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Biomedical subjects

J Fleurette

Publications and source records attributed to J Fleurette.

At least 73 records · Page 4Linked to original sources

Gas-liquid chromatographic analysis of cellular fatty acid methyl esters in Aeromonas species.

The cellular fatty acids of 39 strains belonging to the genus Aeromonas (Aeromonas hydrophila, Aeromonas caviae, Aeromonas sobria, Aeromonas media, Aeromonas schubertii, Aeromonas veronii) were determined by high resolution gas-liquid chromatography. The fatty acid profiles were characterized by major amounts (60% or more) of one saturated (hexadecanoic acid = 16:0) and two unsaturated (hexadecenoic acid = 16:1 and octadecenoic acid = 18:1) acids. While the majority of the strains of the six species exhibited, qualitatively, very similar fatty acid compositions, only minor and inconsistent differences could be observed which would be useful for a distinction of the different taxons. The following fatty acids were qualitatively identified: 12:0, i-13:0, 14:0, 3-OH 13:0, i-15:0, 15:0, 2-OH 14:0, 3-OH 14:0, i-16:0, 16:1, 16:0, i-17:1, i-17:0, a-17:0, 17:0 cyclopropane, 17:1, 17:0, 18:1 (3 isomers), 18:0 and i-20:0. Excellent congruence was found in reproducibility studies. Fatty acid analyses show a great homogeneity within the group and the technique does not appear to be the ideal method in distinguishing between Aeromonas species.

Aeromonas↗

An outbreak of pneumonia and meningitis caused by a previously undescribed gram-negative bacterium in a hot spring spa.

An outbreak of infection caused by a previously undescribed Gram-negative bacterium affected people attending a hot (37 degrees C) spring spa in France in 1987. Thirty-five case of pneumonia and two cases of meningitis occurred. None of these patients died. Attack rates were significantly higher for patients above 70 years old and for male patients. An epidemiological comparison of the 26 hospitalized cases with 52 matched controls suggests that spa treatment early on the first day (OR = 4.8) and attendance at the vapour baths (OR = 10.7) were significant risk factors for acquiring the infection. Person-to-person spread was not thought to have occurred. The same bacterium was isolated from the hot spring water. All strains studied shows a single rRNA gene restriction pattern. Epidemiological data indicated that the thermal water was the source of infection. This outbreak stresses the need for increased surveillance of infections in people attending hot spring spas.

Aged↗

Characterization of clinically significant isolates of Staphylococcus epidermidis from patients with cerebrospinal fluid shunt infections.

Biotyping, slime production, antibiograms, extrachromosomal DNA banding and total DNA restriction analysis were used to characterize Staphylococcus epidermidis strains causing cerebrospinal fluid shunt infections in 11 patients. Infections considered to be community acquired and those acquired in the first 2 weeks of hospital admission were due to oxacillin-susceptible isolates. Multiply resistant strains were isolated from patients who were in hospital for more than 1 month before tube implantation. Slime was detected in staphylococci for 54% of cases, but its expression varied. Strains from different patients could be differentiated from one another by the extrachromosomal DNA bandings and total DNA restriction patterns, but isolates from the same patient were usually similar. During the period of external drainage, epidemiological markers were useful in differentiating persistence of infection from contamination or re-infection by a new strain.

Adult↗

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↗

Description and evaluation of the semiautomated 4-hour ATB 32E method for identification of members of the family Enterobacteriaceae.

A study was performed to compare the rapid identification system ATB 32E (API-bioMérieux SA, La Balme-les-Grottes, France) with conventional biochemical methods for identifying 414 isolates of the family Enterobacteriaceae and the genus Aeromonas, mainly of clinical origin. Overall, 395 strains (95.4%) were correctly identified, with 48 (11.6%) requiring extra tests for complete identification. Ten strains (2.4%) were not identified, and nine (2.9%) were misidentified. The ATB 32E is a suitable alternative for rapid identification of members of the family Enterobacteriaceae.

Autoanalysis↗

Evaluation of API Coryne in comparison with conventional methods for identifying coryneform bacteria.

