Bacterial Growth on a Microfluidic Chip to Study Antibiotic Drug Resistance

Take microfluidic chips with growth and drug chambers separated by a micromechanical valve.

Load wild-type and TMP-resistant mutant E. coli strains, suspended in media, into the growth chambers using pressure, where Trimethoprim (TMP) is the antibiotic tested.

Next, load the drug chambers with media containing a low concentration of TMP to induce cellular stress in bacteria.

Actuate the micromechanical valve to allow TMP diffusion into the growth chambers, enabling TMP entry into the bacteria.

Place the chips within the incubator mounted on the inverted microscope stage and initiate time-lapse imaging.

In wild-type E. coli, TMP binds to the enzyme dihydrofolate reductase, preventing dihydrofolate binding and causing stress-induced filamentation and reduced bacterial multiplication.

However, the mutant strain’s altered DHFR structure prevents TMP binding, allowing normal multiplication.

Observe the time-lapse images.

Wild-type E. coli exhibits filamentation and reduced multiplication under TMP treatment, while the mutant strain exhibits normal morphology and multiplication, indicating antibiotic resistance.

After thawing the daily frozen sample at room temperature for five minutes, inoculate