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M D Kitzis

Publications and source records attributed to M D Kitzis.

At least 55 records · Page 3Linked to original sources
PubMed1991

[In vitro antibacterial activity of a new oral cephalosporin, ceftibuten. Results of a multicenter study].

Minimal inhibitory concentration (MIC) of ceftibuten (CBT) were evaluated by agar dilution for 1,416 bacterial strains isolated in 5 hospitals. For Enterobacteriaceae, MIC 50 and 90% were respectively (micrograms/ml): (I) Naturally non beta-lactamase producing species: E. coli 0.12-0.5, Shigella 0.06-0.12 and Salmonella 0.03-0.12, P. mirabilis 0.16-0.03. (II) Chromosomal penicillinase producing species: K. pneumoniae 0.03-0.5 and K. oxytoca 0.03-0.06. (III) Chromosomal cephalosporin producing species: E. cloacae and C. freundii 1- greater than 128: S. marcescens 0.25-2; indole + Proteus 0.06-0.12. Activity of CBT was not modified on plasmid mediated penicillinase producing strains; however, CBT was inactive on cephalosporinase hyperproducing strains, and its activity was variably reduced on broad spectrum beta-lactamases producing strains. CBT was inactive on P. aeruginosa (MIC greater than or equal to 32) and on A. baumannii (8- greater than 128). Haemophilus and Gonococci, regardless on beta-lactamase production status, were very susceptible to CBT (MIC 50 and 90%: 0.06-0.5 and 0.016-0.06); it is the same situation for Meningococci; B. catarrhalis was generally inhibited by 0.03 to 2 (strains susceptible to penicillin G) and 0.12 to 16 (strains resistant to penicillin G). CBT was inactive on Staphylococci. Enterococci and Streptococci B were generally resistant; Streptococci A, C, G were inhibited by low concentrations: 0.06 to 1 (MIC 50 and 90%: 0.25-0.5), whereas MIC for other Streptococci 0.12 to 128 (MIC 50 and 90%: 8-128) and for Pneumococci were 0.25 to 16 (4-8). These antibacterial properties particularly against Enterobacteriaceae placed CBT in excellent position among oral cephalosporins.

Acinetobacter↗
PubMed1990

In-vitro activity of azithromycin against various Gram-negative bacilli and anaerobic bacteria.

The MICs of azithromycin, erythromycin and roxithromycin were determined (by an agar dilution method) for 65 strains of Gram-negative bacteria responsible for endocarditis and gastrointestinal infections, for 20 strains of non-fermenting Gram-negative bacteria and for 16 strains of anaerobic bacteria. The MICs of azithromycin were up to eight times lower than those of erythromycin and (except in the case of Flavobacterium spp.) up to 16 times lower than those of roxithromycin. Azithromycin was ineffective against strains showing a high degree of erythromycin resistance.

Azithromycin↗
PubMed1990

Pharmacokinetics of sodium fusidate after single and repeated infusions and oral administration of a new formulation.

The pharmacokinetics of sodium fusidate were studied in eight healthy volunteers (five males and three females) aged 21 to 33 years (29.1 +/- 1.5), weight 46 to 79 kg (61.6 +/- 4.0 kg). First, the subjects were given 500 mg of sodium fusidate by infusion over two hours; secondly, one month later, the volunteers were given 500 mg of fusidate by infusion every eight hours for three days; thirdly, two 250 mg tablets of a new film coated formulation were administered as a single dose. Plasma concentrations of fusidate were measured by HPLC. Peak plasma concentrations reached at the end of the first and the last infusions were 52 +/- 5 mg/l and 123 +/- 12 mg/l respectively. The following mean pharmacokinetic parameters were obtained after single intravenous administration: elimination half-life 10 +/- 1 h, total clearance 22 +/- 2 ml/min and volume of distribution 0.30 +/- 0.04 l/kg. After repeated administration the half-life and the volume of distribution remained unchanged whereas total clearance was halved (11 +/- 1 ml/min). This leads to an experimental accumulation ratio (3.6 +/- 0.2) higher than the theoretical one (1.8 +/- 0.1; P less than 0.01). Consequently, mean trough and peak steady state plasma concentrations (81 +/- 9 and 123 +/- 12 mg/l respectively) are higher than those expected from the single dose kinetics (33 +/- 4 and 76 +/- 7 mg/l respectively). This dose regimen leads to concentrations well above the MIC for most sensitive strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1990

The in-vitro activity of cefodizime: a review.

