Effect of fimbriae Dr on antibiotic resistance of recombinant strains: MIC 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.
Overnight cultures of AAEC191A/pCC90 (fimbriae-producing) and AAEC191A/pACYC177 (non-fimbriae-producing) were subcultured in fresh LB medium and diluted to an optical density of 0.005 at 600 nm. Two-fold serial dilutions of kanamycin, spectinomycin, erythromycin, chloramphenicol, and tetracycline were prepared in 96-well microtiter plates. Each well received 150 µl of the diluted bacteria and the corresponding antibiotic dilution.Plates were incubated at 37°C for 18–24 hours. The optical density was monitored using a microplate reader. All measurements were performed in triplicate.  The MIC was determined as the lowest antibiotic concentration that completely inhibited visible bacterial growth. All results were documented in the folder below. 
In the file below, a Word document containing MIC graphs for all tested antibiotics and strains is provided.