Riesgo de mortalidad en infecciones invasoras por Fusarium spp en niños con enfermedades hemato-oncológicas: una revisión sistemática de la literatura

Introducción: Los estudios sobre la infección fúngica invasora (IFI) por Fusarium spp en pacientes pediátricos con patología hemato-oncológica, son escasos, correspondiendo en general a series clínicas descriptas en forma retrospectiva, lo que dificulta conocer en profundidad sus características y evolución. Objetivo: Analizar la evolución fatal de la IFI causada por Fusarium spp en pacientes pediátricos con patología hemato-oncológica, llevándose a cabo una revisión sistemática. Material y Métodos: La búsqueda bibliográfica se realizó con fecha 23 de marzo de 2023, en las principales bases de datos (Medline (a través de PubMed), Embase (a través de Embase-Elsevier), The Cochrane Library (a través de Wiley), Cinahl (a través de EbscoHOST), SCI-EXPANDED y Scielo (a través de la WOS) y Scopus (a través de Scopus-Elsevier) y libre (mediante el motor Google) y revisando las citas de los artículos incluidos. Resultados: Se rescataron 1.341 artículos, de los cuales se descartaron 931 por diversas razones. Mediante el análisis de los textos completos, finalmente se incluyeron 11 estudios. Todos los estudios eran de nivel 4 (serie de casos). Se detectó una notoria heterogeneidad (p < 0,008) entre los mismos. La mediana de la frecuencia de muerte observada implicó a un tercio de los afectados (Md 33 %; Q1:22,7-Q4:75). Conclusiones: La mortalidad por IFI por Fusarium spp fue alta en niños con patología hemato-oncológica, en especial en aquellos con neutropenia profunda y mala respuesta al tratamiento de su enfermedad de base

Background: Studies on invasive fungal infection (IFI) by Fusarium spp in pediatric patients with hemato-oncological pathology are scarce and limited and a few series of cases described retrospectively, which makes it difficult to fully understand their characteristics and outcome. With the aim of analyzing the fatal evolution of these patients, this systematic review was carried out. Methods: The literature search was performed up to March 23, 2023, in the main databases, as Medline (through PubMed), Embase (through Embase-Elsevier), The Cochrane Library (through Wiley), Cinahl (through EbscoHOST), SCI-EXPANDED and Scielo (through WOS) and Scopus (through Scopus-Elsevier) and free (through the Google engine) and reviewing the citations of the included articles. Results: 1341 articles were retrieved, of which 931 were discarded for various reasons. By analyzing its full texts, 11 studies were finally included. It was observed that heterogeneity among them was relevant (p < 0.008). Median frequency of death involved one third of those affected (Md 33%; Q1:22,7-Q4:75). Conclusions: Mortality due to IFI due to Fusarium spp was high in children with hemato-oncological pathology, especially in those with severe neutropenia and poor response to treatment of their underlying disease.

Chemical control of dieback and mango malformation in a semiarid region

The São Francisco Sub medium Valley is a great mango exporter in Brazil. In this semiarid region, diseases such as dieback and mango malformation have reduced the production of this crop. In this work the effectiveness of different active ingredients (flutriafol, methyl-thiophanate, copper hydroxide and fluxapyroxad mixed with pyraclostrobin) was assessed for the control of these diseases in a mango orchard. Monthly assessments of disease incidence were carried out. There was a difference among treatments for the two diseases studied, with flutriafol as the most effective fungicide against dieback and, for the malformation, the mixture of fluxapyroxad and pyraclostrobin and methyl-thiophanate showed the best results.

Caracterización de Fusarium spp. asociado con la pudrición basal de la cebolla de rama / Characterization of Fusarium spp. associated with the basal rot of the green onion

RESUMEN El departamento de Nariño ocupa el cuarto lugar como productor de cebolla de rama, a nivel nacional. En los últimos años, su producción y área de cultivo se han reducido por múltiples limitantes, destacándose, como la más importante, la susceptibilidad al ataque de hongos causantes de pudriciones radicales, los cuales, perjudican el sistema productivo y la rentabilidad. El objetivo del estudio fue caracterizar morfológica y molecularmente las poblaciones de Fusarium, asociados a la enfermedad de pudrición basal de cebolla de rama. Para ello, en los municipios de Pasto, Potosi y Buesaco, se colectaron plantas con síntomas de pudrición basal, acompañada de necrosis de raíces y ablandamiento de tejido. En el laboratorio de Sanidad Vegetal de la Universidad de Nariño, se sembraron tejidos en medio PDA y, a continuación, se purificaron los aislamientos para su posterior caracterización morfológica y molecular. El estudio morfológico, se realizó usando claves taxonómicas para el género Fusarium y la caracterización molecular con cebadores específicos para el género Fusarium y mediante secuenciación. Finalmente, se realizó un análisis filogenético de la variabilidad intraespecífica. Los resultados de la caracterización morfológica y molecular corroboran la presencia de dos especies dentro del género asociadas a esta patología, F. oxysporum f sp. cepae y F. solani. Los análisis filogenéticos muestran alta variabilidad intraespecífica entre los aislamientos de F. oxysporum y F. solani, formando dos complejos Fusarium oxysporum (FOSC) y Fusarium solani (FSSC), manifestando que estas especies no parten de un ancestro común.

