Comparison of the identification results of Candida species obtained by BD PhoenixT and Maldi-TOF (Bruker Microflex LT Biotyper 3.1) / Comparación de los resultados de identificación de especies del género Candida obtenidos por BD PhoenixT y Maldi-TOF (Bruker Microflex LT Biotyper 3.1)

In patients with invasive fungal infections, the accurate and rapid identification of the genus Candida is of utmost importance since antimycotic sensitivity is closely related to the species. The aim of the present study was to compare the identification results of species of the genus Candida obtained by BD PhoenixT (Becton Dickinson -#91;BD-#93;) and Maldi-TOF MS (Bruker Microflex LT Biotyper 3.1). A total of 192 isolates from the strain collection belonging to the Mycology Network of the Autonomous City of Buenos Aires, Argentina, were analyzed. The observed concordance was 95%. Only 10 strains (5%) were not correctly identified by the BD PhoenixT system. The average identification time with the Yeast ID panels was 8h 22 min. The BD PhoenixT system proved to be a simple, reliable and effective method for identifying the main species of the genus Candida.

En pacientes con infecciones fúngicas invasoras, la identificación certera y rápida de las especies del género Candida es de suma importancia, ya que la sensibilidad a los antifúngicos está íntimamente relacionada con la especie. El objetivo del presente estudio fue comparar los resultados de identificación de especies del género Candida obtenidos con el equipo comercial BD PhoenixT (Becton Dickinson -#91;BD-#93;) y con la técnica de Maldi-TOF MS (Bruker Microflex LT Biotyper 3.1.) Se analizaron 192 aislamientos provenientes del cepario perteneciente a la Red deMicología de la Ciudad Autónoma de Buenos Aires, Argentina. La concordancia observada fue del 95%. Solo 10 cepas (5%) no fueron identificadas correctamente por el sistema BD PhoenixT. El tiempo promedio de identificación con los paneles Yeast ID fue de 8 h 22 min. El sistema BD PhoenixT demostró ser un método simple, confiable y efectivo para la identificación de las principales especies del género Candida.

Effectiveness of carboxylic acids from Pichia membranifaciens against coffee rust / Eficácia do ácido carboxílico de Pichia membranifaciens contra a ferrugem do cafeeiro

ABSTRACT Coffee rust is a fungal disease that has affected every coffee-producing region in the world. Given that the effectivity of the protectant and systemic fungicides applied routinely to control the spread of the causative agent of the disease (Hemileia vastatrix) has gradually diminished, besides are harmful to mammals and ecosystems, the objective of this work was to search for a mixture of harmless natural compounds with the potential to be applied in the field. So, a yeast strain producing a battery of long-chain carboxylic acids (CA) with fungicide properties was isolated from soil of coffee crop and identified as Pichia membranifaciens by ITS sequencing. Culture conditions of the yeast were optimized and the CA in the solution were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) as ethyl formate (55.5 g L-1), octadecenoic acid (3.5 g L-1), propionic acid (7.2 g L-1), 3-(octadecanoyl)-propionic acid (7.2 g L-1) and methyl acetate (8.4 g L-1). Randomized field studies were conducted in three different locations in Chiapas, México. Five treatments were tested including three concentrations of the CA solution (389, 584 and 778 ppm) and copper oxychloride (5 000 ppm) as conventional control. The initial coffee rust incidence averages varied between sites: Maravillas (3-9%), Santo Domingo (10-16%) and Búcaro (16-22%). The treatments of CA solution proved to be effective at slowing down the progress of the rust disease even for the sites where initial incidence was high. Likewise, the CA solution reduced the viability of H. vastatrix spores, as assessed by fluorescence microscopy.

