摘要:
为研究金黄色葡萄球菌经冷诱导后对其他环境胁迫耐受性的变化,将耐冷冻能力较强的分离株S.aureus W3与标准菌株S.aureus CICC10201分别在4 ℃下冷胁迫5 h后,测定其在高温、酸碱、氯化钠、过氧化氢、酒精的胁迫下存活率变化。同时对分离株S.aureus W3的生物被膜形成及控制进行了研究。结果表明,经-20 ℃冷藏8周后,S.aureus W3的存活率显著高于S.aureus CICC10201(p<0.05)。经冷诱导后,S.aureus W3在45~60 ℃环境下存活率提升至18.5%。冷诱导使金黄色葡萄球菌对酸敏感性增强但对碱产生交叉抗性。冷诱导后的两株菌在氯化钠中的存活率均降低,S.aureus W3最低下降了24.09%。另外,冷诱导后金黄色葡萄球菌对酒精的耐受性增强。分离株S.aureus W3在冷诱导前后过氧化氢耐受性没有明显变化(p>0.05),但标准菌株S.aureus CICC10201敏感性增强,存活率显著下降(p<0.05)。分离株S.aureus W3较S.aureus CICC10201具有更强的生物被膜形成能力,运用1% 84消毒水能有效清除其生物被膜。本研究为冷冻食品中金黄色葡萄球菌的安全控制提供理论依据。
Abstract:
In order to study the effect of cold induction on other environmental stress tolerance of Staphylococcus aureus, the S. aureus W3 which had strong resistance to freezing and standard strain S.aureus CICC10201 were measured at high temperatures, pH, NaCl, hydrogen peroxide and alcohol after 5 h of cold stress at 4℃. Meanwhile, the biofilm formation ability and control method were studied. The results showed that after 8 weeks of storage at -20℃, the survival rate of S.aureus W3 was significantly higher than that of S.aureus CICC10201 (p<0.05). After cold induction, the survival rates of S. aureus W3 increased by 18.5% at 45~60℃. Cold induction enhanced the sensitivity of S. aureus to acidic environment, but it produced cross resistance to alkaline environment. After cold induction, the survival rate of two strains in hypertonic environment decreased, and the lowest decreased by 24.09%. In addition, the tolerance of S. aureus to alcohol increased after cold induction. For hydrogen peroxide, there was no significant (p>0.05) change in the tolerance of S.aureus W3 before and after induction. But the sensitivity of the S.aureus CICC10201 was enhanced after cold induction, and the survival rate decreased. S.aureus W3 has stronger biofilm formation ability than S.aureus CICC10201, and 1% 84 disinfection can effectively remove its biofilm. This study provides a theoretical basis for the safety control of S. aureus in frozen foods.
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