scholarly journals Proposed MIC quality control guidelines for National Committee for Clinical Laboratory Standards susceptibility tests using seven veterinary antimicrobial agents: ceftiofur, enrofloxacin, florfenicol, penicillin G-novobiocin, pirlimycin, premafloxacin, and spectinomycin.

1996 ◽  
Vol 34 (8) ◽  
pp. 2027-2029 ◽  
Author(s):  
S A Marshall ◽  
R N Jones ◽  
A Wanger ◽  
J A Washington ◽  
G V Doern ◽  
...  
1999 ◽  
Vol 123 (4) ◽  
pp. 285-289 ◽  
Author(s):  
Gary V. Doern ◽  
Angela B. Brueggemann ◽  
Michael A. Pfaller ◽  
Ronald N. Jones

Abstract Objective.—To assess the performance of clinical microbiology laboratories in the United States when conducting in vitro susceptibility tests with Streptococcus pneumoniae. Methods.—The results of a nationwide College of American Pathologists Proficiency Survey test sample, in which susceptibility testing of an isolate of S pneumoniae was performed, were assessed with respect to precision and accuracy. Results.—Wide variability was noted among participating laboratories with both minimum inhibitory concentration procedures and disk diffusion susceptibility tests when both methods were applied to S pneumoniae. Despite this high degree of variation, categorical interpretive errors were uncommon. Numerous laboratories reported results for antimicrobial agents that are not recommended by the National Committee for Clinical Laboratory Standards for tests with S pneumoniae. Conclusions.—Current susceptibility testing practices with S pneumoniae in the United States indicate limited precision and a tendency for laboratories to test and report results obtained with antimicrobial agents of questionable therapeutic value against this organism. Continued efforts to standardize susceptibility testing of S pneumoniae in the United States are warranted. In addition, modifications of existing interpretive criteria may be necessary.


2000 ◽  
Vol 38 (1) ◽  
pp. 453-455
Author(s):  
Brant A. Odland ◽  
Meredith E. Erwin ◽  
Ronald N. Jones

ABSTRACT This multicenter study proposes antimicrobial susceptibility (MIC and disk diffusion methods) quality control (QC) parameters for seven compounds utilized in veterinary health. Alexomycin, apramycin, tiamulin, tilmicosin, and tylosin were tested by broth microdilution against various National Committee for Clinical Laboratory Standards (NCCLS)-recommended QC organisms ( Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Streptococcus pneumoniae ATCC 49619, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853). In addition, disk diffusion zone diameter QC limits were determined for apramycin, enrofloxacin, and premafloxacin by using E. coli ATCC 25922, P. aeruginosa ATCC 27853, and S. aureus ATCC 25923. The results from five or six participating laboratories produced ≥99.0% of MICs and ≥95.0% of the zone diameters within suggested guidelines. The NCCLS Subcommittee for Veterinary Antimicrobial Susceptibility Testing has recently approved these ranges for publication in the next M31 document.


2000 ◽  
Vol 38 (9) ◽  
pp. 3457-3459 ◽  
Author(s):  
A. L. Barry ◽  
M. A. Pfaller ◽  
S. D. Brown ◽  
A. Espinel-Ingroff ◽  
M. A. Ghannoum ◽  
...  

Broth microdilution susceptibility tests of Candidaspecies have now been standardized by the National Committee for Clinical Laboratory Standards (NCCLS). An eight-laboratory collaborative study was carried out in order to document reproducibility of tests of Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258 by the NCCLS method. Replicate broth microdilution tests were used to define control limits for 24- and 48-h MICs of amphotericin B, flucytosine, fluconazole, voriconazole, ketoconazole, itraconazole, caspofungin (MK 0991), ravuconazole (BMS 207147), posaconazole (SCH 56592), and LY 303366.


1995 ◽  
Vol 6 (3) ◽  
pp. 157-160 ◽  
Author(s):  
Andrew E Simor ◽  
Anita Rachlis ◽  
Lisa Louie ◽  
Janet Goodfellow ◽  
Marie Louie

Objective: To determine the prevalence of resistance ofStreptococcus pneumoniaeto penicillin and other antimicrobial agents in metropolitan Toronto.Design: Consecutive pneumococcal isolates from different patients were obtained from two private community-based laboratories and from patients assessed in the emergency department of a tertiary-care teaching hospital in Toronto, Ontario between June and December 1993, and between March and October 1994. In vitro susceptibility testing was done by broth microdilution in accordance with National Committee for Clinical Laboratory Standards guidelines.Results: Twenty (7.3±3.1%) of 274 pneumococcal isolates were resistant to penicillin; six (30%) isolates had high-level resistance (minimal inhibitory concentration [mic] 2.0 μg/mL or greater); and 14 isolates had intermediate resistance (mic0.1 to 1.0 μg/mL). Penicillin-resistant strains were also frequently resistant to tetracycline (55%), cotrimoxazole (50%), erythromycin (40%) and cefuroxime (35%). Resistant strains comprised several serotypes: 19F (six isolates), 9V (three), 23F (three), and one each of 6A, 6B, 14, and 19A; four isolates were nontypeable.Conclusions: There has been a recent emergence of penicillin-resistantS pneumoniaein southern Ontario. National and regional surveillance is warranted to determine the extent of the problem elsewhere in Canada.


1998 ◽  
Vol 36 (3) ◽  
pp. 788-791 ◽  
Author(s):  
J. H. Jorgensen ◽  
M. L. McElmeel ◽  
S. A. Crawford

The MicroScan MICroSTREP panel is a recently marketed frozen broth microdilution panel for susceptibility testing of various streptococci, including Streptococcus pneumoniae. The panel contains 10 antimicrobial agents in cation-adjusted Mueller-Hinton broth supplemented with 3% lysed horse blood, similar in concept to the National Committee for Clinical Laboratory Standards (NCCLS) reference broth microdilution method for testing streptococci. A group of 210 isolates of S. pneumoniae were selected to include isolates with previously documented resistance to agents incorporated in the MICroSTREP panel, as well as recent invasive clinical isolates. All isolates were tested simultaneously with the MICroSTREP panel and an NCCLS reference panel whose drug concentrations were prepared to coincide with those of the MICroSTREP panel. Of the 210 isolates, 5 failed to grow in the MICroSTREP panel; 3 of those also did not grow in the reference panel. Essential agreement of MICs determined by the two methods (test MIC ± one dilution of the reference MIC) was 99.6% overall and ranged from 98.0% with chloramphenicol to 100% with penicillin, ceftriaxone, erythromycin, tetracycline, and vancomycin. There were no very major or major interpretive category errors resulting from the MICroSTREP panel tests. Minor interpretive category errors ranged from 12.2% with cefotaxime and 9.8% with ceftriaxone (due mainly to clustering of MICs for the selected strains near the breakpoints) to 0% with chloramphenicol and vancomycin. These results indicate that the MicroScan MICroSTREP frozen panels provide susceptibility results with pneumococci that are essentially equivalent to results derived by the NCCLS reference broth microdilution procedure.


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