For Enterobacteriaceae, MIC50s and MIC90s of cefodizime (mg/l), respectively, were as follows, for naturally non-beta-lactamase-producing species: Escherichia coli 0.12 and 0.5, Salmonella spp. and Shigella spp. 0.25 and 0.5, Proteus mirabilis 0.016 and 0.03; for chromosomal penicillinase-producing species. Klebsiella spp. 0.25 and 64, and for chromosomal cephalosporinase-producing species. Enterobacter cloacae 1 and 64, Citrobacter freundii 1 and 128, Serratia marcescens 2 and 8: indole-positive Proteus spp. 0.06 and 0.5; and Providencia stuartii 0.5 and 1. The activity of cefodizime was not modified by plasmid-mediated penicillinase-producing strains but cefodizime was inactive against cephalosporinase hyper-producing strains and against expanded broad-spectrum beta-lactamase-producing strains. Cefodizime was noticeably less active against Pseudomonas aeruginosa and Acinetobacter baumannii with MICs ranging from 32 to more than 128 mg/l. Haemophilus spp. and Neisseria gonorrhoeae, regardless of beta-lactamase producing status, as well as N. meningitidis, were highly susceptible (MIC50s and MIC90s less than or equal to 0.008 mg/l). Cefodizime was moderately active against methicillin-susceptible staphylococci (MIC50 and MIC90 8 mg/l) but failed to inhibit methicillin-resistant strains. Enterococci were generally resistant: Streptococcus pyogenes and Str. pneumoniae were inhibited by low concentrations (MIC50 and MIC90 0.12 and 0.5 mg/l). A fairly wide range of MICs was found for anaerobes, with lower values for Clostridium perfringens (MIC50 and MIC90 0.5 and 1 mg/l) than for Bacteroides fragilis (8- greater than 128 mg/l). These results show that cefodizime has similar properties to other third generation cephalosporins and suggest that cefodizime would find a role in the management of hospital infections.

Bacteria↗
PubMed1990

In vitro activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases.

The activities of 15 oral beta-lactams against Klebsiella pneumoniae harboring new extended-spectrum beta-lactamases were studied. All compounds were affected by these enzymes, especially by the SHV derivatives. Except for ceftibuten, the compounds with the greatest intrinsic activity were more affected by the presence of these enzymes than were older compounds with moderate intrinsic activity.

Anti-Bacterial Agents↗
PubMed1990

Interaction between roxithromycin and cyclosporin in heart transplant patients.

Cyclosporin is an immunosuppressive agent commonly used in transplant patients. It is actively metabolised by the cytochrome P450 system and interactions with drugs metabolised by the same system are predictable. This is particularly relevant since cyclosporin has a low therapeutic index and its renal toxicity is concentration-related. Roxithromycin, a new, well-tolerated macrolide with a weak interactive profile, uses the same isoenzyme of the P450 system as cyclosporin. To evaluate its interaction potential in clinical practice, 8 heart transplant recipients treated with cyclosporin for at least 1 month received roxithromycin for 11 days (150 mg twice daily). Bi-weekly controls of plasma cyclosporin concentrations and creatinine levels were carried out before, during and after roxithromycin treatment. A slight nonsignificant rise in cyclosporin concentrations was observed, but creatinine levels remained stable during roxithromycin treatment. Values of cyclosporin concentrations diminished after withdrawal of roxithromycin. Cyclosporin dosage adjustment was not necessary. There was a minor pharmacokinetic interaction, which can be considered safe for the usual therapeutic dosage of roxithromycin used.

Adult↗
PubMed1990

Evolution of enzymatic mechanisms of resistance among beta-lactam antibiotics.

