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At least 19 recordsLinked to original sources
PubMed1992

Mycobacterium avium complex and Mycobacterium tuberculosis in patients infected with the human immunodeficiency virus.

Primary care physicians play an important role in identifying and treating bacterial infections in adults infected with the human immunodeficiency virus (HIV). Mycobacterium avium complex and Mycobacterium tuberculosis are pathogens that can cause systemic or local infection in these patients. We review the epidemiology, pathogenesis, clinical presentation, and principles of treatment for these two mycobacterial pathogens. Because M tuberculosis disease is preventable and curable and yet communicable, physicians should maintain a high degree of suspicion for tuberculosis in HIV-infected adults. In comparison, the goal of treating M avium complex in patients with advanced HIV disease is to reduce constitutional symptoms and improve survival.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Extracellular and intracellular activity of sparfloxacin against Mycobacterium avium complex and Mycobacterium xenopi].

Activity of the new fluoroquinolone sparfloxacin against 30 strains of M. avium complex and 25 strains of M. xenopi was tested in vitro. Sparfloxacin was used alone (determination of MICs and MBCs) and in combination with ethambutol and rifabutin. Synergy studies with determination of the FIC and FBC indices showed that the sparfloxacin-ethambutol combination was synergistic against 10 M. avium complex strains and 12 M. xenopi strains. With the three-drug combination (sparfloxacin-ethambutol-rifabutin), synergy was found against 12 M. avium and 14 M. xenopi strains. Studies of intracellular bacteria showed that the decrease in viable bacteria with the three-drug combination was 1 log for M. avium and 2 log for M. xenopi.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Evaluation of Syngene DNA-DNA probe assays for the identification of the Mycobacterium tuberculosis complex and the Mycobacterium avium complex.

Two hundred mycobacterial cultures were used to evaluate two alkaline-phosphatase-labeled DNA probe (SNAP) kits developed by Syngene (San Diego, CA) for identification of Mycobacterium tuberculosis complex and M. avium complex. The M. tuberculosis complex SNAP probe, when compared with standard biochemical identification tests, gave results that were in agreement at 100% sensitivity and 98.7% specificity. Ninety-nine M. avium complex strains that were previously tested by the Gen-Probe M. avium complex probe assays and mycolic acid analysis were included to evaluate the M. avium complex SNAP assay which contained three probes, A (avium), I (intracellulare), and X. Eight strains identified as members of the M. avium complex by biochemical tests did not react with the three SNAP probes. These strains were also negative by the Gen-Probe assays. However, 23 strains identified as M. avium complex by biochemical tests and mycolic acid analysis and negative with the Gen-Probe assays gave positive results with the X probe and negative results with the A and I probes of the SNAP assay.

Alkaline Phosphatase↗
PubMed2026

Prospective outcomes of adults with speciated Mycobacterium avium complex lung disease, 2021-2026.

RATIONALE: Mycobacterium avium complex lung disease (MAC-LD) is clinically heterogeneous and carries diverse outcomes. OBJECTIVES: To describe predictors of clinical progression of MAC-LD in a state-wide cohort. METHODS: We enrolled adults with MAC-LD from across Virginia, USA starting in 2021. Every 6 months we performed respiratory quality of life questionnaire, scored CT scans, and recorded respiratory mycobacterial cultures including MAC speciation. Outcomes were classified using NTM-NET consensus definitions, factors predicting clinical progression analyzed by Poisson regression, and hierarchical clustering on principal components derived from Factorial Analysis of Mixed Data. MEASUREMENTS AND MAIN RESULTS: Of 105 participants the median follow-up was 917 days. Mean age was 69.8 years, 79 (75%) were women, and 70 (67%) had nodular bronchiectasis. M. intracellulare was the most common species, present in 48 (46%) participants at enrollment, followed by M. avium (29, 28%), and M. intracellulare subspecies chimaera (11, 10%). Only 2 (9%) of 22 evaluable participants met the NTM-NET definition of cure. In all participants after multivariable adjustment, older baseline age (incidence rate ratio 1.03 [1, 1.06], p = 0.04) and fibrocavitary CT scan pattern (2.57 [1.33, 4.96], p = 0.005), were associated with unfavorable 12-month clinical progression. Species type and species persistence contributed to characteristics of three distinct phenotypes of MAC-LD of varying severity and clinical progression. CONCLUSIONS: The majority of participants were not assessable for MAC-LD treatment outcomes using strict NTM-NET definitions. Species informed phenotypes of MAC lung disease are prognostically useful and can inform routine management and trial design.

