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H C Neu

Publications and source records attributed to H C Neu.

At least 91 records · Page 5Linked to original sources
PubMed1990

In vitro activity of Ro 23-9424, a dual-action cephalosporin, compared with activities of other antibiotics.

The in vitro activity of Ro 23-9424, which is desacetyl-cefotaxime linked to fleroxacin, was compared with the activities of cefotaxime, desacetyl-cefotaxime, fleroxacin, ofloxacin, and ciprofloxacin. It inhibited the majority of members of the family Enterobacteriaceae, except for some Serratia marcescens, Citrobacter freundii, and Enterobacter cloacae strains, at less than or equal to 0.25 microgram/ml and had an MIC for 90% of strains tested (MIC90) of 8 micrograms/ml against Pseudomonas aeruginosa. Most group A, B, C, and G streptococci and Streptococcus pneumoniae were inhibited at less than or equal to 0.25 microgram/ml. Ninety percent of the staphylococci were inhibited at less than or equal to 4 micrograms/ml, except for some methicillin-resistant Staphylococcus aureus isolates. The MIC90S of Ro 23-9424 for Enterococcus faecalis and Listeria monocytogenes were greater than or equal to 16 micrograms/ml. Ninety percent of Clostridium perfringens isolates were inhibited by less than or equal to 2 micrograms/ml, whereas Bacteroides fragilis had an MIC90 of 32 micrograms/ml. There was a minimal inoculum size effect. The MICs and MBCs were either identical or within a twofold dilution. The MICs of Ro 23-9424 for Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Staphylococcus aureus increased 16- to 128-fold after 2 weeks of transfer in the presence of Ro 23-9424, showing that the presence of two agents does not prevent resistance.

Anti-Bacterial Agents↗
PubMed1990

In vitro activity of dirithromycin (LY 237216) compared with activities of other macrolide antibiotics.

Dirithromycin inhibited Streptococcus pyogenes, Streptococcus pneumoniae, and other hemolytic streptococci at concentrations of less than or equal to 0.03 to 0.12 micrograms/ml, with 90% inhibition at 0.12 micrograms/ml, which is comparable to results using erythromycin. Group A streptococci, listeriae, and enterococci resistant to erythromycin were resistant to dirithromycin. Erythromycin-susceptible staphylococci were inhibited by 0.5 micrograms/ml, but for erythromycin-resistant isolates MICs were greater than or equal to 8 micrograms/ml. For Haemophilus influenzae, MICs were greater than or equal to 8 micrograms/ml, two- to fourfold greater than for erythromycin. The activity of dirithromycin against staphylococci and streptococci was not decreased by the addition of human serum.

Anti-Bacterial Agents↗
PubMed1990

Fosfomycin trometamol versus amoxycillin--single-dose multicenter study of urinary tract infections.

A randomized trial comparing single-dose therapy with fosfomycin trometamol 3 g versus amoxycillin 3 g was carried out in four centers. There were 158 female patients between 18 and 65 years. The major infecting organism in both groups was Escherichia coli (80%). The overall evaluation showed that fosfomycin trometamol eradicated 81.2% of bacteria and amoxycillin 71.8%. In women younger than 45 years, the cure rate was 88.8% for fosfomycin trometamol and 72.9% for amoxycillin. There was more persistence in the amoxycillin group, but equal recurrence and reinfection for both agents. The most common failure was with E. coli for both agents. Side effects were minimal with 8.7% for fosfomycin trometamol and 11.5% for amoxycillin. Fosfomycin trometamol is effective therapy of acute urinary tract infections in adult females and in selected situations was superior to amoxycillin.

Adolescent↗
PubMed1990

P&T Committee review of fluconazole: an effective alternative to antifungal therapy.

Fluconazole is a new antifungal agent available in both oral and parenteral formulations. According to the experts in this roundtable discussion, fluconazole represents a major clinical advance in the treatment of candidiasis and cryptococcosis in cancer patients, patients with AIDS, organ transplant recipients, and other patients at risk for opportunistic mycoses. The pharmacokinetic profile for fluconazole permits infrequent dosing and also makes it ideal for tissue site infections. Fluconazole's low toxicity gives it an advantage over currently available antifungal therapy and will permit prompt presumptive treatment of selected infections.

Antifungal Agents↗
PubMed1989

Chemical evolution of the fluoroquinolone antimicrobial agents.

