## 6 Biofilms and Healthcare-Associated Infections  
### Biofilms in Hospital Environments: A Persistent Challenge  
Biofilms on hospital surfaces represent a significant issue due to their essential involvement in HAIs. Biofilms are surrounded by a protective EPS, which increases their survival and resistance to disinfection efforts. Biofilms are commonly found on moist and dry surfaces in diverse hospital environments, including medical equipment, furniture, and high-contact areas [169; 170]. Moist biofilms, commonly observed in sinks and drains, are well-documented; however, the emergence of dry surface biofilms (DSBs) presents a significant challenge in infection control. Research demonstrates that approximately 95% of sampled hospital surfaces contain DSBs, underscoring their prevalence and persistence in healthcare settings [171]. DSBs pose distinct challenges, challenging the traditional notion that low-moisture environments are inhospitable to microbial survival. The EPS matrix facilitates the retention of localized moisture and nutrients by microorganisms, thereby supporting their survival on surfaces such as bed rails, tables, electronic devices, and door handles. This adaptation enables pathogens to survive for prolonged periods--weeks or months--on dry surfaces, even in adverse environmental conditions [172; 173]. Biofilms, especially DSBs, present unique infection prevention and control challenges. Biofilms act as reservoirs for pathogens that may be transmitted via direct or indirect contact with patients, healthcare personnel, and medical devices [174]. Research indicates that _S. aureus_ and _Clostridioides difficile_ can contaminate gloves, hands, and clothing, thus promoting the transmission of infections in healthcare settings [175; 176]. In contrast to moist biofilms, which are generally localized in specific environments such as plumbing systems, DSBs exhibit a broader distribution, often present on high-touch surfaces, thereby enhancing their potential for cross-contamination [177]. The significant role of biofilms, especially on dry surfaces, in exacerbating antimicrobial resistance (AMR) is a matter of considerable concern. The biofilm matrix functions as a physical barrier, limiting the penetration of antimicrobial agents and establishing a microenvironment conducive to the horizontal transfer of resistance genes. This protected environment facilitates the survival and proliferation of MDR and XDR pathogens, significantly complicating infection prevention and treatment strategies [123; 178]. _A. buumannmi_ and _P. aeruginosa_, known for their biofilm-forming capabilities, are commonly found in hospital environments and are often associated with outbreaks of HAIs [179; 180]. The ability to form biofilms on dry surfaces enhances resilience and increases the risk of antimicrobial resistance dissemination. The microbial diversity in hospital biofilms is extensive, including bacteria and fungi. Pathogens, including, MDR ESAPEE; _A. buumannii_, _K. pneumoniae_, _Enterobacter_ species, _MRSA_, _E. coli_, _P. aeruginosa_, and _Enterococcus faecalis_ and _facetum_, are frequently detected in biofilms on dry hospital surfaces [181; 182; 183]. _MRSA_ demonstrates a notable capacity for survival on low-moisture surfaces, including bed rails and hospital furniture, where its biofilm state protects against desiccation and chemical disinfectants [184; 185]. MDR _P. aeruginosa_ and _E. coli_ can form biofilms on dry surfaces, even though they typically prefer moist environments [186; 187]. Fungal pathogens such as _C. albicans_ and _Candida auris_ contribute to biofilm formation on hospital surfaces. _C. auris_ is associated with notable healthcare-related outbreaks, attributed to its capacity to form resilient biofilms, endure on hospital surfaces, and resist cleaning agents [188; 189]. Fungal biofilms pose significant risks for immunocompromised patients, potentially resulting in severe systemic infections.