Antibacterial activity and mechanism of action of 3'-azido-3'-deoxythymidine (BW A509U).
BACKGROUND Despite being used by more than 18 million people our understanding of the extent of effects of antiretrovirals on the human body and other organisms remains incomplete. In addition, the direct effect of antiretrovirals on the gut microbiota of HIV infected individuals has been largely overlooked in microbiome studies concerned with HIV infected individuals. METHODS Here we tested 25 antiretrovirals on Bacillus subtilis and Escherichia coli using a broth microdilution assay to assess whether these drugs have an antibacterial effect. RESULTS We found that several widely used antiretroviral drugs have in-vitro antibacterial activity against both gram-positive and gram-negative commensal bacteria. Efavirenz inhibited the growth of B. subtilis with an MIC of 16µg/ml (in all three replicates), while 2',3'-Dideoxyinosine and Zidovudine inhibited the growth of E. coli with an MIC of 16-32µg/ml, and 0.016 - 0.125 µg/ml (respectively). CONCLUSIONS Given the large and increasing number of individuals on antiretrovirals, and the lifelong nature of HIV treatment, this proof-of-concept report could have several potential implications, including an impact of antiretrovirals on bacterial co-infections, as well as potentials for drug discovery and repositioning.