M. intracellulare↗
PubMed1992

[Evaluation of the alkaline-phosphatase labeled DNA probes for Mycobacterium tuberculosis and Mycobacterium avium complex].

Non-radioisotopic, alkaline phosphatase-labeled DNA (AP-DNA) probe tests for the identification of Mycobacterium tuberculosis complex (Mtb) and Mycobacterium avium complex (MAC) were evaluated. The overall agreement, sensitivity and specificity of the AP-DNA probes for Mtb and MAC were 100% respectively compared with the conventional biochemical method. Because the procedure is rapid (it can be completed approximately 120 min), safe (it does not use radioisotopes) and convenient (it does not need the special equipment to be performed), it can be easily performed in any clinical laboratory.

Alkaline Phosphatase↗
PubMed1992

Comparative antigenic analysis of Mycobacterium avium complex (MAC) isolates from AIDS patients.

Sonicates of several Mycobacterium avium complex (MAC) strains isolated from acquired immunodeficiency syndrome (AIDS) patients were characterized in order to study the prominent antigens of these strains. Sonicates of 6-week-old cultures were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. A major 12 kDa glycoprotein antigen was observed in all the sonicates along with other proteins ranging up to 100 kDa. Western blotting, using the 12 kDa M. leprae 'specific' murine monoclonal antibody (MAb) MLO6, indicated the presence of a determinant in the 12 kDa antigen (in all the MAC isolates studied) which was immunologically cross-reactive with the 12 kDa antigen of M. leprae. The transparent variant of MAC 101 also demonstrated MLO6 reactivity while the opaque variant did not. Polyclonal antiserum raised against MAC 101 sonicate reacted with all the MAC isolates in immunodiffusion. These observations point to the cross-reactivity between these strains and suggest that they possess a M. leprae 'specific' determinant on a cross-reacting component which could be involved in virulence.

AIDS-Related Opportunistic Infections↗
PubMed1992

Use of restriction fragment length polymorphisms resolved by pulsed-field gel electrophoresis for subspecies identification of mycobacteria in the Mycobacterium avium complex and for isolation of DNA probes.

Mycobacterial strains from the Mycobacterium avium complex were compared with each other and with Mycobacterium phlei isolates by restriction endonuclease digestion of chromosomal DNA with SspI and analysis by pulsed-field gel electrophoresis. Characteristic profiles were observed for known typed strains, and five groups were identified. Primary bovine isolates identified as Mycobacterium paratuberculosis by classical methods were shown to fall into both the M. paratuberculosis- and M. avium-like groups. M. paratuberculosis 18 was in the latter category. Two Mycobacterium intracellulare strains of different Schaefer serotypes had different digestion profiles. In addition, this system was exploited for the preparation of DNA probes by the isolation, digestion, and subcloning of DNA fragments separated by pulsed-field gel electrophoresis. Probe JC12 hybridized only to M. avium complex strains, but not to M. phlei, showing characteristic hybridization profiles for each of the groups previously identified by pulsed-field gel electrophoresis. The approach taken in the study lends itself to the comparative analysis of members of the M. avium complex and to the isolation and characterization of DNA probes with specificity for these mycobacteria.

DNA Probes↗
PubMed1992

Comprehensive approach to identification of serovars of Mycobacterium avium complex.

Serotyping of nontuberculous mycobacteria, especially those of the Mycobacterium avium complex, provides important epidemiological information, particularly in tracing origins of infections. Seroagglutination with whole cells and polyclonal rabbit antibodies was the original way of identifying serovars and is still commonly used. The discovery of the glycolipid nature of the typing antigens allows differentiation of serovars on the basis of thin-layer chromatography of whole antigens and gas chromatography-mass spectrometry of the characteristic sugars of the oligosaccharide haptens of these antigens. In particular, the generation of monoclonal antibodies to the glycolipid antigens allows facile differentiation of serovars through enzyme-linked immunosorbent assay. All of these protocols were applied in developing a comprehensive approach to the typing of members of the M. avium complex.

