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Biomedical subjects

H Leclerc

Publications and source records attributed to H Leclerc.

At least 73 records · Page 4Linked to original sources

Comparative in-vitro activity of ciprofloxacin against non-fermenters.

The in-vitro activity of ciprofloxacin, a quinolone-carboxylic acid derivative, was compared with those of carbenicillin, azlocillin, cefsulodin, ceftazidime, tobramycin and amikacin against 187 non-fermenters. Only one of the 131 strains of Pseudomonas spp. was not inhibited by 1 mg/l of ciprofloxacin, while these isolates appeared highly resistant to carbenicillin, azlocillin and cefsulodin. Ciprofloxacin was also the best agent against Flavobacterium, Alcaligenes faecalis and Acinetobacter calcoaceticus with MIC90's respectively of 0.5, 4 and 8 mg/l. This new compound appeared bactericidal, and we found a small or no inoculum effect with ciprofloxacin.

Anti-Bacterial Agents↗

Ofloxacin: antibacterial activity, induction of resistance and killing curves.

The antibacterial activity of ofloxacin was compared to that of nalidixic acid, norfloxacin and against various strains. This new quinolone was about 100 times more active than nalidixic acid, and pipemidic acid and generally 2 to 4 fold more active than norfloxacin and pefloxacin except against Pseudomonas aeruginosa. The increase of resistance to ofloxacin, norfloxacin and pefloxacin seems to plateau, usually at about 16 times the initial MIC. The bactericidal activity of ofloxacin also appeared quickly and more rapidly than that of norfloxacin.

Anti-Bacterial Agents↗

[In vitro study of the synergistic effect of cefotiam- aminoglycoside combinations on strains of low susceptibility to this cephalosporin].

Antibacterial activity of cefotiam associated with gentamicin, tobramycin, netilmicin, or amikacin against Enterobacteriaceae strains either moderately susceptible (MIC = 4 to 32 micrograms/ml, 14 strains) or resistant (MIC = 64 to 512 micrograms/ml, 22 strains) to cefotiam was studied using the checkerboard method. High rates of synergic associations (FIC index less than or equal to 0.5) were found, with variations according to the aminoglycoside: 65% for tobramycin and netilmicin, 76% for amikacin, and 81% for gentamicin. Activity of cefotiam is increased by the synergic effect of these associations: of the 36 strains tested, 83, 78 and 76% became susceptible to cefotiam (MIC less than or equal to 4 micrograms/ml) associated with tobramycin, netilmicin or gentamicin, and amikacin respectively.

Amikacin↗

In vitro antibacterial activity of three new quinolone derivatives: rosoxacin, norfloxacin, pefloxacin.

The in vitro activities of rosoxacin, norfloxacin and pefloxacin against 480 bacterial strains were studied. MIC90s of norfloxacin and pefloxacin were less than or equal to 2 micrograms/ml for E. coli, Klebsiella sp., E. cloacae, Proteus sp. and Staphylococcus sp., less than or equal to 8 micrograms/ml for C. freundii, Providencia sp., S. faecalis, and non fermentative Gram-negative bacteria, while they were of 32 micrograms/ml for S. marcescens. Rosoxacin exhibited a lower activity with MIC90s 2 to 16 fold higher against Enterobacteriaceae and P. aeruginosa. Ninety per cent of isolates resistant to nalidixic-acid appeared susceptible to norfloxacin and pefloxacin with MIC less than or equal to 16 micrograms/ml.

4-Quinolones↗

Evaluation of the four-hour rapid 20E system for identification of members of the family Enterobacteriaceae.

A study was conducted to compare the API Rapid 20E 4-h system (API System S.A., France; commercially available in the U.S.A. under the name DMS Rapid E System; DMS Laboratories, Darts Mill, Flemington, N.J.), the API 20E 18- to 24-h system (Analytab Products, Plainview, N.Y.), and a conventional media system to measure the ability of each to identify members of the family Enterobacteriaceae. Comparison tables rather than simple percentage agreement tables were generated to define the particular strengths and weaknesses of each system and to allow the laboratory to best use the data. The Rapid 20E compared quite favorably with conventional media. It yielded correct identifications with 95.9% of the isolates tested (API 20E, 98% identification rate). In 2.5% of the isolates, the Rapid 20E gave only genus identifications, and in 1.4% the organisms did not correspond to any key in the code book and could not be identified by the manufacturer's computer service. The ease of inoculation and the 4-h capability make the Rapid 20E system an extremely attractive development in the field of bacterial identification.

Bacteriological Techniques↗

Combination effect of cefmenoxime with four aminoglycosides on Enterobacteriaceae susceptible and moderately susceptible to this new cephalosporin.

The inhibitory combination effect of cefmenoxime with gentamicin, tobramycin, netilmicin and amikacin against 148 Enterobacteriaceae was compared using the checkerboard agar dilution technique. On average 41% of cefmenoxime-moderately susceptible (MIC between 2 and 32 micrograms/ml) or cefmenoxime-resistant (MIC greater than 32 micrograms/ml) strains were inhibited by synergistic, and 23,5% by partial synergistic cefmenoxime-aminoglycosides combinations. Against cefmenoxime-susceptible strains, these rates of synergy or partial synergy were twofold lower, but only one isolate was not susceptible to these combinations. The amikacin-cefmenoxime interaction was the most performant.

Amikacin↗

[In vitro study of the synergistic effect of cefmenoxime-aminoglycoside combinations apropos of 148 strains of Enterobacteriaceae].