ABSTRACT The department of Nariño occupies the fourth place as producer of green onion nationwide. In recent years, its production and cultivation area has been reduced by multiple limitations, highlighting as the most important, the susceptibility to the attack of fungi causing radical problems, which harm the productive system and profitability. This study was carried out in order to morphologically and molecularly characterizes Fusarium populations associated with green onion basal rot disease. For this, in Pasto, Potosi and Buesaco municipalities, plants were collected with basal rot symptoms, tissue deterioration and root necrosis. In the Plant Health laboratory of the University of Nariño, tissues were planted in PDA medium and subsequently the isolates were purified for further morphological and molecular characterization. The morphological study was carried out using taxonomic keys for the genus Fusarium and molecular characterization with specific primers for the genus Fusarium, and by sequencing. Finally, a phylogenetic analysis of the intraspecific variability was carried out. Morphological and molecular characterization results corroborate the presence of two species within the genus associated with this pathology, F. oxusporum f sp. cepae and F. solani. Phylogenetic analyzes show high intraspecific variability between the isolates of F. oxysporum and F. solani, forming two Fusarium oxysporum (FOSC) complexes and Fusarium solani (FSSC), evidencing that these species do not start from a common ancestor.

Human fusariosis: An emerging infection that is difficult to treat

Abstract Fusarium spp. has been associated with a broad spectrum of emerging infections collectively termed fusariosis. This review includes articles published between 2005 and 2018 that describe the characteristics, clinical management, incidence, and emergence of these fungal infections. Fusarium solani and F. oxysporum are globally distributed and represent the most common complexes. Few therapeutic options exist due to intrinsic resistance, especially for the treatment of invasive fusariosis. Therefore, the use of drug combinations could be an important alternative for systemic antifungal resistance. Increase in the number of case reports on invasive fusariosis between 2005 and 2018 is evidence of the emergence of this fungal infection.

Evaluación de la capacidad patogénica de Fusarium spp. en modelos vegetal y murino / Evaluation of Fusarium spp. pathogenicity in plant and murine models

El género Fusarium es ampliamente conocido por su capacidad fitopatógena, típicamente asociada al marchitamiento vascular. Sin embargo, se ha reportado como un patógeno oportunista en pacientes inmunocompetentes e inmunocomprometidos, por lo que puede ser considerado como un microorganismo de interés en estudios de patogenicidad en diferentes hospederos. Este trabajo evaluó la capacidad patogénica de aislamientos de Fusarium spp. de diferentes orígenes en hospederos vegetales y en un hospedero animal (modelo murino). Doce aislamientos de Fusarium spp. de origen vegetal, animal superficial, humano superficial y humano sistémico fueron inoculados en plantas de tomate, gulupa y clavel, y en ratones BALB/c, inmunocompetentes e inmunosuprimidos. Las pruebas de patogenicidad en plantas no mostraron todos los síntomas asociados al marchitamiento vascular en los tres modelos vegetales, pero la colonización y la necrosis de los haces vasculares observada en todos los casos, independientemente de la especie de Fusarium y el origen del aislamiento, demostró el potencial infeccioso de Fusarium spp. en las diferentes especies de plantas. Por otro lado, las pruebas de patogenicidad en el modelo murino evidenciaron alteraciones del comportamiento. Asimismo, se observó en el modelo murino que todos los aislamientos infectaron y colonizaron diferentes órganos, independientemente de su origen, de la especie o del estado inmunitario del hospedero, pero solamente cinco (de diferente origen y correspondientes a diferentes especies) generaron mortalidad. En contraste, la prueba de inoculación superficial no evidenció lesiones ni colonización. Los resultados observados indican el potencial papel patogénico de los aislamientos de Fusarium spp. en los diferentes tipos de hospederos. Sin embargo, es necesario profundizar en estudios de factores de patogenicidad que expliquen la capacidad de este género para colonizar múltiples hospederos.

