Resistence-plasmide

Plasmids in Staphylococcus aureus that can carry a number of antibiotic resistance genes. These resistance genes encode proteins that either inactivate an antibiotic or affect its uptake into the cell. In Streptococus pyogenes, plasmids have been discovered which show resistance to macrolides, lincosamides and streptogramin B through the genes ermA, ermB and ermT , respectively.

The mechanism of resistance in Staphylococcus aureus is found within the mecA gene , which encodes penicillin-binding protein (PBP) 2a and has a low affinity for ß-lactam antibiotics. PBPs are carboxypeptidases that confer methicillin resistance via cell wall modification.

However, Staphylococcus aureus can also override an appropriate antibiotic by the pathogen creating bypass pathways. The target enzymes are replaced by new enzymes that correspond to the original mechanism of action and are unrelated to the antibiotic. (Development of resistance to trimethoprim). The sum of the resistance mechanisms makes Staphylococcus aureus a potential high-risk germ and has earned its multidrug-resistant variant the nickname "superbug".