The role of RelMtb-mediated adaptation to stationary phase in long-term persistence of Mycobacterium tuberculosis in mice.
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Long-term survival of nonreplicating Mycobacterium tuberculosis (Mtb) is ensured by the coordinated shutdown of active metabolism through a broad transcriptional program called the stringent response. In Mtb, this response is initiated by the enzymatic action of RelMtb and deletion of relMtb produces a strain (H37RvDeltarelMtb) severely compromised in the maintenance of long-term viability. Although aerosol inoculation of mice with H37RvDeltarelMtb results in normal initial bacterial growth and containment, the ability of this strain to sustain chronic infection is severely impaired. Significant histopathologic differences were noted in lungs and spleens of mice infected with H37RvDeltarelMtb compared with controls throughout the course of the infection. Microarray analysis revealed that H37RvDeltarelMtb suffers from a generalized alteration of the transcriptional apparatus, as well as specific changes in the expression of virulence factors, cell-wall biosynthetic enzymes, heat shock proteins, and secreted antigens that may alter immune recognition of the recombinant organism. Thus, RelMtb is critical for the successful establishment of persistent infection in mice by altering the expression of antigenic and enzymatic factors that may contribute to successful latent infection. (+info)
Tuberculous liver abscess not associated with lung involvement.
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Hepatic tuberculosis is one of the uncommon forms of extrapulmonary tuberculosis. We report a 78-year-old woman who developed tuberculous liver abscesses with splenic abscess not associated with pulmonary foci. Ultrasonography and computed tomography of the abdomen showed the low-density lesions in the liver and spleen. Histopathology of specimens obtained by percutaneous needle biopsy revealed coagulation necrosis and epithelioid cells but not tumor cells, suggesting tuberculosis infection in the liver and spleen. Systemic chemotherapy with anti-tuberculous agents led to the improvement of the lesions in the liver as well as spleen. Although tuberculous liver abscess is a very rare case, it should be included in the differential diagnosis of unknown hepatic mass lesions. (+info)
Miliary tuberculosis not affecting the lungs but complicated by acute respiratory distress syndrome.
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A 61-year-old woman was admitted with fever and headache of 10-day duration. She was found to have anemia, jaundice, and signs of meningitis. The erythrocyte sedimentation rate was increased and the tuberculin skin test was positive. A provisional diagnosis of miliary tuberculosis was made and antituberculous therapy was started, although no miliary lesions were seen on chest radiography. However, her condition rapidly deteriorated with diffuse opacification of both lungs and she died on the 7th hospital day. Postmortem examination revealed miliary tuberculosis in several organs but not in the lungs with acute respiratory distress syndrome accounting for the lung pathology. It should be noted that on rare occasions the lungs may not be involved by miliary tuberculosis. (+info)
Case report of lymph nodal, hepatic and splenic tuberculosis in an HIV-positive patient.
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We describe a case of a male patient, 38 years old, HIV-positive (most recent CD4 count about 259/mm(3)), with abdominal pain, nausea, vomiting, anorexia, weight loss, and vespertine high fever with chills. His hemogram showed normocytic and normochromic anemia, with a high erythrocyte sedimentation rate (ESR) and gross granulations in the neutrophils. Transaminases were normal. Bone marrow biopsy evidenced a chronic disease anemia pattern and a lack of infectious agents. Abdominal ultrasound examination showed a normal-size spleen, which exhibited heterogeneous parenchyma and multiple small hypoechoic images, together with small ascites, peripancreatic and para-aortic lymphadenopathy. These findings were confirmed by abdominal CT. The liver was normal in size, but had a hyperechoic image, which was not visualized on CT. Histopathological analysis of one of the multiple abdominal lymph nodes obtained by laparoscopic biopsy exhibited a chronic granulomatous inflammatory process, with caseous necrosis. Tissue sections were positive for BAAR (acid-alcohol-resistant bacillus), and the cultures were positive for Mycobacterium tuberculosis. Anti-tuberculosis treatment was begun, and the patient evolved with improvement of his general state, fever remission and weight gain. Splenic tuberculosis is a rare disease, occurring predominantly in patients in late stages of AIDS and/or disseminated tuberculosis. It is a difficult diagnosis, since there are no specific findings. Hence, complementary examinations, such as abdominal ultrasound/ CT, or fine needle aspiration, are usually necessary for investigation and differential diagnosis. Often, lesion regression after anti-tuberculosis regimens can be seen, and splenectomy is restricted to complicated or refractory disease. (+info)
Unusual presentation of tuberculosis as a splenic mass.
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Tuberculosis is an important health problem in developing countries, with varying clinical presentations depending on the organs/systems involved. Tuberculosis is mostly seen in immuno-compromised individuals, such as those with acquired immune deficiency syndrome or malignancies. Here we report a case of a spleen tuberculoma in a 29-year-old male patient with no known immune deficiency. He first presented with abdominal pain, and subsequent ultrasonographic examination revealed a splenic lesion of 10 cm in diameter. A computerized tomography scan of the abdomen confirmed the presence of a solitary, hypodense, septated cystic lesion. Lack of evidence supporting the presence of a splenic infection or a primary/metastatic malignancy prompted explorative surgery where a septated abscess formation was discovered and splenectomy was performed. Histopathological examination revealed granulomatous inflammatory changes with Langerhans-type giant cells, which are consistent with tuberculosis. For a period of two months, antituberculosis therapy with four drugs, isoniazid, rifampicin, pyrazinamide, and ethambutol, was carried out. Pyrazinamide and ethambutol were quitted at the end of two months. Therapy with isoniazid and rifampicin was planned for an additional 10 months. We would like to call attention to yet another atypical presentation of extrapulmonary tuberculosis. (+info)
Splenic tuberculosis presenting as pyrexia of unknown origin.
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We report a case of a previously healthy 38-year old lady who presented with prolonged fever and hepatosplenomegaly. Intensive investigations were performed for pyrexia of unknown origin which revealed negative. CT scan of the abdomen showed multiple hypodense lesions which did not respond to broad-spectrum antibiotics. Percutaneous biopsy of the splenic lesion revealed granuloma formation and Langhan's giant cells suggestive of TB. She responded well with anti- TB medication but required extended treatment duration of 24 months due to persistence of the splenic lesion on repeated CT scans. This case illustrates a very rare clinical entity of isolated splenic TB with a therapeutic dilemma following incomplete resolution, despite prolonged treatment. (+info)
Isolated hepatosplenic tuberculosis.
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BACKGROUND: Tuberculosis rarely involves the liver and spleen and when it does so, it is usually associated with disseminated disease. METHOD: We report a patient with isolated tuberculosis of the liver and spleen. RESULTS: A 50-year-old man presented with weakness and loss of weight for two months. CT scan of the abdomen showed multiple small hypodense lesions in the liver and spleen. Image-guided biopsy of liver lesion was inconclusive as it showed normal hepatocytes with interspersed lymphocytes. On laparotomy, the liver and spleen were studded with multiple small nodules. A 5-cm wedge of the liver was resected. Histopathological examination confirmed the diagnosis of tubercular hepatitis. A detailed work-up failed to identify any other focus of tuberculosis. CONCLUSION: Although rare, tuberculosis should also be considered in the differential diagnosis for multiple nodules in the liver and spleen, along with lymphoproliferative diseases and metastatic lesions. (+info)