Climate change and its worldwide effects are undeniable. Temperature increase due to climate change may affect foodborne pathogen survival on fresh produce. This study aimed to present an evaluation of climate change impact regarding temperature rise situations, on attachment of different pathogenic Escherichia coli strains on cress grown under controlled conditions. EHEC O157:H7, EAEC O104:H4 and EPEC O26 were inoculated with initial inoculum concentration of 8 log MPN/mL at different stages during growth to observe how inoculation time (7, 14, 21 and 28 days post sowing; dps) and route (seed and leaves) affect pathogen load on fresh produce. This study revealed that temperature increase designed according to mitigation scenarios for climate change (+2, +4 and +6 °C) did not cause any considerable change in pathogen persistence on leaf at 30 dps (~4.5 to 7 log MPN/g). In plants contaminated at later stage (21 and 28 dps), higher bacterial populations were obtained for all temperatures studied. Our results show that E. coli translocated towards leaf portions from seed and established significant amount of pathogen load on leaf (~4 to 5.3 log MPN/g). Also, inoculated bacteria have tightly bound to leaf (~3.5 to 7 log MPN/g) and cannot be eliminated by washing. Although persistence of E. coli O157:H7, O104:H4 and O26 did not differ significantly according to temperature, the bacterial load on the leaves was above infectious dose for humans.

中文翻译：

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气候变化和食品安全：温度对水芹叶上大肠杆菌致病群附着的影响

气候变化及其全球影响是不可否认的。气候变化导致的温度升高可能会影响新鲜农产品上食源性病原体的生存。本研究旨在评估气候变化对温度升高情况以及不同致病性大肠杆菌菌株对受控条件下生长的水芹的附着的影响。EHEC O157:H7、EAEC O104:H4 和 EPEC O26 在生长的不同阶段以初始接种浓度 8 log MPN/mL 进行接种，观察接种时间（播后 7、14、21 和 28 天；dps）和途径的变化（种子和叶子）影响新鲜农产品的病原体负荷。这项研究表明，根据气候变化缓解方案设计的温度升高（+2、+4 和 +6 °C）不会导致 30 dps 时叶片上病原体持久性发生任何显着变化（~4.5 至 7 log MPN/g） 。在后期（21 和 28 dps）污染的植物中，在所有研究温度下都获得了更高的细菌种群。我们的结果表明，大肠杆菌从种子转移到叶子部分，并在叶子上建立了大量的病原体负载（~4 至 5.3 log MPN/g）。此外，接种的细菌与叶子紧密结合（约 3.5 至 7 log MPN/g），无法通过清洗去除。尽管大肠杆菌O157:H7、O104:H4 和 O26 的持久性随温度的变化没有显着差异，但叶子上的细菌负荷高于人类感染剂量。