Question

Mutations in bacterial porins typically lead to antibiotic resistance by

A) changing the orientation of the porin α-helical transmembrane segments to constrict the size of the channel.
B) changing the stereoisomer specificity of the porin transport.
C) blocking diffusion of the antibiotic through the porin channel.
D) disrupting the voltage difference across the porin channel.
E) reversing water transport through the channel.

Answer 1

The correct answer is C) blocking diffusion of the antibiotic through the porin channel. This form of antibiotic resistance involves alterations to porin channels that impede the passage of antibiotics, a strategy used by bacteria to resist the effects of antibiotic treatments.

Step-by-step explanation:

Mutations in bacterial porins can lead to antibiotic resistance primarily through option C) blocking diffusion of the antibiotic through the porin channel. This resistance mechanism involves changes in the porin channels such as alterations in the size, shape, or charge properties that reduce or obstruct the passage of antibiotics through the bacterial cell membrane. As detailed in the provided reference information, bacteria adopt this strategy among others like degrading the antibiotic, modifying the target site, or using efflux pumps to remove the antibiotic from inside the cell.

For instance, a decrease in the amount of OprD porin in Pseudomonas aeruginosa is a known mechanism of resistance to carbapenems. This mechanism by which bacteria become resistant to antibiotics is a significant concern in treatment as it reduces the efficacy of the drugs designed to combat infections.