Grupo de Resistencia Antimicrobiana en Bacterias Patógenas y Ambientales, GRABPA, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
Millennium Initiative for Collaborative Research on Bacterial Resistance (MICROB-R), Valparaíso, Chile.
Microb Biotechnol. 2024 Jan;17(1):e14385. doi: 10.1111/1751-7915.14385. Epub 2024 Jan 10.
Detecting antibiotic residues is vital to minimize their impact. Yet, existing methods are complex and costly. Biosensors offer an alternative. While many biosensors detect various antibiotics, specific ones for beta-lactams are lacking. To address this gap, a biosensor based on the AmpC beta-lactamase regulation system (ampR-ampC) from Pseudomonas sp. IB20, an Antarctic isolate, was developed in this study. The AmpR-AmpC system is well-conserved in the genus Pseudomonas and has been extensively studied for its involvement in peptidoglycan recycling and beta-lactam resistance. To create the biosensor, the ampC coding sequence was replaced with the mCherry fluorescent protein as a reporter, resulting in a transcriptional fusion. This construct was then inserted into Escherichia coli SN0301, a beta-lactam hypersensitive strain, generating a whole-cell biosensor. The biosensor demonstrated dose-dependent detection of penicillins, cephalosporins and carbapenems. However, the most interesting aspect of this work is the high sensitivity presented by the biosensor in the detection of carbapenems, as it was able to detect 8 pg/mL of meropenem and 40 pg/mL of imipenem and reach levels of 1-10 ng/mL for penicillins and cephalosporins. This makes the biosensor a powerful tool for the detection of beta-lactam antibiotics, specifically carbapenems, in different matrices.
检测抗生素残留对于最大限度地减少其影响至关重要。然而，现有的方法既复杂又昂贵。生物传感器提供了一种替代方法。虽然许多生物传感器可以检测各种抗生素，但缺乏针对β-内酰胺类抗生素的特定传感器。为了解决这一差距，本研究开发了一种基于南极假单胞菌 IB20 中 AmpC β-内酰胺酶调控系统（ampR-ampC）的生物传感器。AmpR-AmpC 系统在假单胞菌属中高度保守，因其参与肽聚糖回收和β-内酰胺类抗生素耐药性而被广泛研究。为了创建生物传感器，用 mCherry 荧光蛋白替换了 ampC 编码序列作为报告基因，从而构建了一个转录融合体。然后将该构建体插入到对β-内酰胺类抗生素高度敏感的大肠杆菌 SN0301 中，生成了一种全细胞生物传感器。该生物传感器表现出对青霉素类、头孢菌素类和碳青霉烯类抗生素的剂量依赖性检测。然而，这项工作最有趣的方面是生物传感器在检测碳青霉烯类抗生素时表现出的高灵敏度，因为它能够检测到 8pg/mL 的美罗培南和 40pg/mL 的亚胺培南，并且能够达到青霉素类和头孢菌素类抗生素的 1-10ng/mL 水平。这使得生物传感器成为检测不同基质中β-内酰胺类抗生素（特别是碳青霉烯类抗生素）的有力工具。
