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)

Meropenem is a parenteral carbapenem antibiotic which has excellent bactericidal activity in vitro against almost all clinically significant aerobes and anaerobes. Its high activity is explained by ease of entry into bacteria combined with good affinity for essential penicillin binding proteins, including those associated with cell lysis. Breadth of spectrum is due, in part, to stability to all serine-based beta-lactamases, including those which hydrolyse third-generation cephalosporins. Meropenem has an antibacterial spectrum which is broadly similar to that of imipenem but, whilst slightly less active against staphylococci and enterococci, it is more active against Pseudomonas aeruginosa, all Enterobacteriaceae and Haemophilus influenzae. Amongst common human pathogens, only methicillin-resistant staphylococci and Enterococcus faecium are uniformly resistant to meropenem. The meropenem MICs for penicillin-resistant Streptococcus pneumoniae are higher than for penicillin-susceptible strains but the organisms remain susceptible. Clinical susceptibility in vitro to meropenem is defined by MICs of < or = 4 mg/L, intermediate susceptibility by MICs of 8 mg/L and MICs of > or = 16 mg/L define resistance; equivalent figures for zones of growth inhibition are > or = 14 (susceptible), 12-13 (intermediate) and < or = 11 (resistant) mm. Studies in guinea pig models of systemic infection and infections localised to the lungs, urinary tract and the central nervous system, some of which used immunocompromised animals, confirm the potential of meropenem demonstrated in vitro. These factors, combined with the human plasma, tissue or urinary concentrations of meropenem which exceed modal MICs for the pathogens isolated in clinical trials for most or all of the recommended 8 h dosing interval, predict that meropenem should be efficacious in the treatment of infections at many body sites.
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PMID:Meropenem: a microbiological overview. 854 86

Meropenem and imipenem/cilastatin were compared in an open, randomised prospective multicentre study in the treatment of acute exacerbations of severe chronic obstructive pulmonary disease in hospitalised patients. One-hundred-and-seventy-three patients were enrolled; 164 were evaluable for clinical efficacy and 98 for bacteriological efficacy, with 144 pathogens isolated. The predominant pathogens were Haemophilus influenzae (n = 30), Streptococcus pneumoniae (18), Staphylococcus aureus (12), Pseudomonas aeruginosa (11), Moraxella catarrhalis (8), other Gram-negative bacteria (Neisseria, Klebsiella, Proteus, and Enterobacter spp.) (53) and other Gram-positive bacteria (12). A single bacterial pathogen was identified in 61 patients, whereas two bacterial pathogens were isolated in 31 patients and three in six patients. The clinical response at the end of treatment was very high in both groups with a satisfactory outcome (cured or improved) in 97.6% of the meropenem patients and in 96.3% of the imipenem/cilastatin patients; at follow-up the rates were 89.1% and 89.8%, respectively. The bacterial success (eradication or presumed eradication) was 88.2% in the meropenem group and 89.4% in the comparator group. Nausea or vomiting were reported more frequently in patients treated with imipenem/cilastatin, whereas in the meropenem group an increase in aminotransferases was reported. One patient treated with imipenem/cilastatin was withdrawn from the study due to seizures. Meropenem and imipenem/cilastatin were highly effective for the treatment of severe bacterial exacerbations of chronic bronchitis but meropenem was better tolerated.
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PMID:Treatment of acute bacterial exacerbations of chronic obstructive pulmonary disease in hospitalised patients--a comparison of meropenem and imipenem/cilastatin. COPD Study Group. 854 88

Meropenem and comparator antibiotics, including ceftriaxone, ceftazidime, benzyl penicillin and a combination of ampicillin plus gentamicin, were evaluated in a model of bacterial meningitis in the guinea-pig. The model is an acute infection in which challenge with each organism, if untreated, causes an increase in numbers of white blood cells, elevation of protein concentrations and 6-8 log10 cfu/mL of bacteria in the CSF. Infections caused by Haemophilus influenzae, Neisseria meningitidis, three strains of Streptococcus pneumoniae (two penicillin-resistant), Escherichia coli, Pseudomonas aeruginosa and Listeria monocytogenes all responded to meropenem, which was as active as the comparator agents in all studies, and was more active in most. Of particular note were the results seen against S. pneumoniae (penicillin-resistant) infections, in which meropenem was significantly more effective than ceftriaxone. Also notable were results from the P. aeruginosa infection where meropenem, at low doses, was more effective than ceftazidime. Activity against L. monocytogenes was equivalent to that produced by treatment with the combination of ampicillin plus gentamicin, even when treatment was delayed. These results show that, in an animal model, meropenem penetrates into CSF in concentrations sufficient to produce significant reductions in the numbers of common and less common pathogens.
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PMID:Efficacy of meropenem in experimental meningitis. 854 1

