Scedosporium spp. from Clinical Setting in Argentina, with the Proposal of the New Pathogenic Species Scedosporium americanum.

Species of the genus Scedosporium (family Microascaceae, phylum Ascomycota) are responsible for a wide range of opportunistic human infections, and have a low susceptibility to most antifungal drugs. It is well known that the pattern of Scedosporium species distribution varies according to geographic region. To assess the diversity of Scedosporium species in Argentina involved in human infections, we carried out a retrospective study reviewing 49 strains from clinical samples sent for diagnosis to the National Clinical Mycology Reference Laboratory between 1985 and 2019. Then, a phenotypic characterization, a phylogenetic study and and in vitro susceptibility test to antifungals were carried out. An analysis of combined nucleotide sequences dataset of the internal transcribed spacer of the ribosomal DNA (ITS) and of a fragment of the ß-tubulin gene (BT2) demonstrated that 92 % of the strains belonged to the species S. boydii, S. apiospermum and S. angustum, all them pertaining to S. apiospermum species complex. However, two strains (4%) were identified as S. aurantiacum, a species never reported in clinical settings in the Americas'. Surprisingly, one of them displayed a polycytella-like conidiogenesis, up to date only reported for S. apiospermum. In addition, the strain DMic 165285 was phylogenetically located far away from the rest of the species, so is proposed as the novel species Scedosporium americanum. On the other hand, from all seven antifungals tested, voriconazole and posaconazole were the most active drugs against Scedosporium spp.

Keratitis caused by moulds in Santa Lucía Ophthalmology Hospital in Buenos Aires, Argentina / Queratitis causada por hongos miceliares en el Hospital Oftalmológico Santa Lucía de Buenos Aires, Argentina(AU)

Background. Mycotic keratitis by moulds (MKM) is an important cause for corneal blindness and usually carries an unfavorable prognosis. Aims. This study describes the risk factors and demographic and microbiological features of all MKM cases in Santa Lucía Ophthalmology Hospital during a period of 6 years. Methods. A prospective study was performed for all MKM cases diagnosed between October 2007 and September 2013. Results. Among 157 diagnosed cases, direct microscopic examination and culture were positive in 97 and 96% of the cases respectively. MKM represents 17% of all microbiologically confirmed corneal abscesses. No significant differences were detected in annual MKM frequencies across the study period, suggesting that MKM incidence remains constant over time. A male-to-female ratio was observed (2.8:1); the most affected age groups ranged from 31 to 40 years old (males) and 61-70 years old (females). The most frequent predisposing factor was trauma (40%) followed by the use of contact lenses (9%), herpetic abscesses (5%) and diabetes (4%). The predominant genera were Fusarium (66%), Aspergillus (10%), Curvularia (6%) and Alternaria (4%). The most frequent agent was Fusarium solani species complex (52%). More than two-thirds of the cases were produced by only 3 species or complexes. However, at least 29 different species were detected in the remaining cases. This is the first report of Pholiota sp. as causative agent of human MKM. Conclusions. Argentina lacks extensive epidemiological and clinical data on MKM. This six-year study performed in Argentina is a first step leading to a better understanding of MKM epidemiology in our country (AU)

Antecedentes. La queratitis micótica causada por hongos miceliares (MKM) es una causa importante de ceguera corneal y presenta un pronóstico desfavorable. Objetivos. Describir los factores de riesgo y las características demográficas y microbiológicas de las MKM diagnosticadas en el Hospital Oftalmológico Santa Lucía durante 6 años. Métodos. Se llevó a cabo un estudio prospectivo de todos los casos de MKM diagnosticados entre octubre de 2007 y septiembre de 2013. Resultados. Se diagnosticaron 157 casos de MKM: un 97% con examen directo positivo y un 96% con cultivo positivo. Las MKM representaron el 17% de todos los abscesos corneales microbiológicamente confirmados. No se encontraron diferencias significativas en esta proporción durante los seis años de estudio, lo que demuestra que la incidencia permaneció constante. La proporción varones:mujeres fue 2,8:1; las edades más afectadas fueron 31-40 años en los varones y 61-70 años en las mujeres. El factor predisponente más común fue el traumatismo (40%), seguido del uso de lentes de contacto (9%), abscesos herpéticos (5%) y diabetes (4%). Los géneros predominantes fueron Fusarium (66%), Aspergillus (10%), Curvularia (6%) y Alternaria (4%). Los agentes más frecuentes pertenecían al complejo de especies Fusarium solani (52%). Más de dos tercios de los casos fueron causados únicamente por 3 especies, o complejos de especies, pero en los restantes se detectaron al menos otras 28 especies. Este es el primer informe referente a Pholiota sp. como agente causal de MKM humana. Conclusiones. Argentina carece de datos epidemiológicos y clínicos consolidados sobre MKM. Este estudio contribuye a una mejor comprensión de la epidemiología de esta enfermedad en este país (AU)

Keratitis caused by moulds in Santa Lucía Ophthalmology Hospital in Buenos Aires, Argentina.

