In this study, the levels of expression of nine proteins in the presence of ampicillin (LBP_cg0109, Small heat shock protein; LBP_cg0397, L-serine dehydratase, beta subunit; LBP_cg0719, hypothetical protein; LBP_cg0720, hypothetical protein; LBP_cg0721, Alkaline shock protein; LBP_cg0722, Alkaline shock protein; LBP_cg2704, Formate acetyltransferase activating enzyme; LBP_cg0885, Malate dehydrogenase) were validated by parallel reaction monitoring.