Virulence Factors of Pseudomonas aeruginosa Isolated from ICU

Background: P.aeruginosa has many virulence factors which are the main reason for infection and the emergence of antibiotic resistance leading to an increase of morbidity and mortality. Currently, multidrug resistance is the hardest problem, which made it imperative to search for alternative treatment strategies. Objective: detection of some phenotypic virulence factors of P.aeruginosa isolated from ICU patients and the possibility of any antibiotic resistance related to certain virulence factors released by P. aeruginosa. Methodology: Our study was carried out on patients admitted to ICU Department in Benha University Hospital and infected with P.aeruginosa, the isolates subjected to phenotypic detection of the virulence factors: phospholipase, alkaline protease, lipase, gelatinase, esculin hydrolysis, biofilm formation, hemolysin and DNase production using specific media for each and evaluation of the antibiotic susceptability pattern using Kirby Bauer disk diffusion assay. Results: P.aeruginosa virulence factors were recorded as follow: hemolysin (70%) followed by alkaline protease (68%), phospholipase (62%), gelatinase & biofilm formation (60%) for each, lipase & bile esculin hydrolysis (54%) for each and DNase (2%).High antibiotic resistance was detected to mostly all of the used antibiotic discs. Also, presence of invasive device, prolonged hospital stay, ICU stay and higher number of virulence factors were associated with poor outcome. Conclusions: Production of different phenotypic virulence factors in high amount reflects their important role in spread of infection and pathogenicity with increased antibiotic resistance. Therefore finding anti-virulence factors as adjuvant therapy has an important role in treatment of P. aeruginosa especially MDR isolates.