<i>Escherichia coli</i>'s response to low-dose ionizing radiation stress

Abstract

Low-dose ionizing radiation can trigger a phenomenon known as hormesis in microorganisms, in which exposure to mild stressors like radiation results in beneficial adaptive responses. This study investigated the impact of low-dose X-rays on Escherichia coli's viability and their potential influence on antibiotic susceptibility. The irradiated samples displayed increased bacterial viability compared to non-irradiated controls, with a significant increase observed at 5 and 10 mGy of X-ray radiation exposure. This suggests a stimulating effect of low-dose ionizing radiation on E. coli's viability. To explore the correlation between viability and antibiotic susceptibility, we assessed the inhibition zone diameters for various antibiotics in non-irradiated and irradiated samples. The obtained results showed that the exposure of bacteria to low-dose ionizing radiation resulted in a significant reduction in the inhibition zone diameters for marbofloxacin, amoxicillin/clavulanic acid, ceftiofur, and cefoxitin. These findings suggest that low-dose X-ray radiation exposure can enhance E. coli's viability and its ability to withstand antibiotics, raising potential concerns.

Keywords

• antibiotic susceptibility
• escherichia coli
• low-dose ionizing radiation
• radiation hormesis
• stress response