Multidrug Resistant Microorganisms (MDR) and Biofilm Producers: A Challenge for Hospital Infectious Control

Antimicrobial Resistance (AMR) now represents a major threat to contemporary health care, especially in hospitals, where repeated antimicrobial exposure selects for and facilitates the dissemination of Multidrug-Resistant (MDR) microorganisms. Biofilm growth adds another layer of persistence by increasing microbial tolerance, supporting long-term colonization of medical devices, and worsening clinical and economic outcomes. This narrative review synthesizes evidence on MDR biofilm-forming microorganisms, focusing on resistance mechanisms, epidemiological relevance, and developing therapeutic options. Frequently reported agents include Methicillin-Resistant Staphylococcus Aureus (MRSA), Vancomycin-Resistant Enterococcus (VRE), Pseudomonas aeruginosa, Acinetobacter baumannii, β-lactamase-producing Klebsiella pneumoniae, and Candida spp. Available evidence supports reciprocal reinforcement between antimicrobial resistance and biofilm physiology; organisms growing in sessile communities may tolerate antimicrobial concentrations 10–1000 times higher than comparable planktonic cells. In Latin America, mortality associated with MDR infections has approached 45%. Although nanotechnology, phytochemicals, bacteriophages, and combination regimens show promising antibiofilm effects, most supporting data remain experimental or preclinical. Meaningful reduction of MDR biofilm-associated infection will require coordinated antimicrobial stewardship, stronger epidemiological surveillance, and therapeutic interventions with demonstrated clinical antibiofilm effectiveness.