The genus Fusarium is widely recognized for its phytopathogenic capacity. However, it has been reported as an opportunistic pathogen in immunocompetent and immunocompromised patients. Thus, it can be considered a microorganism of interest in pathogenicity studies on different hosts. Therefore, this work evaluated the pathogenicity of Fusarium spp. isolates from different origins in plants and animals (murine hosts). Twelve isolates of Fusarium spp. from plants, animal superficial mycoses, and human superficial and systemic mycoses were inoculated in tomato, passion fruit and carnation plants, and in immunocompetent and immunosuppressed BALB/c mice. Pathogenicity tests in plants did not show all the symptoms associated with vascular wilt in the three plant models; however, colonization and necrosis of the vascular bundles, regardless of the species and origin of the isolates, showed the infective potential of Fusarium spp. in different plant species. Moreover, the pathogenicity tests in the murine model revealed behavioral changes. It was noteworthy that only five isolates (different origin and species) caused mortality. Additionally, it was observed that all isolates infected and colonized different organs, regardless of the species and origin of the isolates or host immune status. In contrast, the superficial inoculation test showed no evidence of epidermal injury or colonization. The observed results in plant and murine models suggest the pathogenic potential of Fusarium spp. isolates in different types of hosts. However, further studies on pathogenicity are needed to confirm the multihost capacity of this genus.

Effect of fungal incidence on physiological quality of tobacco seeds used in Brazil / Efeito da incidência de fungos na qualidade fisiológica de sementes de tabaco utilizadas no Brasil

The objectives of the present project were to evaluate the sanity and germination of tobacco seed samples cultivated in Brazil and to identify potential pathogenic fungi to the culture. Thirty-four representatives samples of tobacco seeds were evaluated through germination and sanity test by the blotter-test. On the germination test, results were expressed in percentage of seedlings considered normal, abnormal and non-germinated seeds. The percentage of seeds germination varied between 54.5 and 90%. According to sanity test, it was verified the incidence of Alternaria alternata, Cladosporium spp., Fusarium spp., and Phoma spp. The incidence of A. alternata varied from 3 to 67%, and Fusarium spp. varied from 0 to 19%. There was significative positive correlation between the incidence of A. alternata and the percentage of seed germination. Species of Alternaria and Fusarium can be potential pathogens to tobacco culture and an alarm for the necessity of seed treatment of the seeds that are transporting these fungi.(AU)

Os objetivos do presente trabalho foram avaliar a sanidade e a germinação de amostras de sementes de tabaco utilizadas no Brasil e identificar fungos potencialmente fitopatogênicos à cultura. Foram avaliadas 34 amostras representativas de lotes de sementes de tabaco, por meio dos testes de germinação, do método do rolo de germinação, e sua sanidade pelo método do papel de filtro. Os resultados do teste de germinação foram expressos em porcentual de plântulas consideradas normais, anormais e sementes não germinadas. A porcentagem de germinação das sementes variou entre 54,5 e 90%. Mediante o teste de sanidade, foi verificada a incidência dos fungos Alternaria alternata, Cladosporium spp., Fusarium spp. e Phoma spp. A incidência de A. alternata variou de 3 a 67%, e Fusarium spp., de 0 a 19%. Houve correlação significativa positiva entre a incidência de A. alternata e a porcentagem de germinação das sementes. Espécies dos gêneros Alternaria e Fusarium podem ser potenciais patógenos para a cultura do tabaco, alertando para a necessidade do tratamento das sementes portadoras desses fungos.(AU)

Fusariosis en el paciente quemado. Una infección emergente / Fusariosis in burn patients. An emergent infection

Resumen Los procesos infecciosos son una de las principales causas de morbilidad y mortalidad en el paciente quemado. La inmunosupresión, la pérdida de la cubierta cutánea y la mayor supervivencia han favorecido el incremento en la prevalencia de las infecciones micóticas en los enfermos con quemaduras graves. Fusarium spp es causante de un amplio espectro de infecciones. Se han descrito más de 50 especies de Fusarium, de las que Fusarium solani es la más frecuente. Las manifestaciones clínicas de la fusariosis dependen del estado inmunitario del enfermo. Las formas superficiales y localizadas afectan habitualmente a los pacientes inmunocompetentes, la invasiva y diseminada a los inmunodeprimidos, en los que el pronóstico por lo general es malo, en especial si hay neutropenia asociada. Las opciones de tratamiento incluyen voriconazol, posaconazol y anfotericina B, especialmente en su presentación lipídica.