RESUMO A ferrugem do cafeeiro é uma doença que tem afetado as regiões produtoras de café no mundo. Considerando que os funguicidas protetores e sistemáticos que são aplicados rotinariamente para controlar a difusão do agente causador da doença (Hemileia vastatrix) são nocivos para os humanos, animais e ecossistemas, o objetivo deste trabalho é determinar um componente natural com potencial de uso. Uma cepa de levedura produzindo uma bateria de ácidos carboxílicos com ação funguicida foi isolada do solo e identificada como Pichia membranifaciens por sequenciamento ITS. Foram optimizadas as condições de cultura e os ácidos carboxílicos presentes na semi purificada sobrenadante (solução CA) foram caracterizados por cromatografia de gás espectometia de massa (GC-MS) como formato de etilo (55.5 g L-1), ácido octadecenóico (3.5 g L-1), ácido propiônico (7.2 g L-1), 3-(octadecanoil)-ácido propiônico 7.2 g L-1) e acetato de metilio (8.4 g L-1). Estudos do campo foram conduzidos em três locais na região de Chiapas, Mexico. Cinco tratamentos foram testados incluindo três concentrações da solução CA (389, 584 e 778 ppm) e o funguicida comercial contendo oxicloreto de cobre (500 ppm). As médias iniciais de incidência da ferrugem do cafeeiro variou em função do local: Maravilla (3-9%), Santo domingo (10-16%) e Búcaro (16-22%). A solução CA provou ser efetiva retardando o progresso da doença, mesmo nos locais onde a incidência inicial foi elevada. A solução CA reduziu a viabilidade dos esporos de H. Vastatrix, observado por meio de fluorescência.

Portación de levaduras en manos de estudiantes de las carreras de Medicina y Enfermería de la Universidad de Talca, Chile / Carriage of yeasts in the hands of the students of medicine and nursing careers at the University of Talca, Chile

Introducción: En las últimas décadas, la frecuencia de infecciones fúngicas invasivas causadas por levaduras ha aumentado en las Unidades de Cuidados Intensivos (UCI), especialmente en pacientes graves con estadías prolongadas y en inmunocomprometidos. En ocasiones pueden presentarse como infecciones asociadas a la atención de salud (IAAS) por incumplimiento de medidas efectivas en prevención. Candida albicans es la especie más frecuentemente aislada, aunque el número de especies no albicans resistentes a fluconazol ha aumentado y la mortalidad asociada es mayor en los pacientes infectados con estas especies, motivo de preocupación puesto de manifiesto por los datos de vigilancia recientes. Objetivo: establecer la frecuencia de portación de levaduras de importancia clínica aisladas de las manos de estudiantes de las carreras de Medicina y Enfermería de la Universidad de Talca. Métodos: se tomaron 208 muestras de las manos de estudiantes, estas se dividieron en dos categorías: la primera es el ciclo básico de los estudiantes sin contacto con hospitales, la segunda es el pre-clínico y clínico de los estudiantes que tienen contacto con hospitales. Resultados: hubo 11.2 por ciento de portación en manos de estudiantes de Medicina y 9.9 por ciento para los de Enfermería. En los aislamientos predominó la Candida parapsilosis (45.5 por ciento); Candida guillermondii (18.2 por ciento); Candida famata (9.1 por ciento), y Candida albicans (4.5 por ciento) Schwanniomyces etchellsii (18.2 por ciento) y Cryptococcus humícola (4.5 por ciento). Conclusión: la portación de levaduras en manos de estudiantes de carreras de salud, aumenta significativamente en aquellos que tienen mayor contacto con las unidades hospitalarias, así como la diversidad de especies y la cantidad de unidades formadoras de colonias.

Introduction: In the last decades, the frequency of invasive fungal infections caused by yeast has increased in the Intensive Care Units (ICU), especially in severe patients with prolonged stays and in immunocompromised patients. Sometimes they can present as infections associated with health care (IAAS) due to non-compliance with effective prevention measures. Candida albicans is the most frequently isolated species, although the number of non-albicans species resistant to fluconazole has increased and the associated mortality is higher in patients infected with these species, a concern highlighted by recent surveillance data. Objective: to establish the frequency of carrying of yeasts of clinical importance isolated from the hands of students of the careers of Medicine and Nursing of the University of Talca. Methods: 208 samples were taken from the hands of students, these were divided into two categories: the first is the basic cycle of students without contact with hospitals, the second is the pre-clinical and clinical students who have contact with hospitals. Results: there was a: 11.2 percent portation in the hands of medical students and 9.9 percent for Nursing students. In the isolates Candida parapsilosis prevailed (45.5 percent); Candida guillermondii (18.2 percent); Candida famata (9.1 percent), and Candida albicans (4.5 percent) Schwanniomyces etchellsii (18.2 percent) and Cryptococcus humicola (4.5 percent). Conclusion: the carrying of yeasts in the hands of students of health careers increases significantly in those who have greater contact with hospital units, as well as the diversity of species and the number of colony forming units.

