Natural mycobacterium tuberculosis complex infection in a brown howler monkey (Alouatta guariba clamitans) in Brazil.

Neotropical primates rarely exhibit active tuberculosis. A brown howler monkey was found injured in an urban area. Histopathology revealed granulomatous inflammation in the lungs, lymph nodes, and liver. Immunohistochemistry and molecular analysis confirmed the presence of Mycobacterium tuberculosis complex. The findings highlight the importance of TB surveillance in nonhuman primates.

Host Cell Death and Modulation of Immune Response against Mycobacterium tuberculosis Infection.

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), a prevalent infectious disease affecting populations worldwide. A classic trait of TB pathology is the formation of granulomas, which wall off the pathogen, via the innate and adaptive immune systems. Some key players involved include tumor necrosis factor-alpha (TNF-α), foamy macrophages, type I interferons (IFNs), and reactive oxygen species, which may also show overlap with cell death pathways. Additionally, host cell death is a primary method for combating and controlling Mtb within the body, a process which is influenced by both host and bacterial factors. These cell death modalities have distinct molecular mechanisms and pathways. Programmed cell death (PCD), encompassing apoptosis and autophagy, typically confers a protective response against Mtb by containing the bacteria within dead macrophages, facilitating their phagocytosis by uninfected or neighboring cells, whereas necrotic cell death benefits the pathogen, leading to the release of bacteria extracellularly. Apoptosis is triggered via intrinsic and extrinsic caspase-dependent pathways as well as caspase-independent pathways. Necrosis is induced via various pathways, including necroptosis, pyroptosis, and ferroptosis. Given the pivotal role of host cell death pathways in host defense against Mtb, therapeutic agents targeting cell death signaling have been investigated for TB treatment. This review provides an overview of the diverse mechanisms underlying Mtb-induced host cell death, examining their implications for host immunity. Furthermore, it discusses the potential of targeting host cell death pathways as therapeutic and preventive strategies against Mtb infection.

Tuberculosis - The master of disguise: A case of disseminated tuberculosis masquerading as metastatic cancer.

Tuberculosis (TB) is an airborne infectious disease caused by Mycobacterium tuberculosis (MTB). Although it typically affects the lungs (pulmonary TB), one-fifth of TB cases present as extrapulmonary TB. The diagnosis of extrapulmonary TB is often overlooked due to its atypical clinical and radiological manifestations. Differentiating TB from neoplastic conditions poses significant challenges. A 33-year-old female patient was admitted to the emergency clinic with shortness of breath, cough, and abdominal pain. Postero-anterior chest X-ray revealed massive pleural effusion leading to mediastinal shift. With a preliminary diagnosis of malignant pleural effusion, a pleural catheter was inserted, and the patient was referred for a positron emission tomography (PET/CT) to assess the primary site and the optimal location for a biopsy. The PET/CT revealed asymmetric soft tissue thickening on the left side of the nasopharynx, and increased fluorodeoxyglucose (FDG) uptake in the left cervical lymph nodes raised suspicion regarding primary nasopharyngeal cancer. Additionally, there was an increased FDG uptake observed in the mass lesion located in the right upper lobe, mediastinal lymph nodes, pleural surfaces in the left hemithorax, perihepatic areas, and peritoneum, indicating diffuse metastatic disease. Tuberculosis diagnosis was confirmed through biopsies demonstrating granulomatous inflammation in the lung and nasopharynx, along with culturing MTB from pleural effusion. Positron emission tomography played a crucial role in identifying sites of TB involvement. Despite its rarity, healthcare professionals should consider nasopharyngeal TB as a potential diagnosis when evaluating nasopharyngeal masses.

Exploring the Complexities: Understanding the Clinicopathological Spectrum of Tuberculosis in the Head-and-neck Region.

