Standardisation of disk diffusion results for antibiotic susceptibility testing using the sirscan automated zone reader

BMC Microbiology

Erik C Böttger¹  Reinhard Zbinden¹  Michael Hombach¹ 

[1] Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 30/32, 8006 Zürich, Switzerland

关键词: Automation;    Kirby-Bauer;    Inhibition zone diameter;   

Others  :  1142895
DOI  :  10.1186/1471-2180-13-225

 received in 2013-04-06, accepted in 2013-10-03,  发布年份 2013

【 摘 要 】

Background

Standardisation of disk diffusion readings could improve reproducibility and accuracy of antibiotic susceptibility testing (AST). This study evaluated accuracy, reproducibility, and precision of automated inhibition zone reading using the “Sirscan automatic” zone reader (i2a, Perols Cedex, France).

Results

In a first step we compared Sirscan results with manual calliper measurements for comparability and accuracy. Sirscan readings were checked and adjusted on-screen as recommended by the manufacturer. One hundred clinical bacterial isolates representing a broad spectrum of organisms routinely isolated in a clinical laboratory were tested, and zone diameter values and interpretation according to EUCAST guidelines were compared. In a second step we analysed, whether fully automated zone reading can decrease standard deviation of diameter measurements and, thus, improve reproducibility and precision of the disk diffusion method. Standard deviations of manual measurements, on-screen adjusted Sirscan measurements, and fully automated Sirscan readings were compared for 19 repeat independent measurements of inhibition zones of S. aureus ATCC 29213, E. coli ATCC 25922, and P. aeruginosa ATCC 27853 (EUCAST quality control strains).

On-screen adjusted Sirscan and calliper measurements displayed high comparability. No significant differences were detected comparing the results of both reading methods. Standard deviations of inhibition zone diameters were significantly lower for fully automated Sirscan measurements compared with both adjusted Sirscan readings and the manual method, resulting in better reproducibility and precision of the automated readings.

Conclusions

Our results indicate that fully automated zone reading can further improve standardisation of AST by decreasing standard deviation and, thus, improve precision of inhibition zone diameter results.

