2025 Portz Interdisciplinary Fellowship Recipient

Healthcare-associated infections (HAIs) pose significant risks to patients, particularly those wearing contaminated medical devices such as orthoses. Orthoses, widely used to immobilize extremities post-surgery or following injuries, are known to harbor pathogenic (harmful) bacteria, contributing to patient infections that could otherwise be preventable. This study, with its potential to significantly improve patient care, aims to conduct a comprehensive evaluation of inpatient and outpatient orthoses for bacterial contamination and potential biofilm formation, with an overarching goal of enhancing infection prevention strategies including the control of medical biofilms.

Biofilms are communities of the same or different types of bacteria living together on nonliving surfaces. Bacterial biofilms are sometimes referred to as “cities for microbes”. The presence of biofilms on medical devices has been well described in medical literature. These would include internal medical devices made from plastic polymers like urinary catheters. However, very little attention has been focused on externally worn medical devices made from thermoplastic materials used to make patient orthoses (splints) and radiation therapy immobilization forms.

Thermoplastics have low melting temperatures making them ideal to heat and then mold to patient body contours for immobilizing surgical wounds or burns. Thermoplastic orthoses have been shown to become contaminated during patient use with bacterial pathogens. Laboratory-based studies have also shown the ease of contaminating thermoplastic material used to make orthoses and radiation therapy forms. The proposed study seeks to determine the major bacterial “culprits” by recovering them from contaminated orthoses and examining ways to eliminate them as an infection threat.

The proposed study investigates whether or not biofilms are present on patient worn orthotic splints. This study consists of three phases: (1) real-time sampling of in-use patient orthoses in both outpatient and inpatient (e.g. burn ward) settings with subsequent identification of recovered pathogens (2) laboratory-based study applying antibiotic resistant (AR) bacteria to different thermoplastic splint materials to assess biofilm support, and (3) examination of patient splints using high-magnification scanning electron microscopy (SEM) to detect biofilms. This research will lead to a better understanding of how bacteria interact with thermoplastic orthoses in promoting biofilm formation and lead to strategies developed in conjunction with thermoplastic manufacturers to help prevent them.

With a high suspicion of finding AR Pseudomonas aeruginosa and opportunistic yeasts like Candida albicans, these microbes will be applied to four different thermoplastic materials with varying hydrophobicity (wettability) and examined for microbe interactions with each material. Unlike prior studies, this investigation will use serors discharge fluid instead of saline to apply these microbes. This better represents “real world” treatment conditions where wounds weep fluids that could promote biofilm formation.

Specific Aims (excerpt)

My primary aims are three-fold:

1. Evaluate the effects of differing thermoplastic material hydrophobicity on either promoting or inhibiting bacterial biofilm formation.
2. Identify the types/frequency of bacteria and/or fungi present on patient contact areas by sampling in-use patient orthoses in both inpatient and outpatient settings.
3. Determine if microbial biofilms are present on either sampled patient orthotic splints or when applied to thermoplastic sheets via direct examination by scanning electron microscopy (SEM).

Building on prior research, my proposed study seeks to further understand microbial populations and biofilm formation on orthoses in both inpatient and outpatient settings. The study will be structured in two major parts:

1. Sampling forms from inpatients in the burn ward at the Arnold Luterman Regional Burn Center and outpatients seen at the Outpatient Wound and Rehabilitation Clinic both located at USA Health University Hospital, Mobile, AL,
2. Perform a parallel in-laboratory investigation into biofilm formation on 4 thermoplastic sheets used to create patient orthoses of differing hydrophobicity. Pseudomonas aeruginosa is an antibiotic resistant, gram-negative, facultative anaerobe, that will be applied to each sheet due to the severe infections it causes with burn patients along with the expectation of recovering it from in-use orthoses (Jorgensen).

Interdisciplinary Research Components (excerpt)

The core of my research investigates how antibiotic-resistant bacteria adhere to thermoplastic materials used in orthotic fabrication. Through interdisciplinary collaboration, my research seeks to identify and quantify the types of antibiotic-resistant bacteria that adhere to thermoplastic orthotic materials and evaluate the effectiveness of current cleaning methods recommended to patients for maintaining their orthotic devices. This research also aims to develop and disseminate improved cleaning protocols to minimize the risks of HAIs and assess the impact of bacterial adherence on the safety and well-being of patients with open wounds.

This research project incorporates multiple disciplines such as Biomedical Sciences, occupational therapy, infectious diseases, and statistics. Creating an interdisciplinary team of professionals will further strengthen this study. Combining expertise from microbiology and infectious disease fields can only enhance the project's success and contributions to advancing occupational therapy practice. This collaborative effort will ensure a comprehensive understanding of the microbial risks associated with orthotic devices and facilitate the development of practical interventions that can be seamlessly integrated into patients' daily lives. Ultimately, this research aims to bridge the gap between clinical practice and patient education, leading to better health outcomes and fostering a sense of proactive health management among patients. In research, a weakness in one area of expertise may limit progress toward the overall goal. To mitigate this, seeking advice from another discipline can provide valuable insights, helping to address these weaknesses and enhance the project's understanding and outcomes.