金黄色葡萄球菌定性定量检测中显色培养基的效果评价

目的 评估显色培养基对金黄色葡萄球菌定性定量的检测效果。方法 对金黄色葡萄球菌标准菌株、食品样本分离菌株：30株金黄色葡萄球菌、30株其他葡萄球菌,5株常见食源性致病菌分别用金黄色葡萄球菌显色培养基和Baird-Parker培养基进行培养试验,并用国标法和全自动微生物鉴定药敏分析系统对培养结果进行确证鉴定。结果 试验定性结果显示金黄色葡萄球菌在显色培养基上呈紫红色,30株其他葡萄球菌呈蓝色或乳白色,5株常见食源性致病菌其中单核细胞增生李斯特氏菌呈蓝绿色、表皮葡萄球菌呈乳白色、其余3株不生长,可在直观上对几种食品中常见葡萄球菌进行有效区别,而且目标菌在显色培养基和Baird-Parker培养基上计数值无显著差异(P＞0.05),确证结果显示全自动微生物鉴定药敏分析系统结果与GB 4789.10-2016方法结果一致。结论 显色培养基能快速锁定疑似目标菌落,为溯源调查指明方向,定量计数直观有效,配合全自动微生物鉴定药敏分析系统更提高了对目标菌的鉴定效率,更适用于金黄色葡萄球菌定性定量检测。

Evaluation of chromogenic medium in qualitative and quantitative detection of Staphylococcus aureus

Objective To evaluate the qualitative and quantitative detection of chromogenic medium for Staphylococcus aureus. Method 30 strains of S. aureus, 30 strains of other Staphylococcus and 5 strains of foodborne pathogenic bacteria were cultured in S. aureus chromogenic medium and Baird-Parker medium, respectively. The culture results were confirmed and identified by national standard method and automatic microbial identification and drug sensitivity analysis system. Result Qualitative results showed that S. aureus purple, other 30 strains of Staphylococcus milky white or blue, Listeria monocytogenes blue-green, S. epidermidis milk-white, rest of 3 strains not grow on chromogenic medium. Intuitively, common Staphylococcus in foods were effectively differentiated, and there was no significant difference in the counting between the target bacteria on the chromogenic medium and the Baird-Parker medium (P > 0.05). The confirmative results showed that the results of the automatic microbial identification and drug sensitivity analysis system were consistent with the results of the GB 4789.10-2016 method. Conclusion The chromogenic medium can quickly locate the suspected bacterial colonies, be easy to traceability investigate, and effectively and quantitatively count the colonies. It is more suitable for qualitative and quantitative detection of S. aureus with the automatic microbial identification and drug sensitivity analysis system to the identification efficiency of bacteria.