The synergistic effect of cefmenoxime -aminoglycoside combinations against 148 Enterobacteriaceae strains selected for their resistance to beta-lactams was studied. Against the 89 Enterobacteriaceae with cefmenoxime MICs greater than or equal to 2 micrograms/ml, the rates of synergy were high : 73 % (netilmicin), 67 % (amikacin), 64 % (gentamicin) and 56 % (tobramycin). In contrast, cefmenoxime-susceptible strains (CMI less than 2 micrograms/ml) had lower rates : 47 % (gentamicin), 44 % (tobramycin), 43 % (netilmicin), and 42 % (amikacin). Synergistic effects on these bacteria are correlated to cefalotin resistance.

Aminoglycosides↗

Automatic diluter for bacteriological samples.

The described apparatus, carrying 190 tubes, allows automatic and aseptic dilution of liquid or suspended-solid samples. Serial 10-fold dilutions are programmable from 10(-1) to 10(-9) and are carried out in glass tubes with screw caps and split silicone septa. Dilution assays performed with strains of Escherichia coli and Bacillus stearothermophilus permitted efficient conditions for sterilization of the needle to be defined and showed that the automatic dilutions were as accurate and as reproducible as the most rigorous conventional dilutions.

Bacteriological Techniques↗

[In vitro bacteriostatic activity of cefmenoxime (SCE 1365), cefotaxime and moxalactam].

The in vitro activity of cefmenoxime (SCE 1365), a new cephalosporin derivate was compared with two other "third generation" cephalosporins: cefotaxime and moxalactam. Cefmenoxime as cefotaxime and moxalactam were very active against 305 cephalosporinase-producing and cephalosporinase-non-producing Enterobacteriaceae. Cefmenoxime was the most active against Serratia marcescens, Citrobacter freundii, Morganella morganii, Salmonella, Shigella and Yersinia enterocolitica with a mean MIC at least twice lower. Several strains of the species Hafnia alvei, Providencia stuartii and Proteus vulgaris were more resistant. Against Haemophilus influenzae, the activity of the three cephalosporins was higher with a mean MIC between 0,030 and 0,040 microgram/ml. Against carbenicillin-sensible or carpenicillin-resistant Pseudomonas aeruginosa or Acinetobacter calcoaceticus, the three cephalosporins were not performant. Against Staphylococcus aureus, cefmenoxime and cefotaxime had an identical activity with a mean MIC of 1,5 microgram/ml against methicillin-sensible strains and a mean MIC of 5,5 micrograms/ml against methicillin-resistant strains.

Bacteria↗

[Rapid, automatic methods for identifying enterobacteria].

The biochemical testing of Enterobacteriaceae can be rapidly and automatically performed with commercial identification systems. There are three groups of identification systems: the kits, the microtiter plates and laboratory apparatus. The ratios of agreement between these new systems and the conventional tests are equivalent. The two first categories of systems are inexpensive unlike apparatus which must be utilized only in important laboratories.

Automation↗

[Rapid diagnosis of purulent meningitis].

The cerebrospinal fluid of 589 subjects, 78 of whom were suffering from a purulent meningitis were examined. Comparatively by classical bacteriological techniques (direct examination and culture) and by electro-immunodiffusion, latex agglutination, and Limulus endotoxin assay. Soluble bacterial Haemophilus influenzae type B, Neisseria meningitidis group A, C, and Streptococcus pneumoniae antigens, were tested by electro-immunodiffusion and latex agglutination, and soluble bacterial N. meningitidis group B, Listeria monocytogenes and Streptococcus agalactiae antigens by electro-immunodiffusion. Specific antigens and endotoxin were found in 75.8 per cent of the specimens with a rapid answer (120 min). The three tests revealed also only the diagnosis in 29.1 per cent of cases of pneumococcal meningitis, in 33.3 per cent of meningococcal meningitis and in 47 per cent of Gram-negative bacteria meningitis. Only five cerebrospinal fluid from the 589 specimens tested were given a non-specific reaction. These two advantages--sensitivity and specificity--of these three tests render them techniques of the future in the diagnosis of purulent meningitis.

Agglutination Tests↗

[Nitrates in the drinking water and cancer mortality. An epidemiologic study in northern France].

This epidemiological survey was conducted in the Northern country of France, on 753 communes. Nitrate concentration in drinking water was measured from 1974 to 1976. The mean concentration rates (M.C.R.) calculated for the three years, were under 95 mg/l, and 93% were under 43 mg/l. The association between the M.R.C. and digestive and urinary cancer mortality rates observed in the same area (1968-1975) was studied, using different statistical techniques. No systematic relationship was observed taking into account the site of the tumor and the age and the sex of the subjects. The role of other variables is considered in the discussion: duration of exposure, use of other beverages such alcohol or mineral water. The duration of exposure, use of other beverages such alcohol or mineral water. The authors conclude that drinking water does not seem to play a determinant role in the causation of cancer; relationship, if it exists, it remains to be demonstrated.

Adult↗

Rapid and automated identification of Enterobacteriaceae with the abbott MS-2 system and API-20E versus conventional methods.

The ability of the MS-2 (Abbott Laboratories, Diagnostic Division, Dallas, Texas) to rapidly identify Enterobacteriaceae, was evaluated. The results of the MS-2 and of the Analytab API-20E test strip were compared with those obtained from conventional tubed media. The MS-2 and API-20E completely agreed with the conventional method for 92% and 95% of the organisms, respectively. Only 0.5% (MS-2) to 0% (API-20E) of the organisms tested led to complete disagreement. Approximately 6% (MS-2) and 3.5% (API-20E) of the organisms would have shown complete agreement if additional tests had been done. For 1.5% of the organisms the octal code could not be found in the API-20E profile index. It was concluded that the MS-2 system provides a rapid (5 to 6 h) and accurate method for the routine identification of Enterobacteriaceae.

Bacteriological Techniques↗