Host-pathogen interactions in ESKAPE pathogen infections

Abstract

Multidrug-resistant (MDR) pathogens, particularly the ESKAPE organisms Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, pose significant challenges in clinical settings because of their ability to evade host immune responses, resist antibiotic treatment, and cause chronic infections. This chapter delves into the complex host–pathogen interactions that contribute to the persistence and virulence of ESKAPE pathogens. Key mechanisms of immune evasion include the production of protective surface structures such as capsules, lipopolysaccharides, and biofilm matrices, which hinder immune cell recognition and phagocytosis. In addition, many ESKAPE pathogens secrete immunomodulatory factors, such as proteases and superantigens, which disrupt host immune signaling and facilitate bacterial survival. Biofilm formation is particularly important because the biofilm matrix acts as a barrier to both immune responses and antimicrobial agents, promoting persistent infections. Furthermore, ESKAPE pathogens employ antigenic variations to avoid adaptive immune detection, constantly altering surface-expressed proteins to escape recognition by antibodies. Antibiotic resistance mechanisms, including the production of β-lactamases, efflux pumps, and target-site modifications, further complicate treatment and contribute to the chronic nature of these infections. Understanding these molecular interactions is crucial for developing novel therapeutic strategies.