Antimicrobial Activity of Pterocarpus santalinoides, Crescentia cujete, and Azadirachta indica Leaf Extracts on Extended Spectrum Beta Lactamases (ESBL) Producing Escherichia coli

Abstract

Aim: The study investigates the antimicrobial activity of three selected plant leaf extracts—Pterocarpus santalinoides, Crescentia cujete, and Azadirachta indica on extended-spectrum beta-lactamase (ESBL) producing E. coli in clinical isolates from wound and stool specimens. Study Area: Clinical specimens, including stool and wound swabs, were collected from patients at Gregory University Clinics, Uturu. Study Design and Methodology: Standard microbiological methods were employed for bacterial isolation and identification. ESBL-producing isolates were identified using screening and phenotypic confirmatory tests. Molecular analysis was conducted to detect ESBL genes in positive isolates, involving plasmid DNA isolation and PCR analysis. Escherichia coli was most frequently isolated from stool samples than wound samples. Results: Fifty-eight potential ESBL producing organisms were identified, of which 18 (39.1 %) were positive by phenotypic confirmatory disc diffusion test (PCDDT) and 9 (37.5 %) by double-disc synergy test (DDST) as the most E. coli ESBL producing organisms. The nine E. coli confirmed by double-disc synergy test (DDST) as potential ESBL producing isolates were subjected to ESBL genotyping using blaCTX−M, blaVEB , blaSHV and blaTEM. Only one (11.1 %) had ESBL blaTEM and eight (88.9 %) were negative to all the ESBL genes tested.  The antimicrobial susceptibility of the plants leaf extracts against the ESBL E. coli isolates showed that extracts of Pterocarpus santalinoides produced the highest zones of inhibition of 17.9 mm to 30.9 mm, followed by Azadirachta indica leaf extracts having 10.8 mm to 21 mm and the least zones of inhibition were produced by Crescentia cujete leaf extracts (8 mm to18.1 mm). Conclusion: The findings suggest that the selected plant leaf extracts possess significant antimicrobial properties against ESBL-producing bacteria, highlighting their potentials as alternative therapeutic agents in the treatment of infections caused by multidrug-resistant organisms.