Which bacteria are harder to kill?

Which bacteria are harder to kill?

• A. Fungi
• B. Gram-negative
• C. Gram-positive
• D. Viruses

Answer: (B)

Think about how the bacterial cell envelope affects how hard it is for agents to reach and disrupt the cell. Gram-negative bacteria have an outer membrane outside a thin peptidoglycan layer. That outer membrane acts like a shield, limiting the entry of many antibiotics and disinfectants. Porin channels and efflux pumps further control and reduce how much drug can accumulate inside, and many Gram-negatives produce enzymes that inactivate drugs. All of this adds up to a higher level of intrinsic resistance, making them harder to kill than Gram-positive bacteria, which lack that outer membrane and have a thicker but more penetrable peptidoglycan wall. Fungi and viruses aren’t bacteria, and their vulnerabilities differ, but within bacteria, those with the outer membrane tend to be more resistant.

Think about how the bacterial cell envelope affects how hard it is for agents to reach and disrupt the cell. Gram-negative bacteria have an outer membrane outside a thin peptidoglycan layer. That outer membrane acts like a shield, limiting the entry of many antibiotics and disinfectants. Porin channels and efflux pumps further control and reduce how much drug can accumulate inside, and many Gram-negatives produce enzymes that inactivate drugs. All of this adds up to a higher level of intrinsic resistance, making them harder to kill than Gram-positive bacteria, which lack that outer membrane and have a thicker but more penetrable peptidoglycan wall. Fungi and viruses aren’t bacteria, and their vulnerabilities differ, but within bacteria, those with the outer membrane tend to be more resistant.