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)

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.
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PMID:Antimicrobial activity in vitro of cefaclor, a new oral cephalosporin. 62 78

The in-vitro activity of two new quinolone antimicrobials, rufloxacin and MF 961, together with the desmethylated metabolite of rufloxacin (MF 922) were compared with other orally administered agents against 622 bacterial strains. Against Enterobacteriaceae and Pseudomonas aeruginosa rufloxacin was generally active (MIC90 1-8 mg/L) with the exception of Klebsiella and Serratia spp. (MIC90 32 mg/L and Enterobacter spp. (MIC90) 64 mg/L. The respiratory pathogens Haemophilus influenzae and Moraxella catarrhalis were susceptible to rufloxacin (MIC90 0.5 and 1 mg/L respectively) but Streptococcus pneumoniae was less susceptible (MIC90 32 mg/L). Staphylococcus aureus were susceptible to rufloxacin (MIC90 2 mg/L). The rufloxacin metabolite MF 922 was generally as active as its parent. MF 961 was usually two-fold more active than rufloxacin. All three compounds were four to 16 times less active than norfloxacin, but rufloxacin was as active or somewhat more active than norfloxacin against Staphylococcus spp. Any strains showing decreased susceptibility to other quinolones exhibited cross resistance to these new agents. The MBC of rufloxacin and MF 922 was within one dilution of the MIC and human serum had little effect upon the activity of both agents. The protein binding of rufloxacin and MF 922 at 1 and 10 mg/L were 55% and 63.8% and 30.3% and 32.6% respectively. The activity of rufloxacin against four strains of Chlamydia trachomatis and one strain of Chlamydia pneumoniae was determined. The MICs for C. trachomatis were 4-8 mg/L and 4 mg/L for C. pneumoniae.
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PMID:The in-vitro activity of two new quinolones: rufloxacin and MF 961. 132 39

The in vitro activity of L-627, a new parenterally administered carbapenem, was compared with those of imipenem, meropenem, FCE 22101 (a penem), ceftazidime, and ceftriaxone. L-627 was active against members of the family Enterobacteriaceae (MIC for 90% of strains tested [MIC90] ranging from 0.03 to 4 micrograms/ml). L-627 displayed activity equal to that of meropenem against Pseudomonas aeruginosa (MIC90, 2 micrograms/ml), although, as with other carbapenems, the antipseudomonal activity was reduced against D2-deficient strains. Staphylococci and streptococci were susceptible (MIC90 of 1.0 micrograms/ml for Staphylococcus aureus and 0.015 micrograms/ml for group A streptococci). L-627 also had activity against anaerobic bacteria (MIC90, 2.0 micrograms/ml for Bacteroides fragilis). Neisseria gonorrhoeae and Neisseria meningitidis were highly susceptible (MIC90, 0.06 micrograms/ml), and against the common respiratory pathogens (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis), the MIC90s were less than or equal to 2.0 micrograms/ml. The protein binding of L-627 ranged from 13.8 to 22%, depending on the concentration. The presence of human serum had little effect on the MIC or MBC of L-627. These results suggest that L-627 merits further study in the treatment of infections caused by a wide range of pathogens.
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PMID:In vitro activity of L-627, a new carbapenem. 141 83

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.
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PMID:Individual and combined activities of clarithromycin and its 14-hydroxy metabolite in a murine model of Haemophilus influenzae infection. 182

Lomefloxacin has marked activity against Gram-negative bacilli including Enterobacteriaceae, non-fermenting strains and Haemophilus influenzae with 98% of all isolates tested having MICs of 0.25 mg/l or less. Sixty-eight per cent of Pseudomonas aeruginosa strains were sensitive to 1 mg/l with a few strains resistant to 8 or 16 mg/l. Gram-positive cocci were more resistant, particularly streptococci, where the MICs vary between 1 and 8 mg/l. Bactericidal activity was similar to inhibitory activity and the effect of increasing serum concentrations and bacterial inocula was minimal. The MIC and MBC were increased in the presence of urine, particularly at an acid pH 5. Comparative MICs showed that lomefloxacin was more active than ofloxacin and pefloxacin, similar to norfloxacin but less active than ciprofloxacin for Gram-negative bacteria but not for Gram-positive cocci. Comparative studies with sensitivity disc concentrations showed that a 5 micrograms disc was more satisfactory than the 10 micrograms disc as the zone sizes were more suitable for routine testing. Solutions of lomefloxacin showed instability in bright sunlight when 52% of activity was lost in 1 h. Similar instability was shown in impregnated discs which lost up to 40% activity in 6 h exposure. Lomefloxacin showed a wide range of activity against Gram-negative bacteria including multiresistant strains and Pseudomonas spp. Gram-positive bacteria were less susceptible, with streptococci more resistant than staphylococci. Lomefloxacin is well absorbed after oral administration giving high blood and urine concentrations and its prolonged half-life means once daily dosing in the treatment of many types of bacterial infection may be possible.
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PMID:Antibacterial activity of lomefloxacin. 188 17

