UNASSIGNED: Mycobacterium cosmeticum is an emerging rapidly growing mycobacteria (RGM) species that has been rarely reported to cause human disease. RGM catheter-related bloodstream infections (CRBSI) are often challenging to treat given the need for line removal, variable species-dependent antimicrobial susceptibility, combination antimicrobial treatment, and historically longer courses of antibiotics.
UNASSIGNED: We present a case of an immunocompetent pediatric patient with severe hemophilia B and M. cosmeticum CRBSI. While the patient\'s hemophilia B precluded a standard line holiday, he successfully cleared his infection with two line exchanges followed by two weeks of antibiotics.
UNASSIGNED: RGM, including emerging species M. cosmeticum, may be considered in patients with an indolent presentation of CRBSI. Our case suggests source control with shorter courses of antimicrobials can be successful.

Mycobacterium marinum, a photochromogenic, slow-growing mycobacterium, thrives in both marine and freshwater environments. Optimal growth occurs between 25°C and 35°C, with survival becoming challenging above 37°C. Typically, M. marinum enters the body via skin abrasions, often leading to infections of the upper extremities. Diagnosis of M. marinum infection is frequently challenging and delayed due to the difficult pathogen identification. At present, a standardized treatment protocol has yet to be established. Presented herein is a case study detailing an infection of the right hand\'s middle finger caused by M. marinum. Notably, his occupation as a chef, handling fish and seafood post-injury, was a significant factor. Histological examination of the skin biopsy and positive acid-fast staining were consistent with a diagnosis of mycobacterial infection. Pathological examination confirmed a skin infection with infectious granuloma, and tissue section acid-fast staining revealed acid-fast bacill. Cultures on Columbia blood agar yielded rough, flattened, yellow-fleshy colonies after 10 days, which was identified as M. marinum through 16S rRNA sequencing. The patient responded well to a 3-month regimen of oral moxifloxacin (0.4 qd) and linezolid (0.6 qd), resulting in rash resolution and pain relief, with no recurrence observed for 1-year follow-up. This report presents the first documented acid-fast staining images of M. marinum tissue sections and colony morphology photographs, offering an in-depth view of M. marinum\'s morphological characteristics. It aims to enhance awareness of M. marinum infections, underscore the necessity for clinicians to delve into patient histories, and provide a review of the clinical manifestations, diagnostic techniques, therapeutic approaches, and pathogenic mechanisms associated with M. marinum.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are present widely in the natural environment and can invade the human body through the respiratory tract, gastrointestinal tract, and skin. Immunocompromised patients are particularly prone to infection, which primarily affects multiple organs, including the lungs, lymph nodes, and skin. However, cases of NTM bloodstream infections are rare. Here, we report a rare case of Mycobacterium marseillense bloodstream infection with concurrent skin fungal infection in a patient after kidney transplantation. Related literature was reviewed to enhance the understanding of this rare condition.
METHODS: A 58-year-old male with a history of long-term steroid and immunosuppressant use after kidney transplantation presented with limb swelling that worsened over the past two months. Physical examination revealed redness and swelling of the skin in all four limbs, with a non-healing wound on the lower left limb. Skin tissue analysis by metagenomic next-generation sequencing (mNGS) and fungal culture indicated infection with Trichophyton rubrum. Blood culture results suggested infection with Mycobacterium marseillense. After receiving anti-NTM treatment, the patient\'s symptoms significantly improved, and he is currently undergoing treatment.
CONCLUSIONS: Mycobacterium marseillense is a NTM. Gram staining suffered from misdetection, and the acid-fast staining result was positive. This bacterium was identified by mass spectrometry and mNGS analyses. Antimicrobial susceptibility tests for NTM were performed using the broth microdilution method. The results of the susceptibility test showed that Mycobacterium marseillense was sensitive to clarithromycin, an intermediary between moxifloxacin and linezolid. Bacterial clearance requires a combination of drugs and an adequate course of treatment. NTM bloodstream infections are relatively rare, and early identification and proactive intervention are key to their successful management.