Resistance to third-generation cephalosporins occurs as a result of either the production of high concentrations of chromosomal cephalosporinase or, increasingly, the presence of broad-spectrum plasmid-mediated beta-lactamases. Both cases represent the response of bacteria in the hospital setting to the selection pressure brought to bear by the use of these antibiotics. Continued evolution of the plasmid-mediated enzymes is occurring as new antibiotics are introduced, probably reflecting the process that began when the first beta-lactamase apparently evolved from the penicillin-binding proteins. beta-Lactamase inhibitors offer one approach to dealing with the evolution of resistance to previously beta-lactamase-stable antibiotics.

Amino Acid Sequence↗
PubMed1990

[In vitro antibacterial activity of clarithromycin, a new macrolide antibiotic, and regression curve].

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.

Bacteria, Anaerobic↗
PubMed1990

[In vitro antibacterial activity of RU 51746 (sodium salt of cefpodoxime). Results of a multicenter study].

Cefpodoxime proxetil, a new oral cephalosporin, is the prodrug ester of cefpodoxime. Minimal inhibitory concentrations (MIC) of RU 51746 (sodium salt of cefpodoxime: CPD) were evaluated by agar dilution for 1 696 bacterial strains isolated in 5 hospitals. For Enterobacteriaceae, MIC 50 and 90% were respectively (micrograms/ml): (1) naturally non bêtalactamase producing species: E. coli, Shigella and Salmonella 0.25-0.5; P. mirabilis 0.06-0.12. (II) chromosomal penicillinase producing species: Klebsiella 0.12-1. (III) chromosomal cephalosporinase producing species: E. cloacae and C. freundii 2-greater than 128; S. marcescens 2-64; indole + Proteus 0.25-64; P. stuartii 0.25-16. Activity of CPD was not modified on plasmid mediated penicillinase producing strains, but CPD was inactive on cephalosporinase hyperproducing strains, and on broad spectrum bêtalactamases producing strains. CPD was inactive on P. aeruginosa (MIC greater than or equal to 64) and on A. baumannii (16-pi 128). Haemophilus, regardless on bêtalactamase production status, were very susceptible to CPD (MIC less than or equal to 0.25) and B. catarrhalis was generally inhibited by 0.12 to 1. CPD was poorly active on methicillin susceptible Staphylococci (MIC 50 and 90%: 2-4) and inactive on methicillin resistant strains. Enterococci and Listeria monocytogenes were generally resistant; Streptococci A, B, C, G and Pneumococci were inhibited by low concentration: 0.002 to 0.25 (MIC 50 and 90%: 0.016-0.032) whereas MIC for other Streptococci were 0.004 to 32 (MIC 50 and 90%: 0.25-4). These antibacterial properties placed CPD in excellent position among oral cephalosporins.

Anti-Bacterial Agents↗
PubMed1989

In vitro activity of combinations of beta-lactam antibiotics with beta-lactamase inhibitors against cephalosporinase-producing bacteria.

Combinations of different beta-lactam antibiotics, including cefotaxime, with three beta-lactamase inhibitors were tested against cephalosporinase producing bacterial strains. The most significant antagonism was obtained with a combination of clavulanic acid and cefotaxime, while almost no antagonism was observed with sulbactam and tazobactam. In strains belonging to five different species there was a correlation between the levels of cephalosporinase produced after exposure to different concentrations of inhibitors and the MICs of cefotaxime combined with the same concentrations of inhibitors. It is concluded that there is little likelihood of antagonism between beta-lactam antibiotics and sulbactam or tazobactam.

Anti-Bacterial Agents↗
PubMed1989

Pharmacokinetics of amoxycillin/clavulanic acid in serum and ascitic fluid in cirrhotic patients.

