Title: REBUTTAL LETTER FOR INTERNATIONAL FRESH-CUT PRODUCE ASSOCIATION LETTER TO
THE EDITOR OF THE JOURNAL OF FOOD PROTECTION
Authors
Wachtel, Marian
Whitehand, Linda - 5325-01-00, ARS-PWA-WRRC
Mandrell, Robert - rob - 5325-21-00, ARS-PWA-WRRC
Submitted to: Journal of Food Protection
Publication Type: Other
Publication Acceptance Date: April 1, 2002
Publication Date: N/A
Technical Abstract: In his letter, Dr. Gorny expressed concern over whether visual observations should
be considered data, and whether any conclusions can be drawn from such observations that merit
publication. During our E. coli O157:H7 adherence studies of plants grown in soil and inoculated via
irrigation water, we visually observed fluorescent bacteria moving within the vasculature of a lettuce
hypocotyl. Unfortunately, we were unable to record the movement of the bacteria on video. We believe
our observations made under controlled experimental conditions were novel and convincing proof to us
that E. coli were indeed inside the plant. Dr. Gorny feels these observations do not represent data. We
disagree. For example, the Random House dictionary defines data to be "an individual fact, statistic, or
piece of information or a group or body of facts, information, statistics, or the like, either historical or
derived by calculation or experimentation" or "any fact assumed to be a matter of direct observation."
We deliberately used the qualifying term "suggest" to draw attention to the observation without
overstating any conclusions. Our observations and subsequent suggestions, have now been
independently confirmed in a paper published in Applied and Environmental Microbiology 68:397-400.
This paper presents confocal images detailing viable E. coli O157:H7 inside lettuce after irrigation with
contaminated water. We appreciate that the internalization of food-borne pathogens within lettuce tissue
is of concern to the fresh produce industry. However, it should be stressed that our research is done to
assist our industry stakeholders, not to be alarmist.