**6. Conclusions**

*Pseudomonas aeruginosa* is an opportunistic gram-negative bacterium and causes hospital-acquired infections, which associate with a wide range of diseases, such as pneumonia, urinary tract infections, ear infections, folliculitis, puncture wounds, cystic fibrosis, burn infections, endocarditis, endophthalmitis, meningitis, and many others. *Ps. aeruginosa* contains virulence factors that made them able to transmit and also gave them the ability to resist many types of antibiotics; this is associated with many types of genes which are encoded for different antibiotic resistance mechanisms. The efflux pumps is very important mechanism of this bacteria. *Ps. aeruginosa* can cause a wide range of diseases.
