Assessment of Antibacterial Activity of Exopolysaccharide Produced from Pseudomonas aeruginosa strain S16 on Environmental and Clinical Bacteria

Abstract

Abstract Environmental and clinical bacteria have developed resistance to the commonly available antibiotics, erstwhile produced to treat diseases caused by them. Indeed, antibiotic resistance has morphed into an issue of worldwide proportions in urgent need of effective remedies. The aim of this study was to assess the antibacterial activity of exopolysaccharide produced from stock culture of Pseudomonas aeruginosa strain S16 (accession number OQ734845), which had previously been isolated from soil in the environment, on selected identified environmental and clinical bacteria, which were both antibiotic-resistant and antibiotic-susceptible. Bacterial isolates were initially isolated from both soil and pig faecal matter using serial dilution and pour plate methods, before they were identified through biochemical tests. Screening tests for exopolysaccharide production in these isolates, had shown up S16 and F22 as the best producers of exopolysaccharide; identified as Pseudomonas aeruginosa strain S16 (accession number OQ734845) and Providencia vermicola strain F22 (accession number OQ734846), respectively. The latter was not a pseudomonad and was therefore excluded from the study. The antibacterial properties of the exopolysaccharide were then assessed using agar well diffusion assay and it was observed to be effective only against Staphylococcus aureus SO183 at 0.260 g/L and against identified Klebsiella pneumoniae only at 0.156 g/L.The positive controls used in the study were antibiotic discs containing the class of antibiotics susceptible to each selected identified bacterium. The exopolysaccharide from Pseudomonas aeruginosa strain S16, therefore, proved promising as an alternative antibiotic to the present failing antibiotics in common usage.