Hongos patógenos de hemípteros auquenorrincos plaga de cultivos agrícolas : Evaluación de su capacidad biocida como agentes de control

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Toledo, Andrea V.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Growth inhibition of <i>Beauveria bassiana</i> by bacteria isolated from the cuticular surface of the corn leafhopper, <i>Dalbulus maidis</i> and the planthopper, <i>Delphacodes kuscheli</i>, two important vectors of maize pathogens

The phytosanitary importance of the corn leafhopper, Dalbulus maidis (Delong and Wolcott) (Hemiptera: Cicadellidae) and the planthopper, Delphacodes kuscheli (Fennah) (Hemiptera: Delphacidae) lies in their ability to transmit phloem-associated plant pathogens, mainly viruses and mollicutes, and to cause considerable mechanical damage to corn plants during feeding and oviposition. Fungi, particularly some members of the Ascomycota, are likely candidates for biocontrol agents against these insect pests, but several studies revealed their failure to invade the insect cuticle possibly because of the presence of inhibitory compounds such as phenols, quinones, and lipids and also by the antibiosis effect of the microbiota living on the cuticular surface of the host. The present work aims to understand interactions between the entomopathogenic fungus Beauveria bassiana (Balsamao-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) and bacterial antagonists isolated from the cuticular surface of D. maidis and D. kuscheli. A total of 155 bacterial isolates were recovered from the insect's cuticle and tested against B. bassiana. Ninety-one out of 155 strains inhibited the growth of B. bassiana. Bacterial strains isolated from D. maidis were significantly more antagonistic against B. bassiana than those isolates from D. kuscheli. Among the most effective antagonistic strains, six isolates of Bacillus thuringiensis Berliner (Bacillales: Bacillaeae), one isolate of B. mycoides Flügge, eight isolates of B. megaterium de Bary, five isolates of B. pumilus Meyer and Gottheil, one isolate of B. licheniformis (Weigmann) Chester, and four isolates of B. subtilis (Ehrenberg) Cohn were identified.Facultad de Ciencias Agrarias y Forestale

Antagonism of entomopathogenic fungi by <i>Bacillus</i> spp. associated with the integument of cicadellids and delphacids

Entomopathogenic fungi are potential tools to biocontrol cicadellids and delphacids, two groups of insects that cause extensive damage to agricultural crops. However, bacteria living on the host cuticle may inhibit fungal growth. In the present work, following the molecular characterization of 10 strains of Bacillus isolated from the integument of cicadellids and delphacids, we selected isolates of the fungi Beauveria bassiana and Metarhizium anisopliae that are resistant to the antimicrobials secreted by these bacterial strains. The antagonistic activity of the 10 bacterial isolates belonging to the genus Bacillus (i.e., B. amyloliquefaciens, B. pumilus, and B. subtilis) against 41 isolates of Bea. bassiana and 20 isolates of M. anisopliae was investigated in vitro on tryptic soy agar using the central disk test. With this approach, isolates of Bea. bassiana and M. anisopliae resistant to antagonistic bacteria were identified that can be further developed as biological control agents.Facultad de Ciencias Agrarias y Forestale

Antagonism of entomopathogenic fungi by <i>Bacillus</i> spp. associated with the integument of cicadellids and delphacids

Entomopathogenic fungi are potential tools to biocontrol cicadellids and delphacids, two groups of insects that cause extensive damage to agricultural crops. However, bacteria living on the host cuticle may inhibit fungal growth. In the present work, following the molecular characterization of 10 strains of Bacillus isolated from the integument of cicadellids and delphacids, we selected isolates of the fungi Beauveria bassiana and Metarhizium anisopliae that are resistant to the antimicrobials secreted by these bacterial strains. The antagonistic activity of the 10 bacterial isolates belonging to the genus Bacillus (i.e., B. amyloliquefaciens, B. pumilus, and B. subtilis) against 41 isolates of Bea. bassiana and 20 isolates of M. anisopliae was investigated in vitro on tryptic soy agar using the central disk test. With this approach, isolates of Bea. bassiana and M. anisopliae resistant to antagonistic bacteria were identified that can be further developed as biological control agents.Facultad de Ciencias Agrarias y Forestale

Growth inhibition of <i>Beauveria bassiana</i> by bacteria isolated from the cuticular surface of the corn leafhopper, <i>Dalbulus maidis</i> and the planthopper, <i>Delphacodes kuscheli</i>, two important vectors of maize pathogens

