Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:O75191 (H. influenzae)
 4,961 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antimicrobial activity of cefaclor, a new orally administered cephalosporin derivative, was studied in vitro against a variety of Gram-positive and Gram-negative clinical isolates. Both penicillin-resistant and penicillin-susceptible strains of Staphylococcus aureus were susceptible to cefaclor, with mean MICs of 1.44 and 0.93 microgram/ml, respectively. However, the MBC for penicillin-resistant S. aureus was higher than that for the penicillin-susceptible strains. All strains of Streptococcus pyogenes, Streptococcus viridans, and Streptococcus pneumoniae tested were highly susceptible to cefaclor; all strains of Streptococcus faecalis were highly resistant to cefaclor. Strains of Escherichia coli, Klebsiella sp., Proteus mirabilis, and Hemophilus influenzae were susceptible to cefaclor. Eighty per cent of strains of H. influenzae were inhibited by 5 micrograms/ml of cefaclor. Most strains of Enterobacter sp., indole-positive Proteus, Pseudomonas sp., and Serratia sp. were resistant to cefaclor.
 ...
PMID:Antimicrobial activity in vitro of cefaclor, a new oral cephalosporin. 62 78

Clarithromycin is metabolised in man mainly to the 14-hydroxy derivative, which is also biologically active. As this metabolite is not produced in rodents, we used a murine model of Haemophilus influenzae pulmonary infection to compare the in-vivo activity of clarithromycin and 14-hydroxy clarithromycin, alone and in combination, and erythromycin. In terms of bacterial killing, clarithromycin's 14-hydroxy metabolite was much more active than clarithromycin and erythromycin at doses of 100 mg/kg. For the combination tests, low doses of 14-hydroxy clarithromycin (12, 16 and 24 mg/kg) were ineffective alone but potentiated the bactericidal activity of clarithromycin (100 mg/kg) (P less than 0.01-0.001). The in-vivo results can be explained by in-vitro and pharmacokinetic data: the MIC and MBC of 14-hydroxy clarithromycin are half those of clarithromycin and erythromycin, while the combination of clarithromycin and its metabolite was synergistic in terms of bacteriostatic and bactericidal activities. Potentially useful levels of 14-hydroxy clarithromycin were found after oral administration of low doses, with a prolonged half-life compared with that of the parent compound. On the basis of these results it appears that the 14-hydroxy metabolite may have an important role to play in the treatment of bronchopulmonary infections in man due to H. influenzae.
 ...
PMID:Individual and combined activities of clarithromycin and its 14-hydroxy metabolite in a murine model of Haemophilus influenzae infection. 182

Macrolide antibiotics, commonly used in upper and lower respiratory tract infections, are inconsistently active against Haemophilus influenzae. The new azalide, azithromycin, was compared with erythromycin and roxithromycin against this pathogen. Azithromycin (MIC range 0.06-1 mg/l) was four to eight times more potent than erythromycin (MIC range 0.5-8 mg/l) and roxithromycin (MIC range 0.5-16 mg/l). At 1 mg/l, 100% of the strains of H. influenzae were inhibited by azithromycin compared with 16% with erythromycin and 5% with roxithromycin. Azithromycin exhibited a rapid bactericidal effect, with a 99.9% kill at 4 h. The MBC was equal to or up to four-times greater than the MIC.
 ...
PMID:Bacteriostatic and bactericidal activity of azithromycin against Haemophilus influenzae. 215 34

Isolates of Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae and Klebsiella pneumoniae were tested for their bactericidal activity and postantibiotic effect (PAE) with the new penem FCE 22101. The tissue cage model in rabbits was used to study PAE in vivo. The bactericidal activity against all four species was shown to be in the range of 0.05-4.0 mg/l. A 99.9% killing effect at MBC concentrations was reached within 2 hours with S. pneumoniae and K. pneumoniae and within 6-8 hours with S. aureus and H. influenzae. After in vitro exposure by FCE 22101 a PAE in vitro and in vivo was obtained against S. aureus, S. pneumoniae and H. influenzae strains but no PAE could be demonstrated against K. pneumoniae. FCE 22101 showed a good bactericidal activity and PAE against the strains investigated, except for K. pneumoniae.
 ...
PMID:Postantibiotic effect of the penem FCE 22101 against selected gram-positive and gram-negative bacteria in vitro and in vivo by the use of a tissue cage model in rabbits. 231 48