Abstract Infection is the most common and severe cause of morbidity and mortality in burn patients. Immunosuppression, lost of skin and longer survival of this population has increased the frequency of fungal infections. Fusarium species cause a broad spectrum of infections. More than 50 species of Fusarium have been identified, Fusarium solani is the most frequent. The clinical form of fusariosis depends largely on the immune status of the host. Superficial and localized disease occurs mostly in immunocompetent patients and invasive and disseminated disease affects immunocompromised patients. Prognosis is poor, especially among immunocompromised and neutropenic patients. Treatment options include voriconazole, posaconazole and the lipid formulations of amphotericine B.

Actividad antifúngica in vitro de aceite de girasol ozonizado en hongos causales de micosis superficiales / In vitro antifungal activity of ozonated sunflower oil on fungi that cause superficial mycoses

Las micosis superficiales son infecciones causadas por hongos que afectan la parte más superficial de la piel, mucosa, pelos y uñas. En los últimos años no se han creado nuevas drogas para el tratamiento de estas micosis. Por lo que es necesario investigar y desarrollar nuevos compuestos con actividad antifúngica. El aceite de girasol ozonizado, que aún está en estudio, representa una posible alternativa. Se planteó el objetivo de evaluar actividad antifúngica in vitro del aceite de girasol ozonizado en aislados clínicos de micosis superficiales. Se recopilaron cultivos de Candida albicans, Microsporum canis, Trichophyton rubrum, Fusarium spp., los cuales fueron ensayados para determinar su sensibilidad frente al aceite de girasol ozonizado, que consta de una fase oleosa y otra acuosa, empleando el método de referencia por microdilución en caldo según el CLSI y el método de unidades formadoras de colonias. Los datos obtenidos fueron analizados en base a valores numéricos y medidas de tendencia central. Las comparaciones se llevaron a cabo por la prueba estadística U de Mann-Whitney para análisis de variables no paramétricas. Por el método de unidades formadoras de colonias empleando la cepa de C. albicans ATCC90028 se obtuvieron tiempos de letalidad entre 15 y 60 minutos de exposición a las muestras ozonizadas. Por el método de microdilución en caldo se obtuvieron CIM de 0,4% ­ 0,75% para C. albicans; entre 0,75% y 1,5% para Fusarium spp., frente al aceite de girasol ozonizado. Frente a la fracción acuosa ozonizada se obtuvieron CIM entre 1,5% y 6,25% para C. albicans, entre 0,4% y 1,5% para Fusarium spp. Para los dermatofitos, las CIM y CFM frente a la porción acuosa ozonizada fueron ≤ 0,2% y ≤ 0,75%. Se concluye que el aceite de girasol ozonizado, tanto en su fracción oleosa como acuosa, tiene mayor actividad antifúngica que el aceite de girasol virgen.

Superficial fungal infections are caused by fungus that affect the most superficial part of the skin, mucosa, hair and nails. In recent years there have not created new drugs to treat these fungal infections. So it is necessary to research and develop new compounds with antifungal activity. Ozonated sunflower oil, which is still under study, represents a possible alternative. In order to evaluate in vitro antifungal activity of ozonized sunflower oil in clinical isolates of superficial mycosis, it was raised cultures of Candida albicans, Microsporum canis, Trichophyton rubrum, Fusarium spp., which were tested for their sensitivity to ozonized sunflower oil, consisting of an oil phase and another aqueous was collected using the reference method microdilution CLSI broth according to the method and the colony forming units. The data obtained were analyzed based on numerical values and measures of central tendency. Comparisons were carried out by the statistical U Mann-Whitney test for nonparametric analysis variables. By the method of colony forming units using strain C. albicans ATCC90028 lethality times were obtained between 15 and 60 minutes of exposure to ozonized samples. By the method of microdilution, MICs there were obtained 0.4% - 0.75% for C. albicans; between 0.75% and 1.5% for Fusarium spp., against ozonized sunflower oil. Opposite the ozonized aqueous fraction was obtained MIC between 1.5% and 6.25% for C. albicans, from 0.4% to 1.5% for Fusarium spp. For dermatophytes, MIC and MFC against the ozonized aqueous portion were ≤0.2% and ≤0.75%. It is concluded that ozonized sunflower oil, both aqueous and oil fractions has antifungal activitygreater than virgin sunflower oil.

