Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pulmonary colonization and infection of patients with cystic fibrosis by Mycobacterium spp. has recently been recognized as a potentially important clinical problem. However, frequent contamination of mycobacterial cultures by pseudomonads has hampered efforts to define the extent of this problem. This study was done to evaluate current techniques and to establish a more efficient method of recovering mycobacteria from respiratory secretions of patients with cystic fibrosis. Decontamination of respiratory specimens (n = 121) with 0.25% N-acetyl-L-cysteine and 1% sodium hydroxide (NALC-NaOH) was associated with a high rate of pseudomonas overgrowth for both Lowenstein-Jensen slants (74%) and BacTec vials supplemented with PANTA (polymyxin B [50 U/ml], amphotericin B [5 micrograms/ml], nalidixic acid [20 micrograms/ml], trimethoprim [5 micrograms/ml], azlocillin [10 micrograms/ml]) (36%). This overgrowth limited recovery of mycobacteria to only 64% (9 of 14) of specimens positive by smear for acid-fast bacilli (AFB). Decontamination of specimens (n = 441) with NALC-NaOH, followed by 5% oxalic acid treatment, resulted in contamination of only 5% of Lowenstein-Jensen slants and 3% of BacTec vials. AFB were recovered from all 90 AFB smear-positive specimens following the use of this decontamination technique. We recommend that respiratory secretions be decontaminated with NALC-NaOH and oxalic acid to decrease the incidence of Pseudomonas aeruginosa overgrowth.
 ...
PMID:Improved recovery of mycobacteria from respiratory secretions of patients with cystic fibrosis. 846 98

The role of rapidly growing mycobacteria (RGM) as pulmonary pathogens has been unclear. We identified 154 cases of lung disease caused by RGM using the microbiologic and radiographic criteria of the American Thoracic Society (ATS) and availability of the causative organism for study. More than one third of patients had positive lung biopsy cultures. Patients were predominantly white (83%), female (65%) nonsmokers (66%), and they had prolonged periods from onset of symptoms to diagnosis of their disease. Cough was an almost universal presenting symptom, whereas constitutional symptoms became more important with progression of disease. Upper lobe infiltrates were most common (88%), with 77% of patients developing bilateral disease. Cavitation was present in only 16% of the patients. Specific underlying diseases were infrequent, but they included previously treated mycobacterial disease (18%), coexistent Mycobacterium avium complex (8%), cystic fibrosis (6%), and gastroesophageal disorders with chronic vomiting (6%). The majority of isolates (82%) were M. abscessus (formerly M. chelonae subsp. abscessus). Effective treatment for M. fortuitum long disease was accomplished with drug therapy, whereas surgical resection of localized disease was the only effective long-term therapy for M. abscessus. Although the disease was generally slowly progressive, 21 of 154 (14%) patients died as a consequence of progressive RGM lung disease and respiratory failure. RGM should be recognized as a cause of chronic mycobacterial lung disease, and respiratory isolates should be assessed carefully.
 ...
PMID:Clinical features of pulmonary disease caused by rapidly growing mycobacteria. An analysis of 154 patients. 848 42

The fluoroquinolones are characterised by a broad spectrum of antibacterial activity that includes many Mycobacterium, Chlamydia, Legionella, and Mycoplasma species as well as many multiply-resistant bacterial strains, good oral bioavailability, extensive tissue penetration, low protein binding and long elimination half-lives. Numerous clinical trials have shown that these compounds are effective and well tolerated in the treatment of adult patients with various infections, including urinary tract, respiratory tract, skin and soft tissue, bone and joint, and gynaecological infections, sexually transmitted diseases, infectious diarrhoea, infections in immunocompromised patients, and in surgical prophylaxis. Thus, there is increasing pressure to use this class of drugs in paediatric patients. However, concerns regarding adverse effects, particularly cartilage toxicity, have restricted development of the fluoroquinolone compounds for use in this population. Potential indications include Pseudomonas infections (mainly exacerbations of cystic fibrosis), urinary tract, gastrointestinal and central nervous system infections, infections in immunocompromised patients, certain otorhinolaryngological infections and infections caused by multiply-resistant pathogens. To date, clinical experience gained with fluoroquinolones in paediatric infections, which has been mainly on a compassionate-use basis, indicates that well-designed formal studies should be conducted to fully assess the efficacy and tolerability of these agents in specific indications in children.
 ...
PMID:Fluoroquinolones in paediatrics--1995. 854 23

