📝 Article 1: What Are Biofilms – And Why Do They Matter in Aspergillosis?

🧫 What is a biofilm?

A biofilm is a protective layer that microorganisms (like fungi and bacteria) create when they stick to a surface — such as the inside of airways, lung cavities, or medical devices. They secrete a sticky matrix of sugars, proteins, and DNA that holds them together and shields them from harm.

In aspergillosis, Aspergillus fumigatus forms biofilms on:

• Mucus in the lungs

• Cavities or damaged tissue (e.g. in CPA)

• Surfaces of bronchial airways, especially in people with asthma or bronchiectasis

Pseudomonas aeruginosa, a bacterium often found alongside Aspergillus, also forms biofilms — and they can even form mixed (dual-species) biofilms together.

❗Why does this matter?

Biofilms protect the microbes inside by:

• Blocking immune cells from reaching them

• Preventing antibiotics or antifungals from penetrating the biofilm

• Allowing microbes to go dormant, then reactivate later

This is one reason why infections in aspergillosis patients can become chronic, relapse frequently, or be very hard to fully clear.

People with CPA, ABPA, SAFS, or fungal bronchitis may experience:

• Repeated flare-ups or infections despite treatment

• Persistent coughing, breathlessness, or mucus production

• Ongoing inflammation in the lungs, even when cultures are negative

🛠 How are biofilms treated?

Current options include:

1. Antifungals and antibiotics

• Standard antifungals (like voriconazole, posaconazole, isavuconazole) can sometimes penetrate biofilms, but often require longer or higher doses.

• Inhaled antibiotics (e.g. nebulised colistin or tobramycin) are used in bronchiectasis and can help break into bacterial biofilms.

• Combined therapy (targeting both bacteria and fungi) may be used in patients with co-infection.

2. Disrupting the biofilm

• DNase (Pulmozyme) in cystic fibrosis breaks up sticky DNA in mucus where biofilms form.

• Future treatments aim to use enzymes, surfactants, or nanoparticles to dismantle biofilms.

3. Clearing mucus and infected secretions

• Chest physiotherapy, postural drainage, and devices like the Acapella® or Flutter® help remove secretions where biofilms sit.

• Bronchoscopy is occasionally used to clear dense mucus plugs.

🔬 Looking ahead:

Researchers are studying:

• Drugs that target the biofilm matrix directly

• Ways to prevent biofilms from forming in the first place

• New diagnostic tools that detect biofilm presence