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J A Poupard

Publications and source records attributed to J A Poupard.

At least 19 recordsLinked to original sources
PubMed1997

Interpretive criteria for testing susceptibility of staphylococci to mupirocin.

To determine appropriate mupirocin susceptibility testing interpretive criteria, 177 staphylococci were tested by agar dilution, disk diffusion, and E test. E test was found to be a reliable method for determining susceptibility of staphylococci to mupirocin. The agar dilution and disk diffusion results were plotted on a scattergram, and error rates were calculated. No errors were found with susceptibility breakpoints of > or = 4 microg/ml (MIC) and > or = 14 mm (zone diameter).

Anti-Bacterial Agents↗
PubMed1996

Evaluation of 500 gram negative isolates to determine the number of major susceptibility interpretation discrepancies between the Vitek and MicroScan Walkaway for 9 antimicrobial agents.

Although the Vitek and MicroScan Walkaway are two of the most commonly used automated antimicrobial susceptibility test systems, few studies have been performed comparing discrepancies between these systems. In this study, 500 Gram negative clinical isolates were tested against ampicillin, ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanate, imipenem, ciprofloxacin, norfloxacin, mezlocillin, and piperacillin to determine the number of major interpretation discrepancies between the two systems. The 500 isolates consisted of 100 isolates each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Enterobacter species. Each isolate was tested simultaneously in both systems using the same standardized inoculum. Eighty-four major discrepancies occurred, of which 48 were reproducible. The reproducible discrepancy rate, for the 4,500 isolate/antimicrobic combinations tested, was 48 of 4500 (1.06%). The rate for individual antimicrobics varied from 17 of 500 (3.4%) for ampicillin to no discrepancies for ticarcillin or ciprofloxacin. Of the 48 reproducible discrepancies, 44 (92%) were Vitek resistant, MicroScan susceptible. Fifteen (31%) of the Vitek and 21 (44%) of the MicroScan results were confirmed by broth microdilution. Disk diffusion results were in agreement with 15 (31%) of the Vitek and 21 (44%) of the MicroScan results. Twelve (25%) of the broth microdilution and 12 (25%) of the disk diffusion results were intermediate. The broth microdilution and disk diffusion results for the 48 isolates with reproducible discrepancies were in agreement more often with MicroScan. However, there was less very major error comparing the Vitek results for these isolates to the broth microdilution and disk diffusion. Overall, the result of this evaluation indicate that the number of major interpretation discrepancies between the two systems is minimal for the isolate/antimicrobic combinations tested.

Ampicillin↗
PubMed1996

Stability of amoxicillin-clavulanate in BACTEC medium determined by high-performance liquid chromatography and bioassay.

The stabilities of amoxicillin (16 micrograms/ml) and clavulanate (8 micrograms/ml), alone and in combination in BACTEC medium (Middlebrook 7H12B medium), were determined by high-performance liquid chromatography (HPLC) and bioassay. By HPLC, the half-life of amoxicillin (trihydrate and sodium) in combination with clavulanate in nonradiolabelled 7H12B medium was 6.7 days, whereas the half-life of clavulanate in combination with amoxicillin was 2.0 days. By bioassay, the half-lives of amoxicillin trihydrate and clavulanate in radiolabelled 7H12B medium were comparable (7 and 2 days, respectively) to those determined by HPLC. When clavulanate was tested alone, the half-life was determined to be 1.88 days by HPLC and 1.87 days by bioassay. The relatively short half-life of clavulanate can be adjusted by a procedure of "topping up," or adding one-half the concentration of clavulanate every second day, in order to allow accurate amoxicillin-clavulanate MIC testing with the BACTEC mycobacterial susceptibility system.

Amoxicillin↗
PubMed1995

A survey of beta-lactamase-producing Haemophilus influenzae. An evaluation of 5750 isolates.

Previous studies have reported that 15%-34% of Haemophilus influenzae produce beta-lactamase. A surveillance program was developed by SmithKline Beecham Clinical Laboratories to determine the current percentage of beta-lactamase-producing H. influenzae from five selected geographic locations in the United States. In 1993, results of 5750 isolates from specimens submitted to five reference clinical laboratories were evaluated. Data were collected from 29 states and the District of Columbia. The percentages of beta-lactamase-producing H. influenzae was 33% and ranged from 22%-40% for the individual states.

Adolescent↗
PubMed1995

Susceptibilities of nontuberculosis mycobacterial species to amoxicillin-clavulanic acid alone and in combination with antimycobacterial agents.

