Toys, books, cribs harbour bacteria for much longer periods than believed

A new study has shown that two common bacteria, Streptococcus pneumoniae and Streptococcus pyogenes, that cause colds, ear infections, strep throat and more serious infections persist on surfaces for far longer than has been appreciated.

The findings suggested that additional precautions may be necessary to prevent infections, especially in settings such as schools, daycare centers and hospitals.

Senior author Anders Hakansson, PhD, assistant professor of microbiology and immunology in the UB School of Medicine and Biomedical Sciences, said that this is the first paper to directly investigate that these bacteria can survive well on various surfaces, including hands, and potentially spread between individuals."

The UB researchers found that in the day care centre, four out of five stuffed toys tested positive for S. pneumonaie and several surfaces, such as cribs, tested positive for S. pyogenes, even after being cleaned.

The testing was done just prior to the centre opening in the morning so it had been many hours since the last human contact.

He explained 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.

The UB experiments found that month-old biofilm of S. pneumoniae and S. pyogenes from contaminated surfaces readily colonized mice, and that biofilms survived for hours on human hands and persisted on books and soft and hard toys and surfaces in a daycare center, in some cases, even after being well-cleaned.

The study was published in journal Infection and Immunity.