Research: Fluorescence Microscopy-Based Protocol for Detecting Residual Bacteria on Medical Devices

How to study biofilms: technological advancements in clinical biofilm research

Biofilm formation is an important survival strategy commonly used by bacteria and fungi, which are embedded in a protective extracellular matrix of organic polymers. They are ubiquitous in nature, including humans and other animals, and they can be surface- and non-surface-associated, making them capable of growing in and on many different parts of the body. Biofilms are also complex, forming polymicrobial communities that are difficult to eradicate due to their unique growth dynamics, and clinical infections associated with biofilms are a huge burden in the healthcare setting, as they are often difficult to diagnose and to treat. Our understanding of biofilm formation and development is a fast-paced and important research focus. This review aims to describe the advancements in clinical biofilm research, including both in vitro and in vivo biofilm models, imaging techniques and techniques to analyse the biological functions of the biofilm.

Dissolvable alginate hydrogel-based biofilm microreactors for antibiotic susceptibility assays

Biofilms are found in many infections in the forms of surface-adhering aggregates on medical devices, small clumps in tissues, or even in synovial fluid. Although antibiotic resistance genes are studied and monitored in the clinic, the structural and phenotypic changes that take place in biofilms can also lead to significant changes in how bacteria respond to antibiotics. Therefore, it is important to better understand the relationship between biofilm phenotypes and resistance and develop approaches that are compatible with clinical testing. Current methods for studying antimicrobial susceptibility are mostly planktonic or planar biofilm reactors. In this work, we develop a new type of biofilm reactor-three-dimensional (3D) microreactors-to recreate biofilms in a microenvironment that better mimics those in vivo where bacteria tend to form surface-independent biofilms in living tissues. The microreactors are formed on microplates, treated with antibiotics of 1000 times of the corresponding minimal inhibitory concentrations (1000 × MIC), and monitored spectroscopically with a microplate reader in a high-throughput manner. The hydrogels are dissolvable on demand without the need for manual scraping, thus enabling measurements of phenotypic changes. Bacteria inside the biofilm microreactors are found to survive exposure to 1000 × MIC of antibiotics, and subsequent comparison with plating results reveals no antibiotic resistance-associated phenotypes. The presented microreactor offers an attractive platform to study the tolerance and antibiotic resistance of surface-independent biofilms such as those found in tissues.

A water-soluble alternative to simethicone for gastrointestinal endoscopy: Results of a clinical trial

During endoscopy, simethicone defoaming agents are commonly used to improve visualization, but they leave residues and impact drying. This clinical trial involved patients undergoing colonoscopy procedures with substantial bubbles that impeded mucosal wall visibility. As an alternative to simethicone, investigators evaluated a water-soluble, ginger-based gastrointestinal supplement (GI-Ease) that did not contain sugars, thickeners, or binding agents. In 112/114 cases (98%), the bubbles were reduced sufficiently to allow visualization of the gastrointestinal tract, with no adverse events.

The utility of lighted magnification and borescopes for visual inspection of flexible endoscopes

INTRODUCTION

Infections have been linked to damaged or contaminated endoscopes with visible defects. Endoscope processing standards and guidelines state endoscopes should be visually inspected every time they are used. This study evaluated a new visual inspection program using magnification and borescopes in an endoscopy department that had not previously utilized these tools.

METHODS

Site personnel were given visual inspection tools and training before systematically examining fully processed endoscopes twice during a 2-month period. A risk assessment protocol was used to determine whether endoscopes required recleaning, repair, or other action. Findings were documented using log sheets, photographs, and videotapes.

RESULTS

Visible damage and residue or debris were observed in 100% of 25 endoscopes at both assessments, and 76% required repair. Defects at baseline included scratches (88%); channel shredding or peeling (80%); adhesive band disintegration (80%); residual soil or debris (white 84%; black 68%; brown 40%; yellow/green 36%; and orange/red 8%); retained fluid (52%); and dents (40%). Findings were similar at follow-up.

DISCUSSION/CONCLUSIONS

Visual inspection with magnification and borescopes identified actionable defects that could interfere with processing effectiveness in 100% of endoscopes. Infection preventionists have a critical role to play in supporting processing personnel now that standards, guidelines, and manufacturer instructions recommend enhanced visual inspection of every endoscope, every time.