ADAPTATION, PERSISTENCE, AND ANTIMICROBIAL RESISTANCE OF PSEUDOMONAS AERUGINOSA IN THE HOSPITAL ENVIRONMENT

Abstract

Pseudomonas aeruginosa is an opportunistic Gram-negative bacillus widely distributed in the environment and recognized as one of the main etiological agents of healthcare-associated infections, especially in immunocompromised patients or those undergoing invasive procedures. Its clinical relevance stems from the unique combination of high metabolic adaptability, the ability to persist in hospital environments, robust biofilm formation, and the expression of multiple antimicrobial resistance mechanisms. The global emergence and dissemination of multidrug-resistant strains have drastically reduced available therapeutic options, resulting in high morbidity and mortality rates, recurrent therapeutic failures, and a significant increase in hospital costs. P. aeruginosa exhibits intrinsic resistance to several classes of antibiotics, as well as acquired and adaptive mechanisms, including the production of β-lactamases, modification of molecular targets, reduced outer membrane permeability, overexpression of efflux pumps, and alterations in lipopolysaccharide structure. Additionally, biofilm organization confers high tolerance to antimicrobials and hampers the action of the host immune system, favoring chronic and persistent infections. In this context, this article provides a critical and integrated review of the main antimicrobial resistance mechanisms, epidemiological aspects, and hospital importance of Pseudomonas aeruginosa, emphasizing how these characteristics highlight the urgent need for the development of new antibiotics and innovative therapeutic strategies capable of overcoming existing resistance and effectively targeting multidrug-resistant and biofilm-associated bacteria.