SLC51A and escherichia coli infection: Seven outer membrane proteins (OstA, HlpA, Tsx, NlpB, OmpC, YfcU, and OmpA) with high frequency in the sera of healthy individuals show a specific immune protection of 54.54–81.82% against pathogenic E. coli infection, while HlpA and OmpA exhibit cross-protection of 40.74% and 37.04% against S. aureus infection.