**Abstract**

*Pseudomonas aeruginosa* is highly successful in colonizing in all types of environments. *P. aeruginosa* colonizing in adverse environment due to the presence of its virulence factors include production of toxins, proteases hemolysins, and formation of biofilms. In man, the most common opportunist pathogen is *P. aeruginosa*. Metabolically *P. aeruginosa* is versatile. Most of the antibiotics targeted metabolically active cells and bacteria could contribute to decrease in biofilm susceptibility to the antimicrobial agents. Scientists suggested about *Pseudomonas* that it can be catabolized any hydrocarbon in specific time along with availability of oxygen and nitrite. If bacteria are not susceptible to one agent in three or more, it is called as multidrug-resistance strains. The antimicrobial treatments were not suitable when microorganism presented *in vitro* microorganism resistance to antimicrobials used for treatment of the patient which lack of treatment for 24 h after diagnosis of microbial infections. Bacteria have developed resistance against commonly used antibiotics. Treatment of *Pseudomonas* infections is coming harder day by day as its resistance against most of the antibiotics. Because of resistance of bacteria antibiotics, alternative methods are in consideration. These methods include use of lactic acid bacteria (LAB) and most recently nano-particles. That is why they are used as antibacterial agents.

**Keywords:** *P. aeruginosa*, pulmonary infections, acute lung infections, cystic fibrosis, quorum sensing system, virulent genes, antibacterial agents, LAB