INTRODUCTION: Tuberculosis (TB) affecting the head-and-neck area can often resemble cancer, leading to misdiagnosis and delayed treatment. A better understanding of this condition is necessary for early diagnosis and prompt treatment initiation. This study examines the clinical and pathological characteristics of different types of TB in the head-and-neck region. METHODS: This retrospective study analyzed patients diagnosed with TB in the head-and-neck region at a health center between January 1, 2018, and January 1, 2024. The study population consisted of patients who were diagnosed with TB of the head and neck. RESULTS: The study analyzed data from 30 patients, comprising 14 (47%) males and 16 (53%) females, all of whom tested negative for HIV. Most cases (15, 50%) were observed in the age group of 15-24 years, with 5 (15.6%) subjects falling in the age bracket of 0-14 years. Among the types of lesions detected, cervical tubercular adenitis was the most frequently observed lesion, found in 22 (73%) subjects. Females are more susceptible to cervical tubercular adenitis, while males are more likely to experience laryngeal TB. CONCLUSION: The clinical manifestation of TB affecting the head-and-neck region can exhibit a diverse range of symptoms, which may lead to misinterpretation and diagnostic errors. Therefore, health-care practitioners must understand and include the condition in differential diagnoses.

Exploring Sex Differences in Risk Factors and Quality of Life Among Tuberculosis Patients in Herat, Afghanistan: A Case-Control Study.

Objectives: Tuberculosis (TB) is a significant public health concern in Afghanistan, with a high burden of disease in the western province of Herat. This study explored the risk factors of TB and TB's impact on the quality of life of patients in Herat. Methods: A total of 422 TB patients and 514 controls were recruited at Herat Regional Hospital and relevant TB laboratories between October 2020 and February 2021. Data was collected through interviews using a structured questionnaire and the SF-36 questionnaire. Descriptive statistics, chi-square tests, Multivariate General Linear Model, and logistic regression analysis were used to analyze the data. Results: The results showed that male sex (p = 0.023), chronic disease (p = 0.038), lower education levels (p < 0.001), and worse health status (p < 0.001) were significantly associated with higher odds of TB infection. The study also found that TB patients had significantly lower quality of life scores in almost all components (p < 0.05). Conclusion: This study provides important insights into the specific ways in which TB affects the wellbeing of patients in Afghanistan. The findings highlight the importance of addressing the psychological and social dimensions of TB.

MicroRNA-144-3p Inhibits Host Lipid Catabolism and Autophagy by Targeting PPARα and ABCA1 During Mycobacterium Tuberculosis Infection.

MicroRNA-mediated metabolic reprogramming recently has been identified as an important strategy for Mycobacterium tuberculosis (Mtb) to evade host immune responses. However, it is unknown what role microRNA-144-3p (miR-144-3p) plays in cellular metabolism during Mtb infection. Here, we report the meaning of miR-144-3p-mediated lipid accumulation for Mtb-macrophage interplay. Mtb infection was shown to upregulate the expression of miR-144-3p in macrophages. By targeting peroxisome proliferator-activated receptor α (PPARα) and ATP-binding cassette transporter A1 (ABCA1), miR-144-3p overexpression promoted lipid accumulation and bacterial survival in Mtb-infected macrophages, while miR-144-3p inhibition had the opposite effect. Furthermore, reprogramming of host lipid metabolism by miR-144-3p suppressed autophagy in response to Mtb infection. Our findings uncover that miR-144-3p regulates host metabolism and immune responses to Mtb by targeting PPARα and ABCA1, suggesting a potential host-directed tuberculosis therapy by targeting the interface of miRNA and lipid metabolism.

Transmissibility of Mycobacterium pinnipedii in a murine model.

The causative agent of tuberculosis in pinnipeds is Mycobacterium pinnipedii, a member of the Mycobacterium tuberculosis complex (MTC). The natural hosts are pinnipeds; however, other non-marine mammals, including humans, can also be infected. The transmissibility of a pathogen is related to its virulence. The transmissibility of a M. pinnipedii strain (i.e., 1856) was investigated in a murine model and compared with that of two Mycobacterium bovis strains (i.e., 534 and 04-303) with different reported virulence. Non-inoculated mice (sentinels) were co-housed with intratracheally inoculated mice. Detailed inspection of mice to search for visible tuberculosis lesions in the lungs and spleen was performed, and bacillus viability at 30, 60, and 90 days post-inoculation (dpi) was assayed. A transmissibility of 100% was recorded at 30 dpi in sentinel mice co-housed with the inoculated mice from the M. pinnipedii and M. bovis 04-303 groups, as evidenced by the recovery of viable M. pinnipedii and M. bovis from the lungs of sentinel mice. Mice inoculated with M. pinnipedii (1856) and M. bovis (534) survived until euthanized, whereas five of the M. bovis 04-303-inoculated mice died at 17 dpi. This study constitutes the first report of the transmissibility of a M. pinnipedii strain in mice and confirms the utility of this experimental model to study virulence features such as the transmission of poorly characterized MTC species.