In the past decade, significant progress has been made in understanding structure-function relationships of the new quinolones, which have a N-1-substituted, 1,4-dihydro-4-oxo-pyridine-3-carboxylic acid moiety as the basic nucleus. Modification of the groups affixed to positions C-6, C-7, and C-8 has made a major change in the antimicrobial activity, pharmacokinetic, and metabolic properties of the quinolones as have changes in the moieties affixed to the N-1 nitrogen. The new quinolones have a carboxyl group at position 3 and a keto group at C-4. The presence of a fluorine atom at C-6 enhances the deoxyribonucleic acid (DNA) gyrase inhibitory activity as well as the ability of the compounds to inhibit staphylococci. Position C-7 has been one of the most modified sites. Addition of a piperazinyl group markedly increased gram-positive activity, primarily antistaphylococcal activity; lowered the minimal inhibitory concentrations against Enterobacteriaceae, Haemophilus spp., and Neisseria spp.; and added activity against Pseudomonas aeruginosa compared with nalidixic acid. Methyl derivatives of the piperazine group or of the pyrroles have longer half-lives than do unsubstituted moieties. At the N-1 position, a cyclopropyl group appears to be most potent with respect to minimal inhibitory concentrations against Enterobacteriaceae and Pseudomonas. Ofloxacin is unique in that it has an oxygen substituted at C-8 with the substituent part of the ring system formed by fusion to the N-1 position. This has produced excellent in vitro activity against gram-positive species comparable with that of ciprofloxacin, excellent activity against the Enterobacteriaceae, and antipseudomonal activity superior to agents with an ethyl substitution at position N-1. The oxazine ring of ofloxacin provides excellent oral absorption with virtually 95 percent bioavailability; this modification also has prevented metabolism and has provided a long half-life of seven to eight hours.

4-Quinolones↗
PubMed1989

Ofloxacin.

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Humans↗
PubMed1989

Resistance to ciprofloxacin appearing during therapy.

The development of resistance to ciprofloxacin in nine clinical isolates of Pseudomonas aeruginosa was investigated. Isolates had increases in minimal inhibitory concentrations (MICs) from 0.25 to 16 micrograms/ml. The isolates also became resistant to ofloxacin and norfloxacin, but did not show increases in MICs to aminoglycosides, antipseudomonas penicillins, or cephalosporins. One isolate from a patient with endocarditis showed a reduction in a 43-kD outer membrane protein and simultaneous increase in the imipenem MIC. This isolate also showed impaired uptake of ciprofloxacin. Respiratory isolates from cystic fibrosis patients did not show loss of outer membrane protein. MICs were lowered by ethylene diaminetetra-acetic acid, suggesting changes in lipopolysaccharide. Resistant isolates were synergistically inhibited by combinations of ciprofloxacin plus tobramycin or ceftazidime, but MICs remained beyond the achievable serum level.

Bacterial Outer Membrane Proteins↗
PubMed1989

Intravenous/oral ciprofloxacin therapy of infections caused by multiresistant bacteria.

Sixty patients were treated with ciprofloxacin: 19 received only intravenous ciprofloxacin, 41 received intravenous followed by oral ciprofloxacin. The mean duration of therapy was 28 days in the intravenous only group and 10 days intravenously and 80 days orally in the intravenous/oral group. Ten (17 percent) patients received 200 mg intravenously every 12 hours and 49 (82 percent) 300 mg every 12 hours. The overall clinical response was 85 percent, with a bacteriologic response of 70 percent. The lowest bacteriologic response (38 percent) occurred in the 13 patients treated for Pseudomonas respiratory infection. Clinical response occurred in 24 of 26 patients with soft-tissue infection, and 10 of 13 patients with respiratory infection. Of three patients with endocarditis, therapy failed in two with resistance developing in Pseudomonas aeruginosa and Staphylococcus aureus. Overall, 19 percent of 26 P. aeruginosa isolates developed resistance to ciprofloxacin. Toxicity was minor, with phlebitis and nausea most commonly reported. Intravenously administered ciprofloxacin or intravenous followed by oral ciprofloxacin is a safe, effective therapy for serious infections due to multiply resistant gram-negative bacteria, including P. aeruginosa and S. aureus.

Administration, Oral↗
PubMed1989

Case 43-1988.

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Humans↗
PubMed1989

In vitro activity of PD 117596-2, a broad-spectrum difluoroquinolone.

