1/25. Partial interferon-gamma receptor signaling chain deficiency in a patient with bacille Calmette-Guerin and Mycobacterium abscessus infection.Complete deficiency of either of the two human interferon (IFN)-gamma receptor components, the ligand-binding IFN-gammaR1 chain and the signaling IFN-gammaR2 chain, is invariably associated with early-onset infection caused by bacille Calmette-Guerin vaccines and/or environmental nontuberculous mycobacteria, poor granuloma formation, and a fatal outcome in childhood. Partial IFN-gammaR1 deficiency is associated with a milder histopathologic and clinical phenotype. cells from a 20-year-old healthy person with a history of curable infections due to bacille Calmette-Guerin and Mycobacterium abscessus and mature granulomas in childhood were investigated. There was a homozygous nucleotide substitution in IFNGR2, causing an amino acid substitution in the extracellular region of the encoded receptor. Cell surface IFN-gammaR2 were detected by flow cytometry. Cellular responses to IFN-gamma were impaired but not abolished. transfection with the wild-type IFNGR2 gene restored full responsiveness to IFN-gamma. This is the first demonstration of partial IFN-gammaR2 deficiency in humans.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
2/25. Skin and wound infection by rapidly growing mycobacteria: an unexpected complication of liposuction and liposculpture. The Venezuelan Collaborative Infectious and Tropical Diseases Study Group.OBJECTIVE: To describe 10 patients with skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic liposuction and liposculpture. DESIGN: Case series. SETTINGS: Eight private geographically separate surgical facilities from a single metropolitan area. patients: Eight patients with definite and 2 with presumptive cases of skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic surgery procedures during a 24-month period. Microorganisms were isolated from the purulent drainage obtained from wounds or fistulas in 8 cases and were identified as mycobacterium fortuitum (3 cases) and Mycobacterium abscessus (5 cases) by routine microbiologic techniques. Acid-fast bacilli were observed on Ziehl-Neelsen-stained smears in the 2 remaining cases, but these ultimately failed to grow. In 2 of the surgical units, no apparent environmental predisposing factors were identified after thorough microbiologic environmental investigation. Clinically, all patients exhibited signs of inflammation, microabscesses, and purulent wound drainage within 24 months of abdominal and/or thigh liposuction or homologous fat tissue injection. INTERVENTION: A combined therapeutic approach including surgical drainage, debridment, and prolonged (>3 months) treatment with combined antimicrobial agents including clarithromycin was used in all cases. RESULTS: Nine of 10 patients responded to the combined therapeutic approach, and no evidence of infection was present during at least 12 months of follow-up. CONCLUSION: To our knowledge, this is the first series of patients with rapidly growing mycobacterial infections to be described after liposuction and liposculpture. Rapidly growing mycobacteria should be included in the differential diagnosis of skin and soft tissue infection after cosmetic surgery.- - - - - - - - - - ranking = 2keywords = environment (Clic here for more details about this article) |
3/25. Characterization of Mycobacterium bohemicum isolated from human, veterinary, and environmental sources.Chemotaxonomic and genetic properties were determined for 14 mycobacterial isolates identified as members of a newly described species Mycobacterium bohemicum. The isolates recovered from clinical, veterinary, and environmental sources were compared for lipid composition, biochemical test results, and sequencing of the 16S ribosomal dna (rDNA) and the 16S-23S rDNA internal transcribed spacer (ITS) regions. The isolates had a lipid composition that was different from those of other known species. Though the isolates formed a distinct entity, some variations were detected in the features analyzed. Combined results of the phenotypic and genotypic analyses were used to group the isolates into three clusters. The major cluster (cluster A), very homogenous in all respects, comprised the M. bohemicum type strain, nine clinical and veterinary isolates, and two of the five environmental isolates. Three other environmental isolates displayed an insertion of 14 nucleotides in the ITS region; they also differed from cluster A in fatty alcohol composition and produced a positive result in the Tween 80 hydrolysis test. Among these three, two isolates were identical (cluster B), but one isolate (cluster C) had a unique high-performance liquid chromatography profile, and its gas liquid chromatography profile lacked 2-octadecanol, which was present in all other isolates analyzed. Thus, sequence variation in the 16S-23S ITS region was associated with interesting variations in lipid composition. Two of the isolates analyzed were regarded as potential inducers of human or veterinary infections. Each of the environmental isolates, all of which were unrelated to the cases presented, was cultured from the water of a different stream. Hence, natural waters are potential reservoirs of M. bohemicum.- - - - - - - - - - ranking = 8keywords = environment (Clic here for more details about this article) |
4/25. mycobacterium haemophilum infection in a Japanese patient with AIDS.mycobacterium haemophilum has been described as a pathogen that causes cutaneous lesions in immunocompromised patients. A specimen from a skin ulcer on the leg of a Japanese patient with acquired immunodeficiency syndrome yielded acid-fast bacilli on blood agar plates after 4 weeks of incubation at 30 degrees C, but the organism was not found on Ogawa egg slants. The organism was identified as M. haemophilum, on the basis of 16S rRNA gene sequence analysis. Prolonged culture in an optimal environment that includes an iron supplement, and growth temperatures at 28 degrees to 33 degrees C are necessary to grow M. haemophilum. Genotypic characterization of 16S rRNA is useful for a rapid diagnosis of this slowly growing mycobacterium.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
5/25. Inherited disorders of IL-12- and IFNgamma-mediated immunity: a molecular genetics update.In the last 6 years, considerable advances have been made in the molecular analysis of a rare clinical syndrome: Mendelian susceptibility to mycobacterial disease (MSMD). Infection with poorly virulent environmental non-tuberculous mycobacteria (NTM) or vaccination with bacillus Calmette-Guerin (BCG) may cause disseminating and even fatal disease in individuals suffering from this syndrome. Mutations in five genes (IFNGR1, IFNGR2, STAT1, IL12B and IL12RB1) have been shown to be responsible for MSMD and further allelic heterogeneity accounts for the existence of nine distinct inherited disorders. All of these disorders are caused by impaired IFNgamma-mediated immunity. These results have important medical and biological implications. In this report, we update the disease-causing mutations reported in the literature.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
