Fascination with 'bugs' leads to cystic fibrosis research

Dr Katherine Langan presenting at the
2016 CCS postgraduate symposium

by Anne Crawford

As a child, Katherine Langan was intrigued by bugs – but not the type you caught in jars. Dr Langan recalls being fascinated by infectious diseases since she was about 12 witnessing the advent, then spread of HIV/AIDs in Australia. Even then she wondered what could be done about it. 

Dr Langan’s interest in ‘bugs’ took her to Liverpool to study tropical medicine in 2011 and to Bangladesh to see first hand the effects of malaria in one of the country’s major teaching hospitals. The hospital was an eye-opener: there was no running water, no electricity for much of the day, patients had to pay for everything they used and were washed and fed by their families. Dr Langan watched as malaria killed young people who arrived too late to be effectively treated.

Now an infectious diseases specialist at The Alfred undertaking a PhD at the Central Clinical School, her preoccupation is with Pseudomonas aeruginosa, specifically in people with cystic fibrosis.

P. aeruginosa, a key respiratory pathogen in cystic fibrosis, is a challenging infection to treat as it can quickly become resistant to antibiotics. By adulthood, many people with cystic fibrosis are chronically infected with it. The average life expectancy of a person with the disease in Australia is 38 years.

“People with cystic fibrosis and chronic lung infections also get acute exacerbations every now and then,” Dr Langan said.

“In about one in four people, lung function doesn’t return to what it was before these exacerbations and when it happens again and again you get lung function so low that unless the patient has a lung transplant their long-term prognosis is poor,” she said.

Dr Langan’s first paper on P. aeruginosa, published as part of her PhD, reviews and summarises the existing recommendations for treatment of chronic infection and exacerbations.

“The review was able to highlight the areas of further research and the need for more research in better treating these exacerbations,” she said.

It concludes that there is “good evidence” for early eradication therapy to prevent the establishment of chronic infection and for inhaled antibiotics for the management of chronic infection. But the role of two new inhaled antibiotics and optimal treatment strategies for these were yet to be determined, the paper said.

Dr Langan’s research, co-supervised by Professor Anton Peleg, Associate Professor Tom Kotsimbos and Professor Allen Cheng at The Alfred’s Departments of Infectious Diseases and Allergy, Immunology and Respiratory Medicine, is part of ongoing investigations seeking more effective strategies for dealing with P. aeruginosa.

The researchers are conducting a clinical trial focusing on antibiotic treatment of exacerbations and the impact on the microbiome – the community of bacteria in the lung – as well as investigating markers of lung function and markers of inflammation.

“I always knew my focus would be on antibiotics,” Dr Langan said. “They’re such an important treatment for infection ­– but resistance is a big problem,” she said.

Dr Langan, who will finish her thesis this year, is also completing a clinical pharmacology fellowship at the Alfred, supervised by Dr Ingrid Hopper.

Reference:

Langan KM, Kotsimbos T, Peleg AY. Managing Pseudomonas aeruginosa respiratoryinfections in cystic fibrosis. Curr Opin Infect Dis. 2015 Dec;28(6):547-56. doi: 10.1097/QCO.0000000000000217.