Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.
Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, PR China.
J Med Microbiol. 2023 Aug;72(8). doi: 10.1099/jmm.0.001671.
Tigecycline is one of the important antibiotics available for treating infection caused by multiple-drug resistant pathogens. However, the conventional AST methods which are commonly used in clinical microbiology laboratories usually lead to false intermediate or resistant results in testing tigecycline susceptibility, and further mislead clinical antimicrobial therapies. The modified Kirby-Bauer disc diffusion (mKB) method was performed based on the traditional standard Kirby-Bauer disc diffusion (sKB) method.. To evaluate a modified Kirby-Bauer disc diffusion (mKB) method for tigecycline susceptibility testing, for the purpose of providing accurate tigecycline susceptibility results in clinical practice. A total of 4271 nonduplicate clinical strains were isolated from 37 hospitals across China to perform the mKB method, standard Kirby-Bauer disc diffusion (sKB) method, comparing with the reference broth microdilution (BMD) according to the CLSI. Parameters of categorical agreement (CA), minor errors (mE), major errors (ME), and very major errors (VME) were used in this methodological evaluation research. BMD testing showed that 91.3-98.9 % of the , , , , , and strains were susceptible, while 0-3.1% strains were resistant to tigecycline. When testing , mKB demonstrated higher CA than sKB (90.6 % vs 44.8 %) compared to reference BMD. The mE (9.0 % vs 45.2 %), ME (0.5 % vs 10.6 %) and VME (both 0 %) all satisfied the acceptability criteria. mKB also showed higher CA (87.2 % vs 52.0 %) than sKB in comparison with BMD when testing (mainly ). The ME (0.45 % vs 8.1 %) and VME (both 0 %) but not mE (12.4 % vs 40.4 %) met the acceptability criteria. The mKB method can test bacterial susceptibility to tigecycline more accurately than sKB. For the tigecycline-intermediate or -resistant strains by sKB method, BMD or mKB method should be used to verify the results and report reliable tigecycline susceptibility results.
替加环素是治疗多重耐药病原体感染的重要抗生素之一。然而，临床微生物学实验室中常用的常规 AST 方法通常会导致替加环素药敏试验中出现假中介或耐药结果，从而进一步误导临床抗菌治疗。改良 Kirby-Bauer 纸片扩散（mKB）法是在传统标准 Kirby-Bauer 纸片扩散（sKB）法的基础上进行的。为了评估改良 Kirby-Bauer 纸片扩散（mKB）法用于替加环素药敏试验，以在临床实践中提供准确的替加环素药敏结果。我们从中国 37 家医院共分离了 4271 株非重复临床分离株，采用 mKB 法、标准 Kirby-Bauer 纸片扩散（sKB）法进行检测，并与 CLSI 推荐的肉汤微量稀释（BMD）法进行比较。本方法学评价研究采用分类符合率（CA）、小错误（mE）、大错误（ME）和显著大错误（VME）等参数。BMD 检测结果显示，91.3%-98.9%的 、 、 、 、 和 株对替加环素敏感，0%-3.1%的株对替加环素耐药。当检测 时，mKB 与参考 BMD 相比，CA 高于 sKB（90.6% vs 44.8%）。mE（9.0% vs 45.2%）、ME（0.5% vs 10.6%）和 VME（均为 0%）均符合可接受标准。与 BMD 相比，mKB 检测 时，CA 也高于 sKB（87.2% vs 52.0%）。mE（12.4% vs 40.4%）和 VME（均为 0%）不符合可接受标准，而 ME（0.45% vs 8.1%）符合可接受标准。mKB 法比 sKB 法更能准确检测细菌对替加环素的敏感性。对于 sKB 法检测为中介或耐药的替加环素菌株，应使用 BMD 或 mKB 法进行验证，并报告可靠的替加环素药敏结果。
