Soda Fountains Squirt Fecal Bacteria, Study Finds

Jan. 8, 2010— -- Those soda fountain machines found in restaurants and fast food joints may be squirting out liquids contaminated with fecal bacteria, a small study found.

Whether it was self-serve or behind the counter, nearly half of all sodas dispensed from a sample of 30 machines in the Roanoke Valley in Virginia had coliform bacteria -- a group of bacteria banned in drinking water by the U.S. Environmental Protection Agency (EPA) because it indicates the possibility of fecal contamination.

"The EPA regulates our drinking supply, and there can be some bacteria, but one of the things that is not allowed is coliform bacteria," said Renee D. Godard, professor of biology at Hollins University and a co-author of the paper published in the January print issue of the International Journal of Food Microbiology.

"We can't have that in our drinking supply. But they're coming out of these soda fountain machines," she said.

The soda machines had turned into a bacteria metropolis with Escherichia coli (E. coli), species of Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia. Most of the bacteria were resistant to the 11 antibiotics Godard tested on her samples.

"About 70 percent of the beverages had bacteria and 48 percent of them had coliform bacteria," said Godard.

However, only 20 percent of the sodas sampled had coliform bacteria that exceeded the EPA limit for drinking water.

Since the tap water and ice from the machines didn't test positive for bacteria, Godard and her team ruled out the possibility of a valley-wide contamination of the water supply.

Various brands of soft drinks and various types -- sugared, diet or even water -- were contaminated, leading Godard to think that it wasn't the soda, but the machine that was growing bacteria.

From all her testing, Godard still isn't sure where the bacteria came from. Few people observed in the restaurants touched the nozzles of the soda fountain machines and restaurant managers Godard interviewed reported cleaning the nozzles daily.

But only one restaurant manager reported rinsing the plastic tubing within the machines on a regular basis.