Meningitis caused by Mycobacterium fortuitum mimicking tuberculous meningitis in an immunocompetent patient: a case report and literature review.

Abstract Background: Nontuberculous mycobacteria (NTM) are a large group of microorganisms that mainly affect persons who have immune deficiency. Mycobacterium fortuitum is one of them, which usually cause soft tissue or pulmonary disease. Meningitis caused by M. fortuitum is extremely rare and is often confused with tuberculous meningitis (TBM) due to its low prevalence. Case presentation: A 35-year-old woman was referred to our hospital with a history of headache, followed by fever, chills, cough, and vomiting. The results of mycobacterial culture and TSPOT. TB of her cerebrospinal fluid were positive. Therefore, she was diagnosed with tuberculous meningitis and was given anti-tuberculous chemotherapy. During the observation, the CSF results were not significantly improved. Finally, hsp65 gene PCR revealed that the real pathogen was M. fortuitum . The treatment therapy was changed and the patient recovered after one-year combined chemotherapy. Conclusions: In this case we described a patient with M. fortuitum meningitis who was immunocompetent with no trauma or surgical history. The wrong diagnosis with TBM was made due to positive results of both blood and CSF TSPOT. TB . The pathological evidence and microbiological analysis of hsp65 gene PCR suggested the real pathogen to be M. fortuitum . The diagnostic accuracy of blood and CSF TSPOT. TB in case of TBM is moderate. Infections of NTM cannot be excluded when the patient does not respond to anti-tuberculous therapy and it is of great significance to do molecular identification for clinical isolates of mycobacterium.