Question

E. coli and s. epidermidis were chosen to represent gram-negative and gram-positive bacteria, respectively. for a given antibiotic, is there a difference in susceptibility between the gram-positive and gram-negative bacteria?

Answer 1

The susceptibility of E. coli (Gram-negative) and S. epidermidis (Gram-positive) to antibiotics can differ due to their cell wall structures. E. coli's outer membrane can provide resistance, while S. epidermidis's thicker peptidoglycan layer makes it more susceptible to cell wall-targeting antibiotics.

Step-by-step explanation:

Regarding the susceptibility of E. coli and S. epidermidis to antibiotics, these bacteria can indeed exhibit differences in their response due to their cell wall characteristics. E. coli, a Gram-negative bacterium, has a thin peptidoglycan cell wall with an outer membrane containing lipopolysaccharides (LPS), which can contribute to its resistance against some antibiotics. In contrast, S. epidermidis, a Gram-positive bacterium, has a much thicker peptidoglycan layer without an outer LPS membrane, making it susceptible to antibiotics targeting peptidoglycan synthesis.

These structural differences in cell wall composition are key factors in antibiotic susceptibility. For instance, Gram-positive bacteria like S. epidermidis are more susceptible to antibiotics that disrupt cell wall synthesis, such as penicillins and cephalosporins. Meanwhile, Gram-negative bacteria like E. coli may resist these antibiotics due to the protective barrier provided by their outer membrane and can be more sensitive to antibiotics that penetrate this barrier, like aminoglycosides.

Answer 2

Gram-positive and Gram-negative are different in their resistance to antibiotics. It is because of their different structure of cell wall. Gram-positive bacteria have a thick peptidoglycan cell wall and dyes purple in the Gram test (for categorization of bacteria). Gram-negative bacteria have thin peptidoglycan layer and do not turn purple. Gram-positive bacteria are easier to kill because their thick peptidoglycan layer absorbs antibiotics.