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Published on: December 1, 2017
Ascending renal infection following experimental candiduria by Candida tropicalis in immunocompromised mice
Francieli Gesleine Capote-Bonato1, Denis Vinicius Bonato1, Ilan Munhoz Ayer2
1Postgraduate Program in Animal Science with Emphasis on Bioactive Products, Paranaense University (UNIPAR), Praça Mascarenhas de Moraes, 4282-Centro, 87502-210, Umuarama, Paraná, Brazil.
Abstract:
The present study evaluated renal infection resulting from the implantation of C. tropicalis in the bladder of immunosuppressed mice. Yeasts were implanted in two manners: planktonic and via preformed biofilm on a small catheter fragment (SCF). Renal histopathology and cultures was performed 72 and 144 h after cystotomy was carried out in mice from three groups: group I contained non-contaminated mice implanted with a sterile SCF; group II mice received a sterile SCF plus a yeast suspension containing 1 × 107 yeasts/mL in a planktonic form; group III mice were implanted with a SCF containing preformed C. tropicalis biofilm. Viable yeasts were found in the kidneys of mice from both groups II and III. However, after 72 h the planktonic cells (group II) invaded more quickly than the sessile cells (group III). Over a longer period (144 h), group III exhibited a more invasive infection (50% of the animals presented renal infection and the renal fungal load was 3.2 log10 CFU/g tissue) than in group II, where yeasts were not found. C. tropicalis introduced into the bladder in two ways (in planktonic or biofilm form) were able to reach the kidney and establish a renal fungal infection, causing interstitial disorders. The data of the present study therefore support the hypothesis of an ascending pathway for renal infections by C. tropicalis. Furthermore, the biofilm resulted in a greater and progressive risk of renal infection, attributed to the slow detachment of the yeasts.
Insights
Candida tropicalis can cause kidney infections in mice through an ascending pathway from the bladder. Biofilm-associated infections pose a greater, progressive risk compared to planktonic yeast cells.
Area of Science:
- Medical Mycology
- Infectious Diseases
- Urology
Background:
- Renal infections can arise from urinary tract pathogens.
- Candida tropicalis is an opportunistic fungal pathogen.
- Biofilm formation on medical devices is a significant clinical concern.
Purpose of the Study:
- To investigate the renal infection potential of Candida tropicalis introduced into the bladder.
- To compare infection dynamics between planktonic and biofilm forms of C. tropicalis.
- To evaluate the role of biofilm in ascending urinary tract infections.
Main Methods:
- Immunosuppressed mice underwent cystotomy and bladder inoculation with C. tropicalis.
- Yeasts were introduced as planktonic cells or via preformed biofilm on a small catheter fragment (SCF).
- Renal histopathology and cultures were performed at 72 and 144 hours post-inoculation.
Main Results:
- Viable C. tropicalis were detected in kidneys from both planktonic and biofilm inoculation groups.
- Planktonic cells showed faster initial kidney invasion (72h) than biofilm cells.
- At 144h, biofilm inoculation led to a more persistent and invasive renal infection (50% incidence, 3.2 log10 CFU/g).
Conclusions:
- C. tropicalis can ascend from the bladder to establish renal infections in immunosuppressed mice.
- Biofilm formation significantly increases the risk and progression of renal candidiasis.
- The study supports an ascending route for C. tropicalis renal infections, with biofilms posing a sustained threat.
