COMPARATIVE IN VITRO EVALUATION OF LL-37 AND STANDARD ANTIBIOTICS AGAINST ESCHERICHIA COLI ISOLATES FROM URINARY TRACT INFECTIONS: A SUSTAINABLE HEALTHCARE PERSPECTIVE

Objective: This study aimed to evaluates the in vitro antibacterial activity of the human cathelicidin peptide LL-37 towards E. coli which isolated from UTI patients, as well as to compare its effect with the common antibiotics like amoxicillin-clavulanic acid (AMC), aztreonam (ATM), and ceftriaxone (CRO). Method: In well diffusion test, LL-37 showed a clear inhibition zone, revealing strong antimicrobial activity. The time-kill assay also authorized its bactericidal action, showing a ≥3 log₁₀ CFU/mL reduction within few hours and almost complete killing after 24 hours. Results: The mean zone diameter for LL-37 (18.4 ± 1.7 mm) was obviously greater than AMC (13.2 ± 2.1 mm) (p < 0.01) and higher than ATM (16.1 ± 1.9 mm), although the difference with ATM was not significant (p > 0.05). CRO confirmed smaller zone (14.3 ± 1.8 mm), which kind of highlight the stronger effect of LL-37. Novelty:    The results generally supports the idea that LL-37 could be a promising alternative antimicrobial agent, showing strong activity than some of the usual antibiotics against E. coli. Its possible role in treating drug-resistant UTIs still need more studying, especially now when resistance to β-lactam antibiotics keeps increasing.