BACKGROUND: Mycotic keratitis by moulds (MKM) is an important cause for corneal blindness and usually carries an unfavorable prognosis. AIMS: This study describes the risk factors and demographic and microbiological features of all MKM cases in Santa Lucía Ophthalmology Hospital during a period of 6 years. METHODS: A prospective study was performed for all MKM cases diagnosed between October 2007 and September 2013. RESULTS: Among 157 diagnosed cases, direct microscopic examination and culture were positive in 97 and 96% of the cases respectively. MKM represents 17% of all microbiologically confirmed corneal abscesses. No significant differences were detected in annual MKM frequencies across the study period, suggesting that MKM incidence remains constant over time. A male-to-female ratio was observed (2.8:1); the most affected age groups ranged from 31 to 40 years old (males) and 61-70 years old (females). The most frequent predisposing factor was trauma (40%) followed by the use of contact lenses (9%), herpetic abscesses (5%) and diabetes (4%). The predominant genera were Fusarium (66%), Aspergillus (10%), Curvularia (6%) and Alternaria (4%). The most frequent agent was Fusarium solani species complex (52%). More than two-thirds of the cases were produced by only 3 species or complexes. However, at least 29 different species were detected in the remaining cases. This is the first report of Pholiota sp. as causative agent of human MKM. CONCLUSIONS: Argentina lacks extensive epidemiological and clinical data on MKM. This six-year study performed in Argentina is a first step leading to a better understanding of MKM epidemiology in our country.

Genotipificación de aislamientos clínicos de Aspergillus flavus y su relación con aislamientos ambientales de un centro oncohematológico / Genotyping of clinical isolates of Aspergillus flavus and its relationship with environmental isolates of an oncohematological center

Antecedentes. Durante un período de 4 meses, y mientras se llevaba a cabo un muestreo ambiental de aire, se diagnosticaron 2 casos de aspergilosis por Aspergillus flavus en un centro oncohematológico de Buenos Aires, Argentina. Objetivos. Conocer la variabilidad y la relación genética entre los aislamientos clínicos y los ambientales obtenidos en el centro oncohematológico. Métodos. Se utilizaron 2 técnicas de genotipificación con diferente poder discriminatorio (RAPD y AFLP). Una matriz de similitud genética fue calculada usando el método de Jaccard y fue la base para la construcción de un dendrograma por el método de UPGMA. Se estimó el nivel de variabilidad genética por medio del porcentaje de loci polimórficos, número de alelos efectivos y heterocigosidad esperada, y el índice de asociación (IA). Resultados. El dendrograma mostró que los aislamientos de A. flavus recuperados de los pacientes no se relacionaron genéticamente con los del ambiente nosocomial. Los valores más altos de diversidad genética correspondieron a los aislamientos ambientales. El IA estimado para todos los aislamientos sugiere eventos de recombinación. Conclusiones. Los pacientes 1 y 2 no fueron infectados con los aislamientos obtenidos del ambiente hospitalario. Los aislamientos clínicos y ambientales de A. flavus mostraron alta variabilidad genética entre ellos(AU)

Background. During 4 months, and while conducting an environmental sampling of air, 2 cases of aspergillosis by Aspergillus flavus (A. flavus) were diagnosed at an oncohematological center in Buenos Aires, Argentina. Aims. The aim of this study was to know the variability and the genetic relationship between the clinical and environmental isolates, obtained in the oncohematological center. Methods. Two genotyping techniques of different discriminatory power (RAPD and AFLP) were used. A genetic similarity matrix was calculated using Jaccard method and was the basis for the construction of a dendrogram by UPGMA. The level of genetic variability was assessed by measuring the percentage of polymorphic loci, number of effective allele, expected heterocygozity and association index test (IA). Results. The dendrogram reveals that the A. flavus isolates recovered from the patients were not genetically related to those gotten from the rooms occupied by the patients. The environmental isolates had higher values of genetic diversity than the clinical isolates. The IA estimated for all the isolates suggest that recombination events occurred. Conclusions. Patients 1 and 2 were not infected with isolates from the nosocomial environment. Clinical and environmental isolates of A. flavus showed high genetic variability among them(AU)

[Genotyping of clinical isolates of Aspergillus flavus and its relationship with environmental isolates of an oncohematological center]. / Genotipificación de aislamientos clínicos de Aspergillus flavus y su relación con aislamientos ambientales de un centro oncohematológico.

BACKGROUND: During 4 months, and while conducting an environmental sampling of air, 2 cases of aspergillosis by Aspergillus flavus (A. flavus) were diagnosed at an oncohematological center in Buenos Aires, Argentina. AIMS: The aim of this study was to know the variability and the genetic relationship between the clinical and environmental isolates, obtained in the oncohematological center. METHODS: Two genotyping techniques of different discriminatory power (RAPD and AFLP) were used. A genetic similarity matrix was calculated using Jaccard method and was the basis for the construction of a dendrogram by UPGMA. The level of genetic variability was assessed by measuring the percentage of polymorphic loci, number of effective allele, expected heterocygozity and association index test (I(A)). RESULTS: The dendrogram reveals that the A. flavus isolates recovered from the patients were not genetically related to those gotten from the rooms occupied by the patients. The environmental isolates had higher values of genetic diversity than the clinical isolates. The I(A) estimated for all the isolates suggest that recombination events occurred. CONCLUSIONS: Patients 1 and 2 were not infected with isolates from the nosocomial environment. Clinical and environmental isolates of A. flavus showed high genetic variability among them.