Glycopeptides Glycopeptides also interfere with the synthesis of the bacterial cell wall but by a different mechanism than the beta-lactams. It has become the antibiotic of last resort as resistance to the other antibiotics has become more and more common. It is effective against many gram-positive bacteria that have developed resistance to the older antibiotics. Link to discussion of translation. Resistance to Antibiotics None of the antibiotics discussed above is effective against all bacterial pathogens.
Some bacteria are intrinsically resistant to certain of the antibiotics.
Many bacteria acquire resistance to one or more of the antibiotics to which they were formerly susceptible. Bacteria develop resistance by acquiring genes encoding proteins that protect them from the effects of the antibiotic. The genes are often found on plasmids which spread easily from one bacterium to another - even from one species of bacterium to another. These enzyme break the beta-lactam ring at the position shown with the green arrow in the diagram of penicillin G . Likewise synthesis of cephalosporinases defeats the cephalosporins .