Case Report: Rare Community-Acquired Pneumonia with Concurrent Methicillin-Resistant Staphylococcus aureus and Cryptococcus neoformans Infection in an Immunocompetent Young Male

Abstract: Cryptococcal pneumonia predominantly occurs in immunocompromised patients, but its incidence among immunocompetent individuals has been increasing in recent years. However, cases of co-infection with Cryptococcus neoformans and community-acquired methicillin-resistant Staphylococcus aureus ( CA-MRSA ) in immunocompetent hosts remain exceedingly rare. This study reports on a previously healthy 30-year-old male who presented with 20-days cough and 1-day fever. Through nanopore targeted sequencing (NTS) of bronchoalveolar lavage fluid (BLAF) and traditional microbial culture, he was ultimately diagnosed with a co-infection of C. neoformans and CA-MRSA . The patient showed significant improvement after treatment with oral linezolid (0.6 g twice daily) for 2 weeks and oral fluconazole (400 mg once daily) for 6 months. This case highlights that even immunocompetent individuals can simultaneously contract multiple community-acquired pathogens, while also underscoring the clinical utility of NTS in the early diagnosis of co-infections and detection of resistance genes. Keywords: community-acquired methicillin-resistant Staphylococcus aureus , Cryptococcus neoformans , pulmonary infection, nanopore sequencing, case report