PubMed Health⌕ Search

Biomedical subjects

R Cluzel

Publications and source records attributed to R Cluzel.

At least 55 records · Page 3Linked to original sources
PubMed1983

[Effect of trimethoprim at a subinhibitory concentration on the appearance of mutants resistant to rifampicin].

Experiments have been performed to establish the effect of trimethoprim (Tmp) on the emergence of Staphylococcus aureus (S. aureus) mutants to rifampicin (Ramp). Four S. aureus strains were used: two strains with low MIC of Ramp (0,01 microgram/ml), two strains with enhanced MIC of Ramp (2 micrograms/ml). For each of them the frequency of mutants and the mutation rates to Ramp were determined when various concentrations of Tmp were added. Results showed that subinhibitory concentrations of Tmp reduced 10 to 100 folds the frequency of mutants and the rates of mutation to Ramp alone. The more the Tmp concentrations were near the MIC, the more this effect was important.

Drug Resistance, Microbial↗
PubMed1983

[Diffusion of fosfomycin into bone tissue in man].

Fosfomycine diffusion into spongious and cortical bone was studied in 20 patients undergoing total replacement of the hip after an intravenous infusion of 4 g (1 g/h). The serum and bone samples were collected 1 h and 3 h after administration of the drug. Concentrations at 1 h were 105.0 +/- 12.4 micrograms/ml, 19.6 +/- 4.8 micrograms/g and 13.3 +/- 3.7 micrograms/g in serum, spongious bone and cortical bone respectively; at 3 h these concentrations had become respectively 67.8 +/- 15.9 micrograms/ml, 10.0 +/- 4.2 micrograms/g and 8.2 +/- 3.6 micrograms/g. Antibiotic levels in bone tissue decreased in direct ratio to corresponding serum values, the mean tissue/serum ratio remaining at 15 +/- 4%.

Adult↗
PubMed1983

[Rifampicin in the treatment of Staphylococcus arthritis].

Rifampicin is used for treating 20 Staphylococcus septic arthritis, in combination with another antibiotic. The former is chosen for its striking bone diffusion. The average duration of the whole antibiotic treatment is 3 months. Rifampicin is usually prescribed, in daily doses of 1 200 mg for 60 days, after one month of parenteral antibiotherapy. The bactericidal activity is controlled regularly by measuring serum inhibitory titre. For 2 patients, the administration of rifampicin is suspended after 12 and 25 days respectively, due to digestive disorders. Results are evaluated at the end of a period averaging 18 months. Articular infection has been cured in all patients. Taking these results into account, we are able to emphasize that the inclusion of rifampicin in the antibiotic scheme is of great value in treating bone and articular infections.

Adult↗
PubMed1982

[Comparative bactericidal activity of beta-lactam-aminoglycoside combinations against Pseudomonas aeruginosa].

The effects of combining each of 10 beta-lactamins (carbenicillin, ticarcillin, piperacillin, azlocillin, cefotaxime, moxalactam, ceftriaxone, cefoperazone, ceftazidime, cefsulodin) with 6 aminoglycosides were studied in vitro against two strains of Pseudomonas aeruginosa. The bactericidal activity was tested by two methods: solid medium technique of "cellophane transfer" and "checkerboard" method (broth-dilution micromethod partly automatic). No single antagonism was observed. Concerning new penicillins, the percentage of synergy is increasing from carbenicillin, to ticarcillin, to azlocillin and finally to piperacillin. For recent cephalosporins, the most synergistic combinations are obtained with ceftriaxone, cefoperazone and ceftazidime. If aminoglycosides associations are considered, there is a good activity whichever antibiotic chosen, with a higher level for streptomycin and lower one for tobramycin. Dibekacin combinations, also tested by the checkerboard method, are particularly synergistic with azlocillin and piperacillin for new penicillins, and equally well with ceftriaxone for recent cephalosporins.

Aminoglycosides↗
PubMed1982

[Statistical regression analysis for four new cephalosporins (author's transl)].

