J&J/Ethicon gets patent on predicting whether wound is infected
The technique measures the levels of biological molecules associated with an immune response by the body to bacteria in a wound.
By measuring the presence of these molecules, doctors can tell if the wound is likely to become infected.
Doctors will be able to take a swab of a patient's wound after surgery before putting the dipstick into a tube of reactants.
If the chemicals then change colour it means the wound is in the early stages of infection and doctors can combat the bacteria before it gets a foothold.
Breda Cullen, who invented the method, claims that it would also reduce the need to use antibiotics to fight superbugs such as MRSA by stopping them before they cause an infection.
[text from news.scotsman.com]
The GB patent discussed in the Scotsman is presumably related to US published application 20050079542 (10/494507; PCT /GB02/05023)
Claim 1 recites:
A method of predicting or diagnosing clinical infection of a wound comprising measuring the concentration of a marker associated with an inflammatory response in wound fluid, wherein the marker is a fibronectin fragment, a neutrophil protease or a macrophage protease.
The text includes:
 Infection of wounds by bacteria delays the healing process, since bacteria compete for nutrients and oxygen with macrophages and fibroblasts, whose activity are essential for the healing of the wound. Infection results when bacteria achieve dominance over the systemic and local factors of host resistance. Infection is therefore a manifestation of a disturbed host/bacteria equilibrium in favour of the invading bacteria. This elicits a systemic septic response, and also inhibits the multiple processes involved in wound healing. Lastly, infection can result in a prolonged inflammatory phase and thus slow healing, or may cause further necrosis of the wound. The granulation phase of the healing process will begin only after the infection has subsided.
 The persistent presence of bacteria in injured tissue results in the prolonged elevation of proinflammatory cytokines such as interleukin-1 and tumour necrosis factor alpha (TNF-.alpha.). This in turn causes increases in the levels of matrix metalloproteinases, a decreased level of tissue inhibitors to the metalloproteinases (TIMP), and a decreased production of growth factors.
 It has been discovered that wound fluid from wounds that are apparently not clinically infected but which go on to become infected within a few days have high levels of neutrophil elastase activity and may also have high levels of other inflammatory proteases, such macrophage proteases and other neutrophil proteases. Similarly, the concentration of fibronectin fragments may also provide a useful indication of the likelihood of subsequent clinical infection; the presence of such fragments in chronic wounds being mainly due to high levels of elastase activity.
 According to the present invention, there is provided a method of predicting or diagnosing clinical infection of a wound comprising measuring the concentration of a marker associated with an inflammatory response in wound fluid, wherein the marker is a fibronectin fragment, a neutrophil protease or a macrophage protease.