Which of the following are not examples of intrinsic resistance of a bacterium to an antimicrobial drug?SELECT ALL THAT APPLYStaphylococcus aureus (VRSA) strains with altered cell wall–building enzymesMycoplasma pneumoniae lacking a cell wallMycobacterium tuberculosis altering its RNA polymerases to avoid binding by rifampinResistance in Gram-negative bacteria due to their outer membraneClostridioides difficile form endosporesMycobacterium tuberculosis have a waxy cell wall

Intrinsic resistance refers to the natural ability of a bacterium to resist the effects of an antimicrobial drug. This can be due to a variety of factors, including the physical properties of the bacterium, such as the presence of a cell wall, or the bacterium's metabolic processes.

1. Staphylococcus aureus (VRSA) strains with altered cell wall–building enzymes: This is not an example of intrinsic resistance. This is an example of acquired resistance, where the bacteria have developed resistance to the drug over time due to genetic changes.

2. Mycoplasma pneumoniae lacking a cell wall: This is an example of intrinsic resistance. Mycoplasma pneumoniae naturally lacks a cell wall, which is the target of many antimicrobial drugs.

3. Mycobacterium tuberculosis altering its RNA polymerases to avoid binding by rifampin: This is not an example of intrinsic resistance. This is an example of acquired resistance, where the bacteria have developed resistance to the drug over time due to genetic changes.

4. Resistance in Gram-negative bacteria due to their outer membrane: This is an example of intrinsic resistance. The outer membrane of Gram-negative bacteria naturally prevents many drugs from entering the cell.

5. Clostridioides difficile form endospores: This is an example of intrinsic resistance. The ability to form endospores allows bacteria to survive in a dormant state, making them resistant to many drugs.

6. Mycobacterium tuberculosis have a waxy cell wall: This is an example of intrinsic resistance. The waxy cell wall of Mycobacterium tuberculosis naturally prevents many drugs from entering the cell.