The MIC (agar dilution method) and the zone diameter (disk diffusion) were determined for two hundred and sixteen of the most frequently bacterial strains found in hospitals in order to establish the regression curves for four new cephalosporins : cefotaxime, cefoperazone, cefotiam, moxalactam. The dta (MIC, zone size) were represented by a series of points (Mi (Xi Yi) in semilogarithmic rectangular co-ordinates expressed as : Xi = log2 MIC + 7 ; Yi = zone diameter. Firstly, we tried to fit a regression polynomial to this series of points progressing from degree 1, simple equation (standard regression line) 2, 3, etc. in order to reduce if need be, the deviation between the model (polynomial) and the empirical data. For these four cephalosporins a regression polynomial was obtained. Secondly, the global series was divided into three series of points Mi corresponding to three ranges of MIC : MIC less than or equal to 4 microgram/ml ; 4 less than or equal to 16 micrograms/ml; MIC greater than or equal to 16 microgram/ml. A regression line was obtained for each series and compared with each other and each one with the global regression line (they do not coincide statistically). Concerning these antibiotics, it is better to use a regression polynomial rather than apply a standard regression line.

Bacteria↗
PubMed1982

[Penetration of cloxacillin into human bone tissue after oral administration (author's transl)].

Cloxacillin diffusion into spongious and cortical bone was studied in 20 patients undergoing total replacement of the hip, after an oral single-dose of 1 g (10 patients) or an oral dose of 1 g every 8 hours (10 patients). Serum and bone samples were collected 2 and 3 hours after the last dose and assayed for antibiotic concentration by a microbiological method. Bone levels were similar in any group of patients, but significantly higher in spongious bone than in cortical bone. The bone/serum concentration ratios were 0.15 for spongious bone and 0.10 for cortical bone. Calculations from these data showed that adequate local levels inhibitory to Staphylococcus aureus, would be achieved by cloxacillin administration of 1 g dose every 4 hours orally.

Administration, Oral↗
PubMed1981

[Role of the bacteriology laboratory in the diagnosis and treatment of osteoarthritis].

The etiological diagnosis of bone and joint infections, the choice of antibiotics adapted to the responsible bacteria and the supervision of their efficacy depend mainly on the bacteriology laboratory. A routine search for the causal bacteria in various samples, e.g. synovial fluid, blood cultures, synovial biopsy, inter-vertebral disc puncture, permit etiological diagnosis in about 80% of cases. The choice of antibiotics, limited to those whose synovial and bony diffusion is known, depends on the results of in vitro studies of sensitivity of the isolated bacteria (CMI and CMB) and of the bactericidal power of the associations. The measurement of the inhibitory power or concentrations of antibiotic in synovial fluid and serum give an indication of the efficacy of the treatment.

Adult↗
PubMed1979

[Bactericidal activity "in vitro" of sulfamethoxazol-tri-methoprime (SMZ-TMP) alone and in combination with various antibiotics on bacterial strains isolated from urinary tract infections (author's transl)].

The authors study "in vitro" effects of sulfamethoxazol-trimethroprime (SMZ-TMP) on 1 078 bacterial strains isolated from urinary-tract infections during january 1974, the second trimester 1974 and january 1975. Study involves two parts : comparison between bacteriostatic activity of SMZ-TMP, ampicillin and nalidixic acid; evaluation of bactericidal activity of antibiotic associations including SMZ-TMP. MIC study included all strains. On Gram- negative bacilli the bacteriostatic activity of SMZ-TMP (74,6 percent of sensitive strains) was comparable with nalidixic acid (79,6 percent of sensitive strains) and better than ampicillin 31,4 percent of sensitive strains). On staphylococcus strains the bacteriostatic activity of SMZ-TMP (84,6 percent of sensitive strains) is better than ampicillin (36,4 percent of sensitive strains); on streptococcus strains the bacteriostatic activity of ampicillin (71 percent of sensitive strains) is better than SMZ-TMP (5l percent of sensitive strains). 473 associations including SMZ-TMP were studied upon 44 strains of Gram- negative bacilli by bactericidal test. ("Cross disposition" method, derive from "cellophane transfer method".

Ampicillin↗
PubMed1979

[Activity of antibiotics and heavy metals against "Aeromonas" isolated from aquatic environments: phenotypic and genetic transfers (author's transl)].

