Salmonella transfer potential onto tomatoes during laboratory-simulated in-field debris removal

Florida Tomato Good Agricultural Practices (T-GAPs) mandate the removal of dirt and debris from tomatoes during harvest but do not provide any specific regulations or guidance; thus, the current practice of using cloths needs to be evaluated. This study examined Salmonella transfer from inoculated green tomatoes to uninoculated cloths and from inoculated cloths to uninoculated tomatoes, upon single and multiple touches.

food-art-tomatoTomatoes were spot inoculated with a rifampin-resistant Salmonella cocktail (107 CFU per tomato) and were touched with cloth (clean, dirty-dry, dirty-wet) at 0, 1, or 24 h postinoculation. Salmonella was enumerated on tryptic soy agar, followed by enrichments when necessary. The transfer direction was then reversed by touching freshly inoculated cloths with uninoculated tomatoes. Transfer coefficients (TCs) were then calculated. Salmonella TCs from inoculated tomato and cloth were highest when the inoculum was wet (0.44 ± 0.13 to 0.32 ± 0.12), regardless of the condition of the cloth. Although Salmonella TCs from inoculated tomato to uninoculated cloth decreased significantly when the inoculum was dried (0.17 ± 0.23 to 0.01 ± 0.00), low levels of Salmonella were detected on cloth even after 24 h of drying. Inoculated dirty cloth did not transfer more Salmonella compared with inoculated clean cloth, and Salmonella survival was not higher on dirty cloth. When inoculated clean cloth (wet) was touched with 25 tomatoes, significantly higher levels of Salmonella were transferred to the first, second, and fourth tomatoes (0.03 ± 0.10 to 0.09 ± 0.02). However, inoculated dirty-wet (below limit of detection) and dirty-dry (0.00 to 0.04 ± 0.01) cloths transferred similar levels of Salmonella to all 25 tomatoes.

Results indicate a low risk of potential Salmonella contamination when the same cloth is used multiple times for debris removal, especially under high moisture levels. Results also show that the use of dirty cloths did not increase the risk of Salmonella cross-contamination.

Journal of Food Protection®, Number 7, July 2014, pp. 1052-1240, pp. 1062-1068(7)

Sreedharan, Aswathy1; Schneider, Keith R.2; Danyluk, Michelle D.3

What’s on those cloths used to wipe tables at restaurants?

There’s a reason silverware is often delivered on or in a napkin at a restaurant: to prevent contact with the gunk on the table.

All proper-mannered people will unwrap the knife and fork and spoon and tuck the napkin into their shirt collar.

Food comes on a plate. Silverware hits the table. What’s on the table?

One of my favorite questions when dining out is, what was the table wiped with, as a server finishes cleaning up from the previous diners.


Sanitizing stuff.

Lisa Gibson of Access Atlanta notes that various restaurants, from the upscale ones to the deli type and wings spots, face food safety citations related to wiping cloths and sanitizing solution.

When restaurants fall short in this area, inspectors advise the managers on proper procedures. Also, Georgia’s food safety guidelines are clear on this subject:

Cloths in-use for wiping food spills from tableware and carry-out containers that occur as food is being served shall be maintained dry and used for no other purpose.

Cloths in-use for wiping counters and other equipment surfaces shall be held between uses in a chemical sanitizer solution at a concentration specified. …

Cloths in-use for wiping surfaces in contact with raw animal foods shall be kept
separate from cloths used for other purposes.

Dry wiping cloths and the chemical sanitizing solutions in which wet wiping cloths are held between uses shall be free of food debris and visible soil.

How clean was the cloth used to clean tables in your restaurant

A reader asked Katie Fairbank of the Dallas Morning News, "Why do restaurants use those filthy rags to clean off your table

Fairbank says there have been plenty of times that I’ve watched a disgusted lunch companion wipe down a table right after it was swiped clean with a sopping wet dish towel.

