Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026936 (Mycoplasma)
 14,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The performance of the GeneScan algorithm for gene identification has been improved by incorporation of a directed iterative scanning procedure. Application is made here to the cases of bacterial and organnellar genomes. The sensitivity of gene identification was 100% in Plasmodium falciparum plastid-like genome (35 kb) and in 98% in the Mycoplasma genitalium genome (approximately 580 kb) and the Haemophilus influenzae Rd genome (approximately 1.8 Mb). Sensitivity was found to improve in both the Open Reading Frames (ORFs) which have been identified as genes (by homology or by other methods) and those that are classified as hypothetical. False positive assignments (at the nucleotide level) were 0.25% in H. influenzae genome and 0.3% in M. genitalium. There were no false positive assignments in the plastid-like genome. The agreement between the GeneScan predictions and GeneMark predictions of putative ORFs was 97% in M. genitalium genome and 86% in H. influenzae genome. In terms of an exact match between predicted genes/ORFs and the annotation in the databank, GeneScan performance was evaluated to be between 72% and 90% in different genomes. We predict five putative ORFs that were not annotated earlier in the GenBank files for both M. genitalium and H. influenzae genomes. Our preliminary analysis of the newly sequenced G + C rich genome of Mycobacterium tuberculosis H37Rv also shows comparable sensitivity (99%).
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PMID:Gene identification in bacterial and organellar genomes using GeneScan. 1035 88

In addition to erythromycin, macrolides now available in the United States include azithromycin and clarithromycin. These two new macrolides are more chemically stable and better tolerated than erythromycin, and they have a broader antimicrobial spectrum than erythromycin against Mycobacterium avium complex (MAC), Haemophilus influenzae, nontuberculous mycobacteria, and Chlamydia trachomatis. All three macrolides have excellent activity against the atypical respiratory pathogens (C. pneumoniae and Mycoplasma species) and the Legionella species. Azithromycin and clarithromycin have pharmacokinetics that allow shorter dosing schedules because of prolonged tissue levels. Both azithromycin and clarithromycin are active agents for MAC prophylaxis in patients with late-stage acquired immunodeficiency syndrome (AIDS), although azithromycin may be the preferable agent because of fewer drug-drug interactions. Clarithromycin is the most active MAC antimicrobial agent and should be part of any drug regimen for treating active MAC disease in patients with or without AIDS. Although both azithromycin and clarithromycin are well tolerated by children, azithromycin has the advantage of shorter treatment regimens and improved tolerance, potentially improving compliance in the treatment of respiratory tract and skin or soft tissue infections. Intravenously administered azithromycin has been approved for treatment of adults with mild to moderate community-acquired pneumonia or pelvic inflammatory diseases. An area of concern is the increasing macrolide resistance that is being reported with some of the common pathogens, particularly Streptococcus pneumoniae, group A streptococci, and H. influenzae. The emergence of macrolide resistance with these common pathogens may limit the clinical usefulness of this class of antimicrobial agents in the future.
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PMID:The macrolides: erythromycin, clarithromycin, and azithromycin. 1037 39

TWO-PHASE ACTION: Pristinamycin is composed of two active substances A and B. Pristinamycin A (SA) first binds to the ribosome subunit 50s. Pristinamycin B (SB) then locks onto SA causing irreversible inhibition of bacterial protein production. WELL-ADAPTED ACTIVITY SPECTRUM: A member of the streptogramin family of antibiotics, pristinamycin is active against the main bacteria causing respiratory tract infections (pneumococci, S. aureus, H. influenzae) as well as against mycoplasma and anaerobic pathogens. ANTI-PNEUMOCOCCI ACTIVITY: Minimal inhibitory concentrations measured over the last 5 years have confirmed that the antibacterial activity of pristinamycin against pneumococci remains unchanged even for strains which develop resistance to other antibiotics, particularly to penicillin or erythromycin. OTHER BACTERIA: The activity of pristinamycin against H. influenzae is a constant finding (unimodal distribution of MIC). The persistent of pristinamycin activity against S. aureus strains, excepting a few SA- resistant strains and SA + SB- resistant strains, is remarkable. MIC studies have also demonstrated the constant susceptibility of Moraxella catarrhalis, non-groupable streptococci, anaerobic bacteria, and Legionella pneumophila.
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PMID:[In vitro activity of pristinamycin on respiratory bacteria]. 1050 76