A study was performed to evaluate a new manual miniaturized system, API Coryne (API-bioMérieux, Inc., La Balme les Grottes, France), in which conventional biochemical methods were used to identify 240 isolates of coryneform and related bacteria. A total of 40% of the isolates were excluded from the study because they could not be identified by conventional methods. Identifications of the 240 isolates obtained with API Coryne showed a 97.6% concordance with conventional methods (79% after 24 h of incubation, 21% after 48 h of incubation): 158 (65.8%) isolates were identified with no further testing, and extra testing was required for 76 (31.8%) isolates. In three (1.2%) cases, the organisms did not correspond to any key in the code book and could not be identified by the computer service of the manufacturer. Only three (1.2%) strains were misidentified. The system was shown to be reliable and rapid when compared with standard identification methods.

Bacteriological Techniques↗

Detection of flagella in 278 Legionella strains by latex reagent sensitized with antiflagellum immunoglobulins.

To determine whether all Legionella species show common flagellum antigen properties, we developed a reagent using latex beads sensitized with flagellin-specific immunoglobulins that could be used in a simple and rapid agglutination reaction to identify Legionella colonies. A total of 278 strains (68 Legionella reference strains and 210 patient and environmental isolates) were tested. The results were compared with those obtained by a direct immunofluorescence assay using an antiflagellum serum and by morphological observations by electron microscopy. The immunological methods based on the use of a flagellum-specific serum have confirmed the presence of a common flagellum antigen for all Legionella species described to date. Flagella were detected for all the legionellae studied except four species: L. oakridgensis, confirmed as a nonflagellate species; L. brunensis; L. cincinnatiensis; and L. longbeachae serogroup 1. However, we noted a remarkable variability in flagellum expression, of greater or lesser degree, according to the species and their origin. A combination of all three methods of flagellum detection revealed that 86.3% of Legionella strains studied were flagellate. The latex test identified 89.6% of these strains, 97.5% of L. pneumophila, and 100% of L. pneumophila serogroup 1.

Antigens, Bacterial↗

Molecular epidemiology of Staphylococcus haemolyticus strains isolated in an Albanian hospital.

A recent outbreak of erythroderma in young children in an Albanian hospital was investigated. The etiology was not established, but Staphylococcus haemolyticus was frequently isolated from the affected children and from staff working in the same unit. Possible relationships among the isolates were investigated by using classical techniques (biotype, antimicrobial susceptibility, and extrachromosomal DNA pattern) and by restriction endonuclease analysis (REA) of total DNA. Control isolates of proven pathogenicity from hospitalized patients in Lyon, France were subjected to the same procedures. Distinct REA patterns were obtained after digestion with two enzymes in 7 of 10 isolates from five affected children. Six distinct patterns were observed in nine isolates from six staff members; two REA patterns from patient isolates and two from staff members were identical, and these were distinguishable by the other markers examined. Only two different REA patterns were found in the pathogenic control isolates despite the use of a third additional enzyme. Again, the isolates with the same REA patterns could be distinguished by their plasmid profile or antimicrobial resistance profile. REA of total DNA used in combination with other markers indicated that the Albanian isolates differed considerably, whereas the French pathogenic isolates showed little variability.

Albania↗

[In vitro activity of beta-lactam antibiotics in combination with sulbactam against enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter. Results of a multicenter study].

The in vitro antimicrobial activity of ticarcillin (TICAR), mezlocillin (MEZLO), piperacillin (PIPER), cefoperazone (CPZ), cefotaxime (CTX) and ceftazidime (CAZ), alone and in combination with 8 micrograms/ml of sulbactam (SULB), was studied by agar dilution against TICAR resistant strains isolated in 8 hospitals over a period of 3 months in 1989 (747 enterobacteria, 110 Ps. aeruginosa and 48 Acinetobacter sp.). SULB did not modify the activity of beta-lactam antibiotics against Ps. aeruginosa. The 6 beta-lactam antibiotics SULB combinations were only active for 27% of Acinetobacter SULB sensitive. SULB restored the activity of: MEZLO, PIPER, CPZ in Enterobacteria producing a penicillinase; PIPER, CTX and CAZ in Enterobacteria producing a broad-spectrum beta-lactamase; MEZLO, PIPER, CTX and CAZ in M. morganii producing a derepressed cephalosporinase.

