Supplementary Material for: The Effect of Recombinant Human Erythropoietin on Bacterial Growth: A Dual-Edged Sword

<b><i>Background:</i></b> Hypererythropoietinemia is associated with common diseases like non-uremic anaemia where infection burden is high. Erythropoietin (EPO) is also given as therapy for anaemia associated with chronic kidney disease and cancer and in those who are at a higher risk of infections. EPO is known to have an effect on macrophages by which it helps in the growth of some intracellular pathogens. However, its direct role on bacterial growth is currently unknown. <b><i>Summary:</i></b> Here, we investigated the direct effect of recombinant human erythropoietin (rhuEPO) on the growth of pathogenic <i>Escherichia coli</i>, <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>. In silico experiments were designed to gain insight into the mechanisms. We found that 30 IU/L rhuEPO promoted the growth of <i>E. coli</i> and <i>S. aureus</i> and inhibited the growth of <i>P. aeruginosa</i>. In silico observations suggest that bacterial cell surface proteins may interact with the EPO and may cause the observed effects. <b><i>Key Message:</i></b> It appears that some pathogens can explore EPO to proliferate and growth of others are inhibited by the same. The consequence of such observation is a matter of widespread concern for future research.