Antimicrobial Potential of Aulacobolus gravelyi Millipede Haemolymph: A Comprehensive Study on Antibacterial Activity Against Diabetic Foot Ulcer Pathogen

The haemolymph of millipedes has garnered attention for its potential antimicrobial properties, with studies indicating that specific components exhibit activity against diverse pathogens. This research focuses on characterizing and assessing the antibacterial potential of haemolymph extracted from Aulacobolus gravelyi against the diabetic foot ulcer pathogen and Multi-Drug Resistant (MDR) Escherichia coli (E. coli). Various analytical methods, including DPPH assay, flame photometric analysis, UATR analysis, SDS-PAGE and the well diffusion method, were employed to investigate the haemolymph′s properties. The haemolymph, obtained from collected millipedes, underwent centrifugation to eliminate hemocytes. Antioxidant activity of the haemolymph revealed a substantial 69.7% DPPH free radical scavenging activity. Inorganic ion analysis identified sodium and potassium concentrations in the haemolymph as 1508mg/l and 387mg/l, respectively. Qualitative spectral analysis disclosed a remarkable 97% similarity between the haemolymph and Sulfathiazole solution, suggesting potential antimicrobial activity. SDS-PAGE analysis revealed distinct protein bands exceeding 100kDa in the haemolymph, highlighting its complex protein composition. Isolated diabetic foot ulcer pathogen, morphologically identified as gram-negative motile rods, was molecularly confirmed as Pseudomonas aeruginosa through 16S PCR analysis. The haemolymph exhibited an inhibition zone against the Pseudomonas aeruginosa isolated from diabetic wounds, indicating significant antibacterial activity against this pathogen. However, no inhibition zone was observed against MDR E.coli, signifying a lack of antibacterial activity against this resistant strain. This study characterizes the antibacterial properties of Aulacobolus gravelyi millipede haemolymph against clinically relevant bacterial strains. The multifaceted analysis provided a comprehensive understanding of the haemolymph′s potential therapeutic applications. The observed antibacterial activity against the diabetic foot ulcer pathogen, Pseudomonas aeruginosa, underscores the importance of further exploration for developing novel antimicrobial agents derived from millipede haemolymph.