Patogenicidad de especies de Fusarium asociadas a la pudrición basal del ajo en el centro norte de México / Fusarium species associated with basal rot of garlic in North Central Mexico and its pathogenicity

El ajo en México es uno de los cultivos de hortalizas más rentables, más del 83% de esta superficie es aportada por los estados de Zacatecas, Guanajuato, Sonora, Puebla, Baja California y Aguascalientes. La pudrición basal ocasionada por Fusarium spp. se encuentra ampliamente distribuida a nivel mundial; esta enfermedad se ha convertido en una limitante en zonas productoras de cebolla y ajo, no solo en México, sino también en otros países, En México, se ha informado la presencia de Fusarium oxysporum en plantas en Guanajuato y en semillas de ajo en Aguascalientes. En el estado de Morelos se ha reportado la presencia de Fusarium culmorum en cultivares de cebolla. Asimismo, en Aguascalientes se tienen antecedentes de otras especies como Fusarium proliferatum, Fusarium verticillioides, Fusarium solani y Fusarium acuminatum. Para este trabajo se planteó como objetivo identificar las especies de Fusarium encontradas en los estados de Zacatecas, Guanajuato y Aguascalientes, y evaluar su patogenicidad. Se realizaron recolectas de plantas con síntomas de la enfermedad en los estados antes mencionados. De los muestreos realizados se identificaron las especies F. oxysporum, F. proliferatum, F. verticillioides, F. solani y F. acuminatum; las cepas de Aguascalientes identificadas como AGS1A (F. oxysporum), AGS1B (F. oxysporum) y AGSY-10 (F. acuminatum) fueron las que presentaron bajo condiciones de invernadero un mayor índice de severidad.

Garlic in Mexico is one of the most profitable vegetable crops, grown in almost 5,451 ha; out of which more than 83% are located in Zacatecas, Guanajuato, Sonora, Puebla, Baja California and Aguascalientes. Blossom-end rot caused by Fusarium spp is widely distributed worldwide and has been a limiting factor in onion and garlic production regions, not only in Mexico but also in other countries. The presence of Fusarium oxysporum has been reported in Guanajuato and Aguascalientes. Fusarium culmorum has been reported in onion cultivars of Morelos; and Fusarium proliferatum, Fusarium verticillioides, Fusarium solani and Fusarium acuminatum have been previously reported in Aguascalientes. The goal of this work was identifying the Fusarium species found in Zacatecas, Guanajuato and Aguascalientes, to assess their pathogenicity. Plants with disease symptoms were collected from hereinabove mentioned States. The samples resulted in the identification of: F. oxysporum, F. proliferatum, F. verticillioides, F. solani and F. acuminatum species; out of which Aguascalientes AGS1A (F. oxysporum), AGS1B (F. oxysporum) and AGSY-10 (F. acuminatum) strains showed higher severity under greenhouse conditions.

Infecciones por Fusarium spp. en una unidad de quemados pediátrica / Fusarium spp. infections in a pediatric burn unit

Introducción: Fusarium spp. son hongos ubicuos que producen infecciones oportunistas en humanos incluyendo algunas severas en quemados. La literatura sobre infecciones por Fusarium spp. en pacientes quemados pediátricos es escasa. Objetivos: describir los hallazgos clínicos, epidemiológicos y evolutivos de infecciones por Fusarium spp. en pacientes quemados pediátricos. Pacientes y métodos: estudio retrospectivo, descriptivo de infecciones por Fusarium spp. en una unidad de cuidados intensivos pediátrica especializada entre enero de 2006 y marzo de 2015. Resultados: Quince pacientes presentaron infección por Fusarium spp. El 87% eran varones. La mediana de edad fue de 48 meses. En el 67% de los casos la quemadura fue por fuego directo. La superficie corporal quemada fue de una mediana de 45%. El 80% tuvo quemaduras profundas y el 93% presentó un índice de Garcés > 3. La infección fúngica se detectó con una mediana de 11 días desde la injuria. Todos los pacientes tuvieron catéteres centrales durante una mediana de 20 días y trece pacientes requirieron asistencia respiratoria mecánica durante una mediana de 16 días. En 14 pacientes el hongo fue aislado en la quemadura y en un paciente en el hueso. Trece pacientes tuvieron infecciones bacterianas concomitantes. Los antifúngicos de elección fueron anfotericina B y voriconazol. El tratamiento duró una mediana de 23 días. La mediana de internación fue de 55 días. Un solo paciente falleció debido a la infección fúngica. Conclusión: Fusarium spp. es un patógeno poco frecuente en pacientes quemados graves. La mortalidad fue baja (AU)

Introduction: Fusarium spp. are ubiquitous fungi recognized as opportunistic agents of human infections. They can produce severe infections in burn patients. The literature about Fusarium spp. infections in burn pediatric patients is scarce. Objectives: To describe clinical, epidemiological and outcome features of cases of Fusarium spp. infections in burn pediatric patients. Patients and Methods: Retrospective, descriptive study of Fusarium spp. infections in a specialized intensive care from January 2006 to March 2015. Results: 15 patients developed Fusarium spp infections. 87 % were male. Median age was 48 months. Direct fire injury was in ten patients. The affected burn surface was a median of 45%. Twelve patients had a full thickness burn. Fourteen patients had Garces Index>3. Fungal infection appears at a median of 11 days from injury. All patients had central lines during a median of 20 days and thirteen patients had mechanical ventilatory assistance for a median of sixteen days. Fungi vas isolated from burn wound in 14 patients and in bone in one patient. Thirteen patients had bacterial infection also. Amphotericin B was the drug of choice for treatment followed by voriconazole. Median time of complete treatment was 23 days. The median hospital stay was 55 days. One patient died of fungal infection related causes. Conclusion: Fusarium spp. is an uncommon pathogen in severely burn patients. Mortality was low (AU)

