一种能同时富集沙门菌、大肠杆菌和金黄色葡萄球菌的增菌培养基

Study on a Pre-enrichment Medium for the Simultaneous Recovery of Salmonella spp.，Escherichia coli and Staphylococcus aureus

摘要:

研究设计出一种能同时富集培养沙门菌、大肠杆菌和金黄色葡萄球菌的缓冲盐水肉汤（buffed saline broth，BSB），主要组分和含量为：蛋白胨10g、牛肉膏3g、磷酸氢二钠9g、磷酸二氢钾1.5g、添加剂50g、蒸馏水定容至1000mL，pH7.2。将1cfu/mL的上述3种菌同时分别接种到97 mL BSB、蛋白缓冲水、乳糖肉汤、营养肉汤、大肠杆菌肉汤、氯化镁孔雀绿增菌液、7.5%氯化钠肉汤增菌培养基中，37℃增菌18h。结果表明BSB能使这3种菌以相对一致的速度增殖，分别达到10⁶、10⁶、10⁷cfu/mL，并且多重PCR能同时分别扩增沙门菌invA 基因284bp、大肠杆菌phoA基因622bp和金黄色葡萄球菌nuc基因484bp的特异性条带。相反，其他几种培养基则不能同时协调增殖上述3种菌。这些结果表明，BSB有较好的应用前景。

Abstract:

This text involved with a pre-enrichment medium for the simultaneous recovery of Salmonella spp.，Escherichia coli and Staphylococcus aureus.This medium is named buffered saline broth(BSB)，which contains peptone 10g，beef exact 3g，disodium hydrogen phosphate 9g，potassium dihydrogen phosphate 1.5g，additive 50g，deionized water 1 000mL，pH7.2.1cfu per one milliliter of Salmonella spp.，Escherichia coli and Staphylococcus aureus in saline were stimutaneously added to 97 mL of BSB，buffered peptone water，lactose broth，nutrient broth，Escherichia coli broth，rappaport-vassiliadis enrichment broth，7.5% sodium chloride enrichment medium，respectively，and incubated for 18h at 37℃.The results showed BSB was the best enrichment medium，in which Salmonella spp.，Escherichia coli and Staphylococcus aureus multiplied at nearly same speed，and reached at 106、106、107cfu/mL，respectively.Multiplex PCR produced specific amplicons of expected sizes，284bp for Salmonella spp.invA gene，622bp for Escherichia coli phoA gene，484bp for Staphylococcus aureus nuc gene.In contrast，the three bacteria couldnt multiply harmoniously in the other six media.So BSB might be considered as the medium，which could enrich above mentioned three bacteria.