Biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) by Entomopathogenic fungi and their side effects on natural enemies

Background: The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an insect pest species responsible for damages of citrus fruit quality and tree health. This insect is a vector of bacteria ‘Candidatus Liberibacter’ spp. a putative causal agent of citrus greening disease known as Huanglongbing (HLB), considered one of the most destructive diseases of citrus orchards worldwide. Disease management is mainly based on vector control using pesticides which can affect natural enemies that play an important role in pest control. The entomopathogenic fungi (EPF) Beauveria bassiana (2067 and 2121) and Metarhizium anisopliae (2411) were achieved by applying a suspension of 1 × 107 spores against D. citri nymphs and artificially infected the citrus seedlings under controlled and semi-field conditions. Also, the activity of these EPFs on the coccinellid and lacewing predators was evaluated. The effects of the main chemicals used in citrus plantations on the selected fungi for possible combined use was also investigated. Results: The obtained results showed that under controlled conditions, the percentage of insect mortality produced by EPF varied between 82.8 and 85.9%. Under semi-field conditions, the infection and mortality of D. citri caused by the M. anisopliae 2411 strain was significantly higher than that of B. bassiana 2067, 78.9 and 51%, respectively. Non-significant effect of EPF on the natural enemies of D. citri was observed, suggesting that EPF and predators had compatible effects. Conclusion: This study clearly demonstrated that EPF were able to kill D. citri and can be explored as a promissory biocontrol candidate. Simultaneous use in an integrated pest management program could be possible by applying EPF combined with pesticides

In-vitro tests for the biocontrol of Rhipicephalus microplus with entomopathogenic fungi in Uruguay

The common cattle tick, Rhipicephalus microplus, generates millionaire losses in the livestock industry worldwide (US$18 billion/year). In addition to its direct pathogenic effects, as anemia and low production, it´s also the vector of Babesia bigemina, B.bovis and Anaplasma marginale, agents that cause babesiosis and anaplasmosis, which often leads to the death of animals. Control with chemical products has been difficult in recent decades due to the development of resistance, residues in animal products and subproducts and environmental contamination. In Uruguay, acaricide resistance is widely dispersed, and multi-resistant populations have been diagnosed complicating its control, therefore, alternative methods are being thought.Para acceder a la videoconferencia completa, hacer clic en "Enlace externo".Sociedad Latinoamericana de Ecología de Vectore

Selection of Trichoderma strains for biological control of Fusarium nygamai in sorghum (Sorghum bicolor L. Moench)

Uno de los principales problemas que afectan el cultivo de sorgo (Sorghum bicolor) en Uruguay es la enfermedad ocasionada por Fusarium nygamai, responsable de pérdidas en el rendimiento en los cultivos. Además, es capaz de producir micotoxinas como fumonicina, moniliformina y beauvericina, lo que constituye un riesgo para la alimentación animal. El objetivo de este trabajo fue identificar cepas de Trichoderma spp., con potencial de control de F. nygamai en sorgo. Se identificaron dos cepas de Trichoderma asperellum, cinco cepas de Trichoderma atroviride, dos cepas de Trichoderma virens, una cepa de Trichoderma longibrachiatum y dos cepas de Trichoderma sp. aisladas de suelo en plantaciones comerciales de sorgo. Se realizaron cultivos duales y evaluación de metabolitos volátiles in vitro para seleccionar las cepas con la mayor actividad antagonista contra F. nygamai. Las cepas de Trichoderma spp. seleccionadas se evaluaron en ensayos de protección vegetal en plántulas de sorgo inoculadas con F. nygamai. T. asperellum (T6) y T. atroviride (T21) fueron antagonistas efectivos de F. nygamai. Todas las plántulas de sorgo inoculadas con F. nygamai mostraron síntomas de la enfermedad, mientras que el 50% de las plántulas inoculadas con F. nygamai pero tratadas con T. asperellum (T6) permanecieron sanas, recuperando la cepa de los tejidos internos de la raíz, el tallo y las hojas. Estos resultados son promisorios para el desarrollo de una formulación comercial de tratamiento de semillas para el control de F. nygamai en cultivos de sorgo.One of the main problems affecting sorghum (Sorghum bicolor) production in Uruguay is the disease caused by Fusarium nygamai, which is responsible for crop losses and can also produce mycotoxins such as fumonicin, moniliformin and beauvericin. This constitutes a risk for animal feed. The aim of this work was to identify isolates of Trichoderma spp., with F. nygamai control potential in S. bicolor. We identified two strains of Trichoderma asperellum, five strains of Trichoderma atroviride, two strains of Trichoderma virens, one strain of Trichoderma longibrachiatum and two strains of Trichoderma sp. isolated from soils of sorghum commercial plantation. Dual cultures and evaluation of volatile metabolites were performed in vitro to select those strains with the highest antagonistic activity against F. nygamai. S trains of Trichoderma spp. selected were evaluated in plant protection assays in sorghum seedlings inoculated with F. nygamai. Trichoderma asperellum (T6) and T. atroviride (T21) were effective antagonists of F. nygamai. All sorghum seedlings only inoculated with F. nygamai under laboratory conditions evidenced symptoms of disease, while 50% of seedlings inoculated with F. nygamai but treated with T. asperellum (T6) remained healthy. This strain was also recovered from internal tissues of root, stem and leaves. These results are promising for the development of a commercial formulation of seed treatment for the control of F. nygamai in sorghum crops