Colección cornell intraestromal y queratitis po fusarium spp: presentación de dos casos y revisión de la literatura / Collection ntrasstromal corneal and keratits by fusarium spp: report of twwo cases and review of the literature / Recolha cornano intra-estromal e ceratite pr fusarium spp: relato de dois casos e revisão da literatura

Las infecciones oculares por hongos filamentosos han aumentado su incidencia con el pasar de los años. Los traumas corneales, la terapia inmunosupresora y el uso de lentes de contacto han hecho que éstas aumenten su incidencia, pero existe un pequeño porcentaje de paciente que sin ningún factor de riesgo presentan infecciones por estos mohos. En este artículo reportamos dos casos de infección ocular por Fusarium spp. en dos pacientes de 21 y 30 años de edad respectivamente, inmunocompetentes, pertenecientes a las Fuerzas Militares y sin factores de riesgo asociados.

The filamentous fungal eye infections have been increasing in incidence in the last years. Corneal trauma, immunosuppressive therapy and use of contact lenses have increased their incidence, nonetheless a small percentage of patients with no risk factors still present with these mold infections. In this article we report a case of ocular infection by Fusarium spp. in two patients, a 21-year-old and a 30-year-old males. They work with the Military Forces, and were immunocompetent with no risk factors associated to the problem.

As infecções oculares por fungos filamentosos têm aumentado a sua incidência com o passar dos anos. Os traumas da córnea, a terapia imunossupressora e o uso de lentes de contato têm feito que estas aumentem a sua incidência, mas existe uma pequena percentagem de pacientes que semnenhumfator de riscoapresentam infecções por estes bolores. Em este artigo reportamos dois casos de infecção ocular por Fusarium spp. em dois pacientes de 21 e 30 anos de idade respectivamente, imunocompetentes, pertencentes às Forças Militares e semfatores de risco associados.

Validación del inóculo por densitometría para las pruebas de susceptibilidad a los antifúngicos en especies del género Fusarium / Validation of the inoculum by densitometry for antifungal susceptibility testing in Fusarium species

El objetivo de este trabajo fue validar la preparación del inóculo por densitometría para las pruebas de susceptibilidad a los antifúngicos en especies del género Fusarium. Se emplearon 15 aislamientos clínicos de Fusarium spp. para preparar los inóculos por espectrofotometría y contaje de unidades formadoras de colonias en cámara de Neubauer, siguiendo los protocolos establecidos por los documentos de referencia M38-A2 del Instituto de Estándares Clínicos y de Laboratorio (CLSI) y E.DEF 9.1 del Comité Europeo para Pruebas de Susceptibilidad a los Antimicrobianos (EUCAST), respectivamente. En paralelo se determinaron las lecturas por densitometría para ambos procedimientos. Se estableció un rango de 0,5-0,7 unidades McFarland para la preparación del inóculo por densitometría según el CLSI, y un rango de 0,2-0,8 unidades McFarland para la metodología descrita por el EUCAST. Con este estudio, se logró validar la preparación del inóculo para las pruebas de susceptibilidad en Fusarium spp., utilizando la densitometría como método alternativo de los procedimientos descritos internacionalmente, con considerables ventajas para ser implementado en los laboratorios de microbiología clínica. La variabilidad en cuanto a la capacidad de esporulación y tamaño de las conidias, sobre todo en especies poco frecuentes de Fusarium, sugiere la necesidad de validar el inóculo por especie.

The purpose of this work was to validate the preparation of the inoculum by densitometry for antifungal susceptibility testing in Fusarium species. Fifteen clinical isolates of Fusarium spp. were used to prepare the inocula by spectrophotometry and counting of colony forming units in a Neubauer chamber, according to the protocols established by the reference documents M38-A2 of the Clinical and Laboratory Standards Institute (CLSI), and E.DEF 9.1 of the European Committee on Antimicrobial Susceptibility Testing (EUCAST), respectively. Densitometry readings were determined in parallel for both procedures. A range of 0.5-0.7 McFarland units was established for inocula preparation by densitometry according to the CLSI, and a range of 0.2-0.8 McFarland units was established for the methodology described by EUCAST. This study allowed validating the preparation of the inocula for antifungal susceptibility testing in Fusarium spp., using densitometry as an alternative method for other procedures described internationally, with considerable advantages that can be implemented at clinical microbiology laboratories. The variability regarding sporulation capacity and conidia size, especially in less frequent Fusarium species, suggests the need of validating inocula per species.

