Modified culture method detects a high diversity of fungal species in cystic fibrosis patients

Abstract

Cystic fibrosis (CF) is one of the most common genetic lung diseases worldwide. The production of sticky viscous mucus leads to enhanced bacterial colonization and infection, but yeasts and filamentous fungi are also found abundantly in the mucus of patients suffering from CF. The role of fungi in the airways of CF patients is still not understood completely. Furthermore, recent investigations have shown that the spectrum of fungi isolated from the airways of CF patients depends strongly on the methods used. In this study, different mycological culture methods were compared: culture with a native inoculum, culture with homogenization of CF sputum, and culture after homogenization and serial dilutions of CF sputum. Altogether, 934 sputum samples from 113 patients were examined from July 2009 through December 2011. A total of 1,744 fungal isolates was recovered; 20 different yeasts and 14 filamentous fungal species were identified. Candida albicans, C. dubliniensis, and C. parapsilosis were the most common species of yeast. For the filamentous fungi, Aspergillus fumigatus was the most common, followed by Scedosporium apiospermum/Pseudallescheria boydii group and A. terreus. Many fungal, species such as Exophiala dermatitidis, Rasamsonia (Geosmithia) argillacea, and others, were isolated only from homogenized sputum samples. The longitudinal data also show that fungal colonization of CF patients is quite stable, even when treated with itraconazole. In conclusion, we recommend homogenizing CF sputa with a mucolyticum, to prepare serial dilutions, and to use appropriate fungal culture media with added antibiotics.

Long-Term Rasamsonia argillacea Complex Species Colonization Revealed by PCR Amplification of Repetitive DNA Sequences in Cystic Fibrosis Patients

“…Chronic granulomatous disease (CGD) (9, 10, 11) and cystic fibrosis (CF) (12,13,14,15,16,17) are the major underlying clinical conditions. Rasamsonia infections may also occur in bone marrow transplant recipients (18, 19) but also may occur in the absence of any predisposing factors, as evidenced by the pulmonary and aortic graft infection reported by Doyon et al (20) in an immunocompetent individual.…”

Glivne okužbe pri bolnikih s cistično fibrozo

“…Most research indicates that E. dermatitidis has the role of a coloniser in CF and that the isolation from the respiratory tract normally does not indicate an infection. At the moment, the identified risk factors for the colonisation with E. dermatitidis are the age above 12, pancreatic insufficiency and the colonisation with A. fumigatus (40,43). It is interesting that the occurrence of E. dermatitidis drops after the age of 35 (41).…”

“…It is mostly a chronic colonisation, which can be established only after an extended incubation period on classic and/or specific mycological media with the addition of erythritol and chloramphenicol (40). For the isolation of E. dermatitidis, clinical samples have to be incubated for 5 to 7 days on average (43).…”

Pilzpneumonien: Gibtʼs die?

“…Bei Patienten mit Mukoviszidose kann die Lunge darüber hinaus auch noch von vielen anderen Pilzen kolonisiert sein, wie etwa Geosmithia (Rasamsonia) argillacea und Graphium spp. [8], was zu entzündlichen pneumonischen Reaktionen führen kann.…”

“…Enzephalitis, die erst infolge der Lungenherde nach Disseminierung resultieren, wenn die ersten Stadien übersehen wurden und nicht umgehend eine antimykotische Therapie eingeleitet wurde. [8]. Sie dürften eine beträchtliche Rolle bei den nachfolgenden entzündlichen Reaktionen des Lungengewebes spielen [23,24].…”