Caveolin-1 affects early mycobacterial infection and apoptosis in macrophages and mice.

Tuberculosis, caused by Mycobacterium tuberculosis, remains one of the deadliest infections in humans. Because Mycobacterium bovis Bacillus Calmette-Guérin (BCG) share genetic similarities with Mycobacterium tuberculosis, it is often used as a model to elucidate the molecular mechanisms of more severe tuberculosis infection. Caveolin-1 has been implied in many physiological processes and diseases, but it's role in mycobacterial infections has barely been studied. We isolated macrophages from Wildtype or Caveolin-1 deficient mice and analyzed hallmarks of infection, such as internalization, induction of autophagy and apoptosis. For in vivo assays we intravenously injected mice with BCG and investigated tissues for bacterial load with colony-forming unit assays, bioactive lipids with mass spectrometry and changes of protein expressions by Western blotting. Our results revealed that Caveolin-1 was important for early killing of BCG infection in vivo and in vitro, controlled acid sphingomyelinase (Asm)-dependent ceramide formation, apoptosis and inflammatory cytokines upon infection with BCG. In accordance, Caveolin-1 deficient mice and macrophages showed higher bacterial burdens in the livers. The findings indicate that Caveolin-1 plays a role in infection of mice and murine macrophages with BCG, by controlling cellular apoptosis and inflammatory host response. These clues might be useful in the fight against tuberculosis.

The challenges in diagnosing isolated epididymal tuberculosis (TB) in an adolescent male: a case report.

BACKGROUND: Genitourinary tuberculosis (GUTB) is a common form of extrapulmonary TB (EPTB) in children. An example of GUTB is epididymal TB, which usually presents unspecific chronic clinical manifestations. Definitive diagnosis can be conducted based on bacteriologic confirmation and histopathologic results, but this is challenging due to the paucibacillary nature of EPTB. Therefore, we reported the challenges in diagnosing isolated epididymal TB in an adolescent male. CASE PRESENTATION: A 16-year-old male presented to respirology clinic with painful swelling of the left scrotum for 3 months before visiting to the hospital. The symptoms were associated with persistent coughing for 2 months, and physical examination of the left scrotum showed swelling accompanied by cardinal signs. A palpable hard mass was found on the left scrotum, with firm borders, measuring 7 × 4 cm. Laboratory examination and tumor markers were within normal limits, although leukocyturia was found, and the urine culture was negative. Genital ultrasound (US) showed epididymitis sinistra with septal hydrocele, while magnetic resonance imaging (MRI) indicated inhomogeneous left epididymitis with bilateral inguinal lymph node enlargement. Although TB evaluation presented a negative purified protein derivative (PPD) test and bacteriologic examination, chest X-ray (CXR) showed perihilar lymphadenopathy. Based on the clinical and radiologic results suggesting TB, the patient was diagnosed with isolated epididymal TB and received quadruple antituberculosis therapy (ATT) for 6 months. After treatment, the left testicle size started to shrink and was equal to the right testicle, also, there were no signs of inflammation, the body weight increased by 5 kg, and cough disappeared. Sperm analysis at the end of treatment indicated teratozoospermia, which was subsequently treated by the urologic surgery department. CONCLUSIONS: Biopsy and bacteriologic confirmation for TB epididymitis were challenging to perform in the clinical setting. Epididymal TB should be considered in adolescent males with complaints of chronic scrotal swelling and pain. Clinical judgment based on history taking, physical examination, and radiologic features supporting TB features could be helpful in accurate and fast diagnosis for favorable outcome.

Mathematical model of oxygen, nutrient, and drug transport in tuberculosis granulomas.

