Reliability of various antimicrobial susceptibility testing methods for piperacillin/tazobactam in challenging Escherichia coli isolates

IF 3.7 3区医学 Q2 INFECTIOUS DISEASES

Journal of global antimicrobial resistance Pub Date : 2025-01-14 DOI:10.1016/j.jgar.2024.12.028

Faruk Demirocak, Diana Langerak, Erlangga Yusuf

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引用次数: 0

Abstract

Objective

Piperacillin/tazobactam antimicrobial susceptibility testing (AST) against Enterobacterales can be challenging. The aim of this study was to assess the reproducibility of various automated (VITEK 2) and nonautomated AST methods (broth microdilution (BMD), minimum inhibitory concentration (MIC) test strip, and disk diffusion) for piperacillin/tazobactam in ‘challenging’ E. coli isolates.

Methods

We performed 20 repeated ASTs for seven clinical E. coli isolates: Two resistant to piperacillin/tazobactam but susceptible to amoxicillin/clavulanic acid, four isolates with various β-lactamase coding genes (two bla_TEM-1, one bla_OXA-1, and one with plasmidal bla_ampC), and one isolate where VITEK 2 initially could not produce MIC measurements for piperacillin/tazobactam (i.e. no results generated).

Results

Upon repetition, the same MIC as the mode value (i.e. the most frequent MIC value of each AST method) was found between 21% and 87% (BMD), 46% and 100% (VITEK 2), and 48% and 100% (gradient test) of the repetitions. The range of essential agreement percentage (i.e. ±1 doubling dilution from this mode value) was 53–100% (BMD), 63–100% (VITEK 2), and 100% (gradient test). Percent categorical agreement (same susceptible of resistant category using EUCAST breakpoint v. 14.0) was 71–100% (BMD), 85–92% (VITEK 2), 76–100% (gradient test) and 100% (disk diffusion).

Conclusions

: In conclusion, this study provides insight on the reliability of AST results for piperacillin/tazobactam in challenging E. coli isolates. While the results indicate that most methods are generally reproducible, certain isolates may present inconsistent MIC results.

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哌拉西林/他唑巴坦在大肠杆菌中不同药敏试验方法的可靠性

哌拉西林/他唑巴坦抗微生物药敏试验（AST）对肠杆菌具有挑战性。本研究的目的是评估各种自动化（Vitek®2）和非自动化AST方法（肉汤微量稀释（BMD）、最低抑制浓度（MIC）试纸和纸片扩散）在“挑战性”大肠杆菌分离物中检测哌拉西林/他唑巴坦的重复性。我们对7株临床大肠杆菌进行了20次重复AST检测：2株对哌拉西林/他唑巴坦耐药，但对阿莫西林/克拉维酸敏感，4株具有各种β -内酰胺酶编码基因（2株blaTEM-1, 1株blaOXA-1, 1株质粒blaampC）， 1株VITEK®2最初无法对哌拉西林/他唑巴坦进行MIC检测（即没有结果）。重复后，发现与模式值相同的MIC值（即每种AST方法的最常见MIC值）在重复的21%至87% (BMD)， 46%至100% （VITEK®2）和48%至100%（梯度测试）之间。基本一致性百分比（EA，即从该模式值±1倍稀释）的范围为53%至100% (BMD)， 63%至100% （VITEK®2）和100%（梯度测试）。分类一致性百分比（CA，使用EUCAST断点v 14.0的耐药类别相同易感）范围为71%至100% (BMD)， 85%至92% (VITEK®2)，76%至100%（梯度试验）和100%（磁盘扩散）。综上所述，本研究提供了对哌拉西林/他唑巴坦在挑战大肠杆菌分离株中AST结果的可靠性的见解。虽然结果表明大多数方法通常是可重复的，但某些分离株的MIC结果可能不一致。

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来源期刊

Journal of global antimicrobial resistance INFECTIOUS DISEASES-PHARMACOLOGY & PHARMACY

CiteScore

8.70

自引率

2.20%

发文量

285

审稿时长

34 weeks

期刊介绍： The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes. JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR). Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.