Litt Pushpinder K, Kakani Radhika, Jadeja Ravirajsinh, Saha Joyjit, Kountoupis Tony, Jaroni Divya
Department of Animal and Food Sciences, Food and Agricultural Products Center, Oklahoma State University, Stillwater, Oklahoma, USA.
Phage (New Rochelle). 2020 Dec 1;1(4):213-222. doi: 10.1089/phage.2020.0024. Epub 2020 Dec 16.
Shiga-toxigenic (STEC) have caused several produce-associated outbreaks, making it challenging to control these pathogens. Bacteriophages could serve as effective biocontrol. Spinach, lettuce, and cucumbers, inoculated with STEC (O157, O26, O45, O103, O111, O121, O145), were treated with lytic bacteriophages and stored at 4°C for 3 days. Surviving STEC were enumerated and observed under scanning electron microscope (SEM), and data analyzed using one-way analysis of variance (ANOVA) ( < 0.05). Bacteriophage treatments significantly reduced STEC populations, compared with the control ( < 0.05). On spinach and romaine, STEC O26, O45, and O103 were reduced to undetectable levels and STEC O157, O111, O121, and O145 by ∼2 logs CFU/cm. Multiserotype phage cocktail reduced STEC on leafy greens by 1.4 CFU/cm and on cucumbers by 1.7 logs CFU/cucumber. Clusters of STEC cells, surrounded by extracellular matrix, were observed under SEM of positive control, whereas phage-treated produce surface showed fewer cells, with cellular damage. Bacteriophages could be utilized as biocontrol against STEC on fresh produce.
产志贺毒素大肠杆菌（STEC）已引发多起与农产品相关的疫情，给控制这些病原体带来了挑战。噬菌体可作为有效的生物防治手段。将接种了STEC（O157、O26、O45、O103、O111、O121、O145）的菠菜、生菜和黄瓜用裂解性噬菌体处理，并在4°C下储存3天。对存活的STEC进行计数，并在扫描电子显微镜（SEM）下观察，数据采用单因素方差分析（ANOVA）进行分析（P<0.05）。与对照组相比，噬菌体处理显著降低了STEC的数量（P<0.05）。在菠菜和长叶生菜上，STEC O26、O45和O103降至检测不到的水平，STEC O157、O111、O121和O145减少了约2个对数CFU/cm。多血清型噬菌体鸡尾酒使绿叶蔬菜上的STEC减少了1.4个对数CFU/cm，黄瓜上的减少了1.7个对数CFU/黄瓜。在阳性对照的SEM下观察到被细胞外基质包围的STEC细胞簇，而经噬菌体处理的农产品表面显示细胞较少，且有细胞损伤。噬菌体可作为新鲜农产品上STEC的生物防治手段。
