Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was set up to establish the regression curve for clarithromycin inhibition zone diameters (disks 15 micrograms) and MIC to create a strain distribution plot, in order to allow accurate interpretation of the disk diffusion method for testing susceptibility to clarithromycin. 430 bacterial strains were studied in three university hospital. Clarithromycin was active against erythromycin sensitive Staphylococcus aureus and coagulase negative Staphylococci at concentrations of 0.12 to 0.25 microgram/ml (mode 0.25). Erythromycin resistant strains were also resistant to clarithromycin. Enterococci could be divided into two populations, one resistant (MIC greater than 128 micrograms/ml) and the other with MIC of 0.06 to 2 (mode 0.25). This was also the case for Streptococci and Pneumococci with MIC lower for susceptible strains (mode 0.03 to 0.06). Clarithromycin was active on Haemophilus at concentrations of 4 to 64 micrograms/ml (mode 16); MICs for beta-lactamase producing strains were comparable to those of strains not producing. MICs for Neisseria were 0.12 to 16 and for B. catarrhalis 0.016 to 0.5. MIC were 0.5 and 1 (mode 1) for Clostridium perfringens; Bacteroides fragilis strains were inhibited by 0.12 to 8 micrograms/ml (mode 0.5-1). So, antibacterial activity of C was similar to that of E; it was sometimes slightly superior, particularly on Gram positive cocci. For MIC breakpoints of 1 and 4 micrograms/ml, zone size breakpoints should be 23 and 17 mm and for 2 and 8 micrograms/ml, 20 and 15 mm.
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PMID:[In vitro antibacterial activity of clarithromycin, a new macrolide antibiotic, and regression curve]. 214 74

The activity of tosufloxacin (A-60969), a new oral quinolone, and clarithromycin (A-56268, TE-031), a new oral macrolide, was compared in vitro to that of other oral quinolones and beta-lactam antimicrobial agents against clinical isolates of ampicillin and/or chloramphenicol resistant Haemophilus influenzae, penicillin resistant Streptococcus pneumoniae and beta-lactamase producing Branhamella catarrhalis. Results were compared to those for sensitive isolates. Tosufloxacin was the most active compound against Haemophilus influenzae and was more active than ciprofloxacin or ofloxacin against all strains of Streptococcus pneumoniae. Tosufloxacin was also more active than any of the beta-lactam drugs tested against penicillin resistant or relatively penicillin resistant isolates. Clarithromycin was the most active compound tested against both penicillin sensitive and penicillin resistant Streptococcus pneumoniae, and was as active as ciprofloxacin against Branhamella catarrhalis. In view of the favourable in vitro activity against common bacterial respiratory pathogens, tosufloxacin should be considered for clinical trials in adults with respiratory tract infections, while clarithromycin might be useful in treatment of infection with these organisms in all age groups.
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PMID:In vitro activity of tosufloxacin (A-60969) and clarithromycin (A-56268, TE-031) against resistant Haemophilus influenzae, Streptococcus pneumoniae and Branhamella catarrhalis isolates. 214 47

Clarithromycin (TE-031, A-56268) is a new 14-membered ring macrolide antibiotic developed by Taisho Pharmaceutical Co., Ltd. TE-031 has a methoxy group at position 6 in its structure. In the present study, we carried out laboratory and clinical investigations on TE-031 in the field of pediatrics. The obtained results are summarized as follows. The antibacterial activity of TE-031 was investigated against 16 clinically isolated strains of Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, Bordetella pertussis and Campylobacter jejuni. TE-031 showed antibacterial activity comparable to erythromycin. The pattern of changes in TE-031 concentrations in the blood after administration was investigated. In subjects administered the granular preparation of TE-031, Cmax values were 0.64 micrograms/ml in 1 subject given a 5 mg/kg dosage, and 5.94 and 9.02 micrograms/ml in 2 subjects administered with 10 mg/kg. The tablet form of TE-031 was administered to 3 subjects at 5 mg/kg, and Cmax values were 2.09-3.92 micrograms/ml, while T 1/2 values were in a range of 2.9-3.8 hours. When drug concentrations in the urine were investigated, it was found that 6-hour recovery rates were 9.9% (dose: 5 mg/kg) and 53.4% (dose: 10 mg/kg) in the subjects administered the granular form, whereas recovery rates averaged 36.8% in the tablet-administered subjects. In the clinical trial, TE-031 was administered in 2-3 doses/day for 2-18 days. In cases given the granular form, dosages were 12-38 mg/kg/day, while tablets were administered at 12-29 mg/kg/day. The overall clinical efficacy rate was 92.8%, i.e., the drug was effective in 64 of 69 patients. TE-031 was ineffective in 1 case of otitis media, but efficacious in 10 of 10 (100%) cases of upper respiratory infection, 15 of 18 (83.3%) cases of bronchitis and pneumonia, 5 of 6 (83.3%) cases of pertussis, 13 of 13 (100%) cases of mycoplasmal pneumonia, 4 of 4 (100%) cases of Chlamydia psittaci pneumonia, 16 of 16 (100%) cases of gastroenteritis (including 15 cases of Campylobacter gastroenteritis), and 1 (100%) case of impetigo. In bacteriological studies conducted on the patients, the overall elimination rate was 93.1%, i.e., bacterial elimination was obtained in 27 of 29 cases. TE-031 showed especially good bacteriological efficacy (100%) against C. jejuni and B. pertussis, which were eliminated from all of 15 and 2 cases examined, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Laboratory and clinical studies on clarithromycin in pediatrics]. 252 42