Antibodies, Monoclonal↗
PubMed2025

Understanding recurrence in Mycobacterium avium complex pulmonary disease: genotypic strategies to support clinical decision-making.

Pulmonary disease caused by Mycobacterium avium complex (MAC-PD) is a chronic, recurrent disease, and its high recurrence rate after treatment makes clinical management difficult. Distinguishing whether recurrence is due to persistence of existing strains or reinfection with new strains is essential for establishing treatment strategies, preventing overuse of antimicrobials, and establishing infection control measures. According to reports, 54%-74% of MAC-PD recurrence is due to reinfection, which may be mainly related to environmental reservoirs such as household water supply. In this review, we present various clinical scenarios in which MAC-PD recurrence may occur and examine genotyping techniques as a strategy to distinguish and respond to them. From traditional methods such as IS1245-based restriction fragment length polymorphism, pulsed-field gel electrophoresis, and hsp65 and rpoB gene sequencing to high-resolution analysis techniques such as multilocus sequence testing and whole-genome sequencing, the latest molecular typing methods are comprehensively summarized. Integrating these genotype data into clinical settings, standardizing single-nucleotide polymorphism-based interpretation thresholds, and promoting the establishment of a global MAC strain database will make a substantial contribution to more accurately distinguishing the recurrence mechanisms of MAC-PD and establishing personalized treatment strategies.IMPORTANCEThe global burden of nontuberculous mycobacterial pulmonary disease (PD) is increasing, with Mycobacterium avium (MAC)-PD being the most prevalent and clinically challenging form. Its low treatment success rates, high frequency of recurrence, and persistent environmental exposure complicate both diagnosis and management. A critical clinical issue is determining whether recurrence represents true relapse, due to persistence of the original strain, or reinfection with a new strain, as this guides treatment and prevents overtreatment. Genotypic strategies capable of resolving strain-level differences can improve diagnostic accuracy, prevent misclassification, and ultimately support more informed treatment decisions. Therefore, integrating genotyping data into clinical workflows, standardizing single-nucleotide polymorphism thresholds, and establishing a global MAC strain database will not only support personalized treatment but also enhance the broader public health response to this disease.

Humans↗
PubMed1992

Distinctive western blot antibody patterns induced by infection of mice with individual strains of the Mycobacterium avium complex.

Systemic infection of mice with organisms of the Mycobacterium avium complex (MAC) induced antibody responses, characteristic for each of the three tested individual strains. The influence of host genetic factors was reflected up to 3 months after infection by the finding of generally oligobanded and multibanded Western blot patterns in C57B1/6 and BALB/c mice, respectively. Nevertheless, more bands developed at 6 months in C57BL/6 mice. The response to three antigens of 18,000, 38,000 and 24,000 MW was analysed in greater detail. Antibodies to a protease-resistant 18,000 MW band produced only by BALB/c mice were either strain specific, following infection with M. avium, strain Maa-B2, or cross-reactive within MAC, following infection with M. avium strain Maa-A6 and M. paratuberculosis, strain Map-203. Another protease-resistant antigen of 38,000 MW was immunogenic only in Maa-B2 infected mice. This constituent was found to be related to the protease-sensitive antigen of corresponding molecular weight from M. tuberculosis. Two 24,000 MW proteins of M. paratuberculosis were separated by two-dimensional gel electrophoresis: antibodies to the anodic band were induced by Map-203 infection, whilst the cathodic band was revealed by heteroclitic antibodies from Maa-B2-infected mice. The latter antigen is apparently expressed during in vivo replication, but not during in vitro culture of Maa-B2 bacteria. We generally conclude, that the selective antibody patterns after live infection, could be attributed to differences in the release of native antigens within mycobacterial lesions. In view of a high degree of species specificity, some of the immunogenic constituents identified may also be useful for serodiagnostic application.

