Saturday, 24 May 2014

Fighting Bacteria in Biofilms with Antibiotics - A New Discovery

Scientists at the University of British Columbia have made what may be a very significant discovery with respect to antibiotic effectiveness. Antibiotics are chemicals used to kill infectious bacteria in our bodies. At the moment we are at a frightening time in our fight against bacteria. Antibiotics have served us very well in destroying bacteria and curing infections, but they are becoming less and less effective.

Bacteria in a biofilm - public domain photo from the CDC

Antibiotic resistance is a phenomenon in which a bacterium that was once killed by an antibiotic is no longer affected due to a random genetic change. When bacteria without the beneficial genes are killed by an antibiotic, the resistant bacteria have room and resources to multiply. Their helpful genes are passed to their offspring, eventually creating a resistant population. The term "antibiotic resistance" is also used to in another sense, however. It sometimes refers to the difficulty of killing biofilm bacteria with antibiotics.

Biofilms consist of layers of bacteria embedded in a jelly-like material. The bacteria in the biofilm  communicate with each other via chemicals and coordinate their behavior. A bacterial biofilm sometimes seems like one organism. The UBC researchers say that two thirds of human infections are caused by biofilm bacteria.

Bacteria in a protective biofilm are much harder to kill than free-living bacteria.  Biofilms are especially troubling because they form not only on surfaces inside the body but also on implanted medical devices, such as catheters.

The UBC researchers have found a specific peptide - a short chain of twelve amino acids - that stops biofilms from forming when applied to bacteria in lab equipment. They've called the peptide "1018". If this chemical works inside the human body it could be a wonderful advance in the war against bacteria. More research is needed, however. Results in lab equipment and inside our bodies are not always identical.