D-amino acid enhanced the sensitivity of avian pathogenic Escherichia coli to tetracycline and amikacin

• DOI: 10.3389/fvets.2025.1553937
• Publication Date: 2025-03-19T11:11:31Z
• Authors: Jing Wu; Bin Yang; Wei Jiang; Huifang Yin; Xiangan Han; Lili Zhang
• Keywords: Amikacin; Pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) biofilm formation has led to increased antibiotic resistance, presenting a significant challenge for the prevention and control of disease. While certain D-amino acids (D-AAs) have been shown inhibit various bacterial biofilms, role in APEC biofilms remains unexplored. This study investigates effects 19 different D-AAs on clinically isolated biofilm. The results showed that D-tyrosine (D-Tyr), D-leucine (D-Leu), D-tryptophan (D-Trp), D-methionine (D-Met) can reduce by over 50% at concentration 5 mM. Subsequently, four were selected combination treatment with antibiotics (ceftazidime, amikacin, tetracycline, ciprofloxacin). findings reveal D-Tyr enhance sensitivity amikacin while D-Met increases amikacin. mechanisms which further investigated. Following D-Met, scanning electron microscope (SEM) observations indicated reduction number bacteria surface cell crawl, but shape structure cells remain unchanged. Notably, hydrophobicity was decreased 33.86% 56%, output extracellular polysaccharide 46.63% 57.69%, respectively. Additionally, genes related synthesis (pgaA, pgaC, luxS) down-regulated (p < 0.05), whereas porin protein-encoding (ompC ompF) up-regulated inhibited enhanced tetracycline decreasing content down-regulating formation. According involved this study, it provide new ideas APEC.