Penicillin antibiotics will only work well against gram-positive bacteria. Not all bacteria have the exact same cell wall structure. Gram-positive bacteria have cell walls containing much more peptidoglycan compared to gram-negative bacteria. Gram-negative bacterial cell walls also typically contain lipopolysaccharides and a protein layer in addition to peptidoglycan. These extra layers of the wall in gram-negative bacteria mean that penicillin does not have access to the layer of peptidoglycan, so penicillin is much less effective against these types ("Weird Science: Penicillin and the Cell Wall | manoa.hawaii.edu/ExploringOurFluidEarth", 2018). Another disadvantage is that many bacteria have developed resistance to penicillin. Some bacteria can produce enzymes such as β-lactamase or penicillinase that render penicillin ineffective. Bacteria can pass on the ability to produce these enzymes to other bacteria, leading to resistance. To attempt to get around this problem, drugs called β-lactamase inhibitors are now sometimes given along with β-lactam drugs like penicillin (Drawz & Bonomo, 2010). Bibliography: Alexander Fleming Discovery and Development of Penicillin - Landmark - American Chemical
Penicillin antibiotics will only work well against gram-positive bacteria. Not all bacteria have the exact same cell wall structure. Gram-positive bacteria have cell walls containing much more peptidoglycan compared to gram-negative bacteria. Gram-negative bacterial cell walls also typically contain lipopolysaccharides and a protein layer in addition to peptidoglycan. These extra layers of the wall in gram-negative bacteria mean that penicillin does not have access to the layer of peptidoglycan, so penicillin is much less effective against these types ("Weird Science: Penicillin and the Cell Wall | manoa.hawaii.edu/ExploringOurFluidEarth", 2018). Another disadvantage is that many bacteria have developed resistance to penicillin. Some bacteria can produce enzymes such as β-lactamase or penicillinase that render penicillin ineffective. Bacteria can pass on the ability to produce these enzymes to other bacteria, leading to resistance. To attempt to get around this problem, drugs called β-lactamase inhibitors are now sometimes given along with β-lactam drugs like penicillin (Drawz & Bonomo, 2010). Bibliography: Alexander Fleming Discovery and Development of Penicillin - Landmark - American Chemical