Effects of Low-Dose Carbon Monoxide on Antibiotic Efficacy

The impact of intestinal gases, including gasotransmitters, on antibiotic efficacy is severely understudied. This study assessed the effects of low-dose CO (85 µg/g) on the efficacy of various antibiotics in low oxygen conditions using the Kirby-Bauer method against <i>E. coli</i> BW20767/pRL27. Preliminary results showed that exposure to CO exerts variable effects on antibiotic efficacy. This indicates that CO exerts its effects not only through modulation of <i>E. coli</i> 's respiratory chain, but may also involve additional, as-yet unidentified targets independent of terminal oxidase binding. We also observed that <i>E. coli</i> endogenously produces CO as it switches to anaerobic metabolism.