Disseminated fusariosis in a patient with acute lymphoblastic leukaemia: A case report and literature review

Fusarium spp are molds found in the soil and may be saprophytic or fa c u l t a t ive plant p a t h ogens. These are rare but important opportunistic pathogens in immunocompromised patients especially those with hematologic malignancies. Fusarium spp usually cause local infections such as onychomycosis and infections of surgical and burn wound. However more importantly, these pathogens can lead to severe disseminated infection with invo l vement of multiple organs including skin. This disseminated form of fusariosis occurs exclusively in patients with prolonged, severe neutropaenia especially in patients with acute leukaemia or those u n d e rgoing bone marrow transplantation. Prognosis of disseminated fusariosis is usually guarded if not recognized early. We report a rare case of disseminated fusariosis in a patient with acute lymphoblastic leukaemia.

Fusarium species Associated with Fruit Rot of Banana (Musa spp.), Papaya (Carica papaya) and Guava (Psidium guajava)

A total of 60 isolates of Fusarium were isolated from fruit rot of banana (Musa spp.), papaya (Carica papaya) and guava (Psidium guajava). The most common species recovered from the fruit rot of the three fruit crops were F. semitectum (40 %), F. solani (38.3 %), F. verticillioides (11.7 %) and F. oxysporum (10 %). Fusarium semitectum was isolated from fruit rot of banana, papaya and guava; F. oxysporum from banana and papaya; F. solani from banana and guava and F. verticillioides from banana. From pathogenicity tests, F. solani and F. semitectum were pathogenic to both banana and papaya and F. verticillioides to banana. F. oxysporum was not pathogenic to banana and papaya and F. semitectum was not pathogenic to guava. The results of the present study showed the presence of several Fusarium spp. on fruit rot of banana, papaya and guava and several species are found to be pathogenic causing fruit rot on their hosts.

Effects of barley and barley bran contaminated with Fusarium spp. on the growth and feed efficiency of fattening and growing pigs / 대한수의학회지

The present study was carried out to investigate the effect of barley and barley bran contaminated with Fusarium spp on growth performance and feed efficiency of fattening and growing pigs. In experiment 1, total 48 fattening Landrace pigs were used in a fattening trial for 71 days. Pigs weighing around 75 kg were allocated into different substitution groups containing 0, 10, 20 and 30% of barley contaminated Fusarium spp. In experiment 2, total 16 growing Landrace pigs were used in a growing trial for 45 days. Pigs weighing around 29.4 kg were allocated into different substitution groups containing 0, 5, 10 and 20% of barley bran contaminated Fusarium spp. Mycotoxin concentrations of barley and barley bran contaminated with 30% Fusarium spp were 0.452 and 1.049 ppm for deoxynivalenol, 8.125 and 17.646 ppm for nivalenol and 0.023 and 0.029 ppm for zearalenone, respectively. In experiment 1, no differences were found in weight gain and feed intake between control group (0%) and 10 or 20% substitution groups, but in 30% substitution group, weight gain and feed intake were significantly lower (p < 0.05) than those in control group. After slaughtering, the extended haemorrhage of the fundus region in stomach was observed in 20 or 30% substitution groups. In experiment 2, weight gain and feed intake were not significantly different among treatment groups. After slaughtering of experimental pigs, the extended haemorrhage of the fundus region in stomach was observed in pigs fed diet with 20% substitution group. These results suggest that the feeding of diet with contaminated highly levels of Fusarium spp was negative effect on growth and feed efficiency in growing and fattening pig.

Estandarización del inóculo por desintometría para las pruebas de susceptibilidad antifungica en especies de fusarium / Inoculum standadization by densitometry for the antifungal susceptibility testing of fusarium species