Acinetobacter↗

Plasmid profiles and genomic DNA restriction endonuclease patterns of 30 independent Staphylococcus lugdunensis strains.

Extrachromosomal DNA analysis and restriction endonuclease analysis of whole cellular DNA were used to characterize 30 Staphylococcus lugdunensis strains isolated from 13 different hospitals from 1977 to 1988. All the strains were susceptible to most of the antibiotics tested, including penicillin G. A single 3.2 kilobase plasmid was detected in 13 strains and one or two plasmids, ranging from 2.3 to 6.6 kilobases, were found in 7 strains. EcoRI, PstI and PvuII restriction patterns of total cellular DNA were identical for 23 isolates, indicating strong conservation of endonuclease sites in this species. One or two additional DNA bands occurred in seven isolates. Molecular markers show rather little variations between different S. lugdunensis isolates suggesting that they are closely related.

DNA Restriction Enzymes↗

Cefazolin and netilmicin serum levels during and after cardiac surgery with cardiopulmonary bypass.

The kinetics of cefazolin and netilmicin were studied in 10 patients undergoing elective cardiac surgery with hemodilution and cardiopulmonary bypass (CPB). During surgery, but before CPB, cefazolin, 25 mg/kg, and netilmicin, 2 mg/kg, were administered intravenously over 30 minutes. For the 48-hour period following CPB, cefazolin, 25 mg/kg, and netilmicin, 1 mg/kg, were administered intravenously every 8 hours. Initiation of CPB was accompanied by a 28% to 30% decrease in hematocrit and serum antibiotic levels. At the conclusion of surgery, cefazolin and netilmicin serum levels were 41 +/- 12 micrograms/L and 2.5 +/- 0.6 micrograms/mL (mean +/- SD), respectively. During the postoperative period, cefazolin levels were consistently greater than the minimum inhibitory concentration (MIC) for sensitive bacteria (4 micrograms/mL); average netilmicin levels were greater than MIC of sensitive bacteria (2 micrograms/mL) for 2 hours after antibiotic infusion. The netilmicin trough levels were 0.6 +/- 0.5 micrograms/mL. Pharmacokinetic parameters were determined using a model-independent method, and gave the following results during surgery: cefazolin--elimination half-life, 231 minutes, total body clearance, 1.05 mL/kg/min, and steady-state volume of distribution, 243 mL/kg. The values for netilmicin were 249 minutes, 1.18 mL/kg/min, and 353 mL/kg, respectively. Postoperatively there were no significant changes in the disposition of cefazolin, but the elimination half-life of netilmicin was shorter (124 minutes, P less than 0.01) and the total body clearance greater (3.58 mL/kg/min, P less than 0.01) than during surgery.

Adolescent↗

Relationship between free amoeba and Legionella: studies in vitro and in vivo.

In 1980, Robowtham demonstrated that Legionella multiplies in free amoeba cytoplasm and hypothesized that the amoeba could act as a reservoir of virulent bacteria. In this paper we report various aspects of the relationship between amoeba and Legionella. A liquid medium co-culture method was applied to Acanthamoeba sp. and Legionella pneumophila serogroup 1. Within 4 days, Legionella growth increased by 2 log s CFU/ml. Using a direct immunofluorescence assay and electron microscopy, Legionella was shown to grow abundantly inside phagosomes, and bacteria and/or antigen were present on the cytoplasmic membrane of the amoeba. These aspects are very similar to those observed with Legionella-infected alveolar macrophages. The morphology and structure of Legionella cells were modified after 20 days of co-culture: - viable bacteria showed large fatty cytoplasmic inclusions, - gas liquid chromatography analysis demonstrated a decrease in the i16:0 fatty acid ratio. Cystic forms of amoeba were abundant but none contained viable Legionella. In an in-vivo study using a guinea-pig aerosol infection model, we compared the virulence of Legionella in co-culture with Legionella grown on charcoal dialysed yeast extract (CDYE) agar medium. The Legionella obtained by co-culture had an LD 50 (50% lethal dose) similar to that obtained for those grown on CDYE, showing that bacterial virulence is preserved in the cellular model.

Acanthamoeba↗

International collaborative evaluation of the ATB 32 staph gallery for identification of the Staphylococcus species.

