Reconstitution of Gene Network on Penicillin Resistance in E.coli Using Databases Information

The discovery of penicillin has revolutionized the medical industry and saved thousands of lives. But over time, the resistant bacteria to this antibiotic were identified one after another. Antibiotics of the penicillin family have a β-lactam ring in their molecular structure. By competitively binding to transpeptidase, penicillin and other β-lactam antibiotics inhibit its activity. Inhibition of transpeptidase activity prevents cell wall synthesis and causes bacterial death. Resistant bacteria, have β-lactamase enzyme which has the ability to break the C-N bond in the β-lactam ring. In this study, we reconstructed a network of known β-lactamase genes in E.coli. The results showed that ampC gene plays a central role in induction of resistance in E.coli. Molecular function analysis of other β-lactamase genes showed that β-lactamase activity is only a secondary function for them and their main function is to participate in other unrelated cellular processes. Gene ontology analysis showed that the process of resistance to β-lactam antibiotics was positively correlated with electron transport chain. Also, when exposed to β-lactam antibiotics, the cell membrane is the most active cellular component in E.coli and antibiotic resistance is dependent on the β-lactamase function of cell membrane proteins.