A combination of amoxycillin and clavulanic acid (Augmentin) might be useful for first-line treatment of spontaneous bacterial peritonitis in patients with cirrhosis. We have studied the pharmacokinetics of amoxycillin/clavulanic acid in serum and ascitic fluid of six cirrhotic patients. A total of 66 simultaneous serum and ascitic samples were analysed. Following iv injection of 1 g amoxycillin plus 0.2 g clavulanic acid, the ascites to serum AUC ratio was 1.38 for amoxycillin and 1.01 for clavulanic acid, indicating a good distribution of these drugs into the ascitic fluid. In this study, experimental data were fitted to a three compartment body model which revealed that the prolonged serum half-lives of amoxycillin (274 min) and clavulanic acid (200 min) were probably due to the slow return from the ascitic compartment.

Adult↗
PubMed1989

Tigemonam activity against clinical isolates of Enterobacteriaceae and Enterobacteriaceae with known mechanisms of resistance to beta-lactam antibiotics.

Tigemonam, a new oral monobactam, was at least as active as aztreonam or carumonam against clinical isolates of Enterobacteriaceae (MIC90:0.06-16 mg/l). Tigemonam was very stable in the presence of classical plasmid mediated beta-lactamases but its MICs were increased (4-256 mg/l) in the presence of new broad-spectrum plasmid mediated beta-lactamases (either TEM of SHV derivatives). Increased MICs (0.25-8 mg/l) were also observed for different isogenic mutants of Enterobacteriaceae, which either produced high levels of chromosome-encoded cephalosporinases, or had a permeability defect.

Anti-Bacterial Agents↗
PubMed1989

Antibacterial activity of meropenem against gram-negative bacteria with a permeability defect and against staphylococci.

Meropenem, like imipenem, showed a good affinity for high molecular weight PBPs of Escherichia coli and Pseudomonas aeruginosa and had a better affinity for PBP3 than imipenem. Meropenem, like imipenem, also remained almost fully active against permeability mutants of enterobacteria lacking in confirmed or putative porins. This good permeation of the carbapenems may relate to their zwitterionic character. In-vitro, mutants and clinical isolates of P. aeruginosa, for which the MIC of imipenem was greater than or equal to 4 mg/l, were always more sensitive to meropenem. Methicillin resistant staphylococci were sensitive neither to imipenem nor to meropenem.

Bacterial Proteins↗
PubMed1989

[Antibacterial activity of pefloxacin in the urine during the 7 days following a single 800 mg oral dose].

Antibacterial activity of pefloxacin was studied in the urine after a single 800 mg oral dose in ten healthy female volunteers. Urine was collected in 9 periods: 0-6 h, 6-12 h, 12-24 h, 24-28 h, 48-72 h, 72-96 h, 96-120 h, 120-144 h, 144-168 h. Pefloxacin concentrations were assayed in all samples by a microbiological method and by HPLC. Urine antibacterial activity was determined towards five bacterial strains isolated in urine: 2 E. Coli strains, one sensitive and the other resistant to nalidixic acid (Nal-A), 1 Klebsiella pneumoniae resistant to nalidixic acid (Nal-B), 1 Staphylococcus saprophyticus and 1 Streptococcus faecalis; MIC's of pefloxacin against these strains were respectively 0.015, 0.25, 1, 0.50 and 2 micrograms/ml. Pefloxacin mean concentrations as determined by the microbiological method were 91.8 +/- 11.9, 71.7 +/- 7, 44.5 +/- 4.3, 24.4 +/- 4 and 5.4 +/- 0.8 micrograms/ml in the five first urine samples; low levels were present in the urine until the 7th day in 8 volunteers. HPLC results completed the already known data concerning pefloxacin elimination and metabolism; unchanged pefloxacin was excreted at the highest concentration during the 6 first hours; then demethylpefloxacin was eliminated at higher levels than pefloxacin with a ratio of 2/1 after the 24th hour. These two compounds were detectable in the urine during 5 to 7 days; oxodemethylpefloxacin and N-oxyde-pefloxacin were present in lower amounts and during a shorter period.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

[Antibacterial activity of lomefloxacin in the urine during the 4 days following a single 400 mg oral dose].

