Analysis and the impact of CLSI on the automated antimicrobial susceptibility testing system after the update of Enterobacterales and Pseudomonas aeruginosa breakpoints
10.3760/cma.j.cn114452-20241219-00695
- VernacularTitle:CLSI肠杆菌目及铜绿假单胞菌折点更新后对自动化药敏系统的影响及分析
- Author:
Shuo YANG
1
;
Qi WANG
;
Hua YU
;
Xiangning HUANG
;
Kang LIAO
;
Hui WANG
Author Information
1. 北京大学人民医院检验科，北京100044
- Publication Type:Journal Article
- Keywords:
Escherichiacoli;
Klebsiella pneumoniae;
Pseudomonas aeruginosa;
Performance verification test
- From:
Chinese Journal of Laboratory Medicine
2025;48(2):230-240
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To assess the precision of various automated antimicrobial susceptibility testing systems for ciprofloxacin, levofloxacin, piperacillin/tazobactam, amikacin, gentamicin and tobramycin before and after the update of the breakpoints by Clinical and Laboratory Standards Institute.Methods:A total of 65 strains of Enterobacterales (34 Escherichia coli and 31 Klebsiella pneumoniae) and 33 strains of Pseudomonas aeruginosa were collected from Peking University People′s Hospital, Sichuan Provincial People′s Hospital, and the First Affiliated Hospital of Sun Yat-sen University in 2023. Broth microdilution (BMD) was employed as the reference method to assess the accuracy of ten antimicrobial susceptibility panels (NMIC-413, GN09, N335, NMIC45, GN4F, NMIC-150, DL-120E, DL-120NE, ONE-96 and NF-96) in seven automated antimicrobial susceptibility testing systems currently utilized in China. Results:Except for the GN-09, N-335, and NMIC-150, there were breakpoints that were not covered for the minimum inhibitory concentrations reported by the other panels in the validation. There was no very major error (VME) in the verification results except for the cases of not covered. Among the 65 strains of Enterobacterales, the essential agreement rate (EA%) of ciprofloxacin and levofloxacin was higher than 92.3% (60/65), and the categorical agreement rate (CA%) of ciprofloxacin using the new breakpoint decreased from 100% (65/65)-98.5% (64/65) to 95.4% (62/65)-86.2% (56/65). The major error rate (ME%) of N-335 card increased from 1.5% (1/65) to 4.6% (3/65); except for GN-09 and N-335 cards, the CA% of other cards under new breakpoint was ≥96.9% (63/65) with no ME; the EA% of piperacillin/tazobactam was ≥93.8% (61/65), and the CA% under new breakpoint was ≥92.3% (60/65), and the ME% of N-335 card increased from 1.5% (1/65) to 4.6% (3/65). The EA% and CA% under new breakpoint of amikacin, gentamicin and tobramycin were all ≥ 96.9% (63/65) with no ME. Among the 33 tested Pseudomonas aeruginosa isolates, the EA% of ciprofloxacin was ≥93.8% (30/32), and after applying the new breakpoints, the CA% of ciprofloxacin decreased from 90.6% (29/32)-100% (33/33) to 84.4% (27/32)-100% (33/33). On the NMIC-413 card, 2 strains showed ME. For levofloxacin, the EA% was ≥90.9% (30/33), and the CA% of the new breakpoint interpretation decreasing from 90.6% (29/32)-100% to 69.7% (23/33)-93.8% (30/32), with no ME. For amikacin and tobramycin, the EA% was ≥93.8% (30/32), and on most panels, the CA% of new breakpoints for amikacin and tobramycin were ≥96.9% (31/32).Conclusions:At present, the breakpoints cannot be covered by the panels in many automated antimicrobial sensitivity testing systems in China. Ciprofloxacin and levofloxacin did not meet the validation requirements for Enterobacterales and Pseudomonas aeruginosa in most antimicrobial susceptibility testing systems. After the breakpoints updated, it is essential to validate the automated antimicrobial susceptibility system for clinical application.