【 授权许可】

   
2013 Hombach et al.; licensee BioMed Central Ltd.

【 参考文献 】

• [1]Bauer AW, Kirby WM, Sherris JC, Turck M: Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol 1966, 45:493-496.
• [2]Garrec H, Drieux-Rouzet L, Golmard JL, Jarlier V, Robert J: Comparison of nine phenotypic methods for detection of extended-spectrum beta-lactamase production by Enterobacteriaceae. J Clin Microbiol 2011, 49:1048-1057.
• [3]Lavallee C, Rouleau D, Gaudreau C, Roger M, Tsimiklis C, Locas MC, Gagnon S, Delorme J, Labbe AC: Performance of an agar dilution method and a Vitek 2 card for detection of inducible clindamycin resistance in Staphylococcus spp. J Clin Microbiol 2010, 48:1354-1357.
• [4]Tazi A, Reglier-Poupet H, Raymond J, Adam JM, Trieu-Cuot P, Poyart C: Comparative evaluation of VITEK 2 for antimicrobial susceptibility testing of group B Streptococcus. J Antimicrob Chemother 2007, 59:1109-1113.
• [5]Polsfuss S, Bloemberg GV, Giger J, Meyer V, Bottger EC, Hombach M: Practical approach for reliable detection of AmpC beta-Lactamase producing Enterobacteriaceae. J Clin Microbiol 2011, 49:2798-2803.
• [6]Wiegand I, Geiss HK, Mack D, Sturenburg E, Seifert H: Detection of extended-spectrum beta-lactamases among Enterobacteriaceae by use of semiautomated microbiology systems and manual detection procedures. J Clin Microbiol 2007, 45(4):1167-1174.
• [7]Woodford N, Eastaway AT, Ford M, Leanord A, Keane C, Quayle RM, Steer JA, Zhang J, Livermore DM: Comparison of BD Phoenix, Vitek 2, and MicroScan automated systems for detection and inference of mechanisms responsible for carbapenem resistance in Enterobacteriaceae. J Clin Microbiol 2010, 48:2999-3002.
• [8]Fiebelkorn KR, Crawford SA, McElmeel ML, Jorgensen JH: Practical disk diffusion method for detection of inducible clindamycin resistance in Staphylococcus aureus and coagulase-negative staphylococci. J Clin Microbiol 2003, 41:4740-4744.
• [9]Polsfuss S, Bloemberg GV, Giger J, Meyer V, Hombach M: Comparison of European Committee on Antimicrobial Susceptibility Testing (EUCAST) and CLSI screening parameters for the detection of extended-spectrum beta-lactamase production in clinical Enterobacteriaceae isolates. J Antimicrob Chemother 2012, 67:159-166.
• [10]Sanchez MA, Sanchez Del Saz B, Loza E, Baquero F, Canton R: Evaluation of the OSIRIS video reader system for disk diffusion susceptibility test reading. Clin Microbiol Infect 2001, 7:352-357.
• [11]Kolbert M, Chegrani F, Shah PM: Evaluation of the OSIRIS video reader as an automated measurement system for the agar disk diffusion technique. Clin Microbiol Infect 2004, 10:416-420.
• [12]Medeiros AA, Crellin J: Evaluation of the Sirscan automated zone reader in a clinical microbiology laboratory. J Clin Microbiol 2000, 38:1688-1693.
• [13]Nijs A, Cartuyvels R, Mewis A, Peeters V, Rummens JL, Magerman K: Comparison and evaluation of Osiris and Sirscan 2000 antimicrobial susceptibility systems in the clinical microbiology laboratory. J Clin Microbiol 2003, 41:3627-3630.
• [14]Andrews JM, Boswell FJ, Wise R: Evaluation of the Oxoid Aura image system for measuring zones of inhibition with the disc diffusion technique. J Antimicrob Chemother 2000, 46:535-540.
• [15]Korgenski EK, Daly JA: Evaluation of the BIOMIC video reader system for determining interpretive categories of isolates on the basis of disk diffusion susceptibility results. J Clin Microbiol 1998, 36:302-304.
• [16]Geiss HK, Klar UE: Evaluation of the BIOMIC video reader system for routine use in the clinical microbiology laboratory. Diagn Microbiol Infect Dis 2000, 37:151-155.
• [17]Clinical and Laboratory Standards Institute: Performance Standards for Antimicrobial Susceptibility Testing; Tweny-first Informational Supplement. CLSI document M 100-S 21 (ISBN 1-56238-742-1). Wayne, PA, USA: Clinical and Laboratory Standards Institute; 2011.
• [18]European Committee on Antimicrobial Susceptibility Testing: Breakpoint tables for interpretation of MICs and zone diameters. Version 1.3. 2011. http://www.eucast.org/antimicrobial_susceptibility_testing/previous_versions_of_tables/ webcite (1st March 2013, date last accessed
• [19]Hombach M, Böttger EC, Roos M: The critical influence of the intermediate category on interpretation errors in revised EUCAST and CLSI antimicrobial susceptibility testing guidelines. Clin Microbiol Infect 2013, 19:E59-E71.
• [20]Lestari ES, Severin JA, Filius PM, Kuntaman K, Offra Duerink D, Hadi U, Wahjono H, Verbrugh HA: Comparison of the accuracy of disk diffusion zone diameters obtained by manual zone measurements to that by automated zone measurements to determine antimicrobial susceptibility. J Microbiol Methods 2008, 75:177-181.
• [21]European Committee on Antimicrobial Susceptibility Testing: Reading guide. Version 2.0. http://www.eucast.org/fileadmin/src/media/PDFs/EUCAST_files/Disk_test_documents/Reading_guide_v_2.0_EUCAST_Disk_Test.pdf webcite (18th December 2012, date last accessed)