Molecular basis of ampicillin resistance: combinatorial mechanisms and future strategies

Due to the increasing antibiotic resistance profile, the efficacy of ampicillin – one of the main treatment options in clinical practice for many years – has markedly declined. Understanding the molecular processes that reduce the effectiveness of this antibiotic is crucial for optimizing current treatment protocols and designing new drugs that are less susceptible to resistance. This review examines the molecular basis of ampicillin resistance from a multilayered perspective, providing a comprehensive analysis of how processes such as β-lactamase production, alterations in penicillin-binding proteins, porin modifications, efflux pump activation, and synergistic combinations of these mechanisms contribute to ampicillin resistance according to current literature. Furthermore, we discuss how different resistance mechanisms collectively establish a coordinated resistance matrix. Finally, we evaluate how these mechanistic insights can inform the development of next-generation therapeutic strategies to overcome ampicillin resistance and assess the future therapeutic potential of multi-targeted approaches.