Healthcare-Associated Infections: The Role of Microbial and Environmental Factors in Infection Control-A Narrative Review

Abstract

Healthcare-associated infections (HAIs), previously known as nosocomial infections, represent a significant threat to healthcare systems worldwide, prolonging patient hospital stays and the duration of antimicrobial therapy. One of the most serious consequences of HAIs is the increase in the rate of antibiotic resistance (AR) generated by the prolonged, frequent, and sometimes incorrect use of antibiotics, which leads to the selection of resistant bacteria, making treatment difficult and expensive, with direct consequences for the safety of patients and healthcare personnel. Therefore, timely and accurate diagnosis of HAIs is mandatory to develop appropriate infection prevention and control practices (IPC) and new therapeutic strategies. This review aimed to present the prevalence, risk factors, current diagnosis, including artificial intelligence (AI) and machine learning approaches, future perspectives in combating HAIs causative bacteria (phage therapy, microbiome-based interventions, and vaccination), and HAIs surveillance strategies. Also, we discussed the latest findings regarding the relationships of AR with climate change and environmental pollution in the context of the One Health approach. Phage therapy is an emerging option that can offer an alternative to ineffective antibiotic treatments for antibiotic-resistant bacteria causing HAIs. Clinical trials dealing with vaccine development for resistant bacteria have yielded conflicting results. Two promising strategies, fecal microbiota transplantation and probiotic therapy, proved highly effective against recurrent Clostridium difficile infections and have been shown to reduce HAI incidence in hospitalized patients undergoing antibiotic therapy. Artificial intelligence and machine learning systems offer promising predictive capabilities in processing large volumes of clinical, microbiological, and patient data but require robust data integration. Our paper argues that HAIs are still a global challenge, requiring stringent IPC policies, computer vision, and AI-powered tools. Despite promising avenues like integrated One Health approaches, optimized phage therapy, microbiome-based interventions, and targeted vaccine development, several knowledge gaps in clinical efficacy, standardization, and pathogen complexity remain to be answered.

Keywords: Dysbiosis; Hospital-acquired infections; Microbiome; Multidrug resistant; One-Health; Phage therapy; Vaccines.

Fig. 1

Schematic representation of the risk factors linked with HAIs (created with Adobe Illustrator CS6, Adobe Photoshop CS3)

Fig. 2

Workflow for complete and accurate diagnosis of HAIs. (1) Sample collection in HAI diagnosis (surgical wounds, blood, urine, and bronchial aspirates); (2) Isolation of the pure culture and identification by conventional methods (antibiotic susceptibility testing and biochemical identification); (3) DNA isolation and identification by NGS (bacterial DNA and 16S rRNA isolation and sequencing); (4) MS workflow for identifying microorganisms involves placing a fresh colony or biological samples on a MALDI target microplate, which will then be analyzed by mass spectrometry (created with Adobe Illustrator CS6, Adobe Photoshop CS3)

Fig. 3

Environmental changes connected with HAIs expansion. Temperature rise is linked with increased bacterial growth rates and heavy metals or biocides concentrations in soil and water, influencing AMR by co-resistance mechanisms. In addition, wastewater, healthcare and industrial facilities can lead to water pollution by antibiotic, microplastic, pesticide and toxic metals emission, influencing HAIs expansion (created with Adobe Illustrator CS6, Adobe Photoshop CS3)