BACKGROUND Escherichia coli is a widespread gut commensal and often a versatile pathogen of public health concern. E. coli are also frequently found in different environments and/or alternative secondary hosts, such as plant tissues. The lifestyle of E. coli in plants is poorly understood and has potential implications for food safety. METHODS/PRINCIPAL FINDINGS This work shows that a human c...

The sequence of Lettuce chlorosis virus (LCV) (genus Crinivirus) was determined and found to contain unique open reading frames (ORFs) and ORFs similar to those of other criniviruses, as well as 3' non-coding regions that shared a high degree of identity. Northern blot analysis of RNA extracted from LCV-infected plants identified subgenomic RNAs corresponding to six prominent internal ORFs and ...

Stored cut lettuce gradually turns brown on the cut section after several days of storage, because cutting induces phenylalanine ammonia-lyase (PAL) activity, the biosynthesis of polyphenol is promoted, and the polyphenols are oxidized by polyphenol oxidase. In this study, we screened for inhibitors of PAL derived from fermented broths of microbes and from foods and found that a cinnamon extrac...

Fast identification of pesticide residue level in lettuce leaves plays a key role in the test of food safety. In order to identify the different concentrations pesticide residues of lettuce leaves in a fast and nondestructive way, the hyperspectra coupled with chlorophyll fluorescence spectra was used in this research. Transmission electron microscopy (TEM) was used to identify the microstructu...

mulches bring several benefits to lettuce cultivation.a study on the lettuce ‘red rapids’ has been conducted to determine the influence of the different colored plastic mulch on its growth. the experiment consisted of five color treatments as follows; treatment 1- metallic silver (control), treatment 2- red, treatment 3- orange, treatment 4- yellow and treatment 5-green. results showed that the...

This study was conducted to investigate the effect of free chlorine concentrations in wash water on Escherichia coli O157:H7 reduction, survival, and transference during washing of fresh-cut lettuce. The effectiveness of rewashing for inactivation of E. coli O157:H7 on newly cross-contaminated produce previously washed with solutions containing an insufficient amount of chlorine also was assess...

Currently, most fresh-cut processing facilities in the United States use chlorinated water or other sanitizer solutions for microbial reduction after lettuce is cut. Freshly cut lettuce releases significant amounts of organic matter that negatively impacts the effectiveness of chlorine or other sanitizers for microbial reduction. The objective of this study is to evaluate whether a sanitizer wa...

This study investigated the ability of five Salmonella enterica serovars to attach to and colonize intact and cut lettuce (Iceberg, Romaine) and cabbage surfaces. Biofilm formation and attachment of Salmonella serovars to intact and cut leaves were determined. Populations of loosely and strongly attached Salmonella were obtained to calculate the attachment strength (S(R)). Biofilm formation, as...

This study compared the efficacy of chlorine (20-200 ppm), acidic electrolyzed water (50 ppm chlorine, pH 2.6), acidified sodium chlorite (20-200 ppm chlorite ion concentration, Sanova), and aqueous chlorine dioxide (20-200 ppm chlorite ion concentration, TriNova) washes in reducing populations of Escherichia coli O157:H7 on artificially inoculated lettuce. Fresh-cut leaves of Romaine or Iceber...

Soil contamination is a public health concern in many countries but methods to assess dietary risk from soil metal toxicity have not been standardized worldwide. Laboratory data on urban soils are limited and do not adequately link metal content to associated food plant uptake. Cadmium is a health risk because it accumulates in lettuce and may be consumed at high levels by childbearing women. T...