The phytosanitary importance of the corn leafhopper, Dalbulus maidis (Delong and Wolcott) (Hemiptera: Cicadellidae) and the planthopper, Delphacodes kuscheli (Fennah) (Hemiptera: Delphacidae) lies in their ability to transmit phloem-associated plant pathogens, mainly viruses and mollicutes, and to cause considerable mechanical damage to corn plants during feeding and oviposition. Fungi, particularly some members of the Ascomycota, are likely candidates for biocontrol agents against these insect pests, but several studies revealed their failure to invade the insect cuticle possibly because of the presence of inhibitory compounds such as phenols, quinones, and lipids and also by the antibiosis effect of the microbiota living on the cuticular surface of the host. The present work aims to understand interactions between the entomopathogenic fungus Beauveria bassiana (Balsamao-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) and bacterial antagonists isolated from the cuticular surface of D. maidis and D. kuscheli. A total of 155 bacterial isolates were recovered from the insect's cuticle and tested against B. bassiana. Ninety-one out of 155 strains inhibited the growth of B. bassiana. Bacterial strains isolated from D. maidis were significantly more antagonistic against B. bassiana than those isolates from D. kuscheli. Among the most effective antagonistic strains, six isolates of Bacillus thuringiensis Berliner (Bacillales: Bacillaeae), one isolate of B. mycoides Flügge, eight isolates of B. megaterium de Bary, five isolates of B. pumilus Meyer and Gottheil, one isolate of B. licheniformis (Weigmann) Chester, and four isolates of B. subtilis (Ehrenberg) Cohn were identified.Facultad de Ciencias Agrarias y Forestale

Antagonism of entomopathogenic fungi by <i>Bacillus</i> spp. associated with the integument of cicadellids and delphacids

Entomopathogenic fungi are potential tools to biocontrol cicadellids and delphacids, two groups of insects that cause extensive damage to agricultural crops. However, bacteria living on the host cuticle may inhibit fungal growth. In the present work, following the molecular characterization of 10 strains of Bacillus isolated from the integument of cicadellids and delphacids, we selected isolates of the fungi Beauveria bassiana and Metarhizium anisopliae that are resistant to the antimicrobials secreted by these bacterial strains. The antagonistic activity of the 10 bacterial isolates belonging to the genus Bacillus (i.e., B. amyloliquefaciens, B. pumilus, and B. subtilis) against 41 isolates of Bea. bassiana and 20 isolates of M. anisopliae was investigated in vitro on tryptic soy agar using the central disk test. With this approach, isolates of Bea. bassiana and M. anisopliae resistant to antagonistic bacteria were identified that can be further developed as biological control agents.Facultad de Ciencias Agrarias y Forestale

Longitudinal changes in adherence to the portfolio and DASH dietary patterns and cardiometabolic risk factors in the PREDIMED-Plus study

