Most efforts to elucidate virulence mechanisms of mammary pathogenic Escherichia coli (MPEC), causative agent of bovine clinical mastitis, have been failed but some recent studies introduced iron acquisition systems as major role players in pathogenicity. Here, we investigated the different iron uptake systems genotypes and assessed how they relate to virulence potential of MPEC. In total, 217 E. coli isolates (MPEC= 157, fecal isolates= 60) were screened for the presence of nine genes related to iron acquisition (iroN, iutA, fecA, fyuA, sitA, irp2, iucD, chuA and tonB) and phylogenetic groups were also determined. Next, bacterial growth potential and survival in raw and UHT milk which are representative for crucial steps in mastitis development were evaluated. In addition, the mineral consumption of E. coli cultured in milk were measured. The results showed that MPEC strains considerably tend to possess fecA (93%, p= 0.000) and belong to phylogenetic group A (42%, p= 0.042). The fecA+ strains from both mastitis and fecal E. coli had a significant (p= 0.000) growth potential in raw and UHT milk. Interestingly, for the first time, it was shown that fecA+ isolates consumed less amounts of iron and other metal ions. Overall, it seems that the uptake systems related to fecA contributes to overcoming harsh conditions of milk and genetic lineages could also affect pathogenicity of MPEC. These findings could lead us to define MPEC with more clarity based on genotypes or growth potential in milk and possibly promote novel solutions to control mastitis more effectively in future.