The in vitro and in vivo antibacterial activity of A-56268 (TE-031), the 6-O-methyl derivative of erythromycin, was compared with those of erythromycin and other reference drugs. A-56268 had the same spectrum of antibacterial activity as erythromycin. A-56268 was generally 1 log2 dilution more potent or equal to erythromycin against all organisms except haemophilus influenzae and Propionibacterium acnes, for which A-56268 was 1 log2 dilution and 3 log2 dilutions, respectively, less potent. The MBC of A-56268 and erythromycin was not significantly different from the MIC against Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus epidermidis, and H. influenzae but was more than 2 log2 dilutions higher than the MICs for some Staphylococcus aureus strains. Human serum at a concentration of 50% did not change the in vitro potency of A-56268 or erythromycin. A-56268 was similar to erythromycin in being more active at pH 8.0 than at the physiologic pH of 7.3. The activity of A-56268 was synergistic with sulfamethoxazole against 4 of 12 strains of H. influenzae. In mouse protection tests, when administered orally A-56268 was more potent than erythromycin against H. influenzae, S. pyogenes, S. pneumoniae, and S. aureus. After subcutaneous administration the potencies of A-56268 and erythromycin were not statistically different from each other. A-56268 was more potent than erythromycin against Legionella infection in guinea pigs. The concentration of A-56268 in the serum and lung was higher than that of erythromycin after intraperitoneal administration. In A-56268 in the serum and lung was higher than that of erythromycin after intraperitoneal administration. In mice, the peak levels in serum of A-56268 and erythromycin were similar after subcutaneous administration and seven times higher for A-56268 after oral administration. The serum half-life of A-56268 was approximately twice that of erythromycin after administration by both routes.
 ...
PMID:In vitro and in vivo evaluation of A-56268 (TE-031), a new macrolide. 294 95

MIC 90 and MBC 90 of amoxicillin, cefaclor, cefadroxil and cefuroxime axetil have been determined by the microdilution method against 48 organisms responsible of acute respiratory tract infections in children: 17 E. coli, 15 K. pneumoniae, 16 H. influenzae. An inoculum effect and an inhibitory index in blood and bronchial secretions were determined. An inoculum effect was more important for amoxicillin and cefadroxil than for cefuroxime axetil and cefaclor. Against H. influenzae, cefuroxime axetil and cefaclor have a similar activity. Against Enterobacteria, cefuroxime axetil has the lowest MIC 90 and MBC 90 and the highest inhibitory index.
 ...
PMID:[Comparison of in vitro activity of 4 oral beta-lactams on microorganisms responsible for broncho-pulmonary infections in children]. 305 59

The in vitro activities of the new quinolone derivatives ofloxacin, ciprofloxacin, norfloxacin, and pefloxacin against strains of Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis were compared to that of nalidixic acid. Determination of minimal inhibitory concentrations (MICs) was done by agar dilution tests. The new drugs were more active than nalidixic acid. N. meningitidis and H. influenzae (regardless of beta-lactamase production) were highly susceptible. All H. influenzae strains were inhibited by less than or equal to 0.12 mg/l; mode MICs were 0.03 mg/l for norfloxacin and pefloxacin, and 0.50 mg/l for nalidixic acid. All N. meningitidis strains were inhibited by 0.06 mg/l and mode MICs of the new drugs were less than or equal to 0.03 mg/l. Mode MICs for S. pneumoniae were 4 mg/l for norfloxacin and pefloxacin (range 1-16 and 2-8 mg/l respectively) and 1 mg/l for ofloxacin (range 1-4 mg/l). Ofloxacin exhibited a bactericidal activity on H. influenzae (range MBC 0.06-0.50 mg/l; mode MBC: 0.06 mg/l).
 ...
PMID:[Effect ofloxacin on Haemophilus influenza, Streptococcus pneumoniae and Neisseria meningitidis. Comparison with similar molecules]. 316 40