Neither amoxicillin nor clavulanic acid used alone was active at the highest level tested, i.e., 256.0 micrograms/ml, in vitro against 24 isolates of Mycobacterium fortuitum, Mycobacterium kansasii, and Mycobacterium marinum. However, the MIC of an amoxicillin-clavulanic acid combination of 2:1 was < or = 8.0/4.0 micrograms/ml for 50 percent of the isolates tested, with all isolates being inhibited in the range of 4.0/2.0 to 32.0/16.0 micrograms/ml, respectively. Titration of amoxicillin-clavulanic acid with a fixed 2-micrograms/ml concentration of ethambutol resulted in synergistic activity against 3 of 9 isolates of M. fortuitum, 10 of 10 isolates of M. kansasii, and 5 of 5 isolates of M. marinum. This observation was confirmed in a checkerboard analysis in which fractional inhibitory concentrations were < or = 0.5 for 20 of the 24 isolates. Synergistic activity was observed against the other four isolates in one of two trials. On the other hand, titration of amoxicillin-clavulanic acid in the presence of either one or two fixed concentrations of isoniazid, rifampin, cycloserine, tetracycline, or amikacin failed to result in synergism.

Amoxicillin↗
PubMed1995

Update on mupirocin resistance.

Mupirocin inhibits the activity of bacterial isoleucyl-tRNA synthetase resulting in a decrease or cessation of protein synthesis. Expression of resistance in staphylococci has been divided arbitrarily into two groups, low level (minimum inhibitory concentrations [MIC] of between 8 and 256 mg/L) and high level (MICs of > or = 512 mg/L). Low level resistance is associated with spontaneous mutational events, while high level resistance is mediated by a large transferable plasmid. The introduction of a nasal formulation of mupirocin raises many issues concerning staphylococcal breakpoints, since 20,000 mg/L is applied to the mucosal surface to eradicate nasal colonisation with staphylococci, as opposed to eliminating infection. For several years after its introduction reports of resistance in staphylococci were rare. However, the contemporary literature indicates reports of resistance in select populations, particularly associated with dermatology patients. The overall rate of resistance for organisms isolated from the nares is currently unknown. The recent introduction of the E test combined with the 5 microgram screening disk may assist in determining resistance rates in large populations.

Anti-Bacterial Agents↗
PubMed1994

Comparison of mupirocin susceptibility of nasal and nonnasal Staphylococcus aureus isolates.

Susceptibilities of 414 nasal and 586 nonnasal Staphylococcus aureus isolates, both methicillin resistant and methicillin susceptible, to the topical antimicrobial agent mupirocin were compared. A susceptibility of 99.1% was observed for the 1000 isolates. Nasal and nonnasal isolates showed a similar 90% minimum inhibitory concentration (MIC90) and statistically equivalent percent susceptibilities.

Humans↗
PubMed1988

Evaluation of two commercially available test methods to determine the feasibility of testing for respiratory syncytial virus in a community hospital laboratory.

The feasibility of performing respiratory syncytial virus (RSV) testing in a community hospital laboratory was assessed. The Abbott RSV EIA Kit, an enzyme immunoassay (EIA), and the Ortho Respiratory Syncytial Virus Identification Reagent, a direct fluorescent antibody (DFA) technique, were evaluated in terms of technologist time, result time, cost, and agreement of results. There was little difference in the amount of technologist time required for either method. The DFA technique was shown to be much less expensive than the EIA method and also required at least 50% less time to generate a final result. When compared with an indirect fluorescent antibody technique, the EIA technique was more sensitive (87%) than the DFA method (81%). Both methods showed 100% specificity. Based on the findings of this study, the DFA technique was determined to be the more feasible method for a community hospital laboratory to use for the rapid detection of RSV.

Child↗
PubMed1972

Influence of nutrition on the morphology of a strain of Bifidobacterium bifidum.

A mucoid variant of Bifidobacterium bifidum was converted from its normal curved rod or bifid form to a highly branched form when grown in a chemically defined minimal medium. Branching could be prevented by the addition of a mixture of dl-alanine, dl-aspartic acid, l(+)-glutamic acid, and dl-serine, but not when any one of these four amino acids was omitted. Although sodium chloride induced pleomorphism, calcium ions were ineffective in suppressing the appearance of these pleomorphic forms. None of the cell wall precursors tested, viz., N-acetyl-d-glucosamine, alpha-epsilon-diaminopimelic acid, and muramic acid, inhibited branching.

Acetates↗