Antimicrobial strategies for musculoskeletal infections are typically first developed with in vitro models. The In Vitro Section of the 2023 Orthopedic Research Society Musculoskeletal Infection international consensus meeting (ICM) probed our state of knowledge of in vitro systems with respect to bacteria and biofilm phenotype, standards, in vitro activity, and the ability to predict in vivo efficacy. A subset of ICM delegates performed systematic reviews on 15 questions and made recommendations and assessment of the level of evidence that were then voted on by 72 ICM delegates. Here, we report recommendations and rationale from the reviews and the results of the internet vote. Only two questions received a ≥90% consensus vote, emphasizing the disparate approaches and lack of established consensus for in vitro modeling and interpretation of results. Comments on knowledge gaps and the need for further research on these critical MSKI questions are included.

Bacterial biofilms are a major threat to human health, causing persistent infections that lead to millions of fatalities worldwide every year. Biofilms also cause billions of dollars of damage annually by interfering with industrial processes. Recently, cationic pillararenes were found to be potent inhibitors of biofilm formation in Gram-positive bacteria. To identify the structural features of pillararenes that result in antibiofilm activity, we evaluated the activity of 16 cationic pillar[5]arene derivatives including that of the first cationic water-soluble pillar[5]arene-based rotaxane. Twelve of the derivatives were potent inhibitors of biofilm formation by Gram-positive pathogens. Structure activity analyses of our pillararene derivatives indicated that positively charged head groups are critical for the observed antibiofilm activity. Although certain changes in the lipophilicity of the substituents on the positively charged head groups are tolerated, dramatic elevation in the hydrophobicity of the substituents or an increase in steric bulk on these positive charges abolishes the antibiofilm activity. An increase in the overall positive charge from 10 to 20 did not affect the activity significantly, but pillararenes with 5 positive charges and 5 long alkyl chains had reduced activity. Surprisingly, the cavity of the pillar[n]arene is not essential for the observed activity, although the macrocyclic structure of the pillar[n]arene core, which facilitates the clustering of the positive charges, appears important. Interestingly, the compounds found to be efficient inhibitors of biofilm formation were nonhemolytic at concentrations that are ∼100-fold of their MBIC50 (the minimal concentration of a compound at which at least 50% inhibition of biofilm formation was observed compared to untreated cells). The structure-activity relationship guidelines established here pave the way for a rational design of potent cationic pillar[n]arene-based antibiofilm agents.

Fluorescence in situ hybridization (FISH) is a well-established technique that allows the detection of microorganisms in diverse types of samples (e.g., clinical, food, environmental samples, and biofilm communities). The FISH probe design is an essential step in this technique. For this, two strategies can be used, the manual form based on multiple sequence alignment to identify conserved regions and programs/software specifically developed for the selection of the sequence of the probe. Additionally, databases/software for the theoretical evaluation of the probes in terms of specificity, sensitivity, and thermodynamic parameters (melting temperature and Gibbs free energy change) are used. The purpose of this chapter is to describe the essential steps and guidelines for the design of FISH probes (e.g., DNA and Nucleic Acid Mimic (NAM) probes), and its theoretical evaluation through the application of diverse bioinformatic tools.

The International Caries Consensus Collaboration (ICCC) presented recommendations on terminology, methods of carious tissue removal and managing cavitated carious lesions. It identified \'dental caries\' as the disease that dentists should manage by controlling the activity of existing cavitated lesions by preserving as much hard tissue as possible, maintaining pulp sensibility and retaining functional teeth in the long-term. The ICCC recommended the level of hardness as the criterion for determining the clinical consequences of the process of demineralisation and defined new strategies for the selective removal of carious tissue. The starting point is to effectively remove the biofilm from cavitated carious lesions. Only when cavitated carious lesions are either non-cleansable or can no longer be sealed, are restorative interventions indicated, with due regard for the principles of a minimally invasive approach. Applying a restoration facilitates biofilm removal, guards the pulpodental complex and restores form, function and aesthetics.
De International Caries Consensus Collaboration (ICCC) heeft aanbevelingen gepresenteerd over de terminologie, de wijze van verwijderen van carieus weefsel en het behandelen van gecaviteerde carieuze laesies. Ze definieert cariës als de ziekte die behandeld dient te worden door de cariësactiviteit in gecaviteerde dentinelaesies te beheersen, door zoveel mogelijk gezond tandweefsel te behouden, de pulpa te beschermen en gebitselementen lang te laten functioneren. De ICCC beveelt de mate van hardheid aan als criterium om de klinische gevolgen van het demineralisatieproces te bepalen en definieert nieuwe strategieën om carieus weefsel selectief te verwijderen. Uitgangspunt is het adequaat verwijderen van de biofilm uit de gecaviteerde dentinelaesie. Alleen wanneer de gecaviteerde dentinelaesie niet gereinigd of verzegeld kan worden, is het geïndiceerd om invasief te interveniëren, met inachtneming van de principes van een minimaal invasieve benadering. Het aanbrengen van een restauratie vergemakkelijkt plaqueverwijdering, beschermt het pulpodentale complex en herstelt vorm, functie en esthetiek.