Antibacterial activity of lomefloxacin was studied in the urine after single dose of 400 mg in ten healthy female volunteers. Urine was collected in 7 periods: 0-3 h, 3-6 h, 6-12 h, 12-24 h, 24-48 h, 48-72 h, 72-96 h. Lomefloxacin concentration were assayed in all samples by microbiological method. Urine antibacterial activity was determined towards five strains isolated in urine: 2 E. Coli strains one sensitive and the other resistant to nalidixic acid (Nal-A), 1 Klebsiella pneumoniae resistant to nalidixic acid (Nal-B), 1 Staphylococcus saprophyticus and 1 Streptococcus faecalis. MIC's of lomefloxacin against these strains were respectively 0.06, 0.50, 0.50, 0.25 and 4 micrograms/ml. Lomefloxacin mean concentrations were 208.5 +/- 44.2, 104.3 +/- 15.2, 100.5 +/- 17.9, 36.8 +/- 8.2, 9.6 +/- 2.2 micrograms/ml in the five first urine samples. Low levels were present in urine the 4th day. Mean urine elimination percentage was 62.2 +/- 4.2% for the four days, with extreme values from 91.2 to 41.8%. Urine bacteriostatic activity against enterobacteriacae was greater than or equal to 32 the first day reaching 8,192 for the Nal-S E. Coli, it was greater than or equal to 4 the second day. Against staphylococcus it was greater than or equal to 64 the first day, greater than or equal to 16 the second day. Against enterococcus it was greater than or equal to 4 the first day. Against the strains implicated in UTI a bacteriostatic activity was present during 2 days in all subjects.

4-Quinolones↗
PubMed1989

[In vitro antibacterial effect of a new oral cephalosporin, cefixime. Results of a multicenter study].

Minimal inhibitory concentrations (MIC) of cefixime (CXM) were evaluated by agar dilution against 2,469 bacterial strains isolated in 10 hospitals. For Enterobacteriaceae, MIC 50 and 90% micrograms/ml were respectively: (I) naturally non beta lactamase producing species: E. coli and Shigella 0.25-0.5; Salmonella 0.06-0.25; P. mirabilis 0.008-0.032. (II) chromosomal penicillinase producing species: Klebsiella 0.06-2. (III) chromosomal cephalosporinase producing species: E. cloacae and C. freundii 1-greater than 128; S. marcescens 0.25-16; indole + Proteus 0.06-4; P. stuartii 0.032-0.5. Activity of CXM was not modified against plasmid-mediated penicillinase producing strains, but CXM was inactive on cephalosporinase hyperproducing strains and on broad spectrum beta lactamases producing strains. CXM was inactive on P. aeruginosa (MIC 50 and 90%: 64-128) and on A. baumannii (16-128). Haemophilus and Gonococci, regardless of beta-lactamase production status, and Meningococci were very susceptible to CXM (MIC 0.008-0.12). B. catarrhalis was generally inhibited by 0.03 to 0.5. CXM was poorly active on methicillin susceptible Staphylococci (MIC 50 and 90%: 1-64) and inactive on methicillin resistant strains. Enterococci were generally resistant whereas Streptococci and Pneumococci were inhibited by low concentrations: 0.008 to 1. These antibacterial properties place CXM in excellent position among oral cephalosporins.

Cefixime↗
PubMed1989

The incidence of beta-lactamase-producing pathogens.

In addition to the bacteria which naturally are able to enzymatically inactive penicillins and/or cephalosporins, a large number of species may develop this ability through mutation, acquisition of plasmids, or insertion of transposons. Characterization of the beta-lactamase activity of various pathogens has shown that a wide variety of enzymes exists and that new ones continue to evolve. The distribution of the genes for the numerous beta-lactamases vary according to geographic location and pathogen. Recently beta-lactamase inhibitors (sulbactam and clavulanic acid) have become available which, in combination with different beta-lactam antibiotics, expand the activity of those hydrolyzable antibiotics to pathogens producing beta-lactamases. The epidemiology of resistant pathogens and of the beta-lactamase genes that make them resistant are important factors in evaluating the role of these beta-lactam/beta-lactamase inhibitor combinations.

Anti-Bacterial Agents↗