This international collaborative study evaluates a new system (ATB 32 Staph) for the identification of staphylococci taking into account the new novobiocin-sensitive and -resistant species reported. This study involved eight laboratories and 792 strains were tested. The reproducibility obtained for the cumulative results of the inter- and intra-laboratory tests was more than 90%. For 713 strains relevant of a species 95.5% were correctly identified by the system. Eight strains (1.2%) were misidentified and 24 strains (3.3%) were not identified. For 79 strains initially considered as not-classified, 62% were identified at the species level by the new system. The newer ATB 32 Staph gallery is a performant and useful method for routine identification of the currently described staphylococci species from clinical and animal origin.

Animals↗

Instability of characteristics amongst coagulase-negative staphylococci causing endocarditis.

Variation in typing of clinically significant isolates of coagulase-negative staphylococci (CNS) was determined by five typing methods with 143 isolates obtained from 19 patients over periods from 2 days to 1 year. In only one case did all isolates give exactly the same typing pattern by all five tests. No single method, or simple combination, provided a ready means of confirming the relatedness of separate isolates. The most frequently useful tests were antibiotic susceptibility and extrachromosomal DNA banding patterns. However, the results of biotyping, serotyping and phage typing were also helpful in showing the relationship between different isolates from a given patient. In most cases a core pattern varying by the gain or loss of a small number of features, characterised a given patient's isolates. In two causes, apparently radical changes in the infecting organism were observed, and confirmed by restriction endonuclease analysis. Care should be taken when successive isolates of CNS show distinct typing differences in deciding their clinical relevance.

Anti-Bacterial Agents↗

Detection of hippurate hydrolysis by Legionella spp. by using a rapid high-performance liquid chromatography method.

A rapid high-performance liquid chromatography method was developed to determine hippurate hydrolysis by Legionella spp. Benzoic acid, an end product of enzymatic activity, was directly detected by high-performance liquid chromatography after 1 and 24 h of incubation in 1% sodium hippurate. Because of its sensitivity, this procedure offers more precise identification of some Legionella spp.

Chromatography, High Pressure Liquid↗

[Comparison of two systems for identifying coliform enterobacteria newly described or rarely found in clinical practice].

The API 20 EC and ATB 32 GN identification systems were compared for their ability to identify 231 coliform bacteria strains. Agreement with the identification given by conventional methods was achieved for 96.1 p. cent of strains by the API 20 EC gallery and for 95.9 p. cent by the ATB 32 GN system. Complementary tests were needed to identify 9.5 p. cent of strains using the API 20 EC system but 30.3 per cent using the ATB 32 GN system.

Bacteriological Techniques↗

[In vitro antibacterial activity of lomefloxacin, a new fluoroquinolone, against hospital strains. Results of a multicenter study].

Minimal inhibitory concentrations (MICs) of lomefloxacin (LOM) was determined by agar dilution for 2,819 bacterial strains isolated in 1988 in 9 university hospitals. Activity of LOM against nalidixic acid (NAL) susceptible (S) Enterobacteriaceae was close to that of pefloxacin (PEF) (mode MIC: 0.12-0.25 micrograms/ml); like for PEF, this activity was reduced against NAL resistant (R) Enterobacteriaceae (mode MIC: 4). MICs of LOM against P. aeruginosa were between 0.5 and 16 (mode: 2). LOM had also a good activity against NAL S A. baumannii (mode MIC: 0.5) but this activity is reduced against NAL R Acinetobacter (MICs : 4 to 128). LOM was highly active against Haemophilus (mode MIC: 0.06), Gonococci (mode MIC: 0.008), Meningococci (mode MIC: 0.03), Branhamella (mode MIC: 0.12-0.25). LOM showed activity similar to PEF against methicillin susceptible Staphylococci (mode MIC: 0.5-1); the resistant strains are usually methicillin resistant. Similar to the currently available quinolones, LOM is less effective against L. monocytogenes (mode MIC: 8), Enterococci (mode MIC: 4), Streptococci (mode MIC: 4) and Pneumococci (mode MIC: 8). Finally, for the anaerobic bacteria, LOM is more active against Clostridium perfringens (mode MIC: 1) than against Bacteroides fragilis (mode MIC: 32).

4-Quinolones↗