A Delayed Inoculation Model of Chronic <em>Pseudomonas aeruginosa</em> Wound Infection

Abstract

Pseudomonas aeruginosa (P. aeruginosa) is a major nosocomial pathogen of increasing relevance to human health and disease, particularly in the setting of chronic wound infections in diabetic and hospitalized patients. There is an urgent need for chronic infection models to aid in the investigation of wound pathogenesis and the development of new therapies against this pathogen. Here, we describe a protocol that uses delayed inoculation 24 hours after full-thickness excisional wounding. The infection of the provisional wound matrix present at this time forestalls either rapid clearance or dissemination of infection and instead establishes chronic infection lasting 7-10 days without the need for implantation of foreign materials or immune suppression. This protocol mimics a typical temporal course of post-operative infection in humans. The use of a luminescent P. aeruginosa strain (PAO1:lux) allows for quantitative daily assessment of bacterial burden for P. aeruginosa wound infections. This novel model may be a useful tool in the investigation of bacterial pathogenesis and the development of new therapies for chronic P. aeruginosa wound infections.

Filamentous bacteriophage delays healing of Pseudomonas-infected wounds

“…We previously pioneered this model to study the initial establishment of Pa wound infections in otherwise healthy C57BL/6 mice in the absence of foreign material, diabetes, or other forms of immune suppression. 33 , 36 Here, we have adapted this model to study wound healing in the setting of infection over a 2-week time period. In brief, we generated bilateral, full-thickness, excisional wounds on the dorsum of mice.…”

Theranostic gold-in-gold cage nanoparticles enable photothermal ablation and photoacoustic imaging in biofilm-associated infection models

“…The PTNP-with-laser group was the only group that showed no infections in the BLI images after 5 minutes of treatment (Figure 8B). To confirm the reliability of this technique, animals were euthanized, and wound tissues were extracted for bacterial plate counting (75)(76)(77).…”

“…To test the ability to kill bacteria in vivo, a modified S . aureus (Xen36 luminescent strain, a pathogen known to cause wound infections) delayed-inoculation wound infection model and surgery protocols were performed as described previously ( 74 , 77 ). Male 8-to-12-week-old C57BL/6J mice were bred in the vivarium at Stanford University.…”

Optimized Dosing and Delivery of Bacteriophage Therapy for Wound Infections

“…Thus, we developed a mouse PT model with delayed treatment. This model builds on our development of a chronic Pa wound infection model incorporating bacterial biofilms and chronic infection [74][75][76] . In contrast to other murine wound infection models, which introduce phage treatments within a few hours of or even along with bacterial inoculation, we delayed phage treatment to mice 24 hours post-infection (Fig.…”