Physiological abnormalities in pulmonary granulomas-pathological hallmarks of tuberculosis (TB)-compromise the transport of oxygen, nutrients, and drugs. In prior studies, we demonstrated mathematically and experimentally that hypoxia and necrosis emerge in the granuloma microenvironment (GME) as a direct result of limited oxygen availability. Building on our initial model of avascular oxygen diffusion, here we explore additional aspects of oxygen transport, including the roles of granuloma vasculature, transcapillary transport, plasma dilution, and interstitial convection, followed by cellular metabolism. Approximate analytical solutions are provided for oxygen and glucose concentration, interstitial fluid velocity, interstitial fluid pressure, and the thickness of the convective zone. These predictions are in agreement with prior experimental results from rabbit TB granulomas and from rat carcinoma models, which share similar transport limitations. Additional drug delivery predictions for anti-TB-agents (rifampicin and clofazimine) strikingly match recent spatially-resolved experimental results from a mouse model of TB. Finally, an approach to improve molecular transport in granulomas by modulating interstitial hydraulic conductivity is tested in silico.

Mycobacterium tuberculosis SecA2-dependent activation of host Rig-I/MAVs signaling is not conserved in Mycobacterium marinum.

Retinoic acid inducible gene I (Rig-I) is a cytosolic pattern recognition receptor canonically described for its important role in sensing viral RNAs. Increasingly, bacterially-derived RNA from intracellular bacteria such as Mycobacterium tuberculosis, have been shown to activate the same host Rig-I/Mitochondrial antiviral sensing protein (MAVS) signaling pathway to drive a type-I interferon response that contributes to bacterial pathogenesis in vivo. In M. tuberculosis, this response is mediated by the protein secretion system SecA2, but little is known about whether this process is conserved in other pathogenic mycobacteria or the mechanism by which these nucleic acids gain access to the host cytoplasm. Because the M. tuberculosis and M. marinum SecA2 protein secretion systems share a high degree of genetic and functional conservation, we hypothesized that Rig-I/MAVS activation and subsequent induction of IFN-ß secretion by host macrophages will also be conserved between these two mycobacterial species. To test this, we generated a ΔsecA2 M. marinum strain along with complementation strains expressing either the M. marinum or M. tuberculosis secA2 genes. Our results suggest that the ΔsecA2 strain has a growth defect in vitro but not in host macrophages. These intracellular growth curves also suggested that the calculation applied to estimate the number of bacteria added to macrophage monolayers in infection assays underestimates bacterial inputs for the ΔsecA2 strain. Therefore, to better examine secreted IFN-ß levels when bacterial infection levels are equal across strains we plated bacterial CFUs at 2hpi alongside our ELISA based infections. This enabled us to normalize secreted levels of IFN-ß to a standard number of bacteria. Applying this approach to both WT and MAVS-/- bone marrow derived macrophages we observed equal or higher levels of secreted IFN-ß from macrophages infected with the ΔsecA2 M. marinum strain as compared to WT. Together our findings suggest that activation of host Rig-I/MAVS cytosolic sensors and subsequent induction of IFN-ß response in a SecA2-dependent manner is not conserved in M. marinum under the conditions tested.

The etiological spectrum of multiple ring-enhancing lesions of the brain: a systematic review of published cases and case series.

OBJECTIVE: Multiple ring-enhancing lesions of the brain are enigmatic neuroimaging abnormality. In this systematic review, we evaluated the etiological spectrum of these lesions. METHODS: This systematic review adhered to the PRISMA guidelines. We searched PubMed, Embase, Scopus, and Google Scholar up until 15 June 2023. We included case reports and case series. Quality evaluation of each case was based on selection, ascertainment, causality, and reporting. The extracted information included demographic characteristics, clinical features, type and number of multiple enhancing brain lesions, diagnostic procedures, final diagnoses, treatments, and patient outcomes. PROTOCOL REGISTRATION: PROSPERO CRD42023437081. RESULTS: We analyzed 156 records representing 161 patients, 60 of whom were immunocompromised. The mean age was 42.6 years, and 67% of patients experienced symptoms for up to 1 month. A higher proportion of immunocompromised patients (42% vs. 30%) exhibited encephalopathy. Chest or CT thorax abnormalities were reported in 27.3% of patients, while CSF abnormalities were found in 31.7%, more frequently among the immunocompromised. Definitive diagnoses were established via brain biopsy, aspiration, or autopsy in 60% of cases, and through CSF examination or other ancillary tests in 40% of cases. Immunocompromised patients had a higher incidence of Toxoplasma gondii infection and CNS lymphoma, while immunocompetent patients had a higher incidence of Mycobacterium tuberculosis infection and immune-mediated and demyelinating disorders. The improvement rate was 74% in immunocompetent patients compared to 52% in the immunocompromised group. CONCLUSION: Multiple ring-enhancing lesions of the brain in immunocompromised patients are more frequently caused by Toxoplasma gondii infections and CNS lymphoma. Conversely, among immunocompetent patients, Mycobacterium tuberculosis infection and immune-related demyelinating conditions are common.

