Abstract Background: Pseudomonas aeruginosa is an important environmental, opportunistic, and nosocomial pathogen with a significant threat to public health. Combination therapy has many advantages due to the simultaneous action of two drugs on two separate cellular targets. In the present study, the effect of the combination of doxycycline and natural products against planktonic cells, biofilm, and virulence factors of P. aeruginosa was evaluated. Methods: To perform this work, minimal i...