Carbapenems are a class of β-lactam antibiotics with a broad antimicrobial activity spectrum. Owing to their sturdy structures resistant to most β-lactamases, they have been regarded as one of the last-resort antibiotics for combating multidrugresistant bacterial infections. However, the emergence of carbapenem resistance increases predominantly in nosocomial pathogens. To prevent spread of carbapenem resistance in early stages, it is imperative to develop rapid diagnostic tests that will substantially reduce the time and cost in determining carbapenem resistance. Thus, we devised a staining-based diagnostic method applicable to three different Gram-negative pathogens of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae, all with the high potential to develop carbapenem resistance. Regardless of the resistance mechanisms presented by bacterial species and strains, double staining with propidium iodide (PI) and alamar blue (AB) identified resistant bacteria with an average sensitivity of 95.35%, 7 h after imipenem treatments in 343 clinical isolates. Among the three species tested, A. baumannii showed the highest diagnostic sensitivity of 98.46%. The PI and ABmediated staining method could be a promising diagnostic method with high-throughput efficacy and low cost.

中文翻译：

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低成本比色法可快速测定对碳青霉烯的耐药性：碘化丙啶和阿拉玛蓝染色。

碳青霉烯类是一类β-内酰胺类抗生素，具有广泛的抗菌活性。由于其对大多数β-内酰胺酶具有抵抗力的坚固结构，它们被认为是对抗多药耐药细菌感染的最后手段之一。但是，对碳青霉烯类药物的耐药性主要在医院病原体中增加。为了在早期阶段预防碳青霉烯耐药性的蔓延，必须开发快速诊断测试，这将大大减少确定碳青霉烯耐药性的时间和成本。因此，我们设计了一种基于染色的诊断方法，适用于鲍曼不动杆菌，大肠杆菌和肺炎克雷伯菌的三种革兰氏阴性病原体，所有具有发展碳青霉烯耐药性的潜力。不论细菌种类和菌株所表现出的耐药机制如何，在亚胺培南处理后343株临床菌株中，碘化丙啶（PI）和阿拉玛蓝（AB）双重染色均能识别出耐药菌，其平均敏感性为95.35％（亚胺培南治疗7小时后）。在测试的三个物种中，鲍曼不动杆菌显示出最高的诊断灵敏度，为98.46％。PI和AB介导的染色方法可能是一种有前途的诊断方法，具有高通量功效和低成本。