Bioactivity of pyocyanin of Pseudomonas aeruginosa clinical isolates against a variety of human pathogenic bacteria and fungi species

Pyocyanin is blue pigment redox active, secondary metabolites produced by P. aeruginosa. The present study investigated the bioactivity of pyocyanin against certain types of bacteria and fungi causing human infections Objectives: Pyocyanin is blue pigment redox active, secondary metabolites produced by P. aeruginosa. The current study deals with biosynthesis, purification and bioactivity of pyocyanin produced by P. aeruginosa. Design: Pyocyanin extraction was done by chloroform method and concentration was determined by multiplying the optical density at 520 nm by 17.072 expressed as µg/ml. Biological activity of pyocyanin was determined by well diffusion procedure. Results: According to the source of infection, results showed that P. aeruginosa were most common in ear infection (30%) followed by wounds (22%), burns (17%), urine (13%) and each in stool and diabetes (9%). In this study the high resistance of  P. aeruginosa  isolates to antibiotics were 19 (82.6 %) to piperacillin followed by 10(43.5%) to aztreonem, 8(34.8%) to meropenem, 6(26.1%) to amikacin, 5(21.7%) to ciprofloxacin then 2(8.7%) to cefotaxime. the urine isolate produced the largest amount of pyocyanin (15.894 µg/ml). pyaocyanin have antimicrobial activity against Pathogenic bacteria: Shigella,  Staphyllococcus aureus and  Staphyllococcus epidermedis. and pathogenic fungi and yeast: Aspergillus niger, Penicillium spp., Rhizopus spp, Trichophyton  mentagrophyte, Rhodotorula spp., Alternaria alternate , Trichophyton rubrum and Candida spp Conclusions: cefotaxime is the best antibiotic for P. aeruginosa. Antimicrobial activity of pyocyanin against gram positive more than gram negative bacteria but less than that observed against fungi (molds and yeast).