Analysis of the antibiotic activity of a novel spontaneously-biotransformed, phosphorylated, biogenic metal salt-containing hetero-exopolysaccharide produced from Pseudomonas aeruginosa strain S16, isolated from soil from a Nigerian livestock farm, against antibiotic-resistant, representative identified bacteria

Abstract

Antibiotic resistance has morphed into an issue of universal proportions, in urgent need of efficacious solutions. The aim of this research, was to analyze the antibiotic activity of a novel, spontaneously-biotransformed, phosphorylated biogenic metal salt-containing hetero-exopolysaccharide, produced from Pseudomonas aeruginosa strain S16, and characterized in a different study; against laboratory-procured representative antibiotic-resistant, identified bacteria, namely, Klebsiella pneumoniae , Enterobacter cloacae , methicillin-resistant Staphylococcus aureus SO180, Pseudomonas aeruginosa , Escherichia coli and Staphylococcus aureus SO183, that were reported in a different study. Bacteria from soil and hog waste, from a Nigerian livestock farm, were isolated via serial dilution and pour plate methods, and identified through biochemical tests. Exopolysaccharide-production screening tests, demonstrated that isolated bacterium F22 ( Providencia vermicola ) from hog waste, and isolated bacterium S16 ( Pseudomonas aeruginosa strain S16) from soil, were the top two highest-yielding exopolysaccharide producers. Only the latter, a Pseudomonas species, was selected for the study. The exopolysaccharide is a heteropolysaccharide; consists of nitrogen, carbon, phosphorus, sodium, oxygen, calcium, chlorine, magnesium, zinc, potassium, and manganese, oxygen-manganese-oxygen bonds, magnesium oxide, zinc oxide, calcium carbide; and carboxyl, imine/oxime, amide/peptide, nitro, halo, phosphoryl and anhydride reactive groups; and has a scantily wafery surface, with bulbous protrusions, on SEM. The agar pit diffusion assay was used to investigate exopolysaccharide antibiotic activity. The hetero-exopolysaccharide was efficacious against Staphylococcus aureus SO183 at 0.156 g/L and 0.260 g/L and against identified Klebsiella pneumoniae at 0.156 g/L, and may prove an efficacious substitute antibiotic compound.