Neutrophil Extracellular Traps (NETs) Mediated Killing of Carbapenem-resistant Pseudomonas Aeruginosa Isolated From Hospital Acquired Infections in Assiut University Hospitals

Pseudomonas aeruginosa is one of the most common pathogens in healthcare-associated infections worldwide, causing ventilator-associated pneumonia, urinary tract infections in patients with long-term urinary catheterization, wound infections, bloodstream infections, and otitis (reynolds and kollef, 2021).

Carbapenem-resistant-P. aeruginosa infection is a prominent disease connected to healthcare due to multiple mechanisms, such as target alteration, active efflux, decreased permeability, and enzyme degradation (Tenover et al., 2022).

Neutrophils are the most prominent cellular component of the innate immune response and are essential for defense against bacterial infections (Chapple et al., 2023).

In addition to traditional antimicrobial processes of neutrophils, a unique web-like structure, is termed neutrophil extracellular traps (NETs), formed and released by highly active neutrophils. NETs consist of extracellular deoxyribonucleic acid (eDNA) filaments coated with histones and neutrophil granule proteins such as Myeloperoxidase (MPO), neutrophil elastase (NE), lactoferrin, cathepsins, calprotectin, LL-37, and defensin (Papayannopoulos, 2018).

MPO and NE are key components of NETs and play roles in their function and structure. MPO, a heme protein primarily stored in the granules of neutrophils, contributes significantly to microbial killing within NETs. It catalyzes the production of hypochlorous acid from hydrogen peroxide and chloride ions, a reaction central to the antimicrobial properties of NETs. NE, another granule protein extends to modulating inflammation and immune response (Islam et al., 2023).