[Background & aims]: The Portfolio and Dietary Approaches to Stop Hypertension (DASH) diets have been shown to lower cardiometabolic risk factors in randomized controlled trials (RCTs). However, the Portfolio diet has only been assessed in RCTs of hyperlipidemic patients. Therefore, to assess the Portfolio diet in a population with metabolic syndrome (MetS), we conducted a longitudinal analysis of one-year data of changes in the Portfolio and DASH diet scores and their association with cardiometabolic risk factors in Prevención con Dieta Mediterránea (PREDIMED)-Plus trial. [Methods]: PREDIMED-Plus is an ongoing clinical trial (Trial registration: ISRCTN89898) conducted in Spain that includes 6874 older participants (mean age 65 y, 48% women) with overweight/obesity fulfilling at least three criteria for MetS. Data for this analysis were collected at baseline, six months and one year. Adherence to the Portfolio and DASH diet scores were derived from a validated 143-item food frequency questionnaire. We used linear mixed models to examine the associations of 1-SD increase and quartile changes in the diet scores with concomitant changes in cardiometabolic risk factors. [Results]: After adjusting for several potential confounders, a 1-SD increase in the Portfolio diet score was significantly associated with lower HbA1c (β [95% CI]: −0.02% [−0.02, −0.01], P < 0.001), fasting glucose (−0.47 mg/dL [−0.83, −0.11], P = 0.01), triglycerides (−1.29 mg/dL [−2.31, −0.28], P = 0.01), waist circumference (WC) (−0.51 cm [−0.59, −0.43], P < 0.001), and body mass index (BMI) (−0.17 kg/m2 [−0.19, −0.15], P < 0.001). A 1-SD increase in the DASH diet score was significantly associated with lower HbA1c (−0.03% [−0.04, −0.02], P < 0.001), glucose (−0.84 mg/dL [−1.18, −0.51], P < 0.001), triglycerides (−3.38 mg/dL [−4.37, −2.38], P < 0.001), non-HDL-cholesterol (−0.47 mg/dL [−0.91, −0.04], P = 0.03), WC (−0.69 cm [−0.76, −0.60 cm], P < 0.001), BMI (−0.25 kg/m2 [−0.28, −0.26 kg/m2], P < 0.001), systolic blood pressure (−0.57 mmHg [−0.81, −0.32 mmHg], P < 0.001), diastolic blood pressure (−0.15 mmHg [−0.29, −0.01 mmHg], P = 0.03), and with higher HDL-cholesterol (0.21 mg/dL [0.09, 0.34 mg/dL, P = 0.001]). Similar associations were seen when both diet scores were assessed as quartiles, comparing extreme categories of adherence. [Conclusions]: Among older adults at high cardiovascular risk with MetS, greater adherence to the Portfolio and DASH diets showed significant favourable prospective associations with several clinically relevant cardiometabolic risk factors. Both diets are likely beneficial for cardiometabolic risk reduction.The PREDIMED-Plus trial was supported by the Spanish government's official funding agency for biomedical research, ISCIII, through the Fondo de Investigación para la Salud (FIS) and co-funded by European Union ERDF/ESF, “A way to make Europe”/“Investing in your future” (five coordinated FIS projects led by JS-S and JVid, including the following projects: PI13/00673, PI13/00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/00728, PI13/01090, PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI14/00972, PI14/00728, PI14/01471, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183,PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, PI17/00926, PI19/00957, PI19/00386, PI19/00309, PI19/01032, PI19/00576, PI19/00017, PI19/01226, PI19/00781, PI19/01560, and PI19/01332), the Special Action Project entitled: Implementación y evaluación de una intervención intensiva sobre la actividad física Cohorte PREDIMED-Plus grant to JS-S, the European Research Council (Advanced Research Grant 2014–2019, 340918) to MÁM-G, the Recercaixa Grant to JS-S (2013ACUP00194), grants from the Consejería de Salud de la Junta de Andalucía (PI0458/2013, PS0358/2016, and PI0137/2018), a grant from the Generalitat Valenciana (PROMETEO/2017/017), a SEMERGEN grant, and funds from the European Regional Development Fund (CB06/03). This research was also partially funded by EU-H2020 Grant (EAT2BENICE/H2020-SFS-2016-2; Ref 728018). Study resulting from the SLT006/17/00246 grant, funded by the Department of Health of the Generalitat de Catalunya by the call “Acció instrumental de programes de recerca orientats en l'àmbit de la recerca i la innovació en salut”. We thank CERCA Programme/Generalitat de Catalunya for institutional support. This work is partially supported by ICREA under the ICREA Academia programme. IP-G receives a grant from the Spanish Ministry of Education, Culture and Sports (FPU 17/01925). MRBL was supported by “Miguel Servet Type I” program (CP15/00028) from the ISCIII-Madrid (Spain), cofinanced by the Fondo Europeo de Desarrollo Regional-FEDER. AJG was supported by the Nora Martin Fellowship in Nutritional Sciences, the Banting & Best Diabetes Centre Tamarack Graduate Award in Diabetes Research, the Peterborough K.M. Hunter Charitable Foundation Graduate Award and an Ontario Graduate Scholarship. PH-A was supported by a postdoctoral fellowship (Juan de la Cierva-Formación), FJCI-2017–32205, funded by the Ministry of Science and Innovation. RE group has been supported by the ‘Ajut 2017-2021 SGR 1717 from the Generalitat de Catalunya. DJAJ was funded by the Government of Canada through the Canada Research Chair Endowment. JK was supported by the ‘FOLIUM’ programme within the FUTURMed project from the Fundación Instituto de Investigación Sanitaria Illes Balears (financed by 2017 annual plan of the sustainable tourism tax and at 50% with charge to the ESF Operational Program 2014–2020 of the Balearic Islands). JLS was funded by a Diabetes Canada Clinician Scientist Award