We retrospectively studied lung and hilar lymph nodes at autopsy in 18 patients with cystic fibrosis (CF) who had antemortem sputum cultures positive for nontuberculous mycobacteria (NTM). Histologic features were compared with those of 18 patients with CF who had negative antemortem cultures. The most frequent species isolated was M. chelonae group (10 patients). Multiple cultures were positive for NTM in six patients. Three patients were clinically considered to be infected, and two received antimycobacteria drugs. Necrotizing pulmonary granulomas associated with granulomatous organizing pneumonia were found at autopsy in two patients, each of whom had multiple positive sputum cultures and clinical evidence of infection. In one of these, mycobacterial infection was considered to be an important factor in her terminal illness. Neither necrotizing granulomas nor granulomatous organizing pneumonia were seen in the lung tissue of patients whose antemortem cultures were negative for mycobacteria. There was no difference in the prevalence of other granuloma-like lesions between those with and those without positive sputum cultures. No mycobacteria-related granulomas occurred in hilar lymph nodes, although histoplasma granulomas involved hilar lymph nodes of three patients. We conclude that granulomatous mycobacterial lung disease is present in a minority of patients (two of six patients in this study) who have multiple positive cultures. Histologic evidence of infection was not found in patients who had only one of multiple sputum cultures positive for NTM.
 ...
PMID:Nontuberculous mycobacteria in cystic fibrosis. An autopsy study. 875 32

More patients with cystic fibrosis are surviving into adulthood. Primary care physicians need a basic understanding of adult cystic fibrosis and the evaluation of patients with acute decompensation. Respiratory decompensation is usually the result of infective agents, including Pseudomonas aeruginosa, Stentrophomonas maltophilia and Burkholderia cepacia, and requires treatment with intravenous antibiotics. If symptoms worsen, the possibility of another complication, such as pneumothorax, hemoptysis, mycobacterial infection and allergic bronchopulmonary aspergillosis, must be considered. Family physicians can play an important role in the birth to adult care of patients with cystic fibrosis.
 ...
PMID:Treatment of cystic fibrosis in adults. 881 73

Twenty-six clinical isolates of Mycobacterium abscessus resistant to amikacin were identified. Most isolates were from patients with posttympanostomy tube placement otitis media or patients with cystic fibrosis who had received aminoglycoside therapy. Isolates were highly resistant (MICs > 1024 microg/mL) to amikacin, kanamycin, gentamicin, tobramycin, and neomycin (all 2-deoxystreptamine aminoglycosides) but not to streptomycin. Sequencing of their 16S ribosomal (r) RNA revealed that 16 (94%) of 17 had an A-->G mutation at position 1408. In vitro-selected amikacin-resistant mutants of M. abscessus and Mycobacterium chelonae had the same resistance phenotype, and 15 mutants all had the same A-->G substitution at position 1408. Introducing an rRNA operon from Mycobacterium smegmatis with a mutated A-->G at this position into a single functional allelic rRNA mutant of M. smegmatis produced the same aminoglycoside resistance phenotype. These studies demonstrate this 16S rRNA mutation is responsible for amikacin resistance in M. abscessus, which has only one copy of the rRNA operon.
 ...
PMID:A single 16S ribosomal RNA substitution is responsible for resistance to amikacin and other 2-deoxystreptamine aminoglycosides in Mycobacterium abscessus and Mycobacterium chelonae. 960 35

