Project description:We report a case of Mycobacterium smegmatis granuloma in the soft tissues of the first web space of the left hand in a 67-year-old Caucasian woman. She was in good systematic health; there was no recollection of trauma to the hand. A combined regime of prolonged antibiotic therapy and surgical debridement was necessary to ultimately eradicate the infection. The natural history, microbiology, and treatment of this rare hand infection are discussed.
Project description:Mycobacterium longobardum is a slow-growing, nontuberculous mycobacterium that was first characterized from the M. terrae complex in 2012. We report a case of M. longobardum induced chronic osteomyelitis. A 71-yr-old man presented with inflammation in the left elbow and he underwent a surgery under the suspicion of tuberculous osteomyelitis. The pathologic tissue culture grew M. longobardum which was identified by analysis of the 65-kDa heat shock protein and full-length 16S rRNA genes. The patient was cured with the medication of clarithromycin and ethambutol without further complications. To the best of our knowledge, this is the first report of a M. longobardum infection worldwide.
Project description:A 56-year-old woman, without any immunocompromising diseases, was referred to our hospital because of a recurrence of pyogenic spondylitis. Computed tomography revealed multiple osteolytic changes in the whole body. Vertebral magnetic resonance imaging revealed osteomyelitis and spondylitis. Mycobacterium scrofulaceum was detected in sputum cultures, in abscesses from the right knee, and in a subcutaneous forehead abscess. Therefore, the patient was diagnosed with disseminated Mycobacterium scrofulaceum infection. The patient was treated with rifampicin, ethambutol, and clarithromycin, which resulted in symptomatic relief and radiological improvement. We herein report a rare case of disseminated Mycobacterium scrofulaceum infection in an immunocompetent host.
Project description:We identify a putative link between miR-126 and the tsc1a signalling pathway resulting in the suppression of permissive macrophage accumulation at early zebrafish-M. marinum granulomas. Mechanistically, we find a detrimental effect of tsc1a expression that renders zebrafish embryos susceptible to higher bacterial burden and increased cell death via mTOR inhibition.
Project description:Mycobacterium tuberculosis is responsible for nearly 3 million human deaths worldwide every year. Understanding the mechanisms and bacterial factors responsible for the ability of M. tuberculosis to cause disease in humans is critical for the development of improved treatment strategies. Many bacterial pathogens use pili as adherence factors to colonize the host. We discovered that M. tuberculosis produces fine (2- to 3-nm-wide), aggregative, flexible pili that are recognized by IgG antibodies contained in sera obtained from patients with active tuberculosis, indicating that the bacilli produce pili or pili-associated antigen during human infection. Purified M. tuberculosis pili (MTP) are composed of low-molecular-weight protein subunits encoded by the predicted M. tuberculosis H37Rv ORF, designated Rv3312A. MTP bind to the extracellular matrix protein laminin in vitro, suggesting that MTP possess adhesive properties. Isogenic mtp mutants lost the ability to produce Mtp in vitro and demonstrated decreased laminin-binding capabilities. MTP shares morphological, biochemical, and functional properties attributed to bacterial pili, especially with curli amyloid fibers. Thus, we propose that MTP are previously unidentified host-colonization factors of M. tuberculosis.
Project description:IntroductionPeople with Tuberculosis (TB) infection may present with glomerulonephritis (GN). The range of presentations, renal pathologies, and clinical outcomes are uncertain. Whether clinical features that establish if GN etiology is medication or TB related, and possible benefits of immunosuppression remain uncertain.MethodsA scoping review was completed, searching MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science and Conference Abstracts from Inception to December, 2023. The study population included patients with TB infection who developed GN and underwent renal biopsy. All data regarding presentation, patient characteristics, renal pathology, management of TB and GN, and outcomes were summarized.ResultsThere were 62 studies identified, with 130 patients. These cases included a spectrum of presentations including acute kidney injury, nephrotic syndrome and hypertension, and a range of 10 different renal pathology diagnoses. Cases that included immunosuppression and outcomes ranged from complete remission to long-term dialysis dependence. The presence of granulomas (4/4, 100%), anti-glomerular basement membrane disease (3/3, 100%), amyloidosis (75/76, 98.7%), and focal segmental glomerulosclerosis (2/2, 100%) were specific for GN being TB-infection related. On the other hand, minimal change disease was specific for anti-TB therapy related (7/7, 100%). While patients with more aggressive forms of GN commonly were prescribed immunosuppression, this study was unable to confirm efficacy. Only rifampin or isoniazid were implicated in drug-associated GN.DiscussionThis study provides a clear rationale for renal biopsy in patients with TB and GN, and outlines predictors for the GN etiology. Thus, this study establishes key criteria to optimize diagnosis and management of patients with TB and GN.