Antibacterial Effect of Haemolymph Extracts of Edible Snail on Multi-drug Resistant Bacteria

Aim: To evaluate antibacterial effect of haemolymph in edible snail against multi-drug resistant bacterial isolates.

Study Design: This was an experimental study involving susceptibility testing of bacterial isolates to haemolymph extracts of edible snail.

Place and Duration of Study: The experiments were carried out at the School of Biomedical and Allied Health Sciences of the University of Ghana from February to June, 2014.

Methods: Haemolymph was extracted from two Achatina achatina snails (haemolymph extract from one of the snails was labelled “Haemolymph A” and the other “Haemolymph B”). Both haemolymph extracts were tested against 15 multi-drug resistant isolates each of Staphlyococcus aureus, Pseudomonas aeruginosa and Escherichia coli by the agar well diffusion method.

Results: Overall, the proportion of isolates inhibited by Haemolymph A were 20% (3/15) for S. aureus, 20% (3/15) for E. coli and 13.3% (2/15) for P. aeruginosa; the proportion of isolates inhibited by Haemolymph B were 33.7% (5/15) for E. coli, 26.7% (4/15) for S. aureus and 13.3% (2/15) for P. aeruginosa. For both Haemolymphs A and B extracts, S. aureus had the largest mean diameter zone of inhibition of 19.00±3.61mm and 22.25±2.63 respectively. E. coli had the smallest mean diameter for Haemolymph A (13.67±3.22mm) while P. aeruginosa had smallest mean diameter for Haemolymph B (16.00±5.66mm). For each of the three bacterial pathogens, there was no significant difference in the proportion of isolates inhibited by Haemolymph A and Haemolymph B or the mean zone sizes of inhibition (p> 0.5).

Conclusion: Haemolymph of Achatina achatina exhibits antibacterial activity against multi-drug resistant isolates of S. aureus, P. aeruginosa and E. coli. However, there is a high tendency for multi-drug resistant bacterial isolates to be haemolymph-resistant. The antibacterial effect of haemolymph extracts from Achatina achatina snails appear to be consistent.