this threshold. The addition of glycerol increased recovery of gram-negative bacteria after freezing, although this requires further study to draw strong conclusions. The effects on gram-positive species were inconsistent. We conclude that although the addition of glycerol had a small beneficial effect on the sensitivity of detection of bacteria from frozen sheep milk, sensitivity was highest in cultures from fresh milk.