College of Public Health, Division of Environmental Health Sciences, The Ohio State University, 375 Howlett Hall, 2001 Fyffe Court, Columbus, OH 43210, USA.
Can J Microbiol. 2010 Nov;56(11):943-51. doi: 10.1139/w10-082.
The consumption and use of edible flowers as food is growing; however, no study has been conducted to evaluate their role in the cause of food-borne illness or in food safety. Recent food-borne outbreaks traced to fresh herbs have raised concern about their processing and handling. Basil, one of the most commonly used fresh herbs, has been identified as a source of food-borne illness. Baseline assessments of microflora were performed, and the microbial diversity between growing methods (organic vs. conventional) was compared. DNA sequencing was used to identify the microbial flora present on fresh edible flower and basil samples. The most predominant species identified were Enterobacter hormaechei (10%), Acinetobacter calcoaceticus (10%), Enterobacter ludwigii (10%), Enterobacter asburiae (6%), and Enterobacter cowanii (6%). Pseudomonas aeruginosa (6%), Salmonella enterica (6%), and Bacillus amyloliquefaciens (2%) were also isolated. Phylogenetic analysis showed that most species of isolated bacteria belonged to the phyla Gammaproteobacteria (81.2%) and Firmicutes (18.8%). Statistical analysis, diversity index for species richness, and lineage-per-time plots showed that for basil, organically grown samples had a higher microbial diversity than conventionally grown samples. Edible flowers and basil are often grown using organic methods and are commonly consumed raw without any washing or cooking, to preserve aesthetic value, but these practices may pose a potential risk for food-borne illness. The baseline assessment, together with phylogenetic and statistical analyses, indicated possible microbial contamination in edible flowers and basil. The use of statistical estimation of molecular diversity based on the 16S rRNA sequences and lineage-per-time plots with phylogenetic analysis well served as a means for comparing microbial diversity in food samples between the growing methods (organic vs. conventional).
食用花卉作为食物的消费和使用正在增加；然而，尚未有研究评估其在食源性疾病病因或食品安全中的作用。最近追踪到新鲜香草的食源性暴发事件引起了人们对其加工和处理的关注。罗勒，最常用的新鲜香草之一，已被确定为食源性疾病的来源。对微生物区系进行了基线评估，并比较了不同种植方法（有机与常规）之间的微生物多样性。使用 DNA 测序来识别新鲜食用花卉和罗勒样本上存在的微生物菌群。鉴定出的最主要物种为易氏肠杆菌（10%）、醋酸钙不动杆菌（10%）、鲁氏肠杆菌（10%）、阿氏肠杆菌（6%）和考恩肠杆菌（6%）。还分离出铜绿假单胞菌（6%）、肠炎沙门氏菌（6%）和解淀粉芽孢杆菌（2%）。系统发育分析表明，分离出的细菌大多数属于γ变形菌门（81.2%）和厚壁菌门（18.8%）。统计分析、物种丰富度多样性指数和谱系时间图显示，对于罗勒，有机种植的样本比常规种植的样本具有更高的微生物多样性。食用花卉和罗勒通常采用有机方法种植，为了保持美观，通常生吃而不进行清洗或烹饪，但这些做法可能会带来食源性疾病的潜在风险。基线评估以及系统发育和统计分析表明，食用花卉和罗勒可能存在微生物污染。基于 16S rRNA 序列的分子多样性统计估计以及与系统发育分析相结合的谱系时间图，很好地用作比较不同种植方法（有机与常规）之间食物样本中微生物多样性的方法。