Severe CAP is a life-threatening condition defined by the presence of respiratory failure or symptoms of severe sepsis or septic shock. It accounts for approximately 10% of hospitalized patients with CAP. The majority of patients with severe pneumonia have underlying comorbid illnesses, with COPD, alcoholism, chronic heart disease, and diabetes mellitus being the most frequent. S. pneumoniae, Legionella spp, GNEB (especially K. pneumoniae), H. influenzae, S. aureus/spp, Mycoplasma pneumoniae, respiratory viruses (especially influenza viruses), and P. aeruginosa represent the most important causative organisms of severe CAP. Rapid initiation of appropriate antimicrobial treatment is crucial for a favorable outcome. Initial antimicrobial treatment should be based on an epidemiological (empiric) approach. Microbial investigation may be helpful in the individual case but is probably more useful to define local antimicrobial policies based on local epidemiologic and susceptibility patterns. Mortality rates range from 21% to 54%. The most important prognostic factors include general health state of the patient, appropriateness of initial antimicrobial treatment, and the existence of bacteremia, as well as factors reflecting severe respiratory failure, severe sepsis, septic hypotension or shock, and the extent of infiltrates in chest radiograph. Initial antimicrobial treatment should consist of a second (or third) generation cephalosporin and erythromycin. Modifications of this basic regimen should be considered in the presence of distinct comorbid conditions and risk factors for distinct pathogens. Promising new approaches of nonantimicrobial treatment, including noninvasive ventilation, treatment of hypoxemia, and immunomodulation, are under investigation.
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PMID:Severe community-acquired pneumonia. 1051 5

A comparative study of 890 patients with community-acquired pneumonia requiring hospitalization in a community hospital was performed. The patients were divided into an elderly patient group and a non-elderly patient group. The elderly patients with community-acquired pneumonia exhibited frequent atypical symptoms such as dyspnea, consciousness disturbance and complication of shock, and also were frequently in a poor nutritional condition. The causative microorganism was isolated in 40.8% of the elderly patients and in 44.0% of the non-elderly patients. Polymicrobial agents were detected frequently in the elderly patients. Streptococcus pneumoniae (19.4%), MSSA (16.8%), Klebsiella pneumoniae (15.1%) and Haemophilus influenzae (15.0%) were frequently isolated from the sputum of the elderly patients, while Mycoplasma pneumoniae (25.2%), H. influenzae (15.0%), S. pneumoniae (12.2%) and MSSA (10.2%) were frequently isolated from that of the non-elderly patients. Regarding treatment with antibiotics, therapy with a single antibiotic therapy, such as cephem or carbapenem was carried out for the elderly patients, while new quinolone or tetracycline was administered to the non-elderly patients. Although the treatment with antibiotics was adequate according to the guidelines of the American Thoracic Society, the prognosis was poor; i.e.) in the elderly patients an efficacy rate of 74.3% and a mortality rate of 9.5%. In the non-elderly patients, the prognosis was good; i.e.) an efficacy rate of 88.0% and a mortality rate of 1.7%. These results suggest that the most important factors affecting the prognosis were the general condition of elderly patients and delay in an adequate diagnosis and treatment because of atypical clinical findings.
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PMID:[Clinical analysis of community-acquired pneumonia requiring hospitalization in a community hospital--comparison of elderly and non-elderly patients]. 1069 94

