Background: Antibiotic resistance poses a significant threat to patients suffering from infectious diseases. Early readings of antibiotic susceptibility test (AST) results could be of critical importance to ensure adequate treatment. Disc diffusion is a well-standardized, established and cost-efficient AST procedure; however, its use in the clinical laboratory is hampered by the many manual steps involved, and an incubation time of 16-18 h, which is required to achieve reliable test results. Methods: We have evaluated a fully automated system for its potential for early reading of disc diffusion diameters after 6-12 h of incubation. We assessed availability of results, methodological precision, categorical agreement and interpretation errors as compared with an 18 h standard. In total, 1028 clinical strains (291 Escherichia coli , 272 Klebsiella pneumoniae , 176 Staphylococcus aureus and 289 Staphylococcus epidermidis ) were included in this study. Disc diffusion plates were streaked, incubated and imaged using the WASPLab TM automation system. Results and conclusions: Our results demonstrate that: (i) early AST reading is possible for important pathogens; (ii) methodological precision is not hampered at early timepoints; and (iii) species-specific reading times must be selected. As inhibition zone diameters change over time and are phenotype/drug combination dependent, specific cut-offs and expert rules will be essential to ensure reliable interpretation and reporting of early susceptibility testing results.
Background: Antibiotic resistance poses a significant threat to patients suffering from infectious diseases. Early readings of antibiotic susceptibility test (AST) results could be of critical importance to ensure adequate treatment. Disc diffusion is a well-standardized, established and cost-efficient AST procedure; however, its use in the clinical laboratory is hampered by the many manual steps involved, and an incubation time of 16-18 h, which is required to achieve reliable test results. Methods: We have evaluated a fully automated system for its potential for early reading of disc diffusion diameters after 6-12 h of incubation. We assessed availability of results, methodological precision, categorical agreement and interpretation errors as compared with an 18 h standard. In total, 1028 clinical strains (291 Escherichia coli , 272 Klebsiella pneumoniae , 176 Staphylococcus aureus and 289 Staphylococcus epidermidis ) were included in this study. Disc diffusion plates were streaked, incubated and imaged using the WASPLab TM automation system. Results and conclusions: Our results demonstrate that: (i) early AST reading is possible for important pathogens; (ii) methodological precision is not hampered at early timepoints; and (iii) species-specific reading times must be selected. As inhibition zone diameters change over time and are phenotype/drug combination dependent, specific cut-offs and expert rules will be essential to ensure reliable interpretation and reporting of early susceptibility testing results.
Authors: Melanie L Yarbrough; William Lainhart; Allison R McMullen; Neil W Anderson; Carey-Ann D Burnham Journal: Eur J Clin Microbiol Infect Dis Date: 2018-09-29 Impact factor: 3.267
Authors: Romney M Humphries; Susan Kircher; Andrea Ferrell; Kevin M Krause; Rianna Malherbe; Andre Hsiung; C A Burnham Journal: J Clin Microbiol Date: 2018-07-26 Impact factor: 5.948
Authors: Michael Hombach; Marion Jetter; Nicolas Blöchliger; Natalia Kolesnik-Goldmann; Peter M Keller; Erik C Böttger Journal: J Antimicrob Chemother Date: 2018-02-01 Impact factor: 5.790
Authors: Khaled S Allemailem; Abdullah M Alnuqaydan; Ahmad Almatroudi; Faris Alrumaihi; Aseel Aljaghwani; Habibullah Khalilullah; Hina Younus; Arif Khan; Masood A Khan Journal: Pharmaceutics Date: 2021-05-08 Impact factor: 6.321