Case report: Rare pulmonary fungal infection caused by Penicillium digitatum: the first clinical report in China

Abstract

Penicillium digitatum is a common plant pathogen that causes citrus rot, which is extremely rare in humans. We report a case of a 66-year-old man with a history of consuming large amounts of citrus fruits, smoking for 30 years, and a history of emphysema. He had experienced intermittent coughing with sputum for more than 10 years and was admitted to the hospital due to worsening of symptoms over the past month. Despite antibiotic treatment, his condition did not improve. Subsequently, bronchoalveolar lavage fluid (BALF) was detected by metagenomic next-generation sequencing (mNGS), which showed the presence of P. digitatum. The fungal culture of BALF also indicated the presence of the Penicillium genus. The diagnosis was lung infection caused by P. digitatum, and the patient was treated with itraconazole. The lung infection was controlled. This is the third reported case of invasive pulmonary fungal infection caused by P. digitatum worldwide at the genus level, and the first reported case in China. Although human infections caused by P. digitatum are rare, as an emerging opportunistic pathogen, the detection of this fungus in immunocompromised patients should still be clinically important.