非伤寒沙门氏菌引起沙门氏菌病,这种细菌可以污染整个生产链的食物,包括那些作为原材料消费的产品。肠沙门氏菌可以粘附并内化到新鲜农产品中,例如樱桃番茄。据报道,裂解性噬菌体(噬菌体)可用作农业领域的生物防治剂,作为控制红肉中沙门氏菌的替代品,鱼,生菜,和卷心菜。这项研究的目的是表征PHA46鸡尾酒中存在的两种噬菌体,以确定它们的形态,基因组,主机范围,和对不同温度和pH值的抗性;然后评估它们的裂解活性,以减少肠沙门氏菌血清型纽波特和鼠伤寒菌对樱桃番茄的粘附和内化。此外,在这项工作中,我们还探索了PHA46鸡尾酒对S.Newport-45和鼠伤寒沙门氏菌SL1344的毒力的影响,从樱桃番茄的内部回收,关于动物模型秀丽隐杆线虫的寿命。线虫C.elegans,最近已用于测试沙门氏菌的毒力,并且易于在实验室中维护和使用。结果表明,通过透射电子显微镜从PHA46混合物中获得的两种噬菌体的形态对应于肌病毒,对其基因组序列的分析未报告毒力或抗菌素抗性基因.PHA46样品对来自不同沙门氏菌菌株的33种不同血清变体具有特异性,并且在7°C和pH6下显示出稳定性。此外,PHA46鸡尾酒可有效减少S.Newport-45和鼠伤寒沙门氏菌SL1344对樱桃番茄的粘附,平均分别为0.9log10。关于内化细菌,上述血清型的平均减少为1.2log10.秀丽隐杆线虫的寿命实验本身表明,PHA46鸡尾酒对线虫无害,在PHA46混合物的存在下,体外生长的两种沙门氏菌菌株的毒力均降低。总之,这些结果表明,PHA46混合物可能是一种很好的候选物,可用作肠道沙门氏菌的生物防治剂。
Non-typhoid Salmonella enterica causes salmonellosis illness, and this bacterium can contaminate food throughout the production chain, including those that are consumed as raw products. Salmonella enterica can adhere to and internalize into fresh produce such as cherry tomatoes. It has been reported that lytic bacteriophages (phages) can be used as a biocontrol agent in the agricultural field, being an alternative for the control of Salmonella in red meat, fish, lettuce, and cabbage. The aim of this study was to characterize the two phages present in the PHA46 cocktail to determine their morphology, genome, host range, and resistance to different temperatures and pHs values; and later evaluate their lytic activity to reduce the adherence to and internalization of Salmonella enterica serovars Newport and Typhimurium into cherry tomatoes. In addition, in this work, we also explored the effect of the PHA46 cocktail on the virulence of S. Newport-45 and S. Typhimurium SL1344, recovered from the interior of cherry tomatoes, on the lifespan of the animal model Caenorhabditis elegans. The nematode C. elegans, recently has been used to test the virulence of Salmonella and it is easy to maintain and work with in the laboratory. The results revealed that the morphology obtained by Transmission Electron Microscopy of two phages from the PHA46 cocktail correspond to a myovirus, the analyses of their genomes sequences did not report virulence or antimicrobial resistance genes. The PHA46 sample is specific for 33 different serovars from different Salmonella strains and shows stability at 7 °C and pH 6. Also, the PHA46 cocktail was effective in reducing the adherence of S. Newport-45 and S. Typhimurium SL1344 to cherry tomatoes, at an average of 0.9 log10, respectively. Regarding internalized bacteria, the reduction was at an average of 1.2 log10, of the serovars mentioned above. The lifespan experiments in C. elegans showed by itself, that the PHA46 cocktail was harmless to the nematode, and the virulence from both Salmonella strains grown in vitro is diminished in the presence of the PHA46 cocktail. In conclusion, these results showed that the PHA46 cocktail could be a good candidate to be used as a biocontrol agent against Salmonella enterica.