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[Rapid identification and susceptibility to killer toxins of yeasts isolated from non-systemic mycoses]
M P Sangorrín1, C A Lopes, A Rivero
1Departamento de Química, Laboratorio de Microbiología y Biotecnología, Facultad de Ingeniería, Universidad Nacional del Comahue, Buenos Aires 1400 (8300) Neuquén, Argentina.
Abstract:
Rapid identification and susceptibility to killer toxins of yeasts isolated from non-systemic mycoses. The use of quick and reliable yeast identification methods, as well as the development of new antifungal agents with more specific targets, will enable a more efficient treatment of mycoses. In the present work, a total of 53 clinical isolates obtained from non-systemic infections in Neuquén Hospitals and an ophthalmologic clinic in Buenos Aires during 2005, were identified by means of a rapid molecular method (ITS1-5.8S ADNr-ITS2 PCR-RFLP). Additionally, the killer susceptibility of the isolates was tested against reference and indigenous killer yeasts on plate tests. Eight yeast species were identified among the clinical isolates: Candida albicans (52%), Candida parapsilosis (17%), Candida tropicalis (10%), Candida krusei (5%), Candida glabrata (4%), Candida guilliermondii (4%), Kluyveromyces lactis (4%) and Saccharomyces cerevisiae (4%). Sixty-nine percent of the isolates corresponding to the predominant species (C. albicans) were related to vaginal infections. On the other hand, 61% of the yeasts associated with ocular infections were identified as C. parapsilosis. Two indigenous killer isolates DVMais5 and HCMeiss5, belonging to Pichia anomala and P. kluyveri respectively, exhibited the broadest killer spectrum against clinical isolates.
Insights
This study identified yeast species from non-systemic mycoses using rapid molecular methods. Indigenous killer yeasts showed broad spectrum activity against clinical isolates, offering potential for novel antifungal treatments.
Area of Science:
- Medical Mycology
- Molecular Biology
- Antimicrobial Resistance
Background:
- Efficient treatment of mycoses requires rapid yeast identification and novel antifungal agents.
- Non-systemic mycoses present a significant clinical challenge.
- Understanding yeast epidemiology and susceptibility is crucial for effective management.
Purpose of the Study:
- To rapidly identify yeast species from clinical non-systemic mycoses.
- To assess the susceptibility of clinical yeast isolates to killer toxins.
- To explore the potential of indigenous killer yeasts as antifungal agents.
Main Methods:
- Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting the ITS1-5.8S rDNA-ITS2 region for yeast identification.
- Plate-based killer susceptibility assays using reference and indigenous killer yeasts.
- Analysis of 53 clinical yeast isolates from non-systemic infections.
Main Results:
- Eight yeast species were identified, with Candida albicans (52%) being predominant in vaginal infections and Candida parapsilosis (61%) in ocular infections.
- Indigenous killer yeasts Pichia anomala (DVMais5) and Pichia kluyveri (HCMeiss5) demonstrated the broadest killer spectrum against clinical isolates.
- Significant variations in yeast species distribution were observed between vaginal and ocular infections.
Conclusions:
- Rapid molecular identification methods are effective for characterizing yeast populations in non-systemic mycoses.
- Indigenous killer yeasts possess broad-spectrum activity, indicating their potential as a source for new antifungal therapies.
- The findings highlight the importance of species-specific identification and susceptibility testing for targeted mycosis treatment.
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