6/25. Mycobacterium simiae infection in a patient with acquired immunodeficiency syndrome.Mycobacterium simiae is usually an environmental contaminant rarely associated with human disease. We report a fatal case of M.simiae infection in a 37 year old, hiv positive, male from whom the organism was isolated from blood culture. The identification of M.simiae was performed using dna amplification followed by analysis on 3% agarose gel of the amplicon fragments after digestion by restriction endonucleases. The precise identification of mycobacterial isolates to the species level is important, with both epidemiological and therapeutic implications.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
7/25. Evaluation of hypersensitivity pneumonitis among workers exposed to metal removal fluids.hypersensitivity pneumonitis (HP) was identified among employees in an automobile parts manufacturing facility. Mycobacteria immunogenum (MI) was identified as a metal removal fluid (MRF) contaminant at this facility and had been identified as a contaminant in other facilities where HP had occurred. We therefore questioned whether measurement of MI-specific cell-mediated immunity would be associated with HP in this facility. We also questioned whether measures of cell-mediated immunity would be more informative about the presence of HP than evaluation of serum anti-MI antibody levels. Workers were categorized for exposure and disease status by questionnaire and review of medical records. Cell-mediated immunity to MI was assessed by measuring in vitro secretion of cytokines (interleukin 8, tumor necrosis factor alpha, and interferon-gamma) from peripheral blood mononuclear cells or anticoagulated whole blood induced by culture with MI antigen. serum antibodies against MI were also measured. Six study participants met our survey definition for HP and 48 did not. As has been reported for various agents causing HP, serum antibody levels against MI were increased in both exposed workers and workers with HP. serum antibodies did not distinguish between the two. When expressed as a percentage of secretion induced by lipopolysaccharide, MI induced a significant increase in interleukin-8 secretion in exposed participants' whole blood cultures. There were trends for increased MI-induced secretion of interferon-gamma by peripheral blood mononuclear cells from both exposed workers and workers with HP. However, these trends did not attain statistical significance. Thus, several measures of immunity to MI distinguished between exposed and unexposed workers but not between workers with and without HP. These evaluations of cell-mediated immunity were not more informative than measurement of serum antibodies. As was done at this facility, institution of a comprehensive safety and health plan for MRF is necessary to eliminate (or minimize) health effects related to occupational exposures in the machining environment.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
8/25. mycobacterium xenopi, a potential human pathogen.mycobacterium xenopi is infrequently recognized as a cause of pulmonary disease. During a 12-year survey (1978-89),. 108 strains of this Mycobacterium were isolated from 90 persons and 6 hot water samples. From 87 patients 89 occasional strains of M. xenopi were isolated, and 3 patients were diagnosed as having pulmonary mycobacteriosis caused by it. The treatment and the response in these three cases were variable, depending on clinical conditions and sensitivity to drugs. Most of the strains isolated came from patients hospitalized at the Barzilai Hospital, Ashkelon, therefore a local environmental contamination was suspected. The suspicion was confirmed by the isolation of this thermophile organism from the hot water samples of the above hospital.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
9/25. Nontuberculous mycobacterial infection in hematopoietic stem cell and solid organ transplant recipients.nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms. In immunocompetent hosts, they are a rare cause of disease. In immunocompromised hosts, disease due to NTM is well documented. Reports of NTM disease have increased in hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients. This increase may reflect increased numbers of transplants, intensification of immune suppressive regimens, prolonged survival of transplant recipients, and/or improved diagnostic techniques. The difficulty of diagnosis and the impact associated with infections due to NTM in HSCT and SOT recipients necessitates that, to ensure prompt diagnosis and early initiation of therapy, a high level of suspicion for NTM disease be maintained. The most common manifestations of NTM infection in SOT recipients include cutaneous and pleuropulmonary disease, and, in HSCT recipients, catheter-related infection. Skin and pulmonary lesions should be biopsied for histologic examination, special staining, and microbiologic cultures, including cultures for bacteria, nocardia species, fungi, and mycobacteria. Mycobacterial infections associated with catheters may be documented by tunnel or blood (isolator) cultures. Susceptibility testing of mycobacterial isolates is an essential component of optimal care. The frequent isolation of NTM other than mycobacterium avium complex (MAC) from transplant recipients limits the extrapolation of therapeutic data from human immunodeficiency virus-infected individuals to the population of transplant recipients. Issues involved in the management of NTM disease in transplant recipients are characterized by a case of disseminated infection due to mycobacterium avium complex in a lung transplant recipient, with a review of the relevant literature.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
10/25. Catheter-related bloodstream infection caused by Mycobacterium brumae.Mycobacterium brumae is a rapidly growing environmental mycobacterial species identified in 1993; so far, no infections by this organism have been reported. Here we present a catheter-related M. brumae bloodstream infection in a 54-year-old woman with breast cancer. The patient presented with high fever (39.7 degrees C), and >1,000 colonies of M. brumae grew from a quantitative culture of blood drawn through the catheter. A paired peripheral blood culture was negative, however, suggesting circulational control of the infection. The patient was treated empirically with meropenem and vancomycin, and the fever resolved within 24 h. The catheter was removed a week later, and from the tip M. brumae was isolated a second time, suggesting catheter colonization. The organism was identified by colonial morphology, sequence analysis of the 16S rRNA gene, and biochemical tests.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
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