Li Haorong, Zhu Jiangjiang
Department of Chemistry and Biochemistry, Miami University, 651 E High St, Oxford, OH, 45056, USA.
Rapid Commun Mass Spectrom. 2017 Oct 15;31(19):1669-1676. doi: 10.1002/rcm.7949.
Pathogenic foodborne bacteria have been associated with severe infectious disease in humans and animals worldwide. Rapid detection and screening of these foodborne pathogens are critical for our food safety. This study aimed at detecting Escherichia coli and Staphylococcus aureus, two important foodborne bacteria, at the species and strain/serovar level using a mass spectrometry (MS)-based targeted metabolic profiling approach.
Ten E. coli strains (8 out of 10 were foodborne outbreak isolates) and four S. aureus strains were tested at two growth time points. A high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS)-based targeted metabolomics approach was applied for metabolic profile based bacteria detection. A total of 108 metabolites from multiple metabolic pathways were confidently detected from these bacteria.
Our study demonstrated that with only 4 h of enrichment in the same medium, the metabolic profiles from E. coli and S. aureus showed significant difference. Furthermore, seven out of ten E. coli strains and all four tested S. aureus strains showed strain/serovar-level differentiation at the 4-h time point, which indicated great potential for strain level stratification in future food screening using our MS-based targeted metabolic profiling approach.
A targeted metabolomics method was developed to demonstrate the utility of HPLC/MS/MS-based metabolic profiling in rapidly (4 h) differentiating E. coli and S. aureus bacteria, two of the most notorious foodborne bacteria, at both the species and strain/serovar levels. The results indicated that our approach has great potential in the future for fast and specific detection of foodborne pathogenic bacteria based on their metabolic diversity.
致病性食源细菌与全球人类和动物的严重传染病有关。快速检测和筛查这些食源性病原体对我们的食品安全至关重要。本研究旨在使用基于质谱（MS）的靶向代谢谱分析方法，在物种和菌株/血清型水平上检测两种重要的食源细菌——大肠杆菌和金黄色葡萄球菌。
在两个生长时间点对10株大肠杆菌菌株（10株中有8株是食源性暴发分离株）和4株金黄色葡萄球菌菌株进行了测试。采用基于高效液相色谱/串联质谱（HPLC/MS/MS）的靶向代谢组学方法进行基于代谢谱的细菌检测。从这些细菌中可靠地检测到了来自多个代谢途径的总共108种代谢物。
我们的研究表明，在同一培养基中仅富集4小时，大肠杆菌和金黄色葡萄球菌的代谢谱就显示出显著差异。此外，10株大肠杆菌菌株中的7株和所有4株测试的金黄色葡萄球菌菌株在4小时时间点显示出菌株/血清型水平的分化，这表明使用我们基于MS的靶向代谢谱分析方法在未来食品筛查中进行菌株水平分层具有很大潜力。
开发了一种靶向代谢组学方法，以证明基于HPLC/MS/MS的代谢谱分析在快速（4小时）区分两种最臭名昭著的食源细菌——大肠杆菌和金黄色葡萄球菌方面在物种和菌株/血清型水平上的实用性。结果表明，我们的方法在未来基于食源性病原体代谢多样性进行快速和特异性检测方面具有很大潜力。
