Question

Please select the TRUE statement regarding bacterial resistance to antimicrobials.

1) Gram-positive bacteria are intrinsically resistant to certain medications because the lipid bilayer of their outer membrane prevents the molecules from entering.
2) Intrinsic resistance generally occurs through spontaneous mutation or horizontal gene transfer.
3) The genes for antimicrobial resistance are often carried on fertility plasmids (F plasmids).
4) Mycoplasma species lack a cell wall, so they are resistant to penicillin that interferes with peptidoglycan synthesis. This is an example of intrinsic resistance.
5) Acquired resistance is very limited because microorganisms cannot evolve, so are incapable of developing mechanisms to avoid the effects of medications.

Answer 1

The true statement regarding bacterial resistance to antimicrobials is that Mycoplasma species, lacking a cell wall, are intrinsically resistant to penicillin due to its interference with peptidoglycan synthesis. Intrinsic resistance can occur through mutation or horizontal gene transfer, and resistance genes can be spread among bacteria via these mechanisms.

Step-by-step explanation:

The TRUE statement regarding bacterial resistance to antimicrobials among the options provided is: 4) Mycoplasma species lack a cell wall, so they are resistant to penicillin that interferes with peptidoglycan synthesis. This is an example of intrinsic resistance.

Gram-positive bacteria are known for having a thick peptidoglycan layer, not a lipid bilayer outer membrane, which is a characteristic of Gram-negative bacteria. Intrinsic resistance is a baseline resistance that all strains of a certain bacterial species inherently possess. While intrinsic resistance can occur through spontaneous mutation or horizontal gene transfer, the statement as provided mixes elements of intrinsic and acquired resistance. Fertility plasmids can carry genes for antimicrobial resistance, but they are not the same as resistance plasmids. Lastly, the idea that bacteria cannot evolve to develop resistance to antibiotics is false; acquired resistance demonstrates the contrary.

Bacteria can use various mechanisms to become resistant to antibiotics, including drug modification, prevention of cellular uptake or efflux, target modification, target overproduction, and target mimicry. The exchange of drug resistance genes often occurs through horizontal gene transfer, which is a significant mechanism of how resistance spreads among bacteria.