THE EFFECT OF FREEZING AND STORAGE ON THE BACTERIAL FLORA OF PASTEURIZED MILK

SUMMARY: Experiments were designed to determine the effect of freezing and storage on the bacterial population of pasteurized milk. Samples taken on separate occasions sometimes reacted differently to freezing treatment. Significant changes in bacterial numbers occurred after the frozen milk had been stored for 4–5 months at −12°, and this coincided with definite physical changes in the milk. Known numbers of coliaerogenes organisms were added to the pasteurized product in order to study their behaviour when frozen and stored at low temperatures. The counts were significantly lower after storage for 4 months.     

OPTIMIZATION OF THE ENUMERATION OF TOTAL AEROBIC BACTERIAL FLORA IN THE FLESH OF SEAFISH

Abstract The total aerobic flora of seafish flesh is weakly halophilic, and requires on average 1.38% NaCl according to statistical studies. Enumeration is optimal on tryptone soya agar or on NaCl supplemented plate count agar (-H₂S), incubated at 20 and 25C, respectively. Plate count agar (-H₂S) was selected because it can also be used for enumeration of hydrogen sulfide-producing bacteria by degradation of sulfur-containing proteins, which are abundant in fish The models employed are sigmoidal. The initial bioburden is too great for there to be a lag phase during storage in ice at 0C. The models show that when the total aerobic microflora count exceeds 100,000 cfu/g, whole or filleted fish stored on ice at 0C are unfit for consumption.     

淤积性皮炎与皮肤菌群关系的研究

目的：探讨淤积性皮炎与皮肤菌群之间的关系。方法：对21例小腿淤积性皮炎患者皮损，邻近皮肤及鼻孔的皮肤菌群进行检测。并将结果同20例正常人小腿皮肤及鼻孔菌群做了比较，其数据进行统计学处理。结果：金黄色葡萄球菌为淤积性皮炎患者皮肤的主要菌种，其分离率及密度均高于正常对照组。结论：金黄色葡萄球菌可能是淤积性皮炎发生的一个重要因素。     

鱼类病原菌外膜蛋白及其免疫原性研究进展

细菌性疾病是水产养殖病害中最常见且危害甚为严重的一类疾病1。长期以来,一直用于鱼类细菌性疾病防治的西药类药物,由于会导致病原菌产生耐药性,在鱼体内产生药物残留危害人类健康等副作用而被限制使用2。因此,为了选择更加安全有效的防治方法,疫苗免疫逐步得到了人们的重视。