How long can bacteria survive outside the body? Too long!

After returning home sick from a vacation -- my cough is now in its third week, antibiotics notwithstanding -- I wrote a column about how people who fly on airplanes are at an elevated risk for infection of all sorts.

One public health official said proximity to other sick people is a main culprit.  But another expert cautioned that airplanes are given thorough cleanings regularly, and that surfaces might be contaminated.

Recent research from the University at Buffalo in New York state lends new credence to that view.

The authors noted that conventional wisdom has long held that these bacteria won't linger on inanimate objects like furniture, dishes or toys.  But looking at two bacteria in particular in a day care center, they found that four out of five stuffed toys tested positive for one microbe many hours after children had been holding them, and several surfaces,  such as cribs, tested positive for another microbe even after being cleaned.

Specifically, the researchers looked at Streptococcus pneumoniae and Streptococcus pyogenes.

S. pneumoniae is a leading cause of ear infections and respiratory tract infections, and is a common cause of hospital infections, the authors said. S. pyogenes commonly causes strep throat and skin infections in school children but also can cause serious infection in adults, they said.

So what happened? How did the stuff survive?

Senior author Anders Hakansson, assistant professor of microbiology and immunology in the UB School of Medicine and Biomedical Sciences, said that studies of how long bacteria survive on inanimate objects have used cultures grown in laboratory media, called broth-grown planktonic bacteria, and invariably show that bacteria die rapidly, according to a press release about the research.

But they found in research published last year that bacteria form protectrive "biofims" when colonizing human tissue, and that may allow the bacteria to persist on surfaces.

"Commonly handled objects that are contaminated with these biofilm bacteria could act as reservoirs of bacteria for hours, weeks or months, spreading potential infections to individuals who come in contact with them," said Hakansson in the press release.  However, he said more research was needed to understand exactly how people would become infected.

It's certainly cause for ample thought when deciding whether to tuck antibacterial wipes into your carry-on luggage and use them to wipe the plane's tray tables and other surfaces.