Biomedical subjects

H Meugnier

Publications and source records attributed to H Meugnier.

34 records · Page 2Linked to original sources

PubMed1994

Clonal study of enterotoxin-B producing strains of Staphylococcus aureus.

Sixty-nine Staphylococcus aureus strains, 39 of which produced staphylococcal enterotoxin B (SEB+) and 14 of which were associated with toxic shock (TS+), were studied using the following markers: serotyping, phage typing, antibiotyping, ribotyping, zymotyping and pulsed-field electrophoresis typing. Analysis of the results showed that the enterotoxin B producing strains were derived from at least three clones: the first two consisted of methicillin-susceptible strains, while the third included the methicillin-resistant (MRSA) strains. TS+ strains of nongenital origin appeared to be distributed between the three clones, with no specific characters.

Bacteriophage Typing↗

PubMed1993

rRNA gene restriction patterns as an epidemiological marker in nosocomial outbreaks of Staphylococcus aureus infections.

rRNA gene restriction patterns (ribotyping) were compared with phage typing, serotyping, enterotoxins and exfoliatin production in the analysis of 26 Staphylococcus aureus strains isolated from two different nosocomial outbreaks. Total DNA was cleaved by EcoRI restriction endonuclease. After agarose gel electrophoresis and Southern transfer, the hybridization of the membranes was done with radiolabelled 16S rRNA gene from Bacillus subtilis inserted into a plasmid vector. Six to 13 fragments were visualized. A core of common fragments was discerned for all strains tested. A full correlation between ribotyping and conventional markers was observed in only one of the outbreaks studied. In both outbreaks, ribotyping proved helpful in characterizing otherwise untypable strains.

Bacterial Typing Techniques↗

PubMed1993

Chemotaxonomy and molecular taxonomy of some coryneform clinical isolates.

Six reference strains of the genus Brevibacterium as well as fifteen clinical isolates tentatively assigned to the genus using conventional biochemical methods, were the subject of chemotaxonomic and DNA similarity studies. Five of these clinical isolates were assigned either to the genera Aureobacterium, Mycobacterium, Gordona or to Rhodococcus on the basis of their DNA mol% G+C, mycolic acid, amino-acid, sugar and menaquinone contents. Among the ten remaining strains, six were not brevibacteria and only four conformed to the description of the genus Brevibacterium sensu stricto. These strains showed low values of DNA relatedness with Brevibacterium epidermidis ATCC 35514T and Brevibacterium linens ATCC 9174, and could only be described as Brevibacterium spp. The results indicate that studies of chemical markers are essential for the correct identification of brevibacteria.

Bacterial Typing Techniques↗

PubMed1993

Identification of Staphylococcus aureus using a DNA probe: Accuprobe.

A non-isotopic nucleic probe (Accuprobe) has been presented recently by Gen-Probe for the direct specific 1-h identification of Staphylococcus aureus isolated from culture. 50 S aureus strains previously characterized by conventional methods as well as 26 atypical strains (absence of coagulase, thermonuclease and fibrinogen affinity factor) were tested. Moreover, the Accuprobe system was evaluated using 29 other staphylococcal type strains representing all the species described to date. Only the strains that belonged to the S aureus species, including the 26 atypical strains, were detected by Accuprobe, which proved to be a rapid specific mean of identifying S aureus strains, particularly those that are not readily identified by conventional methods.

DNA Probes↗

PubMed1992

Identification of coagulase negative staphylococci isolated from lambs as Staphylococcus caseolyticus.

A group of 17 strains of coagulase negative staphylococci isolated from slaughtered lambs, and which could not be identified with the conventional methods, exhibited high levels of DNA homology (92%) with the S. caseolyticus reference strain. The isolates described in this study provide a more extensive comprehension of S. caseolyticus. The original description of this species was based on only two strains isolated from milk. To our knowledge, S. caseolyticus had never been previously associated with animal microflora.

Abscess↗

PubMed1991

Ofloxacin pharmacokinetics in mechanically ventilated patients.

The pharmacokinetics of ofloxacin were studied in 12 intensive care patients, 6 of whom were under controlled mechanical ventilation. All patients had a creatinine clearance of greater than 80 ml/min per 1.73 m2. They were given 3 mg of ofloxacin per kg of body weight intravenously at a constant flow rate in 30 min twice a day for 7 days. Pharmacokinetic studies were performed on days 1 and 7. Between days 1 and 7, significant increases in the alpha (distribution) and beta (elimination) phase half-lives, the area under the serum concentration-time curve, and peak and trough levels in serum were observed, together with a marked decrease (greater than 50%) in total body clearance. Possible contributing factors for alteration of ofloxacin pharmacokinetics in ventilated patients were patient age, liver dysfunction, drug interaction, and drug accumulation in a deep compartment. This study shows that in intensive care patients the pharmacokinetics of ofloxacin differ from those reported for healthy volunteers.

Critical Care↗

PubMed1990

[Modification of ofloxacin pharmacokinetics induced by prolonged mechanical ventilation].