Selection of Trichoderma strains for biological control of Fusarium nygamai in sorghum (Sorghum bicolor L. Moench)

Uno de los principales problemas que afectan el cultivo de sorgo (Sorghum bicolor) en Uruguay es la enfermedad ocasionada por Fusarium nygamai, responsable de pérdidas en el rendimiento en los cultivos. Además, es capaz de producir micotoxinas como fumonicina, moniliformina y beauvericina, lo que constituye un riesgo para la alimentación animal. El objetivo de este trabajo fue identificar cepas de Trichoderma spp., con potencial de control de F. nygamai en sorgo. Se identificaron dos cepas de Trichoderma asperellum, cinco cepas de Trichoderma atroviride, dos cepas de Trichoderma virens, una cepa de Trichoderma longibrachiatum y dos cepas de Trichoderma sp., aisladas de suelo en plantaciones comerciales de sorgo. Se realizaron cultivos duales y evaluación de metabolitos volátiles in vitro para seleccionar las cepas con la mayor actividad antagonista contra F. nygamai. Las cepas de Trichoderma spp. seleccionadas se evaluaron en ensayos de protección vegetal en plántulas de sorgo inoculadas con F. nygamai. T. asperellum (T6) y T. atroviride (T21) fueron antagonistas efectivos de F. nygamai. Todas las plántulas de sorgo inoculadas con F. nygamai mostraron síntomas de la enfermedad, mientras que el 50 % de las plántulas inoculadas con F. nygamai, pero tratadas con T. asperellum (T6) permanecieron sanas, donde se recuperó la cepa de los tejidos internos de la raíz, el tallo y las hojas. Estos resultados son promisorios para el desarrollo de una formulación comercial de tratamiento de semillas para el control de F. nygamai en cultivos de sorgo.One of the main problems affecting sorghum (Sorghum bicolor) production in Uruguay is the disease caused by Fusarium nygamai, which is responsible for crop losses and can also produce mycotoxins such as fumonicin, moniliformin, and beauvericin. This constitutes a risk for animal feed. The aim of this work was to identify isolates of Trichoderma spp., with F. nygamai control potential in S. bicolor. We identified two strains of Trichoderma asperellum, five strains of Trichoderma atroviride, two strains of Trichoderma virens, one strain of Trichoderma longibrachiatum and two strains of Trichoderma sp., isolated from soils of sorghum commercial plantation. Dual cultures and evaluation of volatile metabolites were performed in vitro to select those strains with the highest antagonistic activity against F. nygamai. The selected s trains of Trichoderma spp. were evaluated in plant protection assays in sorghum seedlings inoculated with F. nygamai. Trichoderma asperellum (T6) and T. atroviride (T21) were effective antagonists of F. nygamai. All sorghum seedlings only inoculated with F. nygamai under laboratory conditions evidenced symptoms of disease, while 50 % of seedlings inoculated with F. nygamai but treated with T. asperellum (T6) remained healthy. This strain was also recovered from internal tissues of root, stem, and leaves. These results are promising for the development of a commercial formulation of seed treatment for the control of F. nygamai in sorghum crops

Comunidades de hongos endófitos de Myrtaceae neotropicales :evaluación de la producción de enzimas y metabolitos bioactivos

Tribunal: Q.F. Alicia Arias, Dra. Elena Fabiano, Dra. Sandra Lupo, Dra. Silvana Vero.Orientador: Dra. Lina Bettucci

Lactobacillus rhamnosus postbiotic-induced immunomodulation as safer alternative to the use of live bacteria

