Resistant bacteria to antimicrobials are increasingly emerging in medical, food industry and livestock environments. The present research work assesses the capability of Salmonella enterica var Typhimurium to become adapted under the exposure to a natural cauliflower antimicrobial by-product infusion in consecutive repeated exposure cycles. Caenorhabditis elegans was proposed as in vivo host-test organism to compare possible changes in the virulent pattern of the different rounds treated S. enterica var Typhimurium and untreated bacterial cells. According to the obtained results, S. enterica var Typhimurium was able to generate resistance against a repeated exposure to cauliflower by-product infusion 5% (w/v), increasing the resistance with the number of exposed repetitions. Meanwhile, at the first exposure, cauliflower by-product infusion was effective in reducing S. enterica var Typhimurium (≈1 log10 cycle), and S. enterica var Typhimurium became resistant to this natural antimicrobial after the second and third treatment-round and was able to grow (≈1 log10 cycle). In spite of the increased resistance observed for repeatedly treated bacteria, the present study reveals no changes on C. elegans infection effects between resistant and untreated S. enterica var Typhimurium, according to phenotypic parameters evaluation (lifespan duration and egg-laying).

中文翻译：

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亚致死/重复暴露于花椰菜浸液下鼠伤寒沙门氏菌耐药性的发生和对秀丽隐杆线虫宿主试验生物的感染影响

医疗、食品工业和牲畜环境中越来越多地出现对抗菌剂的抗性细菌。目前的研究工作评估了沙门氏菌鼠伤寒沙门氏菌在连续重复暴露周期中暴露于天然花椰菜抗菌副产品输液后变得适应的能力。秀丽隐杆线虫被提议作为体内宿主测试生物，以比较不同轮次处理的鼠伤寒沙门氏菌和未处理的细菌细胞的毒力模式的可能变化。根据获得的结果，S. enterica var Typhimurium 能够对重复暴露于 5% (w/v) 的花椰菜副产品输液产生抗性，抗性随着暴露重复次数的增加而增加。同时，在第一次曝光时，花椰菜副产品输注可有效减少 S. enterica var Typhimurium（≈1 log10 循环），并且 S. enterica var Typhimurium 在第二轮和第三轮处理后对这种天然抗菌剂产生抗药性并能够生长（≈1 log10循环）。尽管观察到反复治疗的细菌耐药性增加，但根据表型参数评估（寿命持续时间和产卵），本研究显示耐药性和未治疗的 S. enterica var Typhimurium 之间的线虫感染效果没有变化。