Chapter 70 : Susceptibility Test Methods: General Considerations

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The main objective of susceptibility testing is to predict the outcome of treatment with the antimicrobial agents tested. The test results are generally reported to the treating physician, using the categories of susceptible, intermediate, and resistant. From the laboratory perspective, the key decisions involve the selection of a susceptibility testing method and the antimicrobial agents to be tested for each specimen and pathogen type. The principal methods used internationally are those of the Clinical and Laboratory Standards Institute (CLSI), based in the United States, and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Both organizations have a sophisticated approach to the setting of breakpoints (interpretive criteria) which permit the categorization of the susceptibility test results. This approach includes the collation and analysis of MIC distribution data, pharmacokinetic and pharmacodynamic data and associated target values, and clinical and bacteriological response rates from prospective clinical trials. This analysis is followed by the correlation of MICs and zone diameter distributions in order to establish breakpoints for commonly used methods. Modern susceptibility testing methods are often supplemented by specialized phenotypic and/or molecular testing to ensure that critical resistances and resistance mechanisms are detected.

Citation: Turnidge J. 2015. Susceptibility Test Methods: General Considerations, p 1246-1252. In Jorgensen J, Pfaller M, Carroll K, Funke G, Landry M, Richter S, Warnock D (ed), Manual of Clinical Microbiology, Eleventh Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817381.ch70
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Comparison of zone diameters with MICs of a hypothetical antimicrobial agent. doi:10.1128/9781555817381.ch70.f1

Citation: Turnidge J. 2015. Susceptibility Test Methods: General Considerations, p 1246-1252. In Jorgensen J, Pfaller M, Carroll K, Funke G, Landry M, Richter S, Warnock D (ed), Manual of Clinical Microbiology, Eleventh Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817381.ch70
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1. Rex JH,, Pfaller MA. 2002. Has antifungal susceptibility testing come of age? Clin Infect Dis 35:982989.
2. MacGowan AP,, Wise R. 2001. Establishing MIC breakpoints and the interpretation of in vitro susceptibility tests. J Antimicrob Chemother 48(Suppl S1):1728.
3. Clinical and Laboratory Standards Institute. 2010. Methods for Antimicrobial Dilution and Disk Susceptibility Testing of Infrequently-Isolated or Fastidious Bacteria. Approved Guideline, M45-A2. Clinical and Laboratory Standards Institute, Wayne, PA.
4. Clinical and Laboratory Standards Institute. 2012. Performance Standards for Antimicrobial Disk Susceptibility Tests. Approved Standard M2-A11. Clinical and Laboratory Standards Institute, Wayne, PA.
5. Clinical and Laboratory Standards Institute. 2014. Performance Standards for Antimicrobial Susceptibility Testing. Supplement M100-S24. Clinical and Laboratory Standards Institute, Wayne, PA.
6. European Committee on Antimicrobial Susceptibility Testing. 2012. Antimicrobial Susceptibility Testing. EUCAST Disk Diffusion Test Methodology. http://www.eucast.org/antimicrobial_susceptibility_testing/disk_diffusion_methodology.
7. European Committee on Antimicrobial Susceptibility Testing. 2014. Clinical Breakpoints. http://www.eucast.org/clinical_breakpoints.
8. Andrews JM,, Boswell FJ,, Wise R. 2000. Evaluation of the Oxoid Aura image system for measuring zones of inhibition with the disc diffusion technique. J Antimicrob Chemother 46:535540.
9. Lestari ES,, Severin JA,, Filius PM,, Kuntaman K,, Offra Duerink D,, Hadi U,, Wahjono H,, Verbrugh HA, Antimicrobial Resistance in Indonesia: Prevalence and Prevention (AMRIN). 2008. Comparison of the accuracy of disk diffusion diameters obtained by manual zone measurements to that by automated zone measurements to determine antimicrobial susceptibility. J Microbiol Methods 75:177181.
10. Geiss HK,, Klar UE. 2000. Evaluation of the BIOMIC video reader system for routine use in the clinical microbiology laboratory. Diagn Microbiol Infect Dis 37:151155.
11. Nijs A,, Cartuyvels R,, Mewis A,, Peeters V,, Rummens JL,, Magemrman K. 2003. Comparison and evaluation of Osiris and Sirscan 2000 antimicrobial susceptibility systems in the clinical microbiology laboratory. J Clin Microbiol 41:36273630.
12. Citron DM,, Ostoravi MI,, Karlsson A,, Goldstein EJC. 1991. Evaluation of the E test for susceptibility testing of anaerobic bacteria. J Clin Microbiol 29:21972203.
13. Clinical and Laboratory Standards Institute. 2007. Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria. Approved Standard M11-A7. Clinical and Laboratory Standards Institute, Wayne, PA.