Currently, accurate diagnosis and successful treatment of infection after fracture fixation (IAFF) still impose great challenges. According to the onset of infection symptoms after implantation, IAFF is classified as early infection (<2 weeks), delayed infection (2∼10 weeks) and late infection (>10 weeks). Confirmation of IAFF should be supported by histopathological tests of intraoperative specimens which confirm infection, cultures from at least two suspected infection sites which reveal the same pathogen, a definite sinus or fistula which connects directly the bone or the implant, and purulent drainage from the wound or presence of pus during surgery. Diagnosis of IAFF is built on comprehensive assessment of medical history, clinical signs and symptoms of the patient, and imaging and laboratory tests. The gold standard of diagnosis is histopathological tests. Treatment of IAFF consists of radical debridement, adequate irrigation, implant handling, systematic and local antibiotics, reconstruction of osseous and/or soft tissue defects, and functional rehabilitation of an affected limb. Early accurate diagnosis and appropriate treatment of IAFF play a key role in increasing the cure rate, reducing infection recurrence and disability risk, restoring limb function and improving quality of life of the patient.

OBJECTIVE: To achieve international consensus relating to clinical indicators for a chronic wound, wound infection and biofilm presence to inform the development of international clinical guidance for assessing and managing wound infection.
METHODS: An online Delphi consensus process of international key opinion leaders in infection was undertaken. A literature search underpinned the development of issue statements related to terminology, emerging topics and debate in the field of wound infection. Experts participated in three rounds of consensus voting, sharing their opinions and indicating their level of agreement with the issue statements. Votes were calculated using web-based software that implements a nominal group voting methodology previously published by Research and Development/University of California at Los Angeles.
RESULTS: A total of 14 experts took part in the development process. Consensus was reached on clinical indicators of wound chronicity, wound infection and biofilm presence. Agreement was also reached that the term \'critical colonisation\' should no longer be used to refer to a stage in the wound infection continuum.
CONCLUSIONS: Outcomes from the consensus process were used to inform the development of international, evidence-informed guidance on the assessment and treatment of wound infection to promote improved outcomes for people with wounds.

Biofilm-associated implant-related bone and joint infections are clinically important due to the extensive morbidity, cost of care and socioeconomic burden that they cause. Research in the field of biofilms has expanded in the past two decades, however, there is still an immense knowledge gap related to many clinical challenges of these biofilm-associated infections. This subject was assigned to the Biofilm Workgroup during the second International Consensus Meeting on Musculoskeletal Infection held in Philadelphia USA (ICM 2018) (https://icmphilly.com). The main objective of the Biofilm Workgroup was to prepare a consensus document based on a review of the literature, prepared responses, discussion, and vote on thirteen biofilm related questions. The Workgroup commenced discussing and refining responses prepared before the meeting on day one using Delphi methodology, followed by a tally of responses using an anonymized voting system on the second day of ICM 2018. The Working group derived consensus on information about biofilms deemed relevant to clinical practice, pertaining to: (1) surface modifications to prevent/inhibit biofilm formation; (2) therapies to prevent and treat biofilm infections; (3) polymicrobial biofilms; (4) diagnostics to detect active and dormant biofilm in patients; (5) methods to establish minimal biofilm eradication concentration for biofilm bacteria; and (6) novel anti-infectives that are effective against biofilm bacteria. It was also noted that biomedical research funding agencies and the pharmaceutical industry should recognize these areas as priorities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications.

OBJECTIVE: The long-term impact of treatment strategies proposed by the IDSA guidelines for patients presenting with methicillin-susceptible S. aureus (MSSA) prosthetic joint infection (PJI) is not well-known.
METHODS: Retrospective (2000-2010) cohort study including patients presenting with MSSA hip or knee PJI. A univariate Cox analysis was performed to determine if the non-compliance with IDSA surgical guidelines was a risk factor for treatment failure.
RESULTS: Eighty-nine patients with a mean follow-up of 2.8 years were included. Non-compliance with IDSA surgical guidelines was associated with treatment failure (hazard ratio 2.157; 95% CI [1.022-4.7]). The American Society of Anesthesiologists score, inadequate antimicrobial therapy, and a rifampicin-based regimen did not significantly influence patient outcome.
CONCLUSIONS: Based on the IDSA guidelines, if a patient presenting with MSSA PJI is not eligible for implant retention, complete implant removal is needed to limit treatment failure.

Despite a growing consensus that biofilms contribute to a delay in the healing of chronic wounds, conflicting evidence pertaining to their identification and management can lead to uncertainty regarding treatment. This, in part, has been driven by reliance on in vitro data or animal models, which may not directly correlate to clinical evidence on the importance of biofilms. Limited data presented in human studies have further contributed to the uncertainty. Guidelines for care of chronic wounds with a focus on biofilms are needed to help aid the identification and management of biofilms, providing a clinical focus to support clinicians in improving patient care through evidence-based medicine.
A Global Wound Biofilm Expert Panel, comprising 10 clinicians and researchers with expertise in laboratory and clinical aspects of biofilms, was identified and convened. A modified Delphi process, based on published scientific data and expert opinion, was used to develop consensus statements that could help identify and treat biofilms as part of the management of chronic nonhealing wounds. Using an electronic survey, panel members rated their agreement with statements about biofilm identification and treatment, and the management of chronic nonhealing wounds. Final consensus statements were agreed on in a face-to-face meeting.
Participants reached consensus on 61 statements in the following topic areas: understanding biofilms and the problems they cause clinicians; current diagnostic options; clinical indicators of biofilms; future options for diagnostic tests; treatment strategies; mechanical debridement; topical antiseptics; screening antibiofilm agents; and levels of evidence when choosing antibiofilm treatments.
This consensus document attempts to clarify misunderstandings about the role of biofilms in clinical practice, and provides a basis for clinicians to recognize biofilms in chronic nonhealing wounds and manage patients optimally. A new paradigm for wound care, based on a stepped-down treatment approach, was derived from the consensus statements.