Study on The Frequency of Toxin A, Alginate Genes, And of Clinical Pseudomonas aeroginosa Strains

Pseudomonas aeruginosa is an opportunistic pathogen and one of the most frequent pathogens in nosocomial infections. It causes different types of infections including urinary tract infections and Bacteremiae. This bacterium has many pathogenic factors including; exotoxin A, lipopolysacharide, phospholipase C, pili, elastase and alkaline protease. In this study, frequency of exotoxin A and alginate genes in clinical pseudomonas aeroginosa strains isolated from nosocomial infections were analysed.

50 Pseudomonas aeroginosa strains were isolated in clinical samples of Ilam hospitals and Milad hospital in Tehran. The isolates were identified by biochemical methods, after- wards DNAs were extracted. Next, using special primers for exotoxin A and alginate genes PCR was applied to detect the presence or non-presence of the related geres.

According to PCR results, 37 isolates (74%) and 46 ones (92%) had exotoxin A and alginate respectively. Among Pseudomonas aeroginosa strains isolated from urinary tract infections including 30 isolates, exotoxin A and alginate genes were observed in 21 (70%), and 26 (86/6%) isolates, respectively. Also, in other strains isolated from burn wound infections including 20 isolates, exotoxin A and alginate genes were detected in 16 (80%) and 20 (100%) isolates.

The results of our study confirm that exotoxin A and alginate genes presence is considered an important virulence factor of pseudomonas aeruginosa. The results of our study showed that alginate gene is so important in pseudomonas aeroginosa strains isolated from urinary tract infections and burn wound infections.