14. Jorgensen JH. 1993. Selection criteria for an antimicrobial susceptibility testing system. J Clin Microbiol 31:28412844.
15. Jorgensen JH,, Ferraro MJ,, McElmeel ML,, Spargo J,, Swenson JM,, Tenover FC. 1994. Detection of penicillin and extended-spectrum cephalosporin resistance among Streptococcus pneumoniae clinical isolates by use of the E test. J Clin Microbiol 32:159163.
16. Craig WA,. 2002. Pharmacodynamics of antimicrobials: general concepts and applications, p 122. In Nightingale CH,, Murakawa T,, Ambrose PG (ed), Antimicrobial Pharmacodynamics in Theory and Clinical Practice. Marcel Dekker, New York, NY.
17. Doern GV,, Brecher SM. 2011. The clinical predictive value (or lack thereof) of the results of in vitro antimicrobial susceptibility tests. J Clin Microbiol 49:S11S14.
18. Schreckenberger PC,, Binnicker MJ. 2011. Optimizing antimicrobial susceptibility reporting. J Clin Microbiol 49:S15S19.
19. Chen JR,, Lee SY,, Yang BH,, Lu JJ. 2008. Rapid identification and susceptibility testing using the VITEK 2 system using culture fluids from positive BacT/ALERT blood cultures. J Microbiol Immunol Infect 41:259264.
20. Lupetti A,, Barnini S,, Catagna B,, Nibbering PH,, Campa M. 2010. Rapid identification and antimicrobial susceptibility testing of Gram-positive cocci in blood cultures by direct inoculation into the BD Phoenix system. Clin Microbiol Infect 16:986991.
21. Nguyen DT,, Yeh E,, Perry S,, Luo RF,, Pinsky BA,, Lee BP,, Sisodiya D,, Baron EJ,, Banaei N. 2010. Real-time PCR testing for mecA reduced vancomycin usage and length of hospitalization for patients infected with methicillin-sensitive staphylococci. J Clin Microbiol 48:785790.
22. Wimmer JL,, Long SW,, Cernich P,, Land GA,, Davis JR,, Musser JM,, Olsen RJ. 2012. Strategy for rapid detection and antibiotic susceptibility testing of Gram-negative bacteria directly recovered from positive blood cultures using the Bruker MALDI Biotyper and the BD Phoenix system. J Clin Microbiol 50:24522454.
23. Romero-Gómez MP,, Gómez-Gil R,, Paño-Pardo JR,, Mingorance J. 2012. Identification and susceptibility testing by microorganism by direct inoculation from positive blood culture bottles by combining MALDI-TOF and Vitek-2 Compact is rapid and effective. J Infect 65:513520.
24. Wieser A,, Schneider L,, Jung J,, Schubert S. 2012. MALDI-TOF MS in microbiological diagnostics—identification of microorganisms and beyond (mini review). Appl Microbiol Biotechnol 93:965974.
25. Munson E,, Kramme T,, Culver A,, Hryciuk JE,, Schell RF. 2010. Cost-effective modification of a commercial PCR assay for detection of methicillin-resistance or -susceptible Staphylococcus aureus in positive blood cultures. J Clin Microbiol 48:14081412.
26. Titécat M,, Loïez C,, Senneville E,, Wallet F,, Dezèque H,, Legout L,, Migaud,, Courcol RJ. 2012. Evaluation of rapid mecA gene detection versus standard culture in staphylococcal chronic prosthetic joint infections. Diagn Microbiol Infect Dis 73:318321.
27. Barenfanger J,, Drake C,, Kacich G. 1999. Clinical and financial benefits of rapid identification and antimicrobial susceptibility testing. J Clin Microbiol 37:14151418.
28. Doern GV,, Vautour R,, Gaudet M,, Levy B. 1994. Clinical impact of rapid in vitro antimicrobial susceptibility testing and bacterial identification. J Clin Microbiol 32:17571762.
29. Kerremans JJ,, Verboom P,, Stijnen T,, Hakkart-van Roijen L,, Goessens W,, Verbrugh HA,, Vos MC. 2008. Rapid identification and antimicrobial susceptibility testing reduce antibiotic use and accelerate pathogen-directed antibiotic use. J Antimicrob Chemother 61:428435.
30. Galar A,, Leiva J,, Espinosa M,, Guillén-Grima F,, Hernáez S,, Yuste JR. 2012. Clinical and economic evaluation of the impact of rapid microbiological diagnostic testing. J Infect 65:302309.
31. Bruins M,, Oord H,, Bloembergen P,, Wolfhagen M,, Casparie A,, Degener J,, Ruijs G. 2005. Lack of effect of shorter turnaround time of microbiological procedures on clinical outcomes: a randomised controlled trial among hospitalised patients in the Netherlands. Eur J Clin Microbiol Infect Dis 24:305313.