Las especies del género Fusarium han emergido como patógenos oportunistas en las últimas décadas. La aparición de cepas resistentes y la introducción de nuevos antifúngicos, hace necesaria la realización de las pruebas de susceptibilidad en los laboratorios de microbiología clínica. El objetivo de este estudio fue estandarizar la preparación del inóculo por densitometría para las pruebas de susceptibilidad a los antifúngicos en especies de Fusarium. Se utilizaron 15 aislamientos clínicos de Fusarium spp. y se prepararon los inóculos por espectrofotometría y por contaje de unidades formadoras de conidias en cámara de Neubauer, siguiendo los protocolos establecidos por el CLSI y EUCAST respectivamente, determinando en paralelo sus lecturas por densitometría para ambos procedimientos. Las lecturas densitométricas a través del uso del Densimat®, permitieron establecer un intervalo de 0,5 ­ 0,7 unidades Mc Farland para la preparación del inóculo por la metodología descrita por el CLSI y un rango de 0,2 ­ 0,8 unidades Mc Farland para la metodología según el EUCAST. Con este estudio, pionero en Venezuela, se logró estandarizar la preparación del inóculo óptimo en las pruebas de susceptibilidad para Fusarium spp. utilizando la densitometría como método alternativo, comparable y sustitutivo de los procedimientos descritos internacionalmente, con considerables ventajas (útil, disponible y reproducible) para ser implementado en los laboratorios de microbiología clínica. La variabilidad en cuanto a la capacidad de esporulación y tamaño de las conidias, sobre todo en las especies poco frecuentes de Fusarium, sugiere la necesidad de estandarizar el inóculo por especie.

Fusarium species have emerged like opportunistic pathogens in the last decades. The appearance of new resistant strains and the introduction of new antifungal agents, make necessary susceptibility tests in clinical microbiology laboratories. The objective of this study was to standardize inoculum preparation by densitometry for antifungal susceptibility testing in Fusarium species. Fifteen clinical isolates of Fusarium spp. were used, and the inocula were prepared by spectrophotometry and by conidia forming count in Neubauer chamber, following the establishment protocols of CLSI and EUCAST, respectively, determining in parallel their densitometry readings for both procedures. Densitometry readings by Densimat® allowed to establish an interval of 0.5 - 0.7 Mc Farland units for the inoculum preparation by the CLSI methodology, and a rank of 0.2 - 0.8 Mc Farland units for the methodology according to the EUCAST. With this study, pioneer in Venezuela, it was achieved the standardization of the optimal inoculums preparation for the susceptibility tests in Fusarium spp., using densitometry like an alternative, comparable and substitute method of the described internationally standard procedures, with considerable advantages (useful, available and reproducible) to be applied in clinical microbiology laboratories. The variability as far as both sporulation capability and conidia's size, mainly in less frequent species of Fusarium, suggests the needs to standardize the inoculums by species.

Especies de Fusarium como agentes de queratitis micóticas en adultos en Tucumán, Argentina / Fusarium species as agents of mycotic keratitis in adults, in Tucumán, Argentina

Las queratomicosis por hongos filamentosos son una de las causas de daño en la córnea en los países de climas tropicales y subtropicales y se consideran dentro de las micosis de difícil tratamiento. El presente estudio evalúa la etiología de las queratitis sicóticas en Tucumán (R. Argentina) para determinar su incidencia e importancia clínica regional. En un lapso de 5 años se estudiaron 48 muestras (biopsias, raspados cornéales y/o aspirados oculares) recogidas por el oftalmólogo y enviadas al laboratorio para análisis micológico. Mediante examen directo, cultivos y estudios macro y micromorfológicos se confirmó etiología micótica en 13 pacientes (27 por ciento). De ellos, se identificaron 7 cultivos como Fusarium solani complex, 4 F. oxysporum y 2 F. verticillioides. Estos hallazgos permiten profundizar el conocimiento de los agentes etiológicos locales involucrados y los factores de riesgo, dos aspectos importantes en la prevención y la terapéutica de estas micosis.

Keratomycosis caused by filamentous fungi is one of the agents of damage to the cornea in subtropical and tropical climate countries and belongs to those mycoses identified as of difficult treatment. This study evaluates the etiology of mycotic keratitis in Tucumán (R. Argentina) with the purpose of assessing its incidence and regional and clinical significance. In a 5-year period, 48 samples (biopsy, corneal scrapes and/or ocular aspiration) collected by the oculist were examined and sent to the laboratory for a mycological analysis. By means of direct exam, macro and micromorphological cultures and studies of the presence of mycotic etiology in 13 patients (27 por ciento) was confirmed. Among them 7 cultures such as a Fusarium solani complex, 4 F. oxysporum and 2 F. verticillioides were identified. These findings allow to enlarge the knowledge of the local etiological agents involved as well as the risk factors, two elements that are significant in the prevention and therapeutics of these mycoses.

Evaluation of Two Biologically Active Compounds for Control of Wheat Root Rot and its Causal Pathogens

The main aim of this study is to evaluate the efficiency of two biologically active compounds (Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F. oxysporum, F. solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The K+ efflux and the leakage of UV-absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of K+ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions (chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.