National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.
Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
Front Cell Infect Microbiol. 2020 Sep 25;10:583341. doi: 10.3389/fcimb.2020.583341. eCollection 2020.
The emergence and spread of the novel mobile Tet(X) tetracycline destructases confer high-level tigecycline and eravacycline resistance in and spp. and pose serious threats to human and animal health. Therefore, a rapid and robust Tet(X) detection assay was urgently needed to monitor the dissemination of tigecycline resistance. We developed a rapid and simple assay to detect Tet(X) producers in Gram-negative bacteria based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). This MALDI test was based on the inactivation of tigecycline by a Tet(X)-producing strain after a 3-h incubation of bacterial cultures with tigecycline. Culture supernatants were analyzed using MALDI-TOF MS to identify peaks corresponding to tigecycline (586 ± 0.2 m/z) and a tigecycline metabolite (602 ± 0.2 m/z). The results were calculated using the MS ratio [metabolite/(metabolite + tigecycline)]. The sensitivity of the MALDI test with all 216 test strains was 99.19%, and specificity was 100%. The test can be completed within 3 h. Overall, the MALDI test is an accurate, rapid, cost-effective method for the detection of Tet(X)-producing and spp. by determining the unique peak of an oxygen-modified derivative of tigecycline.
新型可移动 Tet(X) 四环素破坏酶的出现和传播使 和 spp. 对替加环素和依拉环素产生高水平耐药性，对人类和动物健康构成严重威胁。因此，迫切需要一种快速而强大的 Tet(X) 检测方法来监测替加环素耐药性的传播。我们开发了一种基于基质辅助激光解吸电离飞行时间质谱 (MALDI-TOF MS) 的快速简便的革兰氏阴性菌中 Tet(X) 产生菌检测方法。该 MALDI 试验基于 Tet(X) 产生菌与替加环素孵育 3 小时后对替加环素的失活。使用 MALDI-TOF MS 分析培养上清液以鉴定对应于替加环素 (586 ± 0.2 m/z) 和替加环素代谢物 (602 ± 0.2 m/z) 的峰。使用 MS 比值 [代谢物/(代谢物+替加环素)] 计算结果。用所有 216 株测试菌株进行 MALDI 测试的灵敏度为 99.19%，特异性为 100%。该测试可在 3 小时内完成。总体而言，MALDI 试验是一种准确、快速、具有成本效益的方法，通过确定替加环素的氧修饰衍生物的独特峰来检测 Tet(X) 产生的 和 spp.。
