Regulatory Role of Gut Microbiota in MRSA Colonization and Horizontal Transfer of Antibiotic Resistance Genes

Abstract

Antimicrobial resistance (AMR) has become a major global health threat, seriously impairing the efficacy of modern medical anti-infective therapies. With the continuous emergence of multi-drug resistant (MDR) bacteria, the difficulty of clinical infection diagnosis and treatment is increasing, leading to a continuous rise in morbidity, mortality and medical burden. Against this backdrop, the human intestinal microbiota, as a vast microbial ecosystem, plays a key role in regulating host immunity, metabolism and resisting pathogen colonization. The intestinal microbiota is also an important hub for the transmission of antibiotic resistance genes (ARGs). Once the microbiota is imbalanced, that is, when the composition and function of microorganisms are disrupted, it may promote the horizontal transfer of resistance genes, accelerating the colonization and spread of MDR bacteria. This review will systematically elaborate on the role of the intestinal microbiota in the colonization of methicillin-resistant Staphylococcus aureus (MRSA) and how it affects the horizontal transfer of resistance genes, and discuss how to use therapeutic strategies such as probiotics, bacteriophage therapy (BT) and fecal microbiota transplantation (FMT) to curb the spread of resistance, gradually restore microbiota homeostasis, and potentially provide a theoretical basis for the development of targeted microbiota-based personalized treatments to address the increasingly severe problem of resistant bacterial infections.