Evaluación del rendimiento del sistema Rapid™ Yeast Pluz (Remel) a partir de 2 medios de cultivo diferentes / Performance evaluation of Rapid™ Yeast Plus (Remel) system from two different culture media

Dentro del género Candida, la especie más frecuentemente aislada de materiales clínicos es Candida albicans. Debido a la emergencia de otras especies que pueden presentar mayor índice de resistencia a los antifúngicos, se hace necesaria la identificación rápida de aquellas. El objetivo del presente trabajo fue evaluar el rendimiento del sistema RapID™ Yeast Plus a partir de subcultivos en 2 formulaciones diferentes, agar Sabouraud dextrosa modificado por Emmons (medio indicado en el inserto del equipo) y agar Sabouraud glucosado, que es el utilizado habitualmente en los laboratorios de la Ciudad Autónoma de Buenos Aires. Se estudiaron 166 cepas de muestras clínicas provenientes de los distintos hospitales que integran la Red de Micología de la Ciudad de Buenos Aires. De los resultados obtenidos se concluye que se deben mantener las condiciones y el medio de cultivo indicado por el fabricante

Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed

A cost-effective carbohydrate fermentation test for yeast using microtitre plate.

Carbohydrate fermentation test is a well-established technique for speciation of bacteria and fungi. However, long incubation period, cost and procedural complexity may limit its use. Here, we describe a simple modification of conventional carbohydrate fermentation technique using microtitre plate. Thirty-one yeast isolates were identified based on their fermentation property by microtitre plate method and results were compared with conventional method. The modified method had 85.7% sensitivity and 100% specificity. The average time taken to produce positive reaction was 24 hours. When compared with conventional method, modified method reduced turn-around time and cost of processing without significant increase in discordant results.

Identificación rápida y sensibilidad a toxinas killer de levaduras aisladas de micosis no sistémicas / Rapid identification and susceptibility to killer toxins of yeasts isolated from non-systemic mycoses

La identificación rápida y segura de los agentes etiológicos y el desarrollo de nuevos antifúngicos con blancos de acción más específicos resultarán en tratamientos de las micosis más efectivos y menos lesivos. Mediante un método molecular rápido (ITS1-5.8S ADNr-ITS2 PCR-RFLP) se identificaron 53 aislamientos de levaduras provenientes de infecciones no sistémicas registradas en hospitales públicos de la ciudad de Neuquén y en un centro oftalmológico de Buenos Aires durante el año 2005. Adicionalmente y utilizando el método de inhibición del crecimiento en placa, se evaluó la sensibilidad de estas levaduras a toxinas killer producidas por levaduras indígenas de la Patagonia y por cepas de referencia. Ocho especies de levaduras fueron identificadas entre los aislamientos clínicos: Candida albicans (52%) , Candida parapsilosis (17%) , Candida tropicalis (10%) , Candida krusei (5%) , Candida glabrata (4%) , Candida guilliermondii (4%) , Kluyveromyces lactis (4%) y Saccharomyces cerevisiae (4%) . El 69% de los aislamientos de la especie mayoritaria, C. albicans, se relacionó con infecciones vaginales. Por otra parte, el 61% de las levaduras provenientes de infecciones oculares correspondió a la especie C. parapsilosis. En las condiciones de ensayo, las toxinas producidas por las levaduras killer indígenas DVMais5 y HCMeiss5 pertenecientes a las especies Pichia anomala y P. kluyveri, respectivamente, exhibieron el mayor espectro de acción sobre las levaduras aisladas de materiales clínicos.

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.