Chronic mycobacterial meningitis due to Mycobacterium chelonae: a case report

Neurological manifestations of nontuberculous mycobacteria in adults: case series and review of the literature

Introduction

Nontuberculous mycobacteria (NTM) mediated infections are important to consider in cases with neuroinflammatory presentations. We aimed to characterize cases of NTM with neurological manifestations at the National Institutes of Health (NIH) Clinical Center and review the relevant literature.

Materials and methods

Between January 1995 and December 2020, six cases were identified. Records were reviewed for demographic, clinical, and radiological characteristics. A MEDLINE search found previously reported cases. Data were extracted, followed by statistical analysis to compare two groups [cases with slow-growing mycobacteria (SGM) vs. those with rapidly growing mycobacteria (RGM)] and evaluate for predictors of survival. NIH cases were evaluated for clinical and radiological characteristics. Cases from the literature were reviewed to determine the differences between SGM and RGM cases and to identify predictors of survival.

Results

Six cases from NIH were identified (age 41 ± 13, 83% male). Five cases were caused by SGM [Mycobacterium avium complex (MAC) n = 4; Mycobacterium haemophilum n = 1] and one due to RGM (Mycobacterium abscessus). Underlying immune disorders were identified only in the SGM cases [genetic (n = 2), HIV (n = 1), sarcoidosis (n = 1), and anti-interferon-gamma antibodies (n = 1)]. All cases were diagnosed using tissue analysis. A literature review found 81 reports on 125 cases (SGM n = 85, RGM n = 38, non-identified n = 2). No immune disorder was reported in 26 cases (21%). Within SGM cases, the most common underlying disease was HIV infection (n = 55, 65%), and seizures and focal lesions were more common. In RGM cases, the most common underlying condition was neurosurgical intervention or implants (55%), and headaches and meningeal signs were common. Tissue-based diagnosis was used more for SGM than RGM (39% vs. 13%, p = 0.04). Survival rates were similar in both groups (48% SGM and 55% in RGM). Factors associated with better survival were a solitary CNS lesion (OR 5.9, p = 0.01) and a diagnosis made by CSF sampling only (OR 9.9, p = 0.04).

Discussion

NTM infections cause diverse neurological manifestations, with some distinctions between SGM and RGM infections. Tissue sampling may be necessary to establish the diagnosis, and an effort should be made to identify an underlying immune disorder.

Epidemiology, clinical presentation, and predictors of outcome in nontuberculous mycobacterial central nervous system infection: a systematic review

BACKGROUND

CNS manifestations represent an emerging facet of NTM infection with significant mortality. Due to protean presentation and low index of suspicion, many cases are often treated erroneously as tubercular meningitis or fungal infections.

OBJECTIVES

Literature on NTM CNS disease is scarce, with most available data on pulmonary disease. This systematic review aimed to evaluate the epidemiology, clinical presentation, diagnostic modalities, and predictors of outcome in CNS NTM infection.

METHODS

The literature search was performed in major electronic databases (PubMed, Google Scholar, and Scopus) using keywords "CNS," "Central nervous system," "brain abscess," "meningitis," "spinal," "Nontuberculous mycobacteria," "NTM". All cases of CNS NTM infection reported between January 1980 and December 2022 were included.

RESULTS

A total of 77 studies (112 cases) were included in the final analysis. The mean age of all patients was 38 years, with most patients male (62.5%). Mycobacterium avium complex (MAC) was the most common aetiology, followed by M. fortuitum and M. abscessus (34.8%, 21.4% and 15.2%, respectively). The disseminated disease was found in 33% of cases. HIV (33.9%) and neurosurgical hardware (22.3%) were the common risk factors. Intracranial abscess (36.6%) and leptomeningeal enhancement (28%) were the most prevalent findings in neuroimaging. The overall case fatality rate was 37.5%. On multivariate analysis, male gender (adjusted OR 2.4, 95% CI 1.2-7.9) and HIV (adjusted OR 3.7, 95% CI 1.8-6.1) were the independent predictors of mortality). M. fortuitum infection was significantly associated with increased survival (adjusted OR 0.18, 95% CI (0.08-0.45), p value 0.012).

CONCLUSIONS

Current evidence shows the emerging role of rapid-grower NTM in CNS disease. Male gender and HIV positivity were associated with significant mortality, while M fortuitum carries favourable outcomes.

Histopathological Features of Mycobacterium chelonae Infection in Two Farmed Japanese Pufferfish (Takifugu rubripes)

Granulomatous lesions were observed in the swim bladder, kidney, spleen and gills of two farmed Japanese pufferfish (Takifugu rubripes) infected with Mycobacterium chelonae. Three types of lesions were noted: unencapsulated clusters of epithelioid cells without central necrosis (type 1), encapsulated granulomas without central necrosis (type 2) and encapsulated granulomas with central necrosis (type 3). Type 3 lesions occurred most frequently in the swim bladder, while type 1 and type 2 lesions occurred frequently in the kidney and spleen, and the gills exhibited mostly type 1 lesions. This suggests that the lesions in the swim bladder were more fully developed than those occurring elsewhere and that the swim bladder may be more susceptible to infection with M. chelonae. This is the first report describing the histopathological features of M. chelonae infection in Tetraodontidae.

Rhinosinusitis and disseminated cutaneous infection caused by Mycobacterium chelonae in an immunocompromised patient

Mycobacterium chelonae frequently involves the skin, and the disseminated form can be observed in immunocompromised patients. In contrast, rhinosinusitis caused by the bacterium is a rare manifestation, which occurs independently of immune status. We report here a rare case of M. chelonae infection presenting as both disseminated cutaneous infection and rhinosinusitis in an immunocompromised patient. He had received systemic corticosteroids for 11 months due to cryptogenic organizing pneumonia. Before admission, he sustained injuries to his left arm and hand; those injuries succumbed to an infection that would subsequently spread to his other limbs, face, and even nasal cavities. This valuable case suggests that disseminated cutaneous infection by M. chelonae could spread to other organs.