32. Trenholme GM,, Kaplan RL,, Karahusis PH,, Stine T,, Fuhrer J,, Landau W,, Levin S. 1989. Clinical impact of rapid identification and susceptibility testing of bacterial blood culture isolates. J Clin Microbiol 27:13421345.
33. Jett B,, Free L,, Sahm DF. 1996. Factors influencing the Vitek gram-positive susceptibility system’s detection of vanB-encoded vancomycin resistance among enterococci. J Clin Microbiol 34:701706.
34. Katsanis GP,, Spargo J,, Ferraro MJ,, Sutton L,, Jacoby GA. 1994. Detection of Klebsiella pneumoniae and Escherichia coli strains producing extended-spectrum β-lactamases. J Clin Microbiol 32:691696.
35. Tenover FC,, Swenson JM,, O’Hara C,, Stocker SA. 1995. Ability of commercial and reference antimicrobial susceptibility testing methods to detect vancomycin resistance in enterococci. J Clin Microbiol 33:15241527.
36. Tenover FC,, Tokars J,, Swenson J,, Paul S,, Splitalny K,, Jarvis W. 1993. Ability of clinical laboratories to detect antimicrobial-resistant enterococci. J Clin Microbiol 31: 16951699.
37. Ling TKW,, Tam PC,, Liu ZK,, Cheng AFB. 2001. Evaluation of VITEK 2 rapid identification and susceptibility testing system against Gram-negative clinical isolates. J Clin Microbiol 39:29642966.
38. Nadler HL,, Dolan C,, Mele L,, Kurtz SR. 1985. Accuracy and reproducibility of the AutoMicrobic System Gram-negative General Susceptibility-Plus card for testing selected challenge organisms. J Clin Microbiol 22:355360.
39. Sanders CC,, Peyret M,, Moland ES,, Cavalieri SJ,, Shubert C,, Thomson KS,, Boeufgras J-M,, Sanders WE,Jr. 2001. Potential impact of the VITEK 2 System and the Advanced Expert System on the clinical laboratory of a university-based hospital. J Clin Microbiol 39:23792385.
40. Washington JA,, Knapp CC,, Sanders CC. 1988. Accuracy of microdilution and the AutoMicrobic System in detection of β-lactam resistance in gram-negative bacterial mutants with derepressed β-lactamase. Rev Infect Dis 10:824829.
41. Jorgensen JH. 2000. Rapid automated antimicrobial susceptibility testing of Streptococcus pneumoniae by use of the bioMérieux VITEK 2. J Clin Microbiol 38:28142818.
42. Turnidge J,, Kahlmeter G,, Kronvall G. 2006. Statistical characterisation of bacterial wild-type MIC value distributions and the determination of epidemiological cut-off values. Clin Microbiol Infect 12:418425.
43. Kahlmeter G,, Brown DFJ,, Goldstein FW,, MacGowan AP,, Mouton JW,, Österland A,, Rodloff A,, Steinbakk M,, Urbanskova P,, Vatopoulos A. 2003. European harmonization of MIC breakpoints for antimicrobial susceptibility testing of bacteria. J Antimicrob Chemother 52:145148.
44. Turnidge JD,, Paterson DL. 2007. Setting and revising antibacterial susceptibility breakpoints. Clin Microbiol Rev 20:391408.
45. Livermore DM,, Andrews JM,, Hawkey PM,, Ho PL,, Keness Y,, Doi Y,, Paterson D,, Woodford N. 2012. Are susceptibility tests enough, or should laboratories still seek ESBLs and carbapenemases directly? J Antimicrob Chemother 67:15691577.
46. Craig WA. 1998. Pharmacokinetic/pharmacodynamic parameters: rationale for antibacterial dosing of mice and men. Clin Infect Dis 26:110.
47. Drusano GL. 2004. Antimicrobial pharmacodynamics: critical interactions of ‘bug and drug.’ Nat Rev Microbiol 2:289300.
48. Clinical and Laboratory Standards Institute. 2008. Development of In Vitro Susceptibility Testing Criteria and Quality Control Parameters. Approved Guideline M23-A3, 3rd ed. Clinical and Laboratory Standards Institute, Wayne, PA.
49. Mouton JW,, Brown DF,, Apfalter P,, Cantón R,, Giske CG,, Ivanova M,, MacGowan AP,, Rodloff A,, Soussy CJ,, Steinbakk M,, Kahlmeter G. 2012. The role of pharmacokinetics/pharmacodynamics in setting clinical MIC breakpoints: the EUCAST approach. Clin Microbiol Infect 18:E37E45.
