Hi, Here are the answers to your questions: - When - volume / frequency etc - is a pathogen deemed colonised? ANSWER: The term colonized is used when bacteria form colonies (small groups). Colonization in vitro (in the lab) means that visible bacterial colonies are noted. Definitive number of organisms is not known. Colonization in vivo (inside the organism) also means that visible colonies present. In terms of lungs and bronchi, this can be alleged only after bronchoscopy (a tube with camera is inserted inside the lungs). - What are symptoms of respiratory A xylososixidans eg colour of sputum as opposed to other bacteria? ANSWER: There are no symptoms specific to this organism. The diagnosis is suspected with certain risk factors (e.g. this organism lives in water) and is confirmed by the lab. - What is usual effective treatment? ANSWER: Some studies found that anti-pseudomonas antibiotics are very effective against this organism. Some strains are also susceptible for fluoroquinolones. Please check with your doctor for specific drug names. - Is it usual for non-CF bronchiectasis to present with so many (circa 8) lung pathologies? ANSWER: Yes, it is possible. Bronchoectatic disease in the long run is complicated by multiple organisms some of which become resistant to certain antibiotics with time and require change of medications. Hope this helps. Kind Regards,