"I am one of those people," said restaurant legend Gene Street. "I carry my little thing with Clorox wipes around in my car. When I go into a restaurant, I wipe it all down – especially the salt and pepper, since everyone touches their nose or their mouth and then touches them. Can you imagine what could be on those?"

The state and cities have regulations on exactly what restaurants need to do to clean tables. If that rag really is "filthy," the restaurant is not up to code, and the inspectors would like to know about it.

"There are a lot of viruses out there that can be transmitted from a surface," said Chauncy Williams, sanitarian supervisor for the city of Dallas. "Bacteria tend not to live long, but there are instances where a wet surface can help sustain it."

Dallas regulations require restaurants to have wiping cloths available to clean work areas, equipment, counters and customer tables. The cloths are always soaking wet, because they must be stored in a sanitizing solution. The solution itself must be tested periodically throughout the day to make sure it’s the right concentration. If it’s too strong, it could be too toxic. Too weak, and it doesn’t do the job.

Cafes, bars, restaurants and fast-food joints are also supposed to change the solution several times each day to make sure it hasn’t gotten dirty.

Restaurant cleaning cloths pose health risk, says study

I have a number of anecdotal studies going on whenever I go to the supermarket, a restaurant, a baby doctor, and other places.

When we go to a roadhouse-style restaurant, I often watch the servers clean the table with some sort of cloth, and I’ll ask, what is the cloth cleaned with or soaked in? They usually point to some sorta sanitary solution, but aren’t too knowledgeable about how often it’s changed or cleaned. Same with those aprons the chefs are always wiping their hands on – I have dreams of large sample sizes.

The U.K. Health Protection Agency does have some resources so set about to sample those clothes used to wipe down tables in restaurants and takeaways and found they are often contaminated with E coli, listeria and other potentially dangerous bacteria.

The Guardian reports that cloths used to clean surfaces where food is prepared need to be changed regularly or thoroughly disinfected to prevent the growth of bacteria that can cause food poisoning.

HPA researchers sampled 133 cloths used for cleaning in 120 restaurants and takeaways in the north-east of England. They told the HPA’s annual conference at the University of Warwick today that 56% of the cloths contained unacceptable levels of bacteria. The most common were enterobacteriaceae (found on 86 cloths) E coli (21), Staphylococcus aureus (six) and listeria (five).

Only a third of restaurant kitchens (32%) were following the recommendation to use disposable cloths and change them regularly. The remainder had reusable cloths; in 15% of the kitchens, staff were unsure how often they were replaced.

John Harford, of the HPA’s food, water and environmental microbiology laboratory, said there was no reason to suppose restaurant kitchens in the north-east operated differently from those elsewhere in the country. He pointed to the potentially serious consequences for those eating food in or from such restaurants, adding,

"We have had certain outbreaks of food poisoning at a restaurant where we have isolated salmonella from the person who has eaten the meal and we have found salmonella on the cloth in the kitchen as well.”

While most restaurants disinfected their reusable cloths every 10 to 24 hours, a number of restaurants left it longer than 24 hours and some did not know how often their cloths were disinfected.

Lack of food safety costly for diners, eateries; Alabama training center tries to fix errors

Here’s a common scene from many of the mom and pop restaurants I’ve visited: a towel used to sop up juice from raw hamburger meat also is used to wipe down counters.

Phyllis Fenn, a standardization officer with the Alabama Department of Public Health’s bureau of environmental services, has seen the same thing – too often.

The Montgomery Advertiser reports today the Food Safety Training Center on Atlanta Highway is an attempt both to help restaurant owners avoid bad inspections and to protect their customers’ health.

When Alabama adopted the 2005 Food Code, one provision was that at least one person in restaurants where raw foods are handled, including fast-food eateries and sushi bars, would become food safety certified. When the state adopted the code, it opted to go with a lead-in time — Jan. 1 of this year.

The classes can help restaurants improve their health department inspection scores, which is exactly what they are designed to do, Fenn said.

She said the certification class helps restaurants reduce food-related illnesses as well as teaching them about the proper temperatures to cook and hold food (the temperature of food that sits out at a buffet) and proper hygiene.