DNA and Flesh Eating Bacteria

Written by: Paul Arnold • Edited by: Paul Arnold
Updated Nov 25, 2009 • Related Guides: Fever

Flesh eating bacteria conjure up a nasty image of tiny creatures crawling all over bodies devouring flesh. Far from being the product of the warped mind of a screenwriter these bugs exist and cause a rare infection known as necrotising fasciitis. Knowing how they function will help to defeat them.

Flesh Eating Disease

Necrotising fasciitis is a rare disease that can be caused by many different types of harmful bacteria, such as Group A streptococcus, Staphylococcus aureus and Clostridium perfringens. They attack the tissues under the skin's surface including fat and muscle. These start to decay and die as the bacteria release toxins. Infection usually starts at a wound or trauma site. The causative bacteria usually cause mild infections, but in rare cases where an individual has a weakened or lower immune system, or is just recovering from a viral infection, the bacteria can turn nasty. The symptoms include fever, chills, nausea, vomiting or a person may be in pain from an injury that improves over and day or so, before suddenly becoming worse. Early detection and a prescription of antibiotics is vital. However, one of the frightening aspects of the disease is that it can spread quickly, and then the only treatment is surgical removal of the infected areas.

Flesh Eating Bacteria

Photomicrograph of Clostridium perfringens, the bacteria can cause flesh eating disease - image released into the public domain by the Centers for Diseases Control and Prevention

click to enlarge

There are signs that flesh eating bacteria, in common with our many other bacterial foes, are developing resistance to antibiotics. However, the study of the genetics of these harmful bacteria and how they work at the molecular level will equip science with new strategies and therapeutics to wipe them out. If you know how the enemy operates you can design weapons that will bring about its destruction.

Scientists from the University of California, San Diego, School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences have discovered just how Streptococcus pyogenes is able to evade the immune system response and spread throughout the body. It appears that a protease known as SpyCEP (Streptococcus pyogenes cell envelope protease) inactivates and degrades a key molecule that controls the ability of white blood cells to fight bacteria. In the face of this onslaught white blood cells become slow and weak. But when the scientists knocked out a gene encoding SpyCEP the flesh eating bacteria were easily destroyed by neutrophils.

Another way of potentially neutralising the effect of these harmful bacteria could be by stimulating the body's immune system via a vaccine. Another team of researchers (also from UC San Diego) has been looking at Streptococcus M protein, which is critical to its virulence. They inoculated mice with a stable version of the protein and it stimulated their immune systems, providing hope that a similar reaction could be see in humans if a vaccine is developed.

As with any study of harmful bacteria, the more we know about their biological make up, and how they cause disease the better will be our defences and weapons.