Case report: co-infection of Scedosporium and Mycobacterium in lungs

There are hundreds of pathogens that cause lung infections. Compared to infections caused by a single pathogen, mixed infections account for a larger proportion of pulmonary infections and have a more severe clinical presentation, while treatment options differ between the two. We aimed to explore the advantages of metagenomic next-generation sequencing (mNGS) in the diagnosis and treatment of mixed infections.

To investigate the specific pathogens in a 79-year-old male pneumonia patient who had recurrent cough with poor empirical treatment, we collected bronchoalveolar lavage fluid (BALF) from the patient and performed mNGS technology, along with Sanger sequencing and polymerase chain reaction (PCR) was carried out to confirm the authenticity of the pathogens detected by mNGS. The findings showed that rare pathogen Scedosporium boydii (S. boydii, reads: 18) and Mycobacterium avium complex (MAC, reads: 19) were detected, and the patient was subsequently transferred to another hospital for the same mNGS with the same results as the first detection. Therefore, combined treatment with voriconazole, ethambutol, azithromycin, and levofloxacin were given to the S. boydii and MAC for 1 week, and then patient's condition improved and discharged.

mNGS, a non-targeted sequencing technology, could improve the efficiency of clinical diagnosis for mixed infection of rare or atypical pathogens, bring new ideas for clinical pathogen diagnosis, and improve patient prognosis.