A video highlighting the lemon wedge and the bacteria problem is found at the website of ABC Channel 7 News (Arlington, Virginia, U.S.A.).

YouTube also has a video on the lemon wedge at: http://www.youtube.com/watch?v=3UcHYZ_Sc4I.

The abstract by Loving and Perz states the reason for their study, “Restaurateurs often place a lemon slice on the rim of a beverage glass, or afloat in the beverage, as a flavor-enhancer or a decorative garnish. The handling of the lemons before their placement in the beverage may not follow sanitary procedures. The study reported here investigated whether beverage lemon slices contain microbial contamination that could be consumed by a restaurant patron.”

In the experimental procedure used by the researchers, they, “Swabbed samples of the flesh and rind of lemon slices on the rims of beverage glasses were analyzed for microbial contents. Seventy-six lemons from 21 restaurants were sampled during 43 visits.”

Their conclusion was that, “Fifty-three (69.7 percent) of the lemon slices produced microbial growth. Twenty-three (30.3 percent) of the lemon slices produced no microbial growth. A total of 25 different microbial species were recovered from the samples.”

Because the study has become so popular and has been a national news story, a critique of the study appears at: http://www.snopes.com/medical/toxins/lemon.asp.

The “Urban Legends” website states that the study was indeed performed and is a valid scientific study. The critique goes into further details as to what the study does and does not prove.

The authors state within their paper, “It is not possible to definitively identify the origins of the microorganisms. While the Enterobacteriaceae and nonfermentative Gramnegative bacilli could have come from the fingertips of a restaurant employee via human fecal or raw-meat or poultry contamination, they might have contaminated the lemons before they even arrived at the restaurant.”

Thus, the study does not prove the origins of the bacteria on the lemon wedges. The lemons could have arrived at the restaurants contaminated, the knives used to cut the lemons into wedges or slices could have been contaminated, the glasses themselves could have been dirty, the fingers of the waitresses and waiters could have been infected with bacteria, or other valid reasons for contamination could have happened. However, a problem is highlighted in this study.

The authors comment on the potential problems with microbial growth on lemon slices and wedges within their article, “The microbes found on the lemon samples in our investigation all have the potential to cause infectious diseases at various body sites, although the likelihood was not determined in this study.”

Further, “An extensive search of the literature yielded no reported outbreaks or illnesses attributed to lemon slices in beverages. Establishment of an infection would depend upon the number of microbes introduced; this investigation did not include a quantitative determination of the numbers of microorganisms on the lemons. Other factors that would contribute to the establishment of an infection would include whether the organisms were resistant to multiple antibiotics, the general health and age of the individual, the status of the immune system, and the integrity of the mucous membranes of the lips and mouth.”

Thus, the study did not conclude whether anyone in contact with the lemons used in the study actually came down with a serious illness due to the contamination on the lemons.

The authors conclude, “Although lemons have known antimicrobial properties, the results of our study indicate that a wide variety of microorganisms may survive on the flesh and the rind of a sliced lemon. Restaurant patrons should be aware that lemon slices added to beverages may include potentially pathogenic microbes.”

The authors comment: “Further investigations could determine the source of these microorganisms, establish the actual threat (if any) posed by their presence on the rim of a beverage, and develop possible means for preventing the contamination of the lemons. It could also be worthwhile to study contamination on other beverage garnishes, such as olives, limes, celery, and cherries, and to investigate whether alcoholic beverages have an effect not seen with water and soda.”

It would be advisable, as the authors state, that further studies be performed to validate these results and to make further conclusions into the practice of placing lemon slices and wedges on drinks in restaurants. Potential problems could occur, although probably not proven from this study.

The complete Loving/Perz article (“Microbial Flora on Restaurant Beverage Lemon Slices") is found at: http://www.thefreelibrary.com/Microbial+flora+on+restaurant+beverage+lemon+slices.(FEATURES)(Author...-a0172839589.

State health laws in the United States generally require that restaurant workers wear gloves or use tongs while handling food. If the lemon slices and wedges are not free of contamination when arriving at the restaurant, then they should be properly washed before slicing them. When handling lemon slices, gloves should be worn, whether it is while workers are cutting them, placing them on glasses, or other such situations.