Specific detection of Bjerkandera adusta by polymerase chain reaction and its incidence in fungus-associated chronic cough.

Chronic cough is a common symptom at outpatient care. An uncontrollable cough with difficulty in treatment is called chronic idiopathic cough. Recent reports have demonstrated that the presence of basidiomycetous fungi in sputum is an important clinical finding that assists in clarifying the cause of chronic cough in some cases. Research has suggested that Bjerkandera adusta is related to fungus-associated chronic cough (FACC). FACC is defined as a chronic cough associated with basidiomycetous fungi found in induced sputum and can be treated with antifungal medication. B. adusta is one of the basidiomycetous fungi that exist in cosmopolitan environments. The aim of this study was to develop a B. adusta detection method using polymerase chain reaction (PCR) with a specific primer set and to research the incidence of B. adusta in FACC. The new method successfully detected B. adusta from FACC patients. The incidence of B. adusta in FACC was 42.86 %. Antifungal drugs were effective in most cases. Significant differences in treatment duration between B. adusta patients and non-B. adusta patients were observed. It is therefore suggested that the presence of B. adusta may be one of the allergic intractable factors of chronic cough. This finding may provide identifiable differences in clinical manifestations between B. adusta and non-B. adusta in FACC and lead to possible differing remedies to treat the two forms. PCR can specifically detect B. adusta from patients suffering from chronic cough and provides a new diagnosis for FACC associated with B. adusta.