The pharmacokinetics of ofloxacin was studied in 12 intensive care patients, 6 of whom being under mechanical ventilation. All patients had a creatinine clearance greater than 60 ml/min/1.73 m2 and they were given 3 mg/kg. IV ofloxacin within 30 mn, with a twice daily regimen for 7 days. Pharmacokinetic studies were performed on day 1 (D1) and 7 (D7). Between D1 and D7 a significant increase in T 1/2 beta, AUC and blood levels were observed together with a decrease in total body clearance. Creatinine clearance was not modified between D1 and D7 but ofloxacin renal clearance was considerably altered. Abnormalities in ofloxacin renal tubular secretion may account for the drug cumulation which was observed during repeated administration in intensive care patients.

Aged↗

PubMed1989

Determination of G + C content of DNA using high-performance liquid chromatography for the identification of staphylococci and micrococci.

The guanine-plus-cytosine (G + C) content of different species of Staphylococcus and Micrococcus was determined by high-performance liquid chromatography. Purified bacterial DNA was hydrolysed by nuclease P1. The nucleotides were separated by chromatography and quantified by measurement of the optical density at 260 nm. The G + C content of staphylococci ranged from 31.5 to 37.9 moles %, and that of micrococci from 68.7 to 75.2. Most of our results were comparable to those obtained with the thermal method.

Chromatography, High Pressure Liquid↗

PubMed1989

Legionella gratiana sp. nov. isolated from French spa water.

During an epidemiologic survey, an unidentified strain of Legionella was isolated from water of a thermal spa in France. The strain (Lyon 8420412) had the cultural and biochemical characteristics typical of the genus Legionella. In direct immunofluorescence tests, the strain reacted weakly with fluorescein-conjugated antisera prepared against L. bozemanii serogroups 1 and 2, L. longbeachae serogroups 1 and 2 and L. anisa, and failed to react with sera prepared against 36 other species or serogroups. A fluorescein-conjugated antiserum prepared against strain Lyon 8420412 reacted strongly with the homologous strain and only weakly with the above-mentioned species. The cell-wall fatty acid profile, with a predominance of hexadecenoic (16:1) and hexadecanoic (16:0) acids, ubiquinone Q10 as the major quinone and a characteristic protein electrophoresis profile suggested that the isolate was different from other Legionella species. In DNA-DNA hybridization experiments, the strain was distinct from all named Legionella species, and from all unnamed species currently under study at the Centers for Disease Control. The name Legionella gratiana is proposed for the new species (type strain Lyon 8420412; CDC 1242). A serologic survey of antibodies reacting against L. gratiana indicated that personnel or patients at the spa therapy centre where the organism was isolated had higher antibody titres than a control population.

Antibodies↗

PubMed1989

[Peptidoglycan modification of Staphylococcus aureus P18 strain after use of 6 active antibiotics on the bacterial wall].

Six antibiotics active on the cell-wall were tested against a methicillin resistant Staphylococcus aureus P18 strain at the start of exponential growth rate. The concentration was four-fold the MIC determined in a non-hypersaline liquid medium. The peptidoglycan amino-acid content of the various cell wall samples was determined. An antibiotic-free S. aureus P18 and the methicillin-sensitive Cowan I. S. aureus strain were used a controls. Beta lactam antibiotic treatment, oxacillin and cephalothin, induced an increase of alanine content which suggests that only secondary-transpeptidation did not occur. Similar results were obtained using vancomycin. Amino-acid content was not modified by bacitracin, which is in agreement with the results expected. The results obtained for fosfomycin and cefamandole were not easy to interpret.

Anti-Bacterial Agents↗

PubMed1988

Comparative efficacy of five antibiotics on experimental airborne legionellosis in guinea-pigs.

The efficacy of preventive and curative treatment of experimental airborne legionellosis in guinea-pigs was studied for erythromycin, rifampicin, minocycline, doxycycline and pefloxacin. The aerosol was produced from a strain of Legionella pneumophila serogroup 1 and dispersed in a chamber maintained below atmospheric pressure. Guinea-pigs were exposed for 30 min to 1 or 10 LD50 (10(3) or 10(4) viable inhaled organisms). Treatment was preventive or curative. Antibiotic concentrations in lungs and serum were evaluated during treatment. The action of the antibiotics on guinea-pigs infected by 1 LD50 resulted in 100% survival. For the 10 LD50 infection, pefloxacin, minocycline and erythromycin were more active (with 87.5% survivors) than doxycycline (75%) and rifampicin (62.5%). Preventive treatment with pefloxacin or doxycycline gave 100% protection, compared with 87.5% for rifampicin, 50% for erythromycin and 37.5% for minocycline. In this study, treatment of experimental legionellosis was improved, compared with previous publications, by early administration of antibiotics and increased dosage and duration.

Animals↗

PubMed1987

Recovery of pefloxacin in saliva and feces and its action on oral and fecal floras of healthy volunteers.