In this study, 64% of the 197 strains of Aeromonas isolated from different stages of aquatic environment (surface water, sewage...) were resistant to one or two antibiotics, and 20% to four or more antibiotics. These multiresistant strains were only isolated from sewage and their resistances were transferable by conjugation to different species of Gram-negative bacilli. The incidence of these results is discussed.

Aeromonas↗
PubMed1978

[The bactericidal power of antibiotic combinations. Application in the treatment of osteo-articular infections due to Staphylococcus aureus (author's transl)].

Study of the bactericidal power of antibiotic combinations against 18 strains of staphylococcus aureus causing osteoarthritis showed that the combinations most often synergistic or indifferent were: rifampicin + lincomycin or synergistine, rifampicin + fusidic acid, synergistine + fusidic acid or trimethoprim-sulphamethoxazole, cephalosporins + gentamycin, rifampicin or fusidic acid + gentamycin, trimethoprim-sulphamethoxazole + rifampicin or fusidic acid. Study of the antibiotic therapy used here was based upon the inhibitory power of serum and the measurement of antibiotic concentrations in healthy bone. Combinations which are synergistic or indifferent in vitro endow the serum with a high level of bactericidal activity. Certain antagonisms (cephalosporins or penicillin M + rifampicin) found in vitro may be reflected neither clinically nor in study of the inhibitory power of the serum.

Adolescent↗
PubMed1978

[Osteo-articular infections: choice and monitoring of antibiotic therapy. Apropos of 26 observations with an identified organism].

Study of 26 cases of osteo-articular infections with an identified organism collected in a rheumatology department, has confirmed in the first place the increasing importance of gram negative organisms, compared with the staphylococcus which has always mainly predominated in this type of infection. In each case, the authors have made as complete a bacteriological study as possible, including antibiotic sensitivities, the measurement of the minimum inhibitory concentration of the antibiotics on the isolated strains, study of the bactericidal power in vitro of various combinations, and study of the inhibitory power of the serum on the organism. This study of the inhibitory power of the serum approximates most closely to testing the antibiotic activities in vivo, since one cannot make this assessment, in most cases, within the infective focus itself. Rifampicin, with the imperative condition that it is not used alone, is a major antibiotic in the osteo-articular infections, by reason of its very great activity against the staphylococcus, its excelent penetration into bone, and its ease of use. Other recognized anti-staphylococcal antibiotics behave in a more disappointing fashion. When the effectiveness of treatment is checked regularly by the inhibitory power of the serum, together with the other classical criteria of surveillance, cure of the infection as been achieved in every case.

Adolescent↗
PubMed1977

[Comparative study of 7 cephalosporins on "Staphylococcus aureus" by the method of population analysis (author's transl)].

Miscellaneous Staphylococcus aureus populations were tested with seven commercialized cephalosporins. The strains were divided in five groups according to the following criteria: penicillinase production or not: sensitivity to methicillin and cephalosporins; RB type resistance to methicillin; RH and RO type resistance to every beta-lactamine (according to Chabbert and Baudens). For each cephalosporin studied, the population cell analysis performed with these different groups showed the constant heterogeneous arrangement of the individual MIC. However, whatever the staphylococcus group, cephaloridine remains the antibiotic that inhibits the largest number of cells at lower concentration than other cephalosporins. In vitro results were compared with pharmacokinetic data of the different cephalosporins.

Cefazolin↗
PubMed1976

[The resistance of "Pseudomonas" to antibiotics and heavy metal: minimal inhibitory concentrations and genetic transfers (author's transl)].

The antibiotic sensitivity of 43 strains of Pseudomonas and the minimal inhibitory concentration of mercurial derivatives (5 mineral salts and 4 organics compounds) and of silver nitrate to these microorganisms have been studied. Twelve of these strains were P. aeruginosa of hospital origin, and 31 were Pseudomonas from surface water. Resistance against these inhibitory substances let us to established some connections between the different strains. Some strains were selected to transfer resistance markers by conjugation.

Anti-Bacterial Agents↗