Johnston Michael A, Harrison Mark A, Morrow Ruth A
Department of Food Science and Technology, University of Georgia, Athens, Georgia 30602, USA.
J Food Prot. 2009 Jul;72(7):1569-75. doi: 10.4315/0362-028x-72.7.1569.
Fresh-cut lettuce and spinach can become contaminated with pathogens at numerous points from the field to the retail market. Natural microflora present on fresh produce may help reduce the pathogen load. The objective of this study was to isolate natural microflora from fresh-cut iceberg lettuce and baby spinach and to determine whether these bacteria were antagonistic toward Escherichia coli O157:H7. Samples were collected under conditions that mimicked actual practices between production and retail sale. Evidence of naturally occurring microorganisms on fresh lettuce (295 isolates) and spinach (200 isolates) and of possible antagonistic activity toward E. coli O157:H7 was documented. Inhibitory activity by several isolates was due to either acid production or antimicrobial peptides. Bacteria with inhibitory activity were isolated from every step in the processing and handling of the fresh-cut iceberg lettuce and baby spinach.
从田间到零售市场，鲜切生菜和菠菜在多个环节都可能被病原体污染。新鲜农产品上存在的天然微生物群落可能有助于减少病原体数量。本研究的目的是从鲜切的卷心莴苣和小菠菜中分离天然微生物群落，并确定这些细菌是否对大肠杆菌O157:H7具有拮抗作用。在模拟生产和零售之间实际操作的条件下采集样本。记录了新鲜生菜（295株分离菌）和菠菜（200株分离菌）上自然存在的微生物以及对大肠杆菌O157:H7可能的拮抗活性的证据。几种分离菌的抑制活性是由于产酸或抗菌肽所致。在鲜切卷心莴苣和小菠菜的加工和处理的每个步骤中都分离出了具有抑制活性的细菌。
