沙门菌、金黄色葡萄球菌、副溶血性弧菌的选择性共增菌培养基的研制

Development of selective co-enrichment medium for Salmonella,Staphylococcus aureus and Vibrio parahaemolyticus

目的研制一种可同时对沙门菌、金黄色葡萄球菌及副溶血性弧菌进行富集的共增菌培养基SSV,达到同时检测3种食品中常见的食源性致病菌的目的。方法根据3株菌的营养需求,选择不同的培养基组分进行单因素实验,确定选择性共增菌培养基的配方,通过OD_(600 nm)、受损菌复苏、多重聚合酶链式反应(PCR)、培养基选择性4个方面对SSV培养基进行验证。结果确定增菌培养基的成分为:蛋白胨10.0 g、KH_(2)PO_(4)1.5 g、NaCl 15.0 g、LiCl 1.0 g,Na_(2)S_(2)O_(3)5.0 g、去氧胆酸钠0.05 g、甘露醇1.0 g、丙酮酸钠5.0 g,蒸馏水1000 mL。SSV培养基能同时富集以上3株菌,37℃培养16 h后,3株菌的菌体浓度均达到107 CFU/mL及以上;SSV培养基对于受损的目标菌有良好的复苏效果,复苏后OD_(600 nm)较于复苏前增长了3倍;同时多重PCR、培养基选择性也得到很好的验证。结论共增菌培养基SSV可用于同时培养沙门菌、金黄色葡萄球菌和副溶血性弧菌,培养基配制简易,节约成本。后续可与多重PCR检测方法联用,提高检测率和准确性。

Objective A co-enrichment medium SSV which can simultaneously enrich Salmonella,Staphylococcus aureus and Vibrio parahaemolyticus was developed for the simultaneous detection of the above three foodborne pathogens in foods.Methods According to the nutritional needs of the three strains,the medium components were selected by single factor experiments,and the formula of selective co-enrichment medium was developed.The SSV medium was verified through bacterial number change,injured bacteria recovery,multiple polymerase chain reaction(PCR)and medium selectivity.Results The components of enrichment medium were determined as followed:Peptone 10.0 g,KH_(2)PO_(4)1.5 g,NaCl 15.0 g,LiCl 1.0 g,Na_(2)S_(2)O_(3)5.0 g,sodium deoxycholate 0.05 g,mannitol 1.0 g,sodium pyruvate 5.0 g and distilled water 1000 mL.The above three strains could be enriched in SSV medium at the same time.After cultured at 37℃for 16 h,the cell concentrations of the three strains reached 107 CFU/mL at least.SSV medium had a good resuscitation effect on the damaged target bacteria,and the OD_(600 nm) tripled after resuscitatio.At the same time,the function was well verified by multiplex PCR and medium selectivity.Conclusion The co-enrichment medium SSV can be used to simultaneously culture Salmonella,Staphylococcus aureus and Vibrio parahaemolyticus.The preparation of the medium is simple and cost-effective.It can be combined with multiplex PCR to improve the detection rate and accuracy.