A Study of Antimicrobial Effects of Pyocyanin Pigment of Pseudomonas aeruginosa Strains isolated from Environmental Sources gainst Bacteria Cause of Urinary Tract Infections

Today, the treatment has been more difficult because the resistance of human opportunistic pathogens including the urinary tract infections bacteria increased against a wide range of antibiotics.

In this study, Pseudomonas aeruginosa was isolated from environmental surfaces and then the presence of a gene related to pigment biosynthesis was confirmed by PCR. Pyocyanin pigment was extracted by chloroform and its purity was confirmed by the TLC method. Bacteria causing urinary tract infections including Staphylococcus saprophyticus, Escherichia coli, Enterococcus sp. and Klebsiella sp. were collected and the antimicrobial effect of this pigment was investigated by disk placement and well-diffusion methods on each of the above bacteria.

The results of this study showed that the highest sensitivity to pyocyanin pigment extract was related to Staphylococcus saprophyticus and Enterococcus sp. in disk placement and well-diffusion methods. The diameter of the growth inhibition zone without considering the effect of chloroform for both bacteria was 4 and 2 mm in the disk placement method and 4 and 3 mm in the well-diffusion method, respectively. Therefore, pyocyanin pigment had a greater antimicrobial effect on gram-positive bacteria than gram-negative bacteria.

In this study, pigment-producing bacteria were isolated from environmental surfaces due to their lower probability of pathogenicity for humans than strains isolated from clinical samples that have been used in most studies for pigment extraction. Therefore, these strains can be a better option for extracting pyocyanin pigment as an antimicrobial matter that can be replaced with antimicrobial agents and synthetic antibiotics.