Animals↗
PubMed1992

Evaluation of new anti-infective drugs for the treatment and prevention of infections caused by the Mycobacterium avium complex. Infectious Diseases Society of America and the Food and Drug Administration.

The bacteria of the Mycobacterium avium complex are ubiquitous; thus it is often difficult to distinguish environmental contamination from colonization or infection. Patients with either pulmonary or disseminated infection may be enrolled in clinical trials. Disseminated disease occurs mostly in patients infected with the human immunodeficiency virus. In general, a randomized, active-control, double-blinded clinical trial is preferred; there should at least be a blinded evaluator. With regard to immunosuppressed populations, new antimycobacterial drugs need to be evaluated not only for the treatment but also for the prevention of disease. For trials of prophylaxis a placebo-controlled design is ethical until a drug is proven effective; then the use of an active-control regimen is appropriate. Since no regimen has been approved by the U.S. Food and Drug Administration for treatment or prevention of disease caused by the M. avium complex, demonstration of the superiority of the study regimen to the control regimen should be the objective of the clinical trial.

Anti-Bacterial Agents↗
PubMed1992

In vitro, in vivo, and intracellular chemotherapeutic activity of B746, a clofazimine analogue against Mycobacterium avium complex.

B746, an analogue of clofazimine, was compared with the parent compound for its activity against Mycobacterium avium complex (MAC), using several methods. All the studies using simulated in vivo conditions, and those with macrophages from healthy mice or from those treated with these drugs, revealed B746 to be similar to clofazimine. When used alone against experimental MAC infections in beige mice, B746 required an optimal dose of 20 mg/kg. At that dose it proved to be inferior to clofazimine, given at the same dose, but was slightly superior to streptomycin given intramuscularly at 150 mg/kg. On the other hand, in combination with other drugs, it proved to be inferior when given along with either clofazimine or streptomycin. Addition of B746 did not improve the chemotherapeutic efficacy of streptomycin-clofazimine combination in the treatment of established MAC infections of beige mice.

Animals↗
PubMed1992

[Intracellular killing mechanisms of alveolar macrophages against Mycobacterium avium complex].

To clarify the intracellular killing mechanisms of alveolar macrophages against Mycobacterium avium complex, effects of cytokines on O2- and NO2- production from normal and BCG-induced alveolar macrophages were studied. Intracellular growth of M. avium complex was inhibited in the alveolar macrophages stimulated by TNF, but not IFN. Enhancement of O2- production by normal alveolar macrophages stimulated by cytokines, was associated with the inhibition of intracellular growth of M. avium complex. However, when NO2- production by the alveolar macrophages was enhanced by the stimulating of IFN or IFN+TNF, in the presence L-arginine in the culture medium, their defense activity against M. avium complex decreased.

Animals↗
PubMed1992

Clinical and epidemiological importance of typing of Mycobacterium avium complex isolates.

The results of the application of a range of typing procedures to the identification and classification of 6,264 cultures of nontuberculous mycobacteria from human sources and the environment are reported. Seroagglutination, an enzyme-linked immunosorbent assay applied to whole bacteria or the glycolipid typing antigens and based on serovar-specific polyclonal or monoclonal antibodies, thin-layer chromatography of these antigens, and gas chromatography of their specific sugar determinants were used to arrive at identifications. As a result of this comprehensive approach, 4,452 (71%) of all cultures and 88% of those of samples from patients with AIDS proved to be typeable. The rank order of frequency of occurrence of individual organisms within the entire group of isolates was Mycobacterium avium complex serovar 4 greater than serovar 8 greater than serovar 1 greater than serovar 9 greater than serovar 6 greater than serovar 14 greater than serovar 2 greater than M. fortuitum greater than M. kansasii greater than M. xenopi greater than an apparent mixture of serovar 4 and M. xenopi greater than a mixture of serovar 4 and serovar 8. These results were similar but not identical to the pattern observed for isolates obtained from patients with AIDS; the order was M. avium complex serovar 4 greater than serovar 8 greater than serovar 1 greater than a mixture of serovar 4 and M. xenopi, a mixture of serovar 4 and serovar 8 greater than serovar 9 greater than serovar 2 greater than serovar 6. Serotyping was also used to demonstrate the possible clinical significance of nontuberculous mycobacteria recovered from different body sites. Other information on the distribution of M. avium serovars in patients from different geographical environments is provided.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Clinical characteristics of the patients with primary infection of Mycobacterium avium complex].

