Editorial for the Special Issue “Microbial Biofilms: Latest Advances and Prospects”

Microorganisms rarely exist as isolated planktonic cells in natural, clinical, or industrial environments. Instead, they predominantly organize into highly structured communities known as biofilms, in which microbial cells are embedded within a self-produced extracellular polymeric matrix [1,2,3]. This sessile mode of growth provides microorganisms with numerous adaptive advantages, including enhanced protection against environmental stresses, host immune responses, disinfectants, and antimicrobial agents [2]. Consequently, biofilms have emerged as one of the most important challenges in healthcare, food production, pharmaceutical manufacturing, agriculture, and environmental management [4].

The growing recognition of biofilms as major contributors to persistent infections, antimicrobial resistance, industrial contamination, and environmental adaptation has stimulated intensive research efforts aimed at understanding their formation, regulation, ecological significance, and susceptibility to control strategies [5,6,7]. In clinical settings, biofilms are estimated to be associated with the majority of chronic microbial infections and play a central role in the colonization of medical devices, chronic wounds, respiratory tract infections, and healthcare-associated infections [1,2,3,4]. Simultaneously, biofilms are increasingly recognized for their beneficial applications in biotechnology, agriculture, bioremediation, and sustainable production systems, demonstrating the dual nature of these microbial communities [8,9,10]. This dual role is particularly relevant within the One Health framework, which highlights the interconnected impacts of microbial communities on human, animal, and environmental health, as well as agricultural sustainability [11,12].

This Special Issue, entitled “Microbial Biofilms: Latest Advances and Prospects”, was conceived to provide a multidisciplinary platform for researchers investigating the biology, ecology, control, and applications of microbial biofilms. The contributions published in this collection illustrate the remarkable diversity of contemporary biofilm research, encompassing public health challenges, pharmaceutical contamination, natural-product-based antibiofilm strategies, innovative antimicrobial technologies, oral health, and agricultural applications.

The international scope of this Special Issue is reflected in the geographic diversity of its contributions, which include studies from Europe, South America, the Middle East, and Asia. This broad representation highlights the global relevance of biofilm research and demonstrates how challenges associated with biofilm formation, antimicrobial resistance, contamination control, and biotechnological applications transcend geographical boundaries. The contributions gathered in this collection provide valuable perspectives from different scientific communities and application sectors, reinforcing the multidisciplinary and worldwide nature of contemporary biofilm research.

One of the major themes addressed in this Special Issue is the role of biofilms as persistent sources of contamination and infection. Silva-Santana et al. [13] provided a comprehensive review of biofilms formed by members of the Burkholderia cepacia complex (Bcc), highlighting their relevance in pharmaceutical contamination and healthcare-associated infections. The authors discussed the molecular mechanisms governing biofilm formation, quorum sensing regulation, intrinsic antimicrobial resistance, and the remarkable ability of these microorganisms to survive in pharmaceutical products and hospital environments. Their work emphasizes the growing concern surrounding contamination events involving Bcc species and reinforces the need for improved monitoring, detection, and control strategies within pharmaceutical manufacturing systems.

The challenge posed by biofilm-associated antimicrobial resistance was further explored through investigations evaluating novel antimicrobial agents and alternative therapeutic approaches. Andrade et al. [14] reported the antibacterial and antibiofilm activity of a photoactivated ruthenium nitrocomplex, demonstrating that light activation significantly enhanced antimicrobial efficacy. The study revealed promising activity against clinically relevant bacterial pathogens, including biofilm-forming strains, while also showing low cytotoxicity toward mammalian cells. Of particular note was the observed synergistic interaction with conventional antibiotics, reinforcing the potential of metal-based compounds and photodynamic approaches as innovative tools for combating resistant biofilm-associated infections.

Natural products continue to attract considerable attention as sources of new antimicrobial and antibiofilm molecules. Two articles included in this Special Issue exemplify this growing research trend. Krapež et al. [15] investigated the phytochemicals linalool and citronellal against biofilms formed by Escherichia coli and Staphylococcus aureus. Their findings demonstrated that linalool exhibited significant antibiofilm activity, affecting bacterial viability, respiratory activity, membrane integrity, and biofilm biomass. These results support the increasing interest in plant-derived compounds as environmentally friendly alternatives to conventional disinfectants and antimicrobial agents.