Pefloxacin, a new fluoroquinolone, was given to 10 volunteers in single 400-mg oral doses repeated at 12-h intervals during 7 days. Serum, saliva, and feces samples were collected before and at appropriate intervals after the initiation of treatment. Drug concentrations were determined by bioassay. Qualitative and quantitative analyses of the saliva and fecal floras were performed. Mean concentrations in saliva (3.46 micrograms/ml on day 1 and 7.54 micrograms/ml on day 7) were closely related to levels in serum. High concentrations of pefloxacin were found in the feces (645 micrograms/g on day 8). No modification of oral flora was observed. In the fecal flora, members of the family Enterobacteriaceae were eliminated between days 2 and 8. The alterations in streptococci and anaerobic flora were not significant; Bacteroides fragilis was more resistant to pefloxacin after treatment. Clostridium difficile was not detected, and there was no overgrowth by yeasts. No side effects were observed.

Bacteria↗

PubMed1987

Septicemia caused by Sphingobacterium multivorum.

Sphingobacterium multivorum was isolated in pure culture from the blood of a man undergoing chemotherapy for a lymphoma. He responded to appropriate antibiotics and later showed a significant rise in specific serum antibodies. Carbon substrate assimilation tests and fatty acid analysis proved useful in identifying the organism precisely.

Anti-Bacterial Agents↗

PubMed1987

[Pharmacokinetics of ceftriaxone in hemodialysis].

The influence of hemodialysis on the pharmacokinetics of ceftriaxone was studied in 5 patients with chronic renal failure, with a glomerular filtration rate of less than 5 ml/min, and treated by regular hemodialysis. A single dose of 2 g ceftriaxone was administered IV at the end of a hemodialysis, and venous samples were drawn 12 and 24 h thereafter. Two hemodialysis were performed at the 44th (HD1) and the 92nd (HD2) hour, and blood samples were drawn simultaneously on arterial and venous sides of the dialyzer at the onset of HD1 and at the end of HD2. Plasma ceftriaxone concentrations were measured on each sample by both microbiological and chromatographic (HPLC) methods. In these patients, ceftriaxone kinetics are considerably longer than in normal subjects, with an elimination half-life of 16 h, an apparent distribution volume of 800 ml/kg, but without decrease of plasma clearance, except in one patient who had hepatic cytolysis at the time of injection. Plasma concentrations on both sides of dialyzers, or before and after hemodialysis, are not significantly different, and the mean hemodialysis clearance ranges between 26 and 30 ml/min/m2 dialyzer area. According to these data, the dose-interval between successive administrations of ceftriaxone 2 g IV should be 48 h in patients with chronic renal failure, and supplemental doses do not appear necessary after hemodialysis.

Adult↗

PubMed1987

[Diffusion of ceftriaxone in the renal parenchyma].

Diffusion of ceftriaxone in renal parenchyma after IV injection (2 g) was studied in six patients with normal renal function, undergoing nephrectomy. Cortex and medulla of the kidney were studied. Blood samples, tissular fragments and urine were studied for drug concentration using HPLC and microbiologic assay 1, 12 and 24 h after injection. Both methods led to similar results. No difference in drug concentration was found between cortex and medulla. Tissular concentration of ceftriaxone remain higher than MIC for most Enterobacteriaceae strains until 24 h.

Adult↗

PubMed1987

[Doxycycline treatment of experimental legionellosis in guinea pigs infected by aerosol].

The efficacy of curative and preventive treatment by doxycyclin was studied with the same experimental model as during the study of erythromycin [14]. The infectious aerosol was done with a strain of Legionella pneumophila serogroup 1, Philadelphia (ATCC 33152). Male albinos Dunkin-Hartley guinea-pigs were exposed for 30 min to an aerosol dose of 1, 10 or 100 LD 50 (10(3), 10(4) or 10(5) viable organisms). After preliminary assays to find out the efficient posology, doxycyclin was administered intraperitoneally (IP) 18 h after the infection at a dosage of 60 mg/kg/day for 5 days in the animals infected with 1 LD 50, and 75 mg/kg/day in the animals with 10 and 100 LD 50. The preventive treatment (75 mg/kg/day) administered one day before and the day of the infection was tested with animals infected with 10 LD 50. The guinea-pigs were observed 8 days (weight, rectal temperature) and watched over 3 weeks after the end of treatment; serological and bacteriological tests (cardiac blood, lungs, spleen) were performed in every animal; doxycyclin assays (serum, lungs) during treatment were performed by high performance liquid chromatography (HPLC). The treatment of guinea-pigs infected by 1, 10 and 100 LD 50 gave a survival rate of 100%, 75% and 50% respectively. On the other hand the animals which received preventive treatment were all survivors. Seroconversions with antibody titres from 64 to 512 were observed for all the survivors. Bacteriological tests were all negative. The mean doxycyclin concentrations in serum (microgram/ml) and lung (microgram/g) were 1.66 and 11.42 after 24 h of treatment and 5.71 and 18.93 after 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