How Does Hospital Microbiota Contribute to Healthcare-Associated Infections?

Healthcare-associated infections (HAIs) are still a global public health concern, associated with high mortality and increased by the phenomenon of antimicrobial resistance. Causative agents of HAIs are commonly found in the hospital environment and are monitored in epidemiological surveillance programs; however, the hospital environment is a potential reservoir for pathogenic microbial strains where microorganisms may persist on medical equipment surfaces, on the environment surrounding patients, and on corporal surfaces of patients and healthcare workers (HCWs). The characterization of hospital microbiota may provide knowledge regarding the relatedness between commensal and pathogenic microorganisms, their role in HAIs development, and the environmental conditions that favor its proliferation. This information may contribute to the effective control of the dissemination of pathogens and to improve infection control programs. In this review, we describe evidence of the contribution of hospital microbiota to HAI development and the role of environmental factors, antimicrobial resistance, and virulence factors of the microbial community in persistence on hospital surfaces.