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

Abstract

Objectives: 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 Methods: A total of 23 clinical isolates of P. aeruginosa were collected from patients admitted to the General Baqubah Hospital during the period from November 2016 through May 2017. All isolates were cultured on Pseudomonas agar and confirmed by biochemical tests as P. aeruginosa. 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 P. aeruginosa, the most tested isolates were from ear infection (30%) followed by wounds (22%), burns (17%), urine (13%) and both stool and diabetic leg ulcer (9%). Antimicrobial resistant of P. aeruginosa isolates were the following: 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, 2 (8.7%) to cefotaxime.The urine isolates produced the largest amount of pyocyanin (15.894 µg/ml). Pyaocyanin have shown antimicrobial activity against the following bacteria: Shigella spp., Staphylococcus aureus and Staphylococcus epidermedis. Also, pyaocyanin can inhibit the following fungi and yeast: Aspergillus niger, Penicillium

Antibiotic resistance, virulence factors and genotyping of Pseudomonas aeruginosa in public hospitals of northeastern Mexico

“…In this context, the expression of virulence factors depends on microenvironment of infection site even under treatment with antimicrobial drugs and pathogenicity of P. aeruginosa is mediated by virulence factors including toxins, extracellular enzymes, siderophores, and secretion systems that directly inject virulence factors into the eukaryotic host cell [35]. A major virulence factor is biofilm that is a complex matrix that protects bacterium against immune system; another factor is the enzyme elastase (LasB) that supports the infection and colonization process by damaging tissue and degrading immune proteins [36], while pyocyanin is a blue redox active that can directly accept electrons from reducing agents such as NADPH and reduced glutathione [37]; finally alkaline protease cleaves various proteins and impairs host immune response [38]. Moreover, the structural and physiological characteristics of biofilm provides it with an innate protection against antimicrobials, for this reason biofilm-associated bacterium are able to resist antimicrobial agents by different mechanisms, such as an efficient evasion to phagocytosis as well as the host immunological mechanisms.…”

Antifungal Coating Based on Pyocyanin Nanoparticles (Np-Pyo)

“…Pyocyanin is a secondary metabolite involved in natural ecological phenomena of antibiosis and amensalism of P. aeruginosa against its competitors (Jameel et al, 2017;Ghoul & Mitri, 2016). Depending on the concentration of pyocyanin, as well as the susceptibility of the organism exposed to the substance, a biocidal or biostatic effect may result (Arruda et al, 2020).…”

Colour Me Blue: The History and the Biotechnological Potential of Pyocyanin

“…[110] Trichophyton sp. [110] Most microbes, however, can synthesize some metabolites with an inhibitory action that can affect P. aeruginosa. These compounds are secreted to inhibit, but not to kill potential competitors [102].…”