据英国《每日邮报》5月2日报道，美国华盛顿州立大学的科学家发现，大蒜中含有的一种关键成分在抗食物中毒方面，效力比抗生素高100倍。

研究称，检验发现大蒜中的烯丙基硫成分可以轻易破坏细菌的黏稠且具保护性的生物膜，这层生物膜可保护细菌不被毁灭。此外，烯丙基硫不仅比红霉素和环丙沙星这两种抗生素的效力更强大，且见效更快。这项发现可能为找出处理生肉、加工肉的方法找到新路，从而降低感染弯曲杆菌导致的食物中毒危险。

华盛顿州立大学研究人员迈克尔·康克尔（Michael Konkel）说：“这项研究成果令人激动，因为研究显示，烯丙基硫也许可减少环境以及食物供应中的病菌。弯曲杆菌是美国乃至全世界引发食物传染性疾病的最常见病菌。”其感染症状包括腹泻、痉挛、腹痛和发烧等。


Antimicrobial effect of diallyl sulphide on Campylobacter jejuni biofilms

Xiaonan Lu1,2,3, Derrick R. Samuelson1, Barbara A. Rasco2 and Michael E. Konkel1,*

Objectives Bacterial biofilms pose significant food safety risks because of their attachment to fomites and food surfaces, including fresh produce surfaces. The purpose of this study was to systematically investigate the activity of selected antimicrobials on Campylobacter jejuni biofilms.

Methods C. jejuni biofilms and planktonic cells were treated with ciprofloxacin, erythromycin and diallyl sulphide and examined using infrared and Raman spectroscopies coupled with imaging analysis.

Results Diallyl sulphide eliminated planktonic cells and sessile cells in biofilms at a concentration that was at least 100-fold less than used for either ciprofloxacin or erythromycin on the basis of molarity. Distinct cell lysis was observed in diallyl sulphide-treated planktonic cells using immunoblot analysis and was confirmed by a rapid decrease in cellular ATP. Two phases of C. jejuni biofilm recalcitrance modes against ciprofloxacin and erythromycin were validated using vibrational spectroscopies: (i) an initial hindered adsorption into biofilm extracellular polymeric substance (EPS) and delivery of antibiotics to sessile cells within biofilms; and (ii) a different interaction between sessile cells in a biofilm compared with their planktonic counterparts. Diallyl sulphide destroyed the EPS structure of the C. jejuni biofilm, after which the sessile cells were killed in a similar manner as planktonic cells. Spectroscopic models can predict the survival of sessile cells within biofilms.

Conclusions Diallyl sulphide elicits strong antimicrobial activity against planktonic and sessile C. jejuni and may have applications for reducing the prevalence of this microbe in foods, biofilm reduction and, potentially, as an alternative chemotherapeutic agent for multidrug-resistant bacterial strains.