Department of Food Science and Technology, Pondicherry University, Puducherry, 605014, India.
Department of Food Science and Technology, Pondicherry University, Puducherry, 605014, India.
Microb Pathog. 2020 Jan;138:103813. doi: 10.1016/j.micpath.2019.103813. Epub 2019 Oct 22.
Salmonella enterica Typhi and Paratyphi A are food borne pathogens causing typhoid, which is one of the most important food borne disease in the developing world. S. Typhi and S. Paratyphi A are of much concern as multi drug resistance has been on the rise. The current study is aimed to screen phytochemicals for anti quorum sensing (QS) activity against S. Typhi and S. Paratyphi A. Upon screening with swarming assay, tannic acid (TA) showed highest anti-QS activity with minimal concentration of 400μg/ml. The anti-QS activity of TA was confirmed with C. violaceum ATCC 12,472. TA showed 38-43% and 35-50% of inhibition in cell surface hydrophobicity and EPS production respectively. Through FTIR analysis, it has been observed that EPS of treated cells has a considerable change in protein and peptide. TA has also exhibited drastic reduction in the surfactant production as high as 85-90%. Blood sensitivity and antibiotic sensitivity assay revealed that TA significantly sensitizes the S. Typhi and S. Paratyphi A cells to immune components in human blood and antibiotics. It has reduced the resistance of S. Typhi and S. Paratyphi A cells against amikacin, ampicillin, ciprofloxacin, azithromycin, chloramphenicol and gentamycin, thus revitalized the usage of these antibiotics against drug resistant S. Typhi and S. Paratyphi A infections. The consistency of anti-QS potential of TA was further evaluated and established with another eight clinical isolates of S. Typhi and S. Paratyphi A. Thus TA has been proved as a promising anti QS agent that can be developed as a therapeutic combination against S. Typhi and S. Paratyphi A.
肠炎沙门氏菌 Typhi 和 Paratyphi A 是食源性病原体，可导致伤寒，这是发展中国家最重要的食源性疾病之一。由于多药耐药性的上升，S. Typhi 和 S. Paratyphi A 引起了极大的关注。本研究旨在筛选针对 S. Typhi 和 S. Paratyphi A 的群体感应（QS）活性的植物化学物质。通过泳动试验筛选，鞣酸（TA）显示出最高的抗 QS 活性，最小浓度为 400μg/ml。TA 的抗 QS 活性通过 C. violaceum ATCC 12,472 得到证实。TA 分别对细胞表面疏水性和 EPS 产生显示出 38-43%和 35-50%的抑制作用。通过傅里叶变换红外（FTIR）分析，观察到处理细胞的 EPS 在蛋白质和肽方面发生了相当大的变化。TA 还表现出表面活性剂产生的急剧减少，高达 85-90%。血液敏感性和抗生素敏感性试验表明，TA 显著提高了 S. Typhi 和 S. Paratyphi A 细胞对人血液和抗生素中免疫成分的敏感性。它降低了 S. Typhi 和 S. Paratyphi A 细胞对阿米卡星、氨苄西林、环丙沙星、阿奇霉素、氯霉素和庆大霉素的耐药性，从而恢复了这些抗生素对耐药性 S. Typhi 和 S. Paratyphi A 感染的使用。TA 的抗 QS 潜力的一致性进一步用另外 8 株临床分离的 S. Typhi 和 S. Paratyphi A 进行了评估和确立。因此，TA 已被证明是一种有前途的抗 QS 剂，可以开发为针对 S. Typhi 和 S. Paratyphi A 的治疗组合。