The antibacterial activity of LY164846, a new orally administered semisynthetic cephalosporin, was compared with that of amoxicillin-clavulanic acid against 492 potentially pathogenic respiratory tract and dermal isolates. Against groups A, B, and G streptococci; pneumococci; staphylococci (other than methicillin resistant); Haemophilus influenzae; Branhamella catarrhalis; and meningococci, the MICs for 90% of strains tested of LY164846 and amoxicillin-clavulanic acid were less than or equal to 4 and less than or equal to 1 microgram/ml, respectively. LY164846 was equally active against beta-lactamase-positive and -negative strains of Haemophilus and Staphylococcus. MBC to MIC ratios of LY164846 versus H. influenzae were less than or equal to 2, while those with Staphylococcus aureus were more difficult to determine because of skipped tubes or paradoxic effects. There were minimal inoculum, pH, or serum effects on LY164846 activity against H. influenzae and S. aureus. In time-kill studies, LY164846 and amoxicillin-clavulanic acid at double MICs were 99.9 to 100% bactericidal to H. influenzae in 24 h; two times the MIC of LY164846 and four times the MIC of cephalexin were 99.9 to 100% bactericidal to S. aureus in 24 h. Based on error-rate-bounded analysis, the following interpretative guidelines for 30-micrograms LY164846 disk diffusion test diameters are suggested: greater than or equal to 19 mm, susceptible (MIC, less than or equal to 4 micrograms/ml); 16 to 18 mm, intermediate (MIC, greater than 4 but less than or equal to 8 micrograms/ml); less than or equal to 15 mm, resistant (MIC, greater than 8 micrograms/ml).
 ...
PMID:In vitro activity of an orally administered cephalosporin, LY164846, against potentially pathogenic respiratory and dermal bacterial isolates. 348 28

Second generation cephalosporins are frequently used for the treatment of bacteremic Hemophilus influenzae type b infections. "Breakthrough" meningitis during cefamandole therapy has documented the need for adequate cerebrospinal fluid penetration by these antibiotics if they are to be used in the therapy of Hemophilus infections. A child with H. influenzae type b preseptal cellulitis is reported who initially responded to treatment with intravenous cefuroxime and oral cefaclor. However, while still receiving cefaclor, the child was readmitted with H. influenzae meningitis. Microtiter broth dilution susceptibility testing performed during the second admission showed the isolate to be relatively resistant to cefuroxime (minimum bactericidal concentration [MBC] = 4 micrograms/ml) and resistant to cefaclor (MBC greater than 16 micrograms/ml). This experience documents the need to monitor the clinical response closely during therapy of H. influenzae bacteremic infections with these second generation cephalosporin treatment regimens. In addition, attention should be paid to minimum inhibitory concentrations of these cephalosporins, since variations in H. influenzae type b susceptibility to these agents may limit their efficacy.
 ...
PMID:Onset of Hemophilus influenzae type-b meningitis during cefaclor therapy for preseptal cellulitis. 349 4

The antibacterial activity of beta-lactams against H. influenzae is difficult to evaluate as a result of the osmotic-pressure-dependent formation of filaments and spheroplasts whose viability is still under debate. We compared growth curves obtained by optic density measurements and by UFC/ml counts for H. influenzae in the presence of amoxicillin, cefaclor and cefotaxime in various concentrations. Only the early response to antibiotics, observed during the first six hours of antibiotic-culture contact, was considered. Results showed, for each of the three antibiotics: an increase in optic density with formation of abnormal organisms that correlated poorly with antibiotic concentrations; a stable number of UFC/ml for more than 90 mn, followed by a slow fall reaching at the most 1.5 Log 10 UFC/ml at the sixth hour. We conclude that amoxicillin, cefaclor and cefotaxime in active concentrations rapidly produce the formation of abnormal organisms with an increase in biomass as a result. These abnormal organisms lose their viability slowly, even with concentrations greater than 50 time the MIC. Cefaclor's MIC and MBC are underestimated when results are read only after 24 hours.
 ...
PMID:[Growth curves and killing rate of Haemophilus influenzae exposed to amoxicillin, cefaclor and cefotaxime]. 353 10


1 2 Next >>