Worldwide, street vending commerce has grown exponentially, representing in some countries, including Ecuador, a significant proportion of food consumed by the urban population. Pineapple is one of the common fruits sold as ready-to-eat slices by ambulant vendors in the street or on public transport at risk of contamination by various microorganisms. Previously, we selected Lactobacillus plantarum UTNCys5-4 and Lactococcus lactis subsp. lactis Gt28 strains producing peptides with high capacity to inhibit pathogen growth in vitro. In this study, the effect of different edited formulations containing a mixture of Cys5-4/Gt28 peptides was evaluated in vitro and ex vitro against a pathogenic cocktail containing E. coli (2), Salmonella (2) and Shigella (1). The growth of bacterial cocktail co-inoculated with cell-free supernatant containing peptides (formulation T1) and precipitated peptides (formulation T6), in a ratio of Cys5-4/Gt28:1:1 (v/v), results in a decrease of total cell viability with 1.85 and 1.2 log CFU/mL orders of magnitude at 6 h of incubation. About the same decrease (1.9 log CFU/g) was observed when pineapple slices artificially inoculated with the pathogenic cocktail were coated with T1 formulation, indicating the capacity to diminish simultaneous pathogens in situ, thus demonstrating its great biological control and protection. However, the E. coli cell counts reduced by 2.08 log CFU/g while Salmonella and Shigella cell counts reduced by 1.43 and 1.91 log CFU/g, respectively, at 5 days of refrigeration. In the untreated pineapple slices, the total cell density was maintained during storage, suggesting the adaptation of the pathogens to the fruit matrix. The peptide-based formulation exerted a bacteriolytic mode of action inducing pathogenic cell death. The results indicate that coating pineapple slices with peptide-based formulation is a promising approach to protect them from further contamination by microbial spoilage as well as an alternative to increase the food safety.

中文翻译：

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乳酸菌的基于肽的制剂损害了菠萝（菠萝）中病原菌的生长

在全球范围内，街头自动贩卖交易业务呈指数增长，在包括厄瓜多尔在内的某些国家中，城市居民消费的食物占很大比例。菠萝是在街上或在公共交通工具上由活跃的摊贩出售的即食切片常见水果之一，有被多种微生物污染的风险。以前，我们选择了植物乳杆菌UTNCys5-4和乳酸乳球菌亚种。乳酸Gt28菌株产生具有高抑制体外病原体生长能力的肽。在这项研究中，对含有Cys5-4 / Gt28肽混合物的不同编辑制剂在体外和体外针对含有大肠杆菌的致病性混合物的效果进行了评估（2），沙门氏菌（2）和志贺氏菌（1）。与含有肽（配方T1）和沉淀的肽（配方T6）的无细胞上清液共同接种的细菌混合物的生长，以Cys5-4 / Gt28：1：1（v / v）的比例减少孵育6 h时细胞总生存力为1.85和1.2 log CFU / mL数量级。当人工接种致病性鸡尾酒的菠萝切片涂上T1制剂时，观察到大约相同的下降（1.9 log CFU / g），表明其具有就地消灭同时存在的病原体的能力，从而证明了其对生物学的良好控制和保护。但是，沙门氏菌的大肠杆菌细胞数减少了2.08 log CFU / g冷藏5天后，志贺氏菌和志贺氏菌的细胞数分别降低了1.43和1.91 log CFU / g。在未处理的菠萝片中，在储存过程中总细胞密度得以维持，表明病原体适应于水果基质。基于肽的制剂发挥了诱导病原性细胞死亡的溶菌作用模式。结果表明，用基于肽的制剂包被菠萝片是一种有前途的方法，可以保护菠萝片免受微生物变质的进一步污染，并且是提高食品安全性的替代方法。