Community-acquired pneumonia (CAP) remains a common and serious illness with approximately 2-4 million cases reported annually. Management of CAP is therapeutically challenging due to the increasing prevalence of penicillin- and macrolide-resistant pneumococci and beta-lactamase producing Haemophilus influenzae, as well as the increased recognition of 'atypical' pathogens, such as Chlamydia pneumoniae and Mycoplasma pneumoniae, and the frequent need for empiric therapy. We aimed to evaluate the safety and efficacy of moxifloxacin in the treatment of patients with CAP. To do this we carried out a prospective, uncontrolled, non-blind, Phase III clinical trial, in 27 U.S. centers. Patients included in the study were over 18 years of age with signs and symptoms of CAP confirmed by evidence of a new or progressive infiltrate on chest radiograph. The intervention used was moxifloxacin 400 mg PO once daily for 10 days. Sputum samples were collected pretherapy for Gram stain and culture for typical organisms. Culture and serological testing for Chlamydia pneumoniae and Mycoplasma pneumoniae was also performed. Susceptibility to moxifloxacin was determined by disk diffusion and MIC. Clinical and bacteriological responses were determined at the end of therapy (0-6 days post-therapy), follow-up (14-35 days post-therapy) and overall (end of therapy plus follow-up). Analyses were performed on both valid for efficacy and intent-to-treat populations. The primary efficacy variable was overall clinical resolution. Of 254 patients enrolled in the Study, 196 patients were included in the efficacy analyses. The majority of patients were male (58%) and Caucasian (85%) with a mean age of 49 years (range: 18 to 85 years). Only 3% of patients were hospitalized pretherapy. The most common pretherapy organisms identified, by culture or serology, in the valid for efficacy population (i.e. 147 organisms among 116 patients), were: Chlamydia pneumoniae (n=63; 54%), Mycoplasma pneumoniae (n=29; 25%), Streptococcus pneumoniae (n=14; 12%) and Haemophilus influenzae (n=13; 10%). End of therapy, follow-up and overall clinical resolution rates for the valid for efficacy population were 94%, 93% and 93%, respectively. The 95% CI for the overall clinical resolution rate was 88.1%, 95.9%. The overall bacteriological response for patients diagnosed by culture or serological criteria, was 91% (95% CI=84%, 96%). For patients who only met serological criteria for infection, the overall bacteriological response was 94% (60/64). Bacterial response rates for the four most commonly isolated pathogens were: 89% (56/63) for C. pneumoniae, 93% (27/29) for M. pneumoniae, 93% (13/14) for S. pneumoniae and 85% (11/13) for H. influenzae. Drug-related adverse events were reported in 33% (85/254) of moxifloxacin-treated patients. Nausea (9%), diarrhea (6%) and dizziness (4%) were the most commonly reported adverse events. Atypical organisms were isolated in high frequency among patients with CAP. Moxifloxacin 400 mg once daily for 10 days was effective and well-tolerated in the treatment of these adult patients with CAP. Moxifloxacin offers an effective treatment alternative for CAP due to both typical and atypical bacterial pathogens.
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PMID:Efficacy and safety of ten day moxifloxacin 400 mg once daily in the treatment of patients with community-acquired pneumonia. Community Acquired Pneumonia Study Group. 1071 13

Although most respiratory tract infections (RTI) are caused by viruses, various bacteria, particularly Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, are common causes of community-acquired pneumonia, acute exacerbations of chronic bronchitis, otitis media and sinusitis. Empirical antibiotic therapy of patients with RTI must take account of the increasing prevalence of resistance among the predominant pathogens. Europe-wide susceptibility surveillance studies have revealed that resistance to penicillin and macrolides is highly prevalent among isolates of S. pneumoniae from France and Spain. Uniquely, in Italy, macrolide resistance is highly prevalent while the prevalence of penicillin resistance is low. Resistance to other antibiotic classes, including chloramphenicol, doxycycline and, in particular, co-trimoxazole, is associated with penicillin resistance in pneumococci, but resistance to the fluoroquinolones is rare. beta-Lactamase production is the principal mechanism of resistance in isolates of H. influenzae and M. catarrhalis, with fluoroquinolone resistance being detected rarely in these pathogens. In 1998 a surveillance study involving 15 European countries determined the susceptibilities of many respiratory pathogens to a range of antimicrobials, including grepafloxacin. The MIC(90) of grepafloxacin for 1251 isolates of S. pneumoniae was 0.25 mg/L, the MICs for only five strains being >2 mg/L, and 99.4% of all of the isolates tested were inhibited by concentrations </=0.5 mg/L. The MIC(90)s of grepafloxacin for 587 isolates of H. influenzae and 323 of Haemophilus parainfluenzae were 0.015 and 0.06 mg/L, respectively, while that for 509 isolates of M. catarrhalis was 0.03 mg/L. The MIC(90)s for 1164 isolates of methicillin-susceptible Staphylococcus aureus and 435 isolates of Klebsiella pneumoniae were 0.12 and 0.25 mg/L, respectively. Other studies have shown grepafloxacin to be highly active against clinical isolates of Legionella pneumophila (MIC(90) 0.015 mg/L), Mycoplasma pneumoniae (MIC(90) 0.5 mg/L) and Chlamydia pneumoniae (MICs 0.06-0.12 mg/L). Current susceptibility data indicate that fluoroquinolone resistance rates among bacterial respiratory tract pathogens are low in European countries. The enhanced potency and activity of grepafloxacin against isolates of S. pneumoniae, including those exhibiting resistance to unrelated classes of antibiotics, together with its activity against other respiratory tract pathogens, suggest that this drug has considerable potential as empirical therapy of patients with a wide range of RTI.
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PMID:Respiratory pathogens: assessing resistance patterns in Europe and the potential role of grepafloxacin as treatment of patients with infections caused by these organisms. 1071 6