Meropenem is a new DHP-I stable carbapenem with a very promising microbiological, pharmacokinetic and clinical profile. The antibacterial activity of this new agent has been assessed in vitro against 8741 aerobic and 854 anaerobic strains reflecting current incidence and epidemiology in Italy, France, Germany, Spain, Switzerland and United Kingdom. Comparator agents were imipenem, ceftriaxone, vancomycin, ciprofloxacin gentamicin and amikacin. The results of this study show that meropenem has a spectrum of antibacterial activity which embraces the vast majority of clinically significant Gram-positive and Gram-negative aerobes and anaerobes. This is due in part to excellent stability to chromosomal or plasmid mediated beta-lactamases including those which hydrolyse current cephalosporins. Data from the Italian study identified meropenem as the most potent agent against all Enterobacteriaceae, with the exception of Proteus species with were most susceptible to ciprofloxacin. Moreover, meropenem was 10 times more active than the other drugs against Haemophilus and Neisseria and was active against all the anaerobic strains. Conversely, staphylococci and enterococci were more susceptible to imipenem. Overall, these European data showed that meropenem was the most powerful drug against Enterobacteriaceae and it also was the most effective drug tested against the Italian and French Pseudomonas aeruginosa strains. Meropenem was less effective than imipenem or vancomycin against Enterococcus stains but had similar activity to imipen against anaerobes. Based on this microbiological profile, the use of meropenem is appropriate in the empirical treatment of serious infections, including those caused by multiple pathogens.
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PMID:[In vitro antibacterial activity of meropenem, a new carbapenem: European data]. 857 28

Meropenem is a new carbapenem antibiotic that is stable to human renal dehydropeptidase-I (DHP-I) and exhibits potent bactericidal activity against almost all clinically significant aerobic and anaerobic bacteria. Activity is achieved through rapid entry into bacteria, resisting hydrolysis by all serine-based beta-lactamases, both of chromosomal or plasmid origin, and high affinity for vital penicillin binding proteins. The antibacterial spectrum of meropenem has been investigated extensively in a world-wide programme of studies. The results from all of these studies are consistent and identify in vitro differences between meropenem and imipenem. Both agents demonstrate high activity against Gram-positive aerobes with meropenem slightly less active than imipenem but significantly more potent than imipenem against Haemophilus influenza, all Enterobacteriaceae and 2-4 fold more active against Pseudomonas aeruginosa and most other pseudomonas. The spectrum of carbapenems is superior to that of all other beta-lactams. This is achieved, in part, by stability to the chromosomal beta-lactamases which hydrolyse ceftazidime, cefotaxime and ceftriaxone and against which newer agents like cefpirome and cefepime are not fully stable. Meropenem is also stable to the new plasmid-mediated enzymes which are responsible for significant elevation of MIC's of all cephalosporins and penicillins. When tested against P. Aeruginosa which have become resistant to imipenem therapy, these strains remained susceptible to meropenem. The activity of meropenem against anaerobes is at least as potent as metronidazole and clindamycin. These impressive in vitro data have been the basis for an extensive clinical evaluation programme in many indications including infections caused by single or multiple pathogens.
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PMID:[Preclinical evaluation of meropenem, a new parenteral carbapenem]. 857 29