Prospective associations between a priori dietary patterns adherence and kidney function in an elderly Mediterranean population at high cardiovascular risk

Purpose To assess the association between three different a priori dietary patterns adherence (17-item energy reduced-Mediterranean Diet (MedDiet), Trichopoulou-MedDiet and Dietary Approach to Stop Hypertension (DASH)), as well as the Protein Diet Score and kidney function decline after one year of follow-up in elderly individuals with overweight/obesity and metabolic syndrome (MetS). Methods We prospectively analyzed 5675 participants (55-75 years) from the PREDIMED-Plus study. At baseline and at one year, we evaluated the creatinine-based estimated glomerular filtration rate (eGFR) and food-frequency questionnaires-derived dietary scores. Associations between four categories (decrease/maintenance and tertiles of increase) of each dietary pattern and changes in eGFR (ml/min/1.73m(2)) or >= 10% eGFR decline were assessed by fitting multivariable linear or logistic regression models, as appropriate. Results Participants in the highest tertile of increase in 17-item erMedDiet Score showed higher upward changes in eGFR (beta: 1.87 ml/min/1.73m(2); 95% CI: 1.00-2.73) and had lower odds of >= 10% eGFR decline (OR: 0.62; 95% CI: 0.47-0.82) compared to individuals in the decrease/maintenance category, while Trichopoulou-MedDiet and DASH Scores were not associated with any renal outcomes. Those in the highest tertile of increase in Protein Diet Score had greater downward changes in eGFR (beta: - 0.87 ml/min/1.73m(2); 95% CI: - 1.73 to - 0.01) and 32% higher odds of eGFR decline (OR: 1.32; 95% CI: 1.00-1.75). Conclusions Among elderly individuals with overweight/obesity and MetS, only higher upward change in the 17-item erMedDiet score adherence was associated with better kidney function after one year. However, increasing Protein Diet Score appeared to have an adverse impact on kidney health. Trial Registration Number: ISRCTN89898870 (Data of registration: 2014).Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the official Spanish Institutions for funding scientific biomedical research, CIBER Fisiopatologia de la Obesidad y Nutricion (CIBEROBN) and Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigacion para la Salud (FIS), which is co-funded by the European Regional Development Fund (six coordinated FIS projects leaded by JS-S and JVi, including the following projects: PI13/00673, PI13/00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/00728, PI13/01090, PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI14/00972, PI14/00728, PI14/01471, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183, PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, PI17/00926, PI19/00957, PI19/00386, PI19/00309, PI19/01032, PI19/00576, PI19/00017, PI19/01226, PI19/00781, PI19/01560, PI19/01332, PI20/01802, PI20/00138, PI20/01532, PI20/00456, PI20/00339, PI20/00557, PI20/00886, PI20/01158); the Especial Action Project entitled: Implementacion y evaluacion de una intervencion intensiva sobre la actividad fisica Cohorte PREDIMED-Plus grant to JS-S; the European Research Council (Advanced Research Grant 2014-2019; agreement #340918) granted to MAMG.; the Recercaixa (number 2013ACUP00194) grant to JS-S; grants from the Consejeria de Salud de la Junta de Andalucia (PI0458/2013, PS0358/2016, PI0137/2018); the PROMETEO/2017/017 and the PROMETEO 21/2021 grant from the Generalitat Valenciana; the SEMERGEN grant; the Boosting young talent call grant program for the development of IISPV research projects 2019-2021 (Ref.: 2019/IISPV/03 grant to AD-L); the Societat Catalana d'Endocrinologia i Nutricio (SCEN) Clinical-Research Grant 2019 (IPs: JS-S and AD-L). Collaborative Nutrition and/or Obesity Project for Young Researchers 2019 supported by CIBEROBN entitled: Lifestyle Interventions and Chronic Kidney Disease: Inflammation, Oxidative Stress and Metabolomic Profile (LIKIDI study) grant to AD-L. Jordi Salas-Salvado, gratefully acknowledges the financial support by ICREA under the ICREA Academia programme. M.R.-G., is supported by the Ministry of Education of Spain (FPU17/06488). None of the funding sources took part in the design, collection, analysis, interpretation of the data, or writing the report, or in the decision to submit the manuscript for publication