1. Clarithromycin (TE-031, A-56268) was given orally to 46 children with respiratory infections, skin infections and others. A total of 9 patients were excluded; 8 patients refused to take the drug because of it's taste, and 1 patient was later found to have viral pneumonia. Clinical efficacy was therefore evaluated in remaining 37 cases and was good or excellent in 27 cases. 2. Bacteriologically, Haemophilus influenzae strains isolated from 4 patients were eradicated in 1 and decreased in 3, respectively. Haemophilus parainfluenzae and Staphylococcus aureus isolated from 1 patient each were both eradicated. 3. Side effect or abnormal laboratory test values were not observed. 4. Based on the above findings, it appears that TE-031 is a safe and is useful antibiotic for the treatment of mild and moderate respiratory infections. It is necessary, however, to improve the taste of the current granule preparation in order to make the drug more easily palatable to children.
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PMID:[Clinical study of clarithromycin, a new macrolide antibiotic, in children]. 252 49

Clarithromycin (TE-031, A-56268), a new macrolide antibiotic, was administered to a total of 25 child patients (age range: 4 months-12 years) to treat infections; the patients consisted of 23 children who received the drug in the form of granules for children and 2 patients who were given tablets. Daily dosages were 14.3 mg/kg (in 2 divided doses) in 1 patient, and 18.3-30.3 mg/kg (in 3 divided doses) in the other 24 patients. Lengths of administration ranged from 4 to 13 days with 6-8 days for 18 of the patients. The results obtained are summarized as follows. 1. Clinical efficacy evaluations for various infections were as follows: 1 excellent, 4 good and 2 fair cases in 7 cases of pertussis; 3 excellent, 2 good and 1 fair cases in 6 cases of tonsillitis; 1 good case in tonsillitis with bronchitis; 1 excellent and 3 good cases in 4 cases of bronchitis; 1 excellent and 1 good cases in 2 cases of pneumonia; and 4 excellent and 1 good cases in 5 cases of enteritis. Thus, evaluations of a total of 25 patients showed 10 excellent, 12 good and 3 fair cases, with no poor cases. The overall clinical efficacy rate was, therefore, 88.0%. These results were attributed to good antimicrobial activity and absorption of TE-031. 2. Causative bacteria were isolated from 12 of the patients. Bacteriological efficacies of TE-031 on those strains were investigated with the following results. Of 5 Haemophilus influenzae strains, 3 were eliminated, 1 was reduced, and no change was observed in the other.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A clinical study on clarithromycin especially on its granular form for children in pediatrics]. 252 50

Four separate laboratories performed antimicrobial susceptibility tests with 40 Haemophilus influenzae isolates, each tested in triplicate. Erythromycin and a new macrolide, clarithromycin (A-56268; TE-031), were tested by the disk diffusion method, by the agar dilution procedure in two different media, and by broth microdilution tests in four different media. Erythromycin MICs for 90% of the strains were 16 micrograms/ml in Mueller-Hinton broth with 3% lysed horse blood and NAD, 4.0 micrograms/ml in hemophilus test medium, and 2.0 micrograms/ml in supplemented Schaedler broth or in the fastidious broth medium from Beckman Instruments, Inc. Clarithromycin MICs were generally 1 doubling dilution greater than erythromycin MICs in each of the media. Erythromycin disk tests corresponded best with MICs determined in the fastidious broth medium. In that same medium, clarithromycin MICs were about 1 doubling dilution greater than what would be expected from the results of disk tests. Because there were fewer growth failures, hemophilus test medium is recommended for microdilution tests with H. influenzae. Incubation of all tests for a full 24 h without an increased CO2 atmosphere was needed to achieve maximal precision of the tests. Interlaboratory and intralaboratory reproducibility of all tests was satisfactory.
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PMID:Variability of clarithromycin and erythromycin susceptibility tests with Haemophilus influenzae in four different broth media and correlation with the standard disk diffusion test. 297 73

