Dear Colleagues,

The concept that microbial biofilms can enable the survival of microorganisms in various compartments of the human body, as well as on the surface of prostheses and therapeutic devices, is strongly supported by in vitro studies, which have increased exponentially over the past two decades.

However, our understanding of the natural history of this important bacterial growth phenotype remains limited. While biofilms have been demonstrated in vitro in numerous studies, it is worth noting that, with rare exceptions, biofilms were not perfectly correlated with disease.

Most of these studies consist, in fact, of basic science investigation, surveys of clinical isolate collections, with limited clinical relevance, as they do not shed light on the influence of the biofilm phenotype on the clinical outcomes of infected human patients. Furthermore, they suffer from a lack of standardization in biofilm laboratory methods, which makes it difficult to make a meaningful comparison of data across studies and species, and is probably the reason that conflicting results arose from studies looking for an association between biofilm-forming bacteria and more severe clinical outcomes.

More informative clinical studies correlating biofilm formation to patient data, and indicating biofilm phenotype as a risk factor for adverse clinical outcomes are needed, both to advance our understanding of the role of biofilms in human disease and to identify new therapeutic strategies/targets.

For these reasons, this Special Issue welcomes research articles, review articles, short communications and case reports focused mainly (but not only) on the following:

• mechanisms underlying the antimicrobial tolerance of biofilm communities;
• mechanisms in which bacterial biofilms evade, dampen, or actively counterattack the host immune response;
• definition of clinical indicators for biofilm formation (i.e., failure of appropriate antibiotic treatment, recalcitrance to appropriate antibiotic treatment, recurrence of delayed healing on cessation of antibiotic treatment, and unresponsiveness to antimicrobial therapy);
• in vitro predictors of biofilm formation and therapeutic outcomes for biofilm-related infections;
• non-device-related chronic biofilm disease;
• device-related biofilm disease;
• biofilm-related device malfunction;
• classic (antibiotic treatment) and alternative therapeutic strategies to combat biofilm-related infections;
• evaluation of the clinical impact of biofilm formation in human and animal studies;
• standardization of in vitro and in vivo models that allow for biofilm formation under environmental conditions similar to the infection site.

Prof. Dr. Giovanni Di Bonaventura
Dr. Arianna Pompilio
Guest Editors

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• biofilms
• clinical studies
• biofilm microbial interaction
• biofilm-related infections device-related biofilm diseases
• antibiotic tolerance
• host immune response evasion
• biofilm clinical indicators