[Histonet] Real science for real people (and their food)

Morken, Timothy Timothy.Morken <@t> ucsfmedctr.org
Fri Mar 4 14:37:36 CST 2011

Sometimes science helps us in the real world:

<http://www.nytimes.com/>February 28, 2011
The 5-Second Rule
By C. CLAIBORNE RAY<http://topics.nytimes.com/top/reference/timestopics/people/r/claiborne_ray/index.html?inline=nyt-per>
Q. You know the five-second rule for dropped food? Is it really safe if you pick it up in time?
A. "The five-second rule probably should become the zero-second rule," said Dr. Roy M. Gulick, chief of the division of infectious diseases<http://health.nytimes.com/health/guides/specialtopic/travelers-guide-to-avoiding-infectious-diseases/overview.html?inline=nyt-classifier> at Weill Cornell Medical College. "Eating dropped food poses a risk for ingestion of bacteria and subsequent gastrointestinal disease, and the time the food sits on the floor does not change the risk."
In general, if there are bacteria on the floor, they will cling to the food nearly immediately on contact, Dr. Gulick said. Factors that influence the risk and the rate of bacterial transfer include the type of floor; the type of food; the type of bacteria; and how long the bacteria have been on the floor.
In a study published in 2007 in The Journal of Applied Microbiology<http://docs.google.com/viewer?a=v&q=cache:BrqynEsaiVYJ:depts.noctrl.edu/biology/courses/101/handouts/AR2.pdf+dawson+cox+black+simmons+journal+of+applied+microbiology+2007&hl=en&gl=us&pid=bl&srcid=ADGEESiNzTjLZtZf1gSr5sS8yQPVciuArzJabBpzPAWPqdf7_2atJiIFVAAEhZ-gLfk2h0Xe4UK043KWIHSW5P-7WEAmgIaVtOQE55XNNYja9Mgmr0K8OtV3aWq6cJNt63BWpdDXoicZ&sig=AHIEtbSVFJOOgBX7Fhd2p_WDzSL0NG4UnQ>, Clemson University<http://topics.nytimes.com/top/reference/timestopics/organizations/c/clemson_university/index.html?inline=nyt-org> researchers tested salmonella<http://health.nytimes.com/health/guides/disease/salmonella-enterocolitis/overview.html?inline=nyt-classifier> placed on wood, tile or carpet, and dropped bologna on the surfaces for 5, 30 or 60 seconds. With both wood and tile, more than 99 percent of the bacteria were transferred nearly immediately, and there was no difference by the time of contact. Carpet transferred a smaller number of bacteria, again with no difference by contact time. The amount transferred decreased over hours, but there were still thousands of the bacteria per square centimeter on the surfaces after 24 hours, and hundreds survived on the surfaces for as long as four weeks. As few as 10 salmonella bacteria can cause gastroenteritis.C. CLAIBORNE RAY

Tim Morken
Supervisor, Histology, IPOX
UC San Francisco Medical Center
Box 1656
1600 Divisidero St, B217
San Francisco, CA 94115

415.514.6042 (office)
415.885.7409 Fax
tim.morken <@t> ucsfmedctr.org<mailto:tim.morken <@t> ucsfmedctr.org>

More information about the Histonet mailing list