50. Metzler DM,, DeHaan RM. 1974. Susceptibility tests of anaerobic bacteria: statistical and clinical considerations. J Infect Dis 130:588594.
51. Brunden MN,, Zurenko GE,, Kapik B. 1992. Modification of the error-rate bounded classification scheme for use with two MIC break points. Diagn Microbiol Infect Dis 15:135140.
52. Craig BA. 2000. Modeling approach to diameter breakpoint determination. Diagn Microbiol Infect Dis 36:193202.
53. Bell SM. 1988. Additions and modifications to the range of antibiotics tested by the CDS method of antibiotic sensitivity testing. Pathology 20:303304.
54. British Society for Antimicrobial Chemotherapy. 2012. BSAC Methods for Antimicrobial Susceptibility Testing, Version 11.1. British Society for Antimicrobial Chemotherapy, Birmingham, United Kingdom. http://bsac.org.uk/wp-content/uploads/2012/02/Version-11.1-2012-Final-.pdf.
55. Beal SG,, Ciurca J,, Smith G,, John J,, Lee F,, Doern CD,, Gander RM. 2013. Evaluation of the nanosphere Verigene Gram-positive blood culture assay with the VersaTREK blood culture system and assessment of possible impact on selected patients. J Clin Microbiol 51:39883992.
56. Tojo M,, Fujita T,, Ainoda Y,, Nagamatsu M,, Hayakawa K,, Mezaki K,, Sakurai A,, Masui Y,, Yazaki H,, Takahashi H,, Miyoshi-Akiyama T,, Totsuka K,, Kirikae T,, Ohmagari N. 2014. Evaluation of an automated rapid diagnostic assay for detection of gram-negative bacteria and their drug-resistance genes in positive blood cultures. PLoS One 9:e94064. doi:10.1371/journal.pone.0094064.
57. Tenover FC. 2007. Rapid detection and identification of bacterial pathogens using novel molecular technologies: infection control and beyond. Clin Infect Dis 44:418423.
58. Bush K,, Fisher JF. 2011. Epidemiological expansion, structural studies, and clinical challenges of new β-lactamases from gram-negative bacteria. Annu Rev Microbiol 65:455478.
59. Strahilevitz J,, Jacoby GA,, Hooper DC,, Robicsek A. 2009. Plasmid-mediated quinolone resistance: a multifaceted threat. Clin Microbiol Rev 22:664689.
60. Yang J,, Ye L,, Wang W,, Luo Y,, Zhang Y,, Han L. 2011. Diverse prevalence of 16S rRNA methylase genes armA and rmtB amongst clinical multidrug-resistant Escherichia coli and Klebsiella pneumoniae isolates. Int J Antimicrob Agents 38:348351.
61. Leclercq R,, Cantón R,, Brown DF,, Giske CG,, Heisig P,, Macgowan AP,, Mouton JW,, Nordmann P,, Rodloff AC,, Rossolini GM,, Soussy CJ,, Steinbakk M,, Winstanley TG,, Kahlmeter G. 2013. EUCAST expert rules in antimicrobial susceptibility testing. Clin Microbiol Infect 19:141160.
62. Mittman SA,, Huard RC,, Della-Latta P,, Whittier S. 2009. Comparison of BD Phoenix to Vitek 2, MicroScan MICroSTREP, and Etest for antimicrobial susceptibility testing of Streptococcus pneumoniae. J Clin Microbiol 47:35573561.
63. Cunney RJ,, Smyth EG. 2000. The impact of laboratory reporting practices on antibiotic utilisation. Int J Antimicrob Agents 14:1319.
64. Dellit TH,, Owens RC,, McGowan JE,Jr,, Gerding DN,, Weinstein RA,, Burke JP,, Huskins WC,, Paterson DL,, Fishman NO,, Carpenter CF,, Brennan PJ,, Billeter M,, Hooton TM. 2007. Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America guidelines for developing an institutional program to enhance antimicrobial stewardship. Clin Infect Dis 44:159177.
65. McGowan JE. 2012. Antimicrobial stewardship—the state of the art in 2011: focus on outcome and methods. Infect Control Hosp Epidemiol 33:331337.
66. Clinical and Laboratory Standards Institute. 2009. Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data. Approved Guideline M39-A3. Clinical and Laboratory Standards Institute, Wayne, PA.
67. Cantón R,, Bryan J. 2012. Global antimicrobial resistance: from surveillance to stewardship. Part 1: surveillance and risk factors for resistance. Expert Rev Anti Infect Ther 10:12691271.
68. Sahm DF,, Tenover FC. 1997. Surveillance for the emergence of antimicrobial resistance in bacteria. Infect Dis Clin North Am 11:767785.

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