Similarly, Aati et al. [16] evaluated the antimicrobial and antibiofilm properties of medicinal plant-derived honeys against ESKAPE pathogens, a group of microorganisms recognized for their clinical relevance and multidrug resistance. By combining microbiological assays, metabolomic profiling, and molecular docking approaches, the authors identified bioactive compounds potentially involved in β-lactamase inhibition. The study not only demonstrated significant antibacterial and antibiofilm activities but also highlighted the value of integrating experimental and computational methodologies to accelerate the discovery of bioactive natural products capable of overcoming antimicrobial resistance mechanisms.

Beyond healthcare-associated applications, biofilms also play important roles in oral health and dentistry. Badnjević et al. [17] investigated the early development of Streptococcus mutans biofilms on orthodontic aligner materials and evaluated strategies for biofilm control using chlorhexidine-based antiseptics and mechanical brushing. Their findings demonstrated that treatment efficacy depended strongly on exposure time and supported the combined use of antiseptic treatment and brushing as an effective strategy for preventing biofilm accumulation on orthodontic devices. This work contributes valuable information for improving oral hygiene protocols and minimizing biofilm-related complications associated with increasingly popular orthodontic treatments.

While biofilms are frequently regarded as problematic structures, they may also provide significant benefits in environmental and agricultural contexts. This aspect is elegantly illustrated by the work of Sarti et al. [18], who evaluated the application of Bacillus subtilis biofilms as bioinoculants for tomato cultivation in lead-contaminated substrates. Their study demonstrated that biofilm inoculation improved seed germination, plant growth, biomass accumulation, and fruit production, even under conditions of heavy-metal stress. These findings reinforce the growing recognition that beneficial biofilms can be harnessed to enhance agricultural sustainability, improve crop productivity, and mitigate environmental contamination.

Taken together, the articles published in this Special Issue highlight the remarkable complexity and versatility of microbial biofilms. On one hand, biofilms contribute to persistent infections, antimicrobial resistance, pharmaceutical contamination, and medical-device colonization. On the other hand, they offer promising opportunities for sustainable agriculture, environmental remediation, and biotechnological innovation. This duality underscores the importance of developing a comprehensive understanding of biofilm biology that integrates perspectives from microbiology, chemistry, medicine, engineering, environmental sciences, and agricultural research.

The studies presented in this collection also reflect several emerging trends in contemporary biofilm research. These include the search for alternative antimicrobial agents derived from natural products, the development of innovative metal-based antimicrobial compounds, the application of advanced imaging and analytical techniques for biofilm characterization, the integration of metabolomics and computational modeling, and the exploration of biofilm-based technologies for sustainable agricultural production. Such approaches are increasingly aligned with the One Health concept, recognizing the interconnectedness of human, animal, environmental, and agricultural health in addressing microbial challenges.

Despite substantial advances in recent decades, numerous questions remain unanswered. Future investigations should focus on polymicrobial biofilms, microbial interactions within complex communities, host–biofilm relationships, mechanisms underlying biofilm resilience, and the development of more effective antibiofilm therapies. In addition, advances in artificial intelligence, systems biology, nanotechnology, and omics sciences are expected to provide powerful new tools for understanding and controlling biofilm-associated processes.

In conclusion, the contributions collected in this Special Issue provide a comprehensive overview of the latest advances in microbial biofilm research, highlighting both the challenges and opportunities associated with these complex microbial communities. The published studies illustrate the broad impact of biofilms across multiple sectors, ranging from healthcare and pharmaceutical manufacturing to dentistry, agriculture, and environmental sustainability. Collectively, they demonstrate how multidisciplinary approaches integrating microbiology, chemistry, materials science, computational modeling, and biotechnology are driving the development of innovative strategies for biofilm control and exploitation.

As antimicrobial resistance continues to threaten global health and biofilm-associated problems remain difficult to manage, the generation of new knowledge and technologies will be essential. We hope that the findings presented in this Special Issue will stimulate further interdisciplinary collaborations and inspire future investigations aimed at understanding biofilm biology and developing effective solutions for biofilm-related challenges within a One Health framework.