Nontuberculous mycobacteria (NTM) are important opportunistic pathogens in humans, mostly affecting the lungs, and potentially causing progressive disease in individuals with underlying diseases. The prevalence of NTM infections is increasing worldwide. However, Mycobacterium iranicum (M. iranicum) infections are less common. Here we report a 65-year-old female who developed pneumonia caused by Mycobacterium iranicum, which was detected in bronchoalveolar lavage fluid (BALF) through metagenomic next-generation sequencing (mNGS). The patient was treated with moxifloxacin, doxycycline, and sulfamethoxazole/trimethoprim. Symptoms were relieved and lung abnormalities were shown to be partially absorbed on the follow-up chest computed tomography (CT) scans. As we know, this is the first case of Mycobacterium iranicum pulmonary infection identified by mNGS in BALF.

Mycobacterium simiae, a slow-growing non-tuberculous mycobacterium (NTM), presents diagnostic challenges due to its resemblance to Mycobacterium tuberculosis and other NTMs. While NTM infections and tuberculosis share clinical and radiological features, their management strategies differ. Accurate differentiation is pivotal, as misdiagnosing NTM infections such as MDR-TB can lead to ineffective treatments. A case involving an 11-year-old female with tetralogy of Fallot (TOF) and a pulmonary M. simiae infection underscores the importance of precise diagnosis. Enhancing diagnostic methods is imperative to prevent mismanagement of NTM infections and ensure appropriate care.

Nontuberculous mycobacteria (NTM) are exceedingly rare etiological agents of intracranial infections. Among them, Mycobacterium rhodesiae stands out as an even less common pathogen. In this paper, we report the first documented case of a central nervous system (CNS) infection in humans caused by Mycobacterium rhodesiae, which has specific imaging findings and good response to the therapy by using Linezolid, Clarithromycin, and Minocycline. The diagnosis was facilitated by a comprehensive multimodal approach, incorporating multisite imaging, cerebrospinal fluid analysis via next-generation sequencing (NGS), and targeted genetic testing. Furthermore, this paper provides a derivation of the clinical characteristics observed in other documented instances of CNS infections attributable to NTM and based on a review of the current literature. Our experience contributes to the evidence that is needed to understand the full spectrum of NTM-related CNS pathologies and underscores the importance of a multidisciplinary diagnostic process in atypical presentations of intracranial infections.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.

Nontuberculous mycobacteria are a rare but still emerging cause of difficult-to-treat prosthetic joint infection. To our knowledge only 17 cases of M. abscessus complex prosthetic joint infection are reported in literature, of which only 1 is by M. abscessus subps. abscessus. No guidelines are available for this clinical scenario. We describe a 68-years-old female patient with an early-onset M. abscessus subsp. abscessus prosthetic joint infection, successfully treated with a tailored medical-surgical strategy, and present an overview of cases currently available in the literature to assist physicians in the management of these uncommon infections.

BACKGROUND: Immunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients.
METHODS: We describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses.
CONCLUSIONS: The diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are environmental organisms that are increasingly contributing to human infections. Mycobacterium immunogenum, a variant of NTM discovered in 2001, is a rapidly growing mycobacterium that exhibits multidrug resistance. Reports of infections caused by this organism, particularly tenosynovitis in the musculoskeletal system, are limited.
METHODS: A 71-year-old female with vesicular pemphigus, undergoing immunosuppressive therapy, presented with a progressively enlarging tumour on the dorsum of her right hand, along with erythematous papules that extended across her right forearm. The specimens of skin tissues and blood cultures revealed the presence of M. immunogenum. Magnetic resonance imaging evaluation led to the diagnosis of pyogenic extensor tenosynovitis. A multidrug regimen, comprising amikacin and clarithromycin, was initiated, followed by synovectomy. The patient underwent a course of 180 days of antimicrobial therapy and demonstrated no signs of disease recurrence one year after treatment completion.
CONCLUSIONS: Early diagnosis and surgical intervention are crucial to prevent the adverse prognostic implications of pyogenic extensor tenosynovitis caused by M. immunogenum. Effective management requires precise microbial identification and susceptibility testing, necessitating collaborative engagement with microbiological laboratories.