Lung infections

There are many strains of Pseudomonas aeruginosa (P. aeruginosa), which people with CF most often acquire from the environment, and they can usually be gotten rid of or kept under control with early antibiotic treatment. However, if it takes root and starts to become resistant to antibiotics (also known as ‘antimicrobial resistant’), it can cause problems.

There is concern that people with CF are more likely to pick up particular strains of P. aeruginosa from each other that are harder to treat than strains contracted from the environment. This is why CF centres should offer separate clinics for people with CF according to whether or not they have P. aeruginosa.

P. aeruginosa is the most common lung infection in people with CF over the age of 16. 27% of people with cystic fibrosis are living with chronic P. aeruginosa infection, according to 2018 data by the UK CF Registry, 12% fewer than 10 years ago.

What are we doing about it?

Several Trust-funded Strategic Research Centres (SRCs) have been investigating P. aeruginosa. An SRC run by Professor Jane Davies at Imperial College investigated better detection, understanding and treatment of P. aeruginosa, and Professor Davies is leading an SRC, investigating ways to tailor the treatment of P. aeruginosa to the individual.

Another SRC that began in autumn 2019 at the University of Cambridge, led by Dr Martin Welch, looks at why P. aeruginosa specifically adapts to the CF lungs, and how this knowledge might be applied to the development of new treatments. We are also co-funding a number of Venture and Innovation Awards in the area of P. aeruginosa research.

Mycobacterium abscessus (M. abscessus) is the most common strain of non-tuberculous mycobacteria (NTM). M. abscessus is distantly related to tuberculosis and can cause lung infections in people with CF. Some NTM types can cause problems around the time of a lung transplant because they can be difficult to clear from the airways with treatment. Download our factsheet on NTM to read more.

Around 3.9% of people with CF in the UK grew NTM in their sputum in 2021, down from 6.7% in 2019. For those who develop an NTM lung infection, though, it can still be a serious concern.

Read the guidelines on NTM infection issued by Thorax, the international journal for health professionals working in respiratory medicine. These guidelines were developed as a result of Trust-funded research into NTM. Find out more here.

What are we doing about it?

A Trust-funded Strategic Research Centre, led by Professor Andres Floto, worked to discover how M. abscessus spreads and how this can be prevented, why some strains of NTM cause more lung damage than others, and how new drugs might be developed to treat M. abscessus more effectively. A second SRC is now underway that is taking the learnings from the previous research centre to help develop new treatments for people with CF who are infected with M. abscessus.

Burkholderia cepacia complex (B. cepacia) is a rare bacteria that lives in damp or wet places like soil. It was first discovered by Walter Burkholder, a plant scientist, in 1950, who identified it on the skin of onions. It is called a ‘complex’ because there are many species of Burkholderia bacteria, some of which are more harmful than others.

B. cepacia was the first bug discovered to be passed between people with CF, leading to guidelines to minimise person-to-person infection, later becoming known as ‘cross-infection rules’. In the mid to late 1990s, following research into the rise in incidences of B. cepacia, it was decided that people with the bug should be kept apart from others with CF because they could be passing it between each other. Later it was found that there are several types of B. cepacia complex, some more serious than others because of the treatment-resistant nature of the bug, and so people with B. cepacia were further separated when attending outpatient clinics according to which strain they had.

4% of people with CF are living with chronic B. cepacia infection according to 2018 data from the UK CF Registry, 1% more than 10 years ago.

Other strains of B. cepacia complex include Burkholderia cenocepacia (B. cenocepacia) and Burkolderia multivorans (B. multivorans).

What are we doing about it?

Bacteria use clever defences against the body’s immune system. When they have been ‘engulfed’ by immune cells, they shoot out a defensive toxin. This kind of chemical warfare is a common defence by bacteria. As the toxin is specific to the type of bacteria, to develop effective treatments it is important to identify the nature of the toxin. The Trust funded research by Professor Miguel Valvano at Queen’s University Belfast that led to the identification of the defensive toxin that B. cepacia uses to protect itself. In follow-on funding from the Medical Research Council, Professor Valvano is exploring the damage B. cepacia causes the immune cells in more detail. It is hoped that this research will lead to treatments being developed to prevent or correct the toxin damage, in turn reducing inflammation and lung damage in people with cystic fibrosis.

Find out more about B. cepacia and what is being done to combat it here.

Read the UKHSA guidance on carbomer eye gels (November 2023)

As well as infections from bacteria, people with CF are susceptible to developing fungal infections, including the fungus Aspergillus fumigatus. Some of these people will develop more severe conditions as a result of the infection including Aspergillus bronchitis (AB) and allergic bronchopulmonary aspergillosis (ABPA).

Aspergillus infection can lead to accelerated lung damage in people with CF, and the current anti-fungal treatments, which the fungus is also becoming resistant to, have side effects. In addition, having Aspergillus infection will be taken into account during transplant discussions, as it may get worse post-transplant.

15% of people with CF are living with chronic Aspergillus infection according to 2018 data from the UK CF Registry, 7% more than 10 years ago.

What are we doing about it?

A new SRC investigating Aspergillus fumigatus will begin in the autumn. Dr Darius Armstrong James from Imperial College will be investigating the potential of alternative treatment approaches for Aspergillus infection. He and international colleagues working within this SRC will also be seeking to understand more about AB and ABPA, to identify those people who might be susceptible to developing these complications, and to gain clues for effective treatment strategies.

There are a number of other bugs that can affect people with cystic fibrosis. Some of these include:

• Staphylococcus aureus (S. aureus)
• Methicillin-resistant Staphylococcus aureus (MRSA)
• Haemophilus influenzae (H. influenzae)

We are funding millions of pounds worth of research into fighting dangerous infections. Take a look at the Venture and Innovation Awards that we are co-funding to understand and treat infections and read about our Innovation Hub, which is harnessing multidisciplinary world-class research to prevent lung damage in cystic fibrosis.