A collection of 300 Haemophilus influenzae clinical strains was used to assess in vitro susceptibility to carbapenems (meropenem, imipenem) by MIC and disk diffusion methods and to compare disk diffusion test results with two potencies of ampicillin disks (2 and 10 micrograms). The isolates included ampicillin-susceptible or- intermediate (167 strains), beta-lactamase-positive (117 strains), and beta-lactamase-negative ampicillin-resistant (BLNAR; 16 strains) organisms. Disk diffusion testing was performed with 10-micrograms meropenem disks from two manufacturers. Meropenem was highly active against H. influenzae strains (MIC50, 0.06 microgram/ml; MIC90, 0.25 microgram/ml; MIC50 and MIC90, MICs at which 50 and 90%, respectively, of strains are inhibited) and was 8- to 16-fold more potent than imipenem (MIC50, 1 microgram/ml; MIC90, 2 micrograms/ml). Five non-imipenem-susceptible strains were identified (MIC, 8 micrograms/ml), but the disk diffusion test indicated susceptibility (zone diameters, 18 to 21 mm). MIC values of meropenem, doxycycline, ceftazidime, and ceftriaxone for BLNAR strains were two- to fourfold greater than those for other strains. The performance of both meropenem disks was comparable and considered acceptable. A single susceptible interpretive zone diameter of > or = 17 mm (MIC, < = or 4 micrograms/ml) was proposed for meropenem. Testing with the 2-micrograms ampicillin disk was preferred because of an excellent correlation between MIC values and zone diameters (r = 0.94) and superior interpretive accuracy with the susceptible criteria at > or = 17 mm (MIC, < or = 1 microgram/ml) and the resistant criteria at < or = 13 mm (MIC, > or = 4 micrograms/ml). Among the BLNAR strains tested, 81.3% were miscategorized as susceptible or intermediate when the 10-micrograms ampicillin disk was used, while the 2-micrograms disk produced only minor interpretive errors (12.5%). Use of these criteria for testing H. influenzae against meropenem and ampicillin should maximize reference test and standardized disk diffusion test performance with the Haemophilus Test Medium. The imipenem disk diffusion test appears compromised and should be used with caution for detecting strains for which imipenem MICs are elevated.
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PMID:Reevaluation of interpretive criteria for Haemophilus influenzae by using meropenem (10-microgram), imipenem (10-microgram), and ampicillin (2- and 10-microgram) disks. 881 92

This paper on bacterial meningitis looks at aspects inherent in the aetiology and mechanisms underlying neurological damage and pharmacological treatment. Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis are the pathogens most commonly responsible and are able to colonise the host's respiratory mucosae, invade the vascular space, cross the haematoliquoral barrier and survive in the cerebrospinal fluid. The presence of germs in the subarachnoid spaces leads to the onset of inflammation and neurological damage. The most often used pharmacological treatments include, apart from antibiotics, anti-inflammatory drugs (although we have clinical data for corticosteroids only), pentoxyphillin and monoclonal antibodies. Initially empiric, antibiotic therapy is based on the use of drugs that act against the probable pathogenic agents, are capable of surmounting the haematoliquoral barrier and are well tolerated. Prior to the Eighties, the antibiotic of choice was ampicillin associated or otherwise with aminoglycosides. Subsequently, the availability of new drugs (cefotaxime and ceftriaxone) and the appearance of resistance led to changes in therapeutic protocols. Of the carbapenemics, wide spectrum antibiotics with high resistance to beta lactamase, imipenem /cilastatin proved effective although there was a high risk of inducing convulsions in patients with previous neurological damage or kidney failure. Meropenem was able to surmount the haematoliquoral barrier in sufficient concentrations and was well tolerated in patients with prior neurological changes. It has proved effective in clinical studies carried out up to the present.
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PMID:[Current problems in the treatment of bacterial meningitis]. 909 74

The in vitro antibacterial activity of meropenem and up to nine other antimicrobials was compared in studies at 26 North American centers from 1989 to 1992 with use of standardized and controlled procedures for determining minimal inhibitory concentrations (MICs) against 12,483 recent clinical isolates and additional drug-resistant strains. Overall, carbapenems were the most active drugs. The antibacterial activity of meropenem was consistent against random isolates in all centers; however, inclusion of large proportions of multidrug-resistant gram-negative aerobes by some centers did increase MICs of meropenem and the comparators. Meropenem was 4-64 times more active than imipenem against gram-negatives, including Enterobacteriaceae organisms, Pseudomonas aeruginosa, Burkholderia cepacia, Neisseria meningiditis, and Haemophilus influenzae. Imipenem was up to 2-4 times more active than meropenem against some gram-positive cocci, including Enterococcus faecalis. Carbapenems were similarly active against anaerobes, and resistant strains were rarely encountered. Meropenem, unlike imipenem or ceftazidime, was bactericidal for all strains of Enterobacteriaceae, P. aeruginosa, and gram-positive cocci tested at < or = 8 times the MIC. A lack of antibiotic cross-resistance was frequently observed between comparator-resistant strains and meropenem. These data suggest the potential utility of meropenem as a monotherapeutic agent against a broad range of pathogens.
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PMID:Comparative in vitro activity of meropenem versus other extended-spectrum antimicrobials against randomly chosen and selected resistant clinical isolates tested in 26 North American centers. 912 99