The activity of PD 117596-2, a novel quinolone, was compared to that of other quinolones, ceftazidime, imipenem and gentamicin. PD 117596-2 inhibited most Enterobacteriaceae at concentrations less than 0.25 micrograms/ml, being equal or superior in activity to ciprofloxacin and 2- to 4-fold more active than ofloxacin. It inhibited ceftazidime-resistant Enterobacter spp., Citrobacter spp. and Serratia marcescens. The MIC90 for Pseudomonas aeruginosa, including strains with imipenem MICs of 8 micrograms/ml and gentamicin MICs greater than 16 micrograms/ml, was 0.25 micrograms/ml. PD 117596-2 was more active than ciprofloxacin against Pseudomonas cepacia and Pseudomonas maltophilia, and it inhibited Neisseria gonorrhoeae and Haemophilus influenzae at less than 0.03 micrograms/ml. PD 117596-2 inhibited staphylococci at 0.5 micrograms/ml, being 2-fold superior to other quinolones, and with an MIC of 0.25 micrograms/ml was more active against group A, B, C and G streptococci and Streptococcus pneumoniae. MICs for Bacteroides spp. were 2 micrograms/ml compared to 8-32 micrograms/ml for other agents. The frequency of spontaneous resistance was low (less than 10(-10]. Differences in MICs and MBCs were within one dilution, and there was a minimal effect of inoculum size. Although PD 117596-2 was less active at pH 5.5, MICs were less than 0.5 micrograms/ml.

Anti-Infective Agents↗
PubMed1989

Clinical utility of DNA gyrase inhibitors.

Quinolone antibiotics provide potentially important therapy for many infections. These DNA gyrase inhibitors are established as excellent therapy of urinary infections and of diarrheal disease. As reviewed, the compounds have important use in respiratory, skin-structure and bone infections. It is possible that with more extensive use these drugs will show adverse reactions which to date are unknown. A number of other agents in this class with different pharmacological and improved anti-gram-positive and anti-anaerobic activity are in development. These agents will be used increasingly in medicine because of their in vitro activity, pharmacology, and cost-saving by oral therapy.

Animals↗
PubMed1989

Antimicrobial agents: the old and the new.

Although there are many new antimicrobial agents, many of the old antibiotics are still useful in the treatment of infections, particularly those in the community. Antimicrobial resistance patterns and special pharmacologic properties should influence the selection of newer antimicrobial agents. Change from parenteral therapy to oral therapy should increase to avoid the complications of intravenous therapy and to reduce hospital costs. Older antibiotics that are less costly should be used when the etiology and susceptibility of infecting pathogens are known. There will continue to be new antibiotics produced. Understanding the microbiologic and pharmacologic advantages of the new agents compared with older agents is essential if the new agents are to be used properly and not destroyed by inappropriate use.

4-Quinolones↗
PubMed1989

In-vitro activity of FCE 22101 and synergy studies with other antimicrobial agents.

FCE 22101 is a penem antibiotic with broad in-vitro activity similar to that of imipenem, although less active against Pseudomonas aeruginosa. Combinations of FCE 22101 with ciprofloxacin or gentamicin against methicillin-resistant Staphylococcus aureus and methicillin-resistant Staph. epidermidis resulted in addition or indifference by the chequerboard method. The combination of FCE 22101 and gentamicin against Streptococcus faecalis was usually additive. Against Enterobacter cloacae FCE 22101 had MICs of 16 mg/l whilst in combination with gentamicin (0.25-0.12 mg/l) the MICs were reduced to less than 2 mg/l. Ciprofloxacin and FCE 22101 showed only addition against Enterobacter spp. similar results were obtained with the combinations of FCE 22101 and gentamicin or ciprofloxacin tested against Citrobacter freundii. With Serratia spp. FCE 22101 and gentamicin showed synergy, but FCE 22101 and ciprofloxacin showed indifference. Similar results were obtained with strains of Escherichia coli and Klebsiella, Proteus, and Providencia spp. FCE 22101 plus gentamicin, or aztreonam, against Ps. aeruginosa usually showed indifference, but with ciprofloxacin addition was the rule. In general the combination of FCE 22101 with other agents resulted in an additive rather than a synergistic effect.

Anti-Bacterial Agents↗
PubMed1989

Comparative in vitro activity and beta-lactamase stability of FK482, a new oral cephalosporin.