Members of the family Pasteurellaceae are classified in part by whether or not they require an NAD supplement for growth on laboratory media. In this study, we demonstrate that this phenotype can be determined by a single gene, nadV, whose presence allows NAD-independent growth of Haemophilus influenzae and Actinobacillus pleuropneumoniae. This gene was cloned from a 5.2-kb plasmid which was previously shown to be responsible for NAD independence in Haemophilus ducreyi. When transformed into A. pleuropneumoniae, this cloned gene allowed NAD-independent growth on complex media and allowed the utilization of nicotinamide in place of NAD on defined media. Sequence analysis revealed an open reading frame of 1,482 bp that is predicted to encode a protein with a molecular mass of 55,619 Da. Compared with the sequence databases, NadV was found to have significant sequence homology to the human pre-B-cell colony-enhancing factor PBEF and to predicted proteins of unknown function identified in the bacterial species Mycoplasma genitalium, Mycoplasma pneumoniae, Shewanella putrefaciens, Synechocystis sp., Deinococcus radiodurans, Pasteurella multocida, and Actinobacillus actinomycetemcomitans. P. multocida and A. actinomycetemcomitans are among the NAD-independent members of the Pasteurellaceae. Homologues of NadV were not found in the sequenced genome of H. influenzae, an NAD-dependent member of the Pasteurellaceae, or in species known to utilize a different pathway for synthesis of NAD, such as Escherichia coli. Sequence alignment of these nine homologues revealed regions and residues of complete conservation that may be directly involved in the enzymatic activity. Identification of a function for this gene in the Pasteurellaceae should help to elucidate the role of its homologues in other species.
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PMID:Identification of a plasmid-encoded gene from Haemophilus ducreyi which confers NAD independence. 1115 28

Telithromycin is a new ketolide antimicrobial, specifically developed for the treatment of community-acquired respiratory tract infections. It has a wide spectrum of antibacterial activity against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. It also has activity against atypical pathogens, such as Chlamydia pneumoniae, Legionella pneumophila and Mycoplasma pneumoniae. Telithromycin maintains activity against beta-lactam and macrolide-resistant respiratory tract pathogens and does not appear to induce cross-resistance to other members of the macrolide-lincosamide-streptogramin (MLS) group of antimicrobials. It demonstrates bactericidal activity against S. pneumoniae and H. influenzae and has a prolonged concentration-dependent post-antibiotic effect (PAE) in vitro. The drug has favourable pharmacokinetics following oral administration. It is well absorbed, achieves good plasma levels and is highly concentrated in pulmonary tissues and white blood cells. In clinical trials, telithromycin given orally at a dose of 800 mg once daily for 5 - 10 days was as effective as comparator antimicrobials for the treatment of adults with community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis and group A-beta-haemolytic streptococcal pharyngitis or tonsillitis. The adverse events and safety profile were similar to comparator antimicrobials. The most common adverse events were diarrhoea, nausea, headache and dizziness. Telithromycin should provide an effective, convenient and well-tolerated once-daily oral therapy for treatment of respiratory infections.
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PMID:Telithromycin: a new ketolide antimicrobial for treatment of respiratory tract infections. 1117 47

Pneumonia acquired in Community (CAP) may be a primary disease occurring in healthy individuals or secondary to predisposing factors or comorbidity. Prevalence of CAP is 2.6 to 5% for all ages, in USA 12%, for over 65 years 30%. Streptococcus pneumoniae is the commonest pathogen 30-50%, H. influenzae in COPD, the atypical pneumonia Mycoplasma pn., M. catharralis, Legionella pn., Enterobacteria, anaerobics often in hospital survey. In children is different RSV, Parainfluenzae type 3, Rhinovirus in the first 2 years old. Others are S. pneumoniae, H. influenzae, Chlamydia sp., etc. Appropriate empiric antibiotic therapy choices are based in guidelines. The most common pathogen is S. pneumoniae, isolates raised resistance rates to Penicillin to 20-50%, 40% in our country and also to Macrolides, with potential clinical failure (21-40%). Specially in elderly people and with the comorbidity are recommended the 23 valent polysaccharide vaccine, effective in bacteremic pneumonia 70-80%. Is not effective in children under 2 years, for that is important conjugated vaccine Hib (toxoids T, D, CRM197, OMP Nm) to prevent carriers, otitis media and reduce exacerbation of these respiratory infections.
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PMID:[Current interest of antipneumococcal vaccination]. 1120 55


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