Effect of fimbriae Dr on antibiotic resistance of recombinant strains: disk diffusion assay

Fimbriae DR form dense structures on the bacterial surface, which can act as a barrier and potentially reduce antibiotic penetration. This experiment investigates how the presence of fimbriae DR affects the antibiotic resistance of AAEC191A strains by comparing fimbriae-producing (pCC90) and non-fimbriae-producing (pACYC177) strains using the disk diffusion method.
Disk diffusion assay was performed using LA agar plates poured with 20 ml of medium. A 3.5 ml top agar (1 volume of LA and 2 volumes of LB) containing 100 µl of overnight cultures of AAEC191A/pCC90 (fimbriae-producing) and AAEC191A/pACYC177 (non-fimbriae-producing) was poured onto the plates. After solidification, nine serial dilutions (0–10⁻⁸) of each antibiotic were prepared and spotted onto the agar (15 µl in water and 10 µl in ethanol). The plates were incubated at 37°C for 24 hours. The results were documented as photographs and stored in the folder below.
The folder contains photographic documentation of the disk diffusion assay performed on AAEC191A/pCC90  and AAEC191A/pACYC177  strains. Images show inhibition zones obtained for kanamycin, spectinomycin, erythromycin, chloramphenicol, and tetracycline. Each condition was performed in triplicate to ensure reproducibility.