一种能同时富集沙门氏菌、金黄色葡萄球菌和单增李斯特菌的培乔基

目的]设计制备一种能够同时富集沙门氏菌、金黄色葡萄球菌及单增李斯特菌的复合增菌肉汤.方法]挑选合适的添加剂进行单因素实验,确定增菌肉汤的成分及配比,采用平板计数法及三重荧光PCR技术验证肉汤的增菌效果.结果]结果得到一种能同时富集沙门氏菌、金黄色葡萄球菌及单增李斯特菌的选择性增菌肉汤(SSL),经验证SSL可使得3种目标菌以相对一致的速度进行富集,经过37℃ 150 r/min振荡培养24 h后,菌体浓度到达10~7～10~8 CFU/mL,非目标菌生长受到抑制.应用荧光PCR扩增样品,可同时得到3种目标菌的扩增曲线.在710份实际样品检测中,无假阳性及假阴性报告.结论]研究结果表明,SSL肉汤可用于沙门氏菌、金黄色葡萄球菌及单增李斯特菌的共增菌,可用于多重PCR检测的前增菌.

A multi-pathogen selective enrichment broth for simultaneous growth of Salmonella enteritidis,Staphylococcus ayureus,and Listeria monocytogenes

Objective] A selective enrichment broth (SSL) was formulated to allow simultaneous growth of Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogens .Methods] Suitable additive agents were selected by single factor experiment, the enrichment effect of the broth for the three pathogens were evaluated by conventional detection method and real-time PCR. Results] A selective enrichment broth,SSL,was obtained by adding the selective agents,including nalidixic acid, lithium chloride, and potassium tellurite, in the basic brothi and sodium pyruvate and mannitol as the supplemented elements. Recovery of three target pathogens in SSL was obtained within 24 h of incubation at 37 ℃, yielding cell dnesities of 10~7- 10~8 CFU/mL. Meanwhile,SSL broth effectively inhibited the growth of non-target organisms. 710 samples were detected by SSL with real-time PCR, and there is no error report. Conclusion] SSL is demonstrated to be a promising new multiplex selective enrichment broth for simultaneous detection of the three most prominent foodborn pathogens by multipathogen detection on a single assay platform.