The in vitro activities of several 14-, 15- and 16-membered macrolides were compared with that of erythromycin. In general, 14-membered macrolides such as erythromycin, clarithromycin, and flurithromycin were more active against streptococci and Bordetella pertussis than was the 15-membered macrolide azithromycin, which was more active than 16-membered macrolides such as miocamycin and rokitamycin. Clarithromycin was the most active compound against Streptococcus pyogenes, pneumococci, Listeria monocytogenes, and Corynebacterium species. Legionella pneumophila was most susceptible to miocamycin, clarithromycin, and rokitamycin. Branhamella catarrhalis, Neisseria gonorrhoeae, and Haemophilus influenzae were most susceptible to azithromycin. Azithromycin and dirithromycin were the most active compounds against Campylobacter jejuni. MICs of 16-membered macrolides for strains expressing inducible-type resistance to erythromycin were less than or equal to 1 microgram/ml, whereas none of the compounds had activity against strains expressing constitutive-type resistance. The MICs of roxithromycin, miocamycin, rokitamycin, and josamycin increased in the presence of human serum, whereas MICs of the other compounds either were unchanged or decreased.
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PMID:Comparative in vitro activities of new 14-, 15-, and 16-membered macrolides. 325 53

Pharmacodynamic parameters have become increasingly important for the determination of the optimal dosing schedules of antibiotics. In this study, the postantibiotic effects (PAEs), the postantibiotic sub-MIC effects (PA SMEs), and the sub-MIC effects (SMEs) of roxithromycin, clarithromycin, and azithromycin on reference strains of Streptococcus pyogenes group A, Streptococcus pneumoniae, and Haemophilus influenzae were investigated. The PAE was induced by 2x MICs (S. pneumoniae) or 10x MICs of the different drugs for 2 h, and the antibiotics were eliminated by washing and dilution. The PA SMEs were studied by addition of 0.1, 0.2, and 0.3x MICs during the postantibiotic phase of the bacteria, and the SMEs were studied by exposition of the bacteria to the drugs at the sub-MICs only. Growth curves were followed by viable counts for 24 h. The SMEs were generally very short. A PAE of 2.9 to 8 h was noted for all antibiotics against all strains. Clarithromycin induced a statistically significantly shorter PAE on S. pneumoniae than did roxithromycin and azithromycin and did so also against H. influenzae in comparison with azithromycin. The PA SMEs were long and varied at 0.3x MIC between 6.4 19.6 h. This pronounced suppression of regrowth of bacteria which are first treated with a suprainhibitory concentration of antibiotics and then reexposed to sub-MIC levels indicates that long dosing intervals for macrolides and azalides can be allowed.
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PMID:Postantibiotic effects and postantibiotic sub-MIC effects of roxithromycin, clarithromycin, and azithromycin on respiratory tract pathogens. 769 10

Some recently marketed macrolide antimicrobial agents possess physiochemical, antimicrobial, and pharmacokinetic advantages that enable their wider clinical use against Haemophilus influenzae infections. A five-laboratory study assessed the validity of existing or proposed azithromycin, clarithromycin, and erythromycin interpretive criteria for tests with H. influenzae isolates. National Committee for Clinical Laboratory Standards (NCCLS) methods, criteria, and quality-control guidelines were used. A total of 350 H. influenzae strains were processed, including fresh clinical isolates (250 strains) and replicate tests of 100 stock cultures sampling strains isolated from 1984 to 91. Azithromycin interpretive criteria (susceptible at < or = 4 micrograms/ml, > or = 12 mm) produced a 99.8% absolute agreement between the minimum inhibitory concentrations and disk diffusion results (0.2% false-susceptible error). Clarithromycin breakpoint criteria (susceptible at < or = 8 micrograms/ml, > or = 13 mm; and resistant at > or = 32 micrograms/ml, < or = 10 mm) produced high minor interpretive error, but < or = 1% combined false-susceptible and false-resistant discrepancies. Erythromycin interpretive guidelines were initially proposed for susceptible at < or = 0.5 microgram/ml, > or = 26 mm. This categorizes nearly all H. influenzae strains as resistant to this older macrolide. The NCCLS should consider the proposed erythromycin criteria for publication in appropriate tables, and a class drug should also be selected (azithromycin) that would best predict macrolide-class susceptibility for those agents indicated by the US Food and Drug Administration for H. influenzae infection chemotherapy (azithromycin and clarithromycin). No serious interpretive problems were observed with the current NCCLS criteria using Haemophilus test medium.
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PMID:Validation of NCCLS macrolide (azithromycin, clarithromycin, and erythromycin) interpretive criteria for Haemophilus influenzae tested with the Haemophilus test medium. National Committee for Clinical Laboratory Standards. 792 21

Clarithromycin and azithromycin are among the new generation of macrolides that have recently been approved for use. Compared with currently available antibiotics, these agents may be given less frequently and, in the case of azithromycin, for a shorter duration. In vitro data suggest an antimicrobial advantage of both clarithromycin and azithromycin against atypical mycobacterial and toxoplasmal species and possibly Haemophilus influenzae. The cost of both these agents is substantially higher than that of erythromycin and doxycycline, although the convenience of single-dose azithromycin is appealing compared with a 7-day course of doxycycline for chlamydial urethritis and cervicitis. These agents appear to offer advantages over erythromycin in the treatment of Mycobacterium avium-intracellulare. Additional data are needed to establish their role in other bacterial infections.
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PMID:The new macrolides. Azithromycin and clarithromycin. 812 99


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