The in vitro activity of meropenem (formerly SM-7738), a new carbapenem, was compared with that of imipenem and five other broad-spectrum antimicrobials (ceftazidime, cefotaxime, piperacillin, piperacillin/tazobactam, and ciprofloxacin) against 30,254 clinically significant pathogens isolated in nine countries worldwide. Overall, the carbapenems, meropenem and imipenem, were the most active drugs. Meropenem was four- to 64-fold more active than imipenem against Gram-negative bacteria, including the Enterobacteriaceae, Pseudomonas aeruginosa, Burkholderia cepacia, Haemophilus influenzae, and Neisseria meningitidis. Meropenem was also quite active against ceftazidime-resistant strains of Enterobacteriaceae, inhibiting 87.5 to 100% at < or = 4 micrograms/ml. In contrast, imipenem was four- to eight-fold more active than meropenem against Gram-positive species, including methicillin-susceptible strains of Staphylococcus aureus and Staphylococcus epidermidis, Streptococcus pneumoniae, and Enterococcus faecalis. Among the anaerobes, strains resistant to meropenem or imipenem were encountered very rarely. These extensive data provide additional in vitro support for the clinical use of meropenem as a broad spectrum antimicrobial agent active against key pathogenic species of bacteria.
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PMID:A review of the in vitro activity of meropenem and comparative antimicrobial agents tested against 30,254 aerobic and anaerobic pathogens isolated world wide. 932 42

Meropenem is a beta-lactamic carbapenem derived from thienamycin and is structurally characterized by the presence of a beta-methyl group in position C1 which confers stability to the molecule versus renal dehydropeptidase 1 (DHP-1), thereby making the coadministration of an enzyme inhibitor unnecessary. Its esterochemical configuration of the lateral chain in C2 (dimethyl carbomoilpyrrolidenethium) increases the activity versus gram negative bacteria (enterobacteria and pseudomonas) and moreover, may explain the reduction in the proconvulsive effect observed in imipenem/cilastatin. Meropenem has great bactericide power and has a very wide spectrum of activity depending on it low molecular weight and zwiterionic structure, stability versus almost all the clinically important beta-lactamases and high affinity for the PBPs. It covers gram positive aerobes (Staphylococcus aureus, coagulase negative staphylococci, streptococci including Streptococcus pneumoniae resistant to penicillin, Enterococcus faecalis, Rhodococcus equi, Listeria monocytogenes) and gram negative bacteria (enterobacteria, P. aeruginosa, Acinetobacter, Aeromonas, Plesiomonas, Vibrio, Haemophilus influenzae, Neisseria, Moraxella) and anaerobes (Bacteroides, Prevotella, Porphyromonas, Fusobacterium, Clostridium, Peptostreptococcus, and Propionibacterium acnes), being more active than imipenem versus gram negatives: P. aeruginosa (2-4-fold), enterobacteria (2-32-fold) and H. influenzae (4-8-fold) and less active versus the gram positives (enterococci, streptococci and staphylococci). Meropenem has no activity on Enterococcus faecium, S. aureus resistant to methycillin, Stenotrophomonas maltophilia and other genera producers of chromosomic methalo-beta-lactamases (carbapenemases). Resistance may be due to impermeability given the loss of the OprD porin (OprD2 in enterobacteria and P. aeruginosa) loss of different membrane proteins (Proteus mirabilis, Proteus rettgeri, Enterobacter cloacae, Enterobacter aerogenes), modifications of the PBPs (gram positive) and the production of carbapenemases (chromosomic methalo-beta-lactamases).
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PMID:[Meropenem: microbiologic perspective]. 941 64


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