Phage adsorption-driven colorimetric broad-spectrum detection of foodborne Enterobacter hormaechei using...

Enterobacter hormaechei, A zoonotic pathogen with escalating prevalence in global food sources, severely jeopardizes food safety, necessitating the development of high-performance detection methods. Herein, a novel colorimetric detection strategy integrating phages and nanozymes was proposed for foodborne E. hormaechei. Initially, four homologous phages (EhpYZU05, EhpYZU08, EhpYZU9-1 and EhpYZU10), which were isolated using E. hormaechei YZU05 as the host bacterium, were modified on the surface of NH₂-MIL-88B(Fe) to fabricate four phage@NH₂-MIL-88B(Fe) nanozymes. These nanozymes exhibit peroxidase-like activity, catalyzing 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction in presence of H₂O₂. With introduction of multiple host or non-host E. hormaechei strains, TMB chromogenic reaction catalyzed by phage@NH₂-MIL-88B(Fe) nanozymes can be specifically inhibited. This inhibition occurs due to the specific phage adsorption of phage@NH₂-MIL-88B(Fe) nanozymes towards these host or non-host E. hormaechei strains, indirectly blocking their catalytic sites. Leveraging this principle, colorimetric broad-spectrum detection of E. hormaechei was achieved. Additionally, this method demonstrated reliable recoveries (96.7 % ∼ 103.3 %) when applied to detect real food matrices, highlighting its high reliability in practical scenarios. This approach not only clarifies the intrinsic mechanism of phage-modified nanozymes for target bacteria detection but also provides a robust and reliable method for early pathogen detection, thereby significantly contributing to food safety enhancement.