Clinical characteristics are analyzed in patients with primary infection of Mycobacterium avium complex (MAC). The definition of primary infection of MAC are determined as follows; 1) MAC is found several times since the beginning of the disease, 2) clinical symptoms or abnormal shadow corresponding to MAC infection on chest roentgenogram, 3) no old tuberculous lesions nor other abnormal shadows like bronchiectasis, 4) no abnormal serological results suggesting other bacterial or viral infections. According to this definition, 17 out of 84 MAC patients are diagnosed as primary MAC infection, and clinical features are analyzed in these 17 patients. Average age of patients is 61.1 +/- 12.9 year old. This age is significantly higher than that of inpatients with pulmonary tuberculosis in our hospital, and lower than that of all MAC patients including secondary infection. Five (29.4%) are male and 12 (70.6%) are female, the ratio of male to female is 1 to 2.4. This value is significantly different with that of inpatients with pulmonary tuberculosis in our hospital who show about 3 to 1. Most of the patients complained of cough with sputum, especially of hemosputum. Eleven out of 17 patients (64.7%) complained repeated hemosputum. The frequency of hemosputum is very high compared with that of the patients with pulmonary tuberculosis (about 20%). No compromised condition was present except for a patient with Behçet's disease who are taking steroid hormone. Roentgenographic features of primary infection are those of scattered small nodular lesions in the peripheral part of the lung, thin wall cavity formation, no contraction of the diseased lung nor dislocation of the trachea.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1977

Sources of Mycobacterium avium complex infection resulting in human diseases.

Human disease caused by organisms in the Mycobacterium avium complex occur virtually worldwide. A 20-year ongoing study conducted in Western Germany has been analyzed to elucidate the ecologic and epidemiologic characteristics of these infections in man. Organisms included in this investigation have been cultured from man, from domestic and wild animals and fowl, and from a variety of environmental sources. In addition to the usual taxonomic studies of these bacilli, infrasubspecific typing by seroagglutination has enabled identification of 3 distinct serogroups: the classical Mycobacterium avium strains (serovars avium 1, 2, and 3), the intermediate group (avium serovars 4, 5, 6, 8, 9, 10, and 11), and the less frequently encountered organisms, the 11 remaining avium serovars (7 and 12 through 21). Analysis of the number of strains in each of the 3 serogroups, derived, respectively, from man, from animals, and from the environment, has enabled us to draw some conclusions regarding reservoirs and sources of human infection with these agents.

Animals↗
PubMed1992

Disseminated Mycobacterium avium complex infection: clinical identification and epidemiologic trends.

To evaluate the incidence of disseminated Mycobacterium avium complex infection (DMAC) and to define the association between signs and symptoms and development of DMAC in patients with human immunodeficiency virus (HIV) infection, all cases of DMAC at Grady Memorial Hospital Infectious Disease Clinic (Atlanta) between 1985 and 1990 were reviewed, and a prospective study of the association of symptoms with DMAC was done. Between 1985 and 1990, DMAC occurred in 16% of patients with AIDS. Incidence increased from 5.7% in 1985-1988 to 23.3% in 1989-1990 (P less than .001). Median time from AIDS diagnosis to diagnosis of DMAC increased from 4.5 months in 1985-1988 to 8 months in 1989-1990 (P less than .02). In the prospective study, DMAC was seen only in persons with a CD4+ count less than 100 cells/mm3 and was associated with fever (P less than .03), anemia (P less than .001), weight loss (P less than .01), diarrhea (P less than .01), and elevated alkaline phosphatase (P less than .01). It is recommended that all such HIV-infected persons have mycobacterial blood cultures done.

Acquired Immunodeficiency Syndrome↗