Evaluation of the Antimicrobial Activity of Chlorella vulgaris Against MDR Bacteria Isolated from Diabetic Wound Pus Samples

Background: The aim of this study was to isolate and characterize pathogenic microbes from the pus of diabetic patients and to evaluate the antibiotic susceptibility of multidrug-resistant (MDR) isolates along with their resistance patterns against the microalgae Chlorella vulgaris extract (CVE). Methods: This hospital-based biphasic research study (cross-sectional and experimental) included 100 pus samples from diabetic patients. Out of these, 10 isolates were identified as multidrug-resistant (MDR) and were subsequently subjected to further characterization. Two methods were employed to evaluate the antimicrobial activity of the microalgae Chlorella vulgaris. Since the Kirby-Bauer disc diffusion method did not provide sufficient results, a turbidity assay was performed in an ELISA 96-well microtiter plate to evaluate the inhibitory effect of microalgae CVE on bacterial growth. To assess the biofilm-forming ability of pus isolates and to evaluate the inhibitory potential of CVE against their biofilms standard microtiter plate assays were performed. Results: The CVE exhibited species-dependent antibiofilm activity against pus isolates from diabetic patients. The strongest % inhibition at MIC with algal extract was observed in Acinetobacter species (48.28%) and Streptococcus pyogenes (42.12%), while the weakest response was noted in Klebsiella pneumoniae (27.48%). Overall CVE demonstrated significant inhibitory potential (p < 0.05) with comparatively stronger effects against certain Gram-negative and selected Gram-positive bacteria. Conclusion: Microalgae CVE exhibited antimicrobial and anti-biofilm activity against MDR isolates from diabetic patients with the strongest effects on Acinetobacter species and Streptococcus pyogenes indicating its potential as a natural therapeutic requiring further mechanistic and in vivo validation. DOI: https://doi.org/10.59564/amrj/03.04/003