Carbapenems are typically a treatment of choice for MDR Acinetobacter baumannii; however, the emergence of carbapenem-resistant strains has elevated this pathogen to the critical priority pathogen list 1 by the World Health Organization for new research and development. Since carbapenem resistance is frequently mediated by carbapenemases, particularly oxacillinases, and metallo-beta-lactamases; antibody-based carbapenemase detection tests can be developed for rapid and affordable diagnosis of the infection. However, the development of such tests requires the availability of high-quality target proteins for the generation of specific antibodies, their characterization, and assay optimization. In this study, we have reported a streamlined workflow to obtain a purified preparation of tagless and functionally active recombinant OXA-23 enzyme, which is one of the major determinants of carbapenem resistance in Acinetobacter baumannii. The recombinant protein has been expressed in the heterologous expression host Escherichia coli using auto-induction and purified using a single step of affinity chromatography followed by removal of the affinity tag using TEV protease. The simple protocol reported here is expected to facilitate the production of other carbapenemases and similar proteins for the development of diagnostics and therapeutics to support our fight against anti-microbial-resistant bacteria.
Key words: Acinetobacter baumannii, anti-microbial resistance, carbapenemase, carbapenem resistance, OXA-23
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