Touching Lives - March 2012
Tracing the cause of a deadly infection
Pseudomonas aeruginosa can be a dangerous bacterium and a leading cause of death among people with cystic fibrosis. Researchers funded by Action Medical Research have identified some of the reasons why it is so dangerous.
The healthy among us have little to fear from Pseudomonas aeruginosa, but for some, infection is deadly. The bacterium can kill within 24 hours of striking and is a major cause of hospital-acquired infection, with an estimated 10,000 cases a year in the UK alone.
The risks are even higher for people with cystic fibrosis. Up to 80 per cent of adults with the condition unknowingly carry the bacteria in their lungs and are therefore more prone to infection. All too often infection is severe – initial fever, cough, shortness of breath and chest pain can progress worryingly quickly until the patient is at substantial risk of organ failure, pneumonia, septicaemia and even death. Survivors can be left disabled for life.
Unfortunately, treating people with Pseudomonas infections can be tricky, as the bacteria are renowned for their resistance to antibiotics. Individual Pseudomonas bacteria also differ considerably from one another. For example, some strains are adept at spreading from one person to another, others to surviving or resisting antibiotics. They’re also constantly evolving.
Researchers, led by Dr Kumar Rajakumar at the University of Leicester, set to work studying the genetic differences between a wide spectrum of different Pseudomonas bacteria. They successfully identified two areas of DNA that affect how the bacteria cause infections and how they may develop resistance to antibiotics. They also identified a hyper-virulent strain adapted to causing acute lung infections.
This work is key to paving the way for better ways to prevent, diagnose and treat Pseudomonas infections. It could even lead to new screening tools that could tell doctors whether people have been infected with a particularly nasty strain of the bacteria.