Pulmonary sclerosing pneumocytoma - approaching a solitary pulmonary nodule and the limitations of risk prediction models.

Our case is an asymptomatic, non-smoking, East Asian woman in her 40s presenting with a solitary pulmonary nodule (SPN). On imaging, the 1.7 cm solid SPN located in the left upper lobe, was rounded in morphology and moderately fluorodeoxyglucose avid. The clinical pretest probability of malignancy assessed by risk prediction models such as Brock (19.1%), Mayo Clinic (56.2%) and Herder (51.4%) was discordant. She underwent a percutaneous CT-guided needle biopsy, establishing a diagnosis of pulmonary sclerosing pneumocytoma (PSP). PSP is a rare benign lung neoplasm with indolent growth characteristics that has been described predominantly in non-smoking women. Our case illustrates the limitations of applying existing risk prediction models in Asia where the epidemiology and biology of lung cancer differ significantly from the Caucasian derivation cohorts. Additionally, the risk models do not account for tuberculosis, which is endemic in Asia and can mimic malignancy. Non-surgical lung biopsy remains useful in minimising unnecessary thoracotomy.

T cell-specific P2RX7 favors lung parenchymal CD4+ T cell accumulation in response to severe lung infections.

CD4+ T cells are key components of the immune response during lung infections and can mediate protection against tuberculosis (TB) or influenza. However, CD4+ T cells can also promote lung pathology during these infections, making it unclear how these cells control such discrepant effects. Using mouse models of hypervirulent TB and influenza, we observe that exaggerated accumulation of parenchymal CD4+ T cells promotes lung damage. Low numbers of lung CD4+ T cells, in contrast, are sufficient to protect against hypervirulent TB. In both situations, lung CD4+ T cell accumulation is mediated by CD4+ T cell-specific expression of the extracellular ATP (eATP) receptor P2RX7. P2RX7 upregulation in lung CD4+ T cells promotes expression of the chemokine receptor CXCR3, favoring parenchymal CD4+ T cell accumulation. Our findings suggest that direct sensing of lung eATP by CD4+ T cells is critical to induce tissue CD4+ T cell accumulation and pathology during lung infections.

Rare primary pulmonary mucosa-associated lymphoid tissue lymphoma misdiagnosed with tuberculosis: A case report.

RATIONALE: Primary pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) is a rare subtype of non-Hodgkin lymphoma with a relatively low incidence rate clinically. Atypical clinical symptoms and nonspecific chest computed tomography features of the disease make it difficult to determine and treatment is delayed. We discuss the diagnosis and treatment of a patient with primary pulmonary MALToma to raise clinicians' awareness of this condition. PATIENT CONCERNS: A 66-year-old male patient with a medical history of tuberculosis has been experiencing progressive exacerbation of respiratory symptoms and nonresponsive treatment without an unclear diagnosis for 5 years. He was transferred to our hospital because a nonspecific soft tissue mass in the right upper lobe of the lung was found on his chest computed tomography. Laboratory results with serum immunofixation electrophoresis showed polyclonal immunoglobulin (Ig) G, IgM, IgA, and λ-light chain on admission. DIAGNOSIS: Pathological examination and immunohistochemical staining of lung biopsy revealed a definitive diagnosis of pulmonary MALToma with stage IV. INTERVENTIONS AND OUTCOMES: The patient received immunotherapy with anti-CD20 monoclonal antibody (rituximab), and showed significant clinical improvement at the 6-month follow-up. CONCLUSIONS AND LESSONS: Diagnosis of primary pulmonary MALToma mainly relies on histopathological examination, and comprehensive laboratory examinations are also necessary. Clinicians should combine laboratory tests (such as immunofixation electrophoresis in our case) to assist in medical diagnosis in cases of atypical clinical manifestations and imaging characteristics. Immunotherapy appears to be the main treatment protocol for advanced patients.