Many attempts have been made to search for safer immunomodulatory agents that enhance the immune response and reduce the number and severity of infections in at-risk populations. The use of postbiotics, non-viable microbial cells or cell fractions that confer a health benefit to the consumer, represents a safe and attractive way to modulate and enhance the immune function in order to improve human health. Therefore, the aim of this work is to evaluate the immunoregulatory effect of Lactobacillus rhamnosus CRL1505 postbiotics in a complex culture system using human intestinal epithelial cells (IECs) and dendritic cells (DCs) differentiated from peripheral blood mononuclear cells. First, we demonstrated that L. rhamnosus CRL1505 differentially modulate human IECs and DCs after the challenge with the TLR4 agonist LPS. The CRL1505 strain down-regulated CD40, CD80 and CD86 expression in DCs, and increased their production of TNF-α, IL-1β, IL-6 and IL-10. Interestingly, the non-viable strain was able to modulate the immune response of both types of human cells. Then, we showed that cell wall (CW1505) and peptidoglycan (PG1505) from L. rhamnosus CRL1505 modulated TLR4-triggered immune response in IECs and DCs. Of interest, CW1505 showed a strong stimulatory effect while the PG1505 presented immune characteristics that were more similar to viable and non-viable CRL1505. To date, several molecules of immunobiotics were identified, that can be connected to specific host-responses. We hereby demonstrated that peptidoglycan of L. rhamnosus CRL1505 is a key molecule for the immunobiotic properties of this strain in human IECs and DCs. Likewise, the result of these studies could provide predictive tools for the in vivo efficacy of postbiotics and the scientific basis for their future applications in immunocompromised patients.Fil: Salva, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Instituto Pasteur de Montevideo; UruguayFil: Tiscornia, Inés. Instituto Pasteur de Montevideo; Uruguay. Universidad ORT Uruguay; UruguayFil: Gutiérrez, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Alvarez, Gladis Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Bollati Fogolín, Mariela. Instituto Pasteur de Montevideo; Urugua

Combined biological and chemical control of Neotropical leaf-cutting ants (Acromyrmex spp.) under field conditions

Acromyrmex crassispinus and Acromyrmex heyerii are two of the leaf-cutting ants found in Uruguay. These ants are dominant herbivores in the Neotropics and constitute an economically important pest in agriculture and forestry, causing severe defoliations in very young plants. Although Metarhizium anisopliae and Beauveria bassiana are well-known entomopathogens, the main aim of this study was to evaluate the use of these fungi together with lower doses of chemical products for insect control. This combined application of entomopathogenic fungi with insecticides for reducing ant populations under field conditions could be a more environment-friendly solution. The effect of different commercially available insecticides on conidia viability in vitro was also evaluated. Under field conditions spores of B. bassiana and M. anisopliae were assayed in ant nests with a previous application of fipronil and sulphluramid. The loss of nest activity after 1 or 2 weeks showed the effectivity of the conidia formulation and the fipronil and sulphluramid doses in Eucalyptus plantation

Photodegradation of chlorpyrifos in water by UV/H2O2 treatment: toxicity evaluation

Chlorpyrifos (CP) is an organophosphorus pesticide widely used in agriculture. Due to its toxicity, it has been necessary to develop a treatment to eliminate the environmental wastes generated by this substance. The combination of UV radiation and hydrogen peroxide seemed an interesting option to reduce the concentration of CP in water, as it has proved to be a simple and effective method to degrade other similar pesticides. The purpose of this work is to study the effect of different initial concentrations of H2O2 on the degradation of commercial CP in water using UV/H2O2. Conversions of 93% were achieved in 20 min with 450 mg L 1 of H2O2 initial concentration (0.16 mg of CP degraded per mg of H2O2 consumed). The total organic carbon analysis showed interesting mineralization values, reaching a 70% conversion after 4 h of reaction. In addition, this degradation procedure leads to a clear reduction of the toxicity of the reaction mixture over Vibrio fischeri.Fil: Femia, J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mariani, Melisa Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Zalazar, Cristina Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Tiscornia, Ines Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Decontamination of commercial chlorpyrifos in water using the UV/H2O2 process

In this work, a commercial formulation of chlorpyrifos in water was treated using the UV/H2O2 process. To the best of our knowledge, the degradation of commercial formulations of CP in water by this method has not been so widely studied. The optimal amount of oxidizing agent to be incorporated and the behavior of the degradation rate of chlorpyrifos were studied. Total organic carbon was measured in order to evaluate the mineralization rate of the treated mixture. In addition, the toxicity during the photodegradation was evaluated by employing the Microtox acute toxicity test.Fil: Femia, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Mariani, Melisa Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Cassano, Alberto Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Zalazar, Cristina Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Tiscornia, Ines Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Los polimorfismos en el promotor del gen IL 10 pueden contribuir con la susceptibilidad a la enfermedad celíaca

