Final answer:
The bacteria use efflux pumps to perform active transport, moving antibiotics out of the cell against the concentration gradient and preventing effective treatment, leading to antibiotic resistance.
Step-by-step explanation:
When an antibiotic enters the cells of E. coli, which is a type of negative pathogenic bacteria, the bacteria may try to pump the antibiotic out of the cell using a mechanism called efflux pump. This process represents a type of active transport because it involves the movement of molecules against their concentration gradient using energy. Efflux pumps are capable of actively transporting antimicrobial drugs out of the cell, which prevents the accumulation of the drug to a level that would be antibacterial. As a result, this can lead to antibiotic resistance, as the drugs are unable to reach their intended target within the bacteria. Examples of antibiotics that are commonly resisted through efflux pumps include B-lactams, tetracyclines, and fluoroquinolones. This resistance mechanism is a significant challenge in the treatment of bacterial infections and contributes to the problem of multidrug resistance.