Isolation and characterization of multi-drug-resistant Microbacterium esteraromaticum bacteriophage: assessment of antibacterial efficacy and genomic insights.

Microbacterium esteraromaticum, a common bacterium utilized in the degradation of organic pollutants, is prevalently found in the wastewater environments of rural areas. However, the excessive use of antibiotics in recent years has endowed M. esteraromaticum with a broad spectrum of antibiotic resistance, transforming it into a potential high-risk contaminant capable of disseminating antibiotic resistance genes (ARGs) within the environment. Lytic bacteriophages, due to their characteristic ability to lysogenize and specifically target host bacteria, have emerged as potent biocontrol agents. In this study, a specific bacteriophage, CASP3, targeting the multi-drug resistant M. esteraromaticum (MDR-ME), was isolated from a wastewater treatment facility. The assessment of phage CASP3 revealed several noteworthy characteristics, including good tolerance and a targeted effect against multidrug-resistant MDR-ME. Studies observed that CASP3, to some extent, reduced the ARGs carried by its host. Furthermore, it demonstrated good environmental compatibility, with no significant potential risks identified. The successful isolation of CASP3 not only provides a new addition to phage resources targeting this bacterium but also offers a potential biocontrol tool for mitigating ARG dissemination and reducing public health risks in rural areas.