Introducción: La activación de las respuestas inmunes innata y adaptativa en la enfermedad celíaca, lleva a una alteración de la red local de citoquinas y desarrollo de inflamación y lesión intestinal. Los polimorfismos en el promotor del gen IL10 podrían jugar un papel en la determinación de la expresión fenotípica de la enfermedad celíaca, desbalanceando el equilibrio a favor de un aumento de la expresión de citoquinas proinflamatorias. Objetivo: analizar la contribución de polimorfismos de nucleótido simple en el gen IL10 en la susceptibilidad a la enfermedad celíaca. Materiales y métodos: se extrajo ADN de sangre entera de 40 pacientes con enfermedad celíaca y de 80 controles y se amplificó una región en el promotor del gen de IL10 que contiene los polimorfismos -1082 (rs1800896G/A), -819 (rs1800871C/T) y -592 (rs1800872C/A). Se secuenciaron amplicones de 695pb y, paracada polimorfismo, se estableció la presencia del alelo en homocigosis o heterocigosis. Se determinó el riesgo mediante el cálculo odds ratio (OR), considerando estadísticamente significativo un p < 0,05.Resultados: presentaron riesgo de desarrollar enfermedad celíaca los polimorfismos rs1800871T/C(OR = 2,22 [1,23 ? 4,01]; p = 0,0073) y rs1800872A/C (OR = 2,78 [1,27?6,09]; p = 0,009), con unmodelo dominante. El riesgo se asoció al sexo femenino (OR = 3,49, IC 95% [1,32 ? 9,19]; p = 0,009) y a concentraciones de a-tTG-IgA ≥ 100 U/ml (OR = 2,63, IC 95% [1,10 ? 6,28]; p = 0,03). Conclusiones: presentan riesgo de enfermedad celíaca los portadores del alelo menos frecuente T del rs1800871T/C y del alelo menos frecuente A del rs1800872A/C en el promotor del gen IL10, con un modelo dominante. El haplotipo que muestra asociación para el desarrollo de enfermedad celíaca es ATA. El análisis estratificado indica mayor riesgo de desarrollar la enfermedad en los portadores de los genotipos TC y TT del polimorfismo rs1800871T/C y de los genotipos AC y AA del polimorfismo rs1800872A/C asociados al sexo femenino y a las concentraciones de a-tTG-IgA ≥100 U/ml.Introduction: The activation of innate and adaptive immune responses in celiac disease leads to an alteration of the local cytokine network and the development of inflammation and intestinal injury. The polymorphisms in the IL10 gene promoter could play a role in determining the phenotypic expression of celiac disease, changing the balance towards an increase in the expression of proinflammatory cytokines. Objective: To analyze the contribution of simple nucleotide polymorphisms in the IL10 gene to the susceptibility to celiac disease. Materials and methods: We extracted DNA from whole blood of 40 patients with celiac disease and from 80 healthy individuals and then amplified a region in the IL10 gene promoter that contains the polymorphisms -1082 (rs1800896 G/A), -819 (rs1800871C/T) and -592 (rs1800872C/A). We sequenced 695-bp amplicons, and, for each polymorphism, established the presence of alleles in homozygosis or heterozygosis. We determined the risk by calculating the Odds Ratios (OR), considering a p<0.05 statistically significant. Results: The rs1800871T/C (OR = 2.22 [1.23-4.01], p = 0.0073) and rs1800872A/C (OR = 2.78 [1.27 -6.09], p = 0.009) polymorphisms were associated with celiac disease risk, with a dominant model. The risk was associated with females (OR = 3.49, 95% CI [1.32-9.19], p = 0.009) and with concentrations of a-tTG-IgA≥100 U/ml (OR = 2.63, 95% CI [1.10-6.28], p = 0.03). Conclusions: Carriers of the less frequent allele T of rs1800871T/C and the less frequent allele A of rs1800872A/C in the promoter of the IL10 gene, with a dominant model, present a risk of celiac disease. The haplotype that shows association with the development of celiac disease is ATA. The strategic analysis indicates a higher risk of developing celiac disease in carriers of the TC and TT genotypes of the rs1800871T/C polymorphism and of the AC and AA genotypes of the rs1800872A/C polymorphism associated with the female sex and concentrations of α-tTG-IgA ≥100 U/ml.Fil: López, Miryan Susana. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Tiscornia, María Mercedes. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Rosas, Rocio Ayelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Di Carlo, Maria Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Zapata, Pedro Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentin