Rajabzadeh Safieh, Bahreini Masoumeh, Sharifmoghadam Mohammad Reza
Department of Food Sciences and Technology, Resarch Institute of Food Sciences and Technology, Mashhad, Iran.
Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
Iran J Microbiol. 2018 Dec;10(6):385-393.
Traditional culture methods for detection of food-borne pathogens, a major public health problem, are simple, easily adaptable and very practical, but they can be laborious and time consuming. In this study, we eliminated culturing steps by developing a new separation method and therefore, decreased the detection time of food-borne pathogens ( serovar Typhimurium, O157:H7 and ) to a few hours.
We used alkaline water and different alkaline buffers to elute bacteria from the lettuce surface as a model for ready-to-eat vegetables. Buffers used were as follows: 1) 0.05 M glycine; 2) 0.05 M glycine -100 mM Tris base -1% (w/v) beef extract; 3) buffer peptone water; 4) buffer phosphate saline. Buffers were adjusted to pH of 9, 9.5 and 10. In order to elute the bacteria, the lettuce pieces were suspended into buffers and shacked for 30, 45 and 60 min. Moreover, a multiplex PCR method for the simultaneous detection of food-borne pathogens was performed.
The results showed that buffer peptone water at pH 9.5 for 45 min have high ability to elute bacteria from the lettuce surface and the bacteria can be detected using multiplex PCR.
We developed a new rapid and efficient method for simultaneous separation of food-borne pathogens. This method eliminates culturing stages and permits the detection and identification of target pathogens in a few hours.
传统的食源性病原体检测培养方法是一个重大的公共卫生问题，操作简单、易于调整且非常实用，但可能费力且耗时。在本研究中，我们通过开发一种新的分离方法省去了培养步骤，从而将食源性病原体（鼠伤寒血清型、O157:H7等）的检测时间缩短至数小时。
我们使用碱性水和不同的碱性缓冲液从生菜表面洗脱细菌，以此作为即食蔬菜的模型。使用的缓冲液如下：1）0.05 M甘氨酸；2）0.05 M甘氨酸 - 100 mM Tris碱 - 1%（w/v）牛肉浸出液；3）缓冲蛋白胨水；4）磷酸盐缓冲盐水。将缓冲液的pH值调至9、9.5和10。为了洗脱细菌，将生菜片悬浮于缓冲液中并振荡30、45和60分钟。此外，还采用了多重PCR方法同时检测食源性病原体。
结果表明，pH值为9.5的缓冲蛋白胨水在振荡45分钟时具有从生菜表面高效洗脱细菌的能力，并且可以使用多重PCR检测这些细菌。
我们开发了一种新的快速高效的方法，用于同时分离食源性病原体。该方法省去了培养阶段，能够在数小时内检测和鉴定目标病原体。