We determined the effect of the combination of rifampin and fleroxacin against Enterobacteriaceae and streptococcal species. None of the 65 isolates tested by checkerboard assay demonstrated synergy, 12% of isolates showed an additive effect; 86.7% were indifferent, and only 1 isolate showed antagonism. The mean FIC was 1.2. When using 2 and 8 micrograms/ml of rifampin, fleroxacin MICs of 285 isolates of Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae, staphylococci, streptococci, Bacteroides, and Clostridium were not increased, but synergy was not demonstrated. Time-kill studies against Escherichia coli, P. aeruginosa, Enterobacter cloacae, Staphylococcus aureus, and Enterococcus faecalis failed to show increased killing when the two agents were present at one-half the MBC. The fleroxacin-rifampin interaction is one of indifference but provides coverage for species not adequately inhibited by fleroxacin.
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PMID:Fleroxacin combined with rifampin. 190 34

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.
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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.
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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

WIN 57273 is a new fluoroquinolone that has an expanded spectrum of activity against Staphylococcus spp. (MIC for 90% of isolates [MIC90], 0.008 microgram/ml), Enterococcus faecalis (MIC90, 0.06 microgram/ml), Bacillus spp. (MIC90, 0.03 micrograms/ml), Listeria monocytogenes (MIC90, 0.06 microgram/ml), Streptococcus spp. (MIC90, 0.03 microgram/ml), and Bacteroides fragilis group strains (MIC90, 0.5 microgram/ml). Like other fluoroquinolone compounds, WIN 57273 was active against members of the family Enterobacteriaceae (97% of strains inhibited by less than or equal to 2 micrograms/ml), Haemophilus, Branhamella, and Neisseria strains (100% susceptible), Acinetobacter spp. (100% susceptible), and Pseudomonas aeruginosa (68% susceptible). We observed that WIN 57273 was very active against cephalosporin- or aminoglycoside-resistant gram-negative strains but shared cross-resistance with other fluoroquinolones. Increasing inoculum concentrations had minimal effects on WIN 57273 MICs, and the drug was considered to be bactericidal based on reference MBC and kill curve analyses. Unlike most previously studied drugs in this class, WIN 57273 had increased activity (three- to fourfold) at low pH. Rates of mutation to WIN 57273 resistance at eight times its MIC were in the range of 5.6 x 10(-8) to greater than 1.4 x 10(-9). This new compound possesses a wide potential spectrum of use, and it should be evaluated further by in vitro and in vivo studies.
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PMID:In vitro evaluation of WIN 57273, a new broad-spectrum fluoroquinolone. 232 79

Cefixime (CFM) is a new hemi-synthetic orally active cephalosporin which exhibits a particular affinity for PBPs 3, 1a, 1bs. Its penetration through the Gram negative bacilli outer membrane is similar to that of third generation cephalosporins. The MICs were assessed by the agar dilution method against 2,489 bacterial strains collected in 10 hospitals. Against Enterobacteriaceae, MICs50 and 90 are respectively (mg/l): naturally non beta-lactamase-producing species: E. coli and Shigella: 0.25-0.5, Salmonella: 0.06 - 0.25, P. mirabilis: 0.008 - 0.0.32; chromosomal penicillinase producing species: Klebsiella: 0.06 - 2; chromosomal cephalosporinase producing species: E. cloacae and C. freundii: 1 - greater than 128, S. marcescens: 0.25 - 16, Proteus indole: + 0.06 - 4, P. stuartii: 0.032 - 0.5. CFM activity is not altered in strains producing an acquired penicillinase. On the other hand, CFM appears to be inactive against cephalosporinase hyperproducing mutants and its activity is variably decreased against expanded spectrum beta-lactamase producing strains. CFM is inactive against P. aeruginosa (MIC50 and 90: 64 - 128) and against A. baumannii (16 - 128). Haemophilus and gonococci, beta-lactamase producing or not, as well as meningococci, are highly susceptible to CFM (MIC 0.008 - 0.12). B. catarrhalis is usually inhibited by 0.03 to 0.5. CFM is moderately active against meticillin-sensitive staphylococci (MIC50 and 90: 1-64), and inactive against meticillin-resistant strains. Enterococci are usually resistant, whereas streptococci and pneumococci are inhibited by low concentrations: 0.08 to 1. CFM is a bactericidal antibiotic, as shown by MBC and killing curves determination. These antibacterial properties relate CFM to the third generation cephalosporins and position the compound in an excellent place among the orally active cephalosporins.
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PMID:[Antibacterial effect of cefixime]. 253 May 28


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