The prevalence of nontuberculous mycobacteria (NTM) isolated from the lower airways of adult cystic fibrosis (CF) patients appears to be increasing. Different centers of USA, England, Sweden and Ireland have reported a prevalence ranging from 1.5 to 19.5%. The aim of the present study was to investigate the presence of NTM in patients assisted at these centers. A total of 92 sputum specimens and/or gastric contents from 40 CF patients were studied. Ages of patients ranged from 4 months to 25 years. Samples were obtained during acute exacerbation or in routine check-up. Mycobacterium avium-intracellulare complex strains were isolated from six patients with moderate or severe clinical manifestations. Five of these patients were considered as being colonized by NTM. Active mycobacterial disease was diagnosed in one patient and he underwent treatment. The index of bacterial contamination of cultures was very high early along the study (57%), decreasing to 2.8% later due to a change in the methodology used in the processing of samples. It was concluded that the presence of NTM is relatively frequent in patients with CF, even in children with moderate or severe compromise, a fact which strongly suggests that NTM should be systematically searched for considering the possibility that the patients might develop active disease.
 ...
PMID:[Nontuberculous mycobacteria in patients with cystic fibrosis]. 971 92

During the past year, additional insights into systems that regulate antimicrobial peptide production in Drosophila were reported. Granulysin, a peptide stored in the cytoplasmic granules of human natural killer cells and cytolytic T cells, was shown to kill Mycobacterium tuberculosis. More data implicating antimicrobial peptides in the pathogenesis of bronchopulmonary infections in cystic fibrosis appeared. Studies that examined the potential contributions of antimicrobial peptides to regional innate immunity gained in prominence. Efforts to design peptide analogues to prevent or treat infections continued.
 ...
PMID:Antimicrobial peptides in mammalian and insect host defence. 1004 45

Cystic fibrosis (CF) patients require higher dosages of many antibiotics. The relapse of tuberculosis in one CF patient, and the repeated growth of Mycobacterium avium-intracellulare in another, despite conventional therapy, raised the question of whether the serum levels of the antimycobacterial drugs were adequate. Antimycobacterial drug serum concentrations were assayed in 10 CF patients with pulmonary mycobacterial disease. Serum levels below the proposed target range were seen 2 h after drug intake in the initial four patients treated: for rifampicin in 2/3, ethambutol in 3/4 and for clarithromycin in 2/3 patients, despite standard dosages. Reassays after dose adjustment and assays in six other patients showed that adequate levels were not achieved 4 h after clarithromycin in 3/5, ethambutol in 1/5, ciproflaxacin in 1/2 and ofloxacin in 2/2 patients. The patient with relapse of tuberculosis and the patient with continuous growth of M. avium-intracellulare improved and became culture negative after dose adjustment. Low drug serum levels is one reason for therapy failure in cystic fibrosis patients with mycobacterial disease. Therapeutic drug monitoring is recommended.
 ...
PMID:Therapeutic drug monitoring in patients with cystic fibrosis and mycobacterial disease. 1051 12

We present a case of a patient with cystic fibrosis who was thought to be colonized with Mycobacterium abscessus for 13 yr prior to developing clinically apparent mycobacterial infection. However, histologic evidence indicated that invasive mycobacterial disease was present from the onset. While accepting that chronic endobronchial colonization with atypical mycobacteria may occur in patients with cystic fibrosis, the repeated isolation of mycobacteria from the sputum of these patients should alert the clinician to the possibility of indolent disease. Early consideration of treatment for this infection should occur in any patient with cystic fibrosis in whom there is an unexplained deterioration in lung function. The recent introduction of high dose ibuprofen raises concerns about its possible contribution to the progression of the infection.
 ...
PMID:Mycobacterium abscessus infection in cystic fibrosis. Colonization or infection? 1067 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>