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Pathogenicity of Hansenula anomala in model of immunocompromised mice
J R Cermeño-Vivas1, J M Torres-Rodríguez, J M Corominas
1Department of Parasitology and Microbiology, Universidad de Oriente, Ciudad Bolívar, Venezuela.
Abstract:
Systemic infections caused by opportunistic fungi have shown an increased frequency in the past 10 years, particularly in immunocompromised patients. Hansenula anomala is an ascosporogenous yeast of the Ascomycetes class found in the skin, throat, and digestive tract transient normal flora. This study was conducted to compare the pathogenicity of H. anomala and Candida albicans in a model of immunocompromised mice. Thirty-eight Swiss mice were divided into two groups as follows: 30 animals received an intraperitoneal (i.p.) injection of cyclophosphamide (200 mg/kg) four days before the induction of infection with H. anomala (1 x 10(6) yeasts/mL), and 8 animals received 100 mg/kg of cyclophosphamide at 3-day intervals during 3 weeks before inoculation of 1 x 10(7) yeasts/mL. All animals were treated with amoxicillin/clavulanic acid (40 mg/kg) four days before induction of infection. A group of mice inoculated with C. albicans (ATCC 64548) served as control. Tissue samples from the lung, spleen, liver, and kidney for histological and mycologic studies were obtained at necropsy. In each animal, the number of viable yeasts per gram of kidney was determined. The organs most frequently infected by H. anomala were the kidneys and the liver (20%), and the lung (10%). However, in conditions of sustained immunosuppression, H. anomala was found in 65.5% of the organs examined. It is concluded that in an experimental model of immunocompromised mice, the pathogenicity of H. anomala was low.
Insights
Opportunistic fungal infections are rising, especially in immunocompromised individuals. This study found Hansenula anomala has low pathogenicity in immunocompromised mice compared to Candida albicans.
Area of Science:
- Medical Mycology
- Infectious Diseases
- Immunocompromised Host Research
Background:
- Systemic fungal infections by opportunistic pathogens are increasing, particularly in immunocompromised patients.
- Hansenula anomala, a yeast, is part of the normal flora but its pathogenic potential is under investigation.
- Candida albicans serves as a benchmark for fungal pathogenicity studies.
Purpose of the Study:
- To compare the pathogenicity of Hansenula anomala and Candida albicans in an experimental model.
- To evaluate H. anomala's infection potential in immunocompromised mice.
Main Methods:
- Swiss mice were immunosuppressed using cyclophosphamide and treated with amoxicillin/clavulanic acid.
- Mice were inoculated with H. anomala or Candida albicans.
- Histological and mycological analyses were performed on tissue samples from multiple organs.
Main Results:
- H. anomala primarily infected kidneys and liver (20%), and lungs (10%) under standard immunosuppression.
- Under sustained immunosuppression, H. anomala was detected in 65.5% of examined organs.
- The study established a comparative model for fungal pathogenicity.
Conclusions:
- Hansenula anomala demonstrated low pathogenicity in the experimental model of immunocompromised mice.
- Further research is needed to understand the clinical significance of H. anomala in immunocompromised individuals.