Pathomorphological characteristics of tuberculous placenta and its clinical implication.

BACKGROUND: The study of pathologic diagnosis of placental TB is rare. The aim of this study is analyzing the pathomorphological characteristics of tuberculosis (TB) placenta during pregnancy and its clinical significance. METHODS: Nineteen cases of placental tissue specimens during pregnancy were collected from June 2015 to February 2022 at Shanghai Public Health Clinical Center, the only inpatient center for pregnant women with TB in Shanghai, China. Hematoxylin-eosin staining, acid-fast staining, and molecular testing were applied to analyze them comprehensively in combination with clinical information. RESULTS: Among the 19 cases, 7 cases caused intrauterine stillbirth, 3 cases received artificial abortion required by the pregnant woman, the other 9 cases received standard delivery and the infants survived, however, 3 of them were low-weight preterm infants, and another 1 case suffered mild intrauterine asphyxia. The 9 surviving infants were followed-up, of which 3 cases got congenital TB. For pathological characteristics of placental tissues under light microscopy, there were 3 cases of epithelioid granuloma formation, 13 cases of acute fetal membranitis, 4 cases of caseous necrosis, 7 cases of inflammatory necrosis, 10 cases of coagulative necrosis, and 6 cases with small focal calcifications. All placental tissues were positive for acid-fast staining and polymerase chain reaction (PCR). Molecular pathological diagnosis showed that 18 cases were positive for Mycobacterium tuberculosis, with 1 case not having received examination. CONCLUSIONS: Combining acid-fast staining and molecular pathological testing is helpful for accurately diagnosing placental TB.

[Breast tuberculosis. Report of two cases]. / Tuberculosis mamaria. Reporte de dos casos.

Two cases of mammary tuberculosis (TB) are presented, one of them with additional pleural and lymph node involvement. Both were HIV-negative, with no history of previous TB, with long-standing breast lesions. Both presented a successful outcome with antituberculosis treatment. Breast TB is a very rare pathology that is difficult to diagnose. The cases are presented to consider their differential diagnosis in patients with chronic mastitis and/or nodular or ulcerated lesions of the breast. Multidisciplinary management is recommended.

Se presentan los casos de dos pacientes con tuberculosis (TB) mamaria, una de ellas también con compromiso pleural y ganglionar. Ambas HIV negativas, sin antecedentes de TB previa, con lesiones mamarias de largo tiempo de evolución. Las dos presentaron buena evolución con tratamiento antifímico. La TB mamaria es una afección muy poco frecuente de difícil diagnóstico. Se presentan los casos con el fin de plantear su diagnóstico diferencial en pacientes con mastitis crónicas y/o lesiones nodulares o ulceradas de la mama. Se recomienda el manejo multidisciplinario.

Mechanopathology of biofilm-like Mycobacterium tuberculosis cords.

Mycobacterium tuberculosis (Mtb) cultured axenically without detergent forms biofilm-like cords, a clinical identifier of virulence. In lung-on-chip (LoC) and mouse models, cords in alveolar cells contribute to suppression of innate immune signaling via nuclear compression. Thereafter, extracellular cords cause contact-dependent phagocyte death but grow intercellularly between epithelial cells. The absence of these mechanopathological mechanisms explains the greater proportion of alveolar lesions with increased immune infiltration and dissemination defects in cording-deficient Mtb infections. Compression of Mtb lipid monolayers induces a phase transition that enables mechanical energy storage. Agent-based simulations demonstrate that the increased energy storage capacity is sufficient for the formation of cords that maintain structural integrity despite mechanical perturbation. Bacteria in cords remain translationally active despite antibiotic exposure and regrow rapidly upon cessation of treatment. This study provides a conceptual framework for the biophysics and function in tuberculosis infection and therapy of cord architectures independent of mechanisms ascribed to single bacteria.