FK482 is an oral aminothiazolyl hydroxyimino cephalosporin with a C-3 vinyl group. Its activity was compared with those of cephalexin, cefuroxime, cefixime, and amoxicillin-clavulanate. FK482 inhibited 90% of Staphylococcus aureus isolates at 1 micrograms/ml and 90% of Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus pneumoniae isolates at less than or equal to 0.012 micrograms/ml, superior to cephalexin and cefuroxime and similar to cefixime. It did not inhibit oxacillin-resistant S. aureus. FK482 inhibited 90% of Enterococcus faecalis isolates at 8 micrograms/ml. Although 90% of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella species, and Shigella species isolates were inhibited by less than or equal to 2 micrograms/ml, FK482 was less active than cefixime against Citrobacter, Enterobacter, Morganella, Serratia, and Providencia species, with MICs for many isolates of greater than 8 micrograms/ml. FK482 inhibited Haemophilus influenzae and Neisseria gonorrhoeae at concentrations comparable to that of cefixime and superior to those of cephalexin and cfaclor. Bacteroides and Pseudomonas species were resistant. FK482 was not hydrolyzed by the TEM-1 and TEM-2 beta-lactamases but was hydrolyzed by TEM-3 and the Proteus vulgaris enzyme. It had a high affinity for chromosomal beta-lactamases.

Amoxicillin↗
PubMed1989

In vitro activity of dactimicin, a novel pseudodisaccharide aminoglycoside, compared with activities of other aminoglycosides.

The in vitro activity of dactimicin, a new pseudodisaccharide aminoglycoside which possesses a formimidoyl group, was compared with those of gentamicin, tobramycin, and amikacin against 500 isolates. Dactimicin inhibited 90% of isolates from the family Enterobacteriaceae at a concentration of less than or equal to 4 micrograms/ml. It was more active than amikacin against Klebsiella pneumoniae, Serratia marcescens, Citrobacter diversus, Enterobacter agglomerans, Yersinia species, and Salmonella species, with an MIC for 90% of the strains (MIC90) of less than or equal to 4 micrograms/ml. The MIC90s for the Pseudomonas aeruginosa isolates were greater than 128 micrograms/ml. Dactimicin did not inhibit most methicillin-resistant Staphylococcus aureus isolates and coagulase-negative staphylococci but had an MIC50 (MIC for 50% of strains tested) of 2 micrograms/ml against methicillin-susceptible S. aureus isolates and coagulase-negative staphylococci. Dactimicin in combination with piperacillin acted synergistically against 75% of Escherichia coli, K. pneumoniae, S. marcescens, and S. aureus isolates. It exhibited an excellent postantibiotic suppressive effect on E. coli. Dactimicin was active against organisms possessing aminoglycoside-modifying enzymes including AAC(2')-b, AAC(3)-III, -IV, and -V, and AAC(6')-Ia, -Ib, Ic, -II, and -IV but was not active against isolates which contained AAC(3)-I and the bifunctional APH(2")-AAC(6')-I. Its lack of activity against P. aeruginosa appeared to be permeability related since in the presence of EDTA P. aeruginosa was susceptible, as were mutant isolates resistant because of permeability barriers.

Aminoglycosides↗
PubMed1989

In vitro activity and beta-lactamase stability of a new carbapenem, SM-7338.

SM-7338, a new carbapenem, inhibited most members of the family Enterobacteriaceae at MICs of 0.015 to 0.25 microgram/ml, including Klebsiella oxytoca, Citrobacter freundii, Enterobacter cloacae, and Proteus vulgaris isolates resistant to cefotaxime, ceftazidime, piperacillin, and gentamicin. It was two- to eightfold more active than imipenem, but it inhibited Pseudomonas aeruginosa at 1 to 8 micrograms/ml, which was comparable to the activity of imipenem. Haemophilus, Neisseria, and Branhamella species were inhibited by less than or equal to 0.25 microgram/ml, which was superior to the activity of imipenem. SM-7338 inhibited Staphylococcus aureus and coagulase-negative staphylococci at 0.25 microgram/ml, but for methicillin-resistant isolates MICs were 4 to 16 micrograms/ml. Group A, B, and C streptococci and Streptococcus pneumoniae were inhibited by less than or equal to 0.03 microgram/ml. Bacteroides species, including clindamycin-resistant isolates, were inhibited by 0.25 microgram/ml. There was no major inoculum size effect, and the MBCs were within a dilution of the MICs. SM-7338 was more active than imipenem at an acid pH under anaerobic conditions. Plasmid beta-lactamases of TEM-1, TEM-2, TEM-3, TEM-5, SHV-1, SHV-2, PSE-1, PSE-2, PSE-3, OXA-2, OXA-3, OXA-4, OXA-5, and OXA-7; Staphylococcus aureus enzymes; and the chromosomal beta-lactamases P-99 and K-1; Morganella species; and Proteus vulgaris did not hydrolyze SM-7338. The repeated transfer of organisms increased the MICs of SM-7338, as it did the MICs of imipenem.

Anti-Bacterial Agents↗