TY - JOUR
T1 - Less Is More
T2 - When to Repeat Antimicrobial Susceptibility Testing
AU - Sarink, Maarten J.
AU - Bode, Lonneke G.M.
AU - Croughs, Peter
AU - de Steenwinkel, Jurriaan E.M.
AU - Verkaik, Nelianne J.
AU - van Westreenen, Mireille
AU - Vogel, Marius
AU - Yusuf, Erlangga
N1 - Publisher Copyright:
© 2023 American Society for Microbiology. All Rights Reserved.
PY - 2023/8
Y1 - 2023/8
N2 - This study investigated the frequency of change of the antimicrobial susceptibility pattern when the same isolate was found in the same patient in various situations. We used laboratory data collected over a period of 8 years (January 2014 to December 2021) at the clinical microbiology laboratory of a tertiary hospital for Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Pseudomonas aeruginosa, and Staphylococcus aureus. Antimicrobial susceptibility tests (AST) were performed using Vitek 2 automated system. We determined essential agreement and categorical agreement, and introduced the new terms essential MIC increase and change from nonresistant to resistant to present changes in antimicrobial susceptibility over time. During the study period, 18,501 successive AST were included. The risk for S. aureus to be resistant to any antibiotic upon repeated culture was,10% during a follow-up of 30 days. For Enterobacterales, this risk was approximately 10% during a follow-up of 7 days. For P. aeruginosa, this risk was higher. The longer the follow-up period, the higher the risk that the bacteria would show phenotypic resistance. We also found that some drug-bug combinations were more likely to develop phenotypical resistance (i.e., E. coli/amoxicillin-clavulanic acid and E. coli/cefuroxime). A potential consequence of our finding is that if we regard a risk of resistance below 10% as acceptable, it may be feasible to omit follow-up AST within 7 days for the microorganisms investigated in this study. This approach saves money, time, and will reduce laboratory waste. Further studies are needed to determine whether these savings are in balance with the small possibility of treating patients with inadequate antibiotics.
AB - This study investigated the frequency of change of the antimicrobial susceptibility pattern when the same isolate was found in the same patient in various situations. We used laboratory data collected over a period of 8 years (January 2014 to December 2021) at the clinical microbiology laboratory of a tertiary hospital for Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Pseudomonas aeruginosa, and Staphylococcus aureus. Antimicrobial susceptibility tests (AST) were performed using Vitek 2 automated system. We determined essential agreement and categorical agreement, and introduced the new terms essential MIC increase and change from nonresistant to resistant to present changes in antimicrobial susceptibility over time. During the study period, 18,501 successive AST were included. The risk for S. aureus to be resistant to any antibiotic upon repeated culture was,10% during a follow-up of 30 days. For Enterobacterales, this risk was approximately 10% during a follow-up of 7 days. For P. aeruginosa, this risk was higher. The longer the follow-up period, the higher the risk that the bacteria would show phenotypic resistance. We also found that some drug-bug combinations were more likely to develop phenotypical resistance (i.e., E. coli/amoxicillin-clavulanic acid and E. coli/cefuroxime). A potential consequence of our finding is that if we regard a risk of resistance below 10% as acceptable, it may be feasible to omit follow-up AST within 7 days for the microorganisms investigated in this study. This approach saves money, time, and will reduce laboratory waste. Further studies are needed to determine whether these savings are in balance with the small possibility of treating patients with inadequate antibiotics.
UR - http://www.scopus.com/inward/record.url?scp=85168786758&partnerID=8YFLogxK
U2 - 10.1128/jcm.00463-23
DO - 10.1128/jcm.00463-23
M3 - Article
C2 - 37436180
AN - SCOPUS:85168786758
SN - 0095-1137
VL - 61
SP - e0046323
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
IS - 8
ER -