Antimicrobial Effect of Diphenyl Ditelluride (PhTe)2 in a Model of Infection by Escherichia coli in Drosophila melanogaster

Diphenyl ditelluride (PhTe) 2 , an organotelluric compound with pharmacological and toxicological attributes, has shown promise in microorganism studies. Drosophila melanogaster , an alternative animal model, is gaining popularity for novel antimicrobial research due to its cost-effectiveness, versatility, and similarity to vertebrate models. Given the rising antibiotic resistance, particularly in Escherichia coli ( E. coli ), the exploration of novel antimicrobials is of utmost importance. In (PhTe) 2 safety validation, our findings indicate an 50% lethal concentration (LC 50 ) of 41.74 µM for (PhTe) 2 following a 48-h exposure period in Drosophila melanogaster . To assess potential motor and neurological deficits, we conducted behavioral analyses employing negative geotaxis and open field tests. Our outcomes reveal alterations in exploratory behavior at concentrations exceeding 50 µM (PhTe) 2 in the flies. Consequently, we have established the optimal treatment concentration for Drosophila melanogaster as 10 µM (PhTe) 2 . Upon safety validation, we gauged the antimicrobial potential of (PhTe) 2 through an oral infection model involving axenic flies. After exposing these flies to E. coli for 18–20 h, we treated them with 10 µM of (PhTe) 2 for various time spans (0, 3, 6, 12, 24, and 48 h), followed by plating and colony counting. The logarithmic bacterial load curve demonstrated the antimicrobial impact of the compound, highlighting a significant reduction in bacterial load after 3 h of exposure to 10 µM (PhTe) 2 , with an enhancement of antimicrobial potential lasting up to 48 h. Given these results, we state that 10 µM (PhTe) 2 was safe and presented antimicrobial potential, reducing the bacterial load in Drosophila melanogaster . Graphical Abstract