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Solubilization of inorganic P-sources and production of siderophores and indole-3-acetic acid (IAA) by Beauveria brongniartii were quantified and then, the effects of biofertilization using B. bron...

Antecedentes: El agente causal de la Sigatoka Negra, Mycosphaerella fijiensis Morelet, es el principal problema fitosanitario en la producción de banano y plátano en el continente Americano.Objetivos: Evaluar la actividad antifúngica de tres extractos etanólicos de propóleo sobre el crecimiento in vitro de M. fijiensis.Métodos: Se estableció un bioensayo dosis respuesta con tres extractos etanólicos de propóleo (EEP: PTeco1, PTeco2 y PYuc) empleando cuatro concentraciones (1.25, 2.5, 5.0 y 10.0% v/v). Se determinaron la tasa de crecimiento diaria (TCD), porcentaje de inhibición del crecimiento micelial (%ICM), concentración efectiva media (CE50) y contenido de fenoles totales.Resultados y conclusiones: El EEP PYuc redujo la TCD y presentó los %ICM más altos en M. fijiensis. La CE50 más baja fue para PYuc (0.24%) seguida de PTeco1 (0.86%) y PTeco2 (3.34%). PYuc (140.47 μg/mL) mostró mayor contenido de fenoles totales al compararlo con PTeco1 (100.94 μg/mL) y PTeco2 (105.82 μg/mL). En conclusión, por su baja CE50 el propóleo PYuc posee mayor actividad antifúngica en comparación a los dos propóleos locales estudiados.

Gran parte del fosforo (P) contenido en los fertilizantes inorganicos aplicados al cultivo de papaya var. Maradol ( Carica papaya L.) se inmoviliza al precipitarse con algunos cationes del suelo (Ca 2+ , Mg 2+ , Fe 3+ y Al 3+ ), quedando indisponible para las plantas. Una alternativa para dejar el P nuevamente disponible es el uso hongos microscopicos solubilizadores de este elemento (HMSP). Sin embargo, estos microorganismos son susceptibles a residuos de herbicidas en los suelos. Los objetivos de este estudio fueron aislar HMSP de la rizosfera de Carica papaya , evaluar en cultivo semisolido y liquido su habilidad para solubilizar Ca 3 (PO 4 ) 2 y FePO 4 , y determinar su susceptibilidad a los herbicidas glifosato y 2,4-D. De los 15 aislamientos obtenidos, SP5 solubilizo cualitativamente mejor el Ca 3 (PO 4 ) 2 con un indice de solubilizacion (IS) de 5.6, mientras que el mayor IS (1.4) para FePO 4 se observo con Beauveria bassiana SP9. En fermentacion liquida, Penicillium sp. SP1 (108.5 mg/L) y Penicillium hispanicum SP16 (106.5 mg/L) solubilizaron al 100 % el Ca 3 (PO 4 ) 2 , en tanto que P. hispanicum SP16 solubilizo la mayor cantidad de FePO 4 con 39.6 mg/L. En los analisis de exposicion de los HMSP a herbicidas, P. hispanicum SP16 resulto tolerante al glifosato al obtener una concentracion letal media (CL 50 )de 5376.0 mg/L, valor mayor a la dosis aplicada en campo (1836 mg/L); sin embargo, fue susceptible al 2,4-D al obtener una CL 50 de 3256.0 mg/L, valor menor a la dosis aplicada en campo (3705.0 mg/L). La rizosfera de C. papaya alberga HMSP con potencial para el desarrollo de biofertilizantes, tomando en cuenta su capacidad para solubilizar fuentes inorganicas de P (Ca 3 [PO 4 ] 2 y FePO 4 ) y tolerancia a herbicidas convencionales (glifosato y 2,4-D).

The banana root borer [Cosmopolites sordidus Germar (Coleoptera: Curculionidae)] is the most harmful insect pest currently affecting organic banana plantations in Mexico. The use of entomopathogenic fungi to control C. sordidus populations is a biological control method that presents a promising alternative to conventional means. This study aimed to evaluate the virulence of native isolates of entomopathogenic fungi Cordyceps bassiana and Metarhizium anisopliae against C. sordidus adults under laboratory and field conditions. In laboratory assays, 12 isolates of C. bassiana and nine isolates of M. anisopliae were tested. In field trials, Cb174 (C. bassiana) and Ma148 (M. anisopliae) isolates and their co-application were evaluated. Cordyceps bassiana isolates Cb171 and Cb174 resulted in adult mortalities of 80.2 and 77.5% and had the lowest median lethal concentrations (LC50) of 6.4 × 106 and 5.4 × 106 conidia mL−1, respectively. Regarding the median lethal time (TL50), the most virulent isolates of C. bassiana were Cb171 and Cb190 with 9.49 and 9.55 days, respectively. For M. anisopliae, the Ma148 isolate was the most virulent (LC50 = 8.6 × 106 conidia mL−1 and LT50 = 12.61 days) and led to an adult mortality of 76.9%. In field trials, two tested isolates (C. bassiana Cb174 and M. anisopliae Ma148) were both able to reduce C. sordidus populations by 48.5% and their co-application by 38.1%. Percentage of mycosis in captured adults was over 50% for the entire evaluation period (1.6 months), which confirms the efficacy of entomopathogenic fungi. Both Cb174 and Ma148 are good candidates for developing formulated products to use in the integrated pest management of C. sordidus in Mexican organic banana plantations.

The annual infestation pattern of R. sanguineus sensu lato (Latreille) was studied for dogs in a tropical sub-humid region of Mexico. Infestation was monitored for a year at five veterinary clinics in different parts of the urban area of Colima City, Mexico. Dogs were considered positive for infestation when at least one specimen of any stage of the parasite was identified by physical search. R. sanguineus occurred throughout the year, with 21.4% average (446/2083; 95% C.I. 19-23) and infestation ranging from 17% in January to 29% in May. Seasonal distribution was homogeneous: spring 22.2% (96/432), summer 21.5% (103/477), autumn 21.4% (132/616), and winter 20.6% (115/558). No correlation was found between seasonal prevalence and weather during a season (p > 0.01). Tick specimens and all parasitic stages were found throughout the year. There were more larvae in March to June, September, and November; nymphs in March to May and December; and more adults in January, February, July, and October. Activity of each stage of ticks where dogs are always available indicated that R. sanguineus develop at least three generations per year.

espanolRESUMEN El objetivo del presente estudio fue evaluar la idoneidad de cepas nativas de Trichoderma para el control biologico de la roya tardia de la hoja (RTH), en una plantacion organica de Rubus idaeus, bajo condiciones de malla sombra. Se evaluaron cuatro tratamientos: T1) Trichoderma sp. cepa Clombta; T2) Trichoderma sp. cepa Chlorolota; T3) Co-aplicacion de ambas cepas de Trichoderma (Clombta + Chlorolota) y T4) Control, el cual consistio en la aplicacion de dos productos biologicos: Bacillus subtilis (Fungizard®) y extracto botanico de Larrea tridentata (CleanCrop®)]. Se evaluo la severidad de la enfermedad, el indice de severidad de la enfermedad (IS) y el area bajo la curva de progreso de la enfermedad (ABCPE). La co-aplicacion de Trichoderma sp. cepas Chlorolota y Clombta (de 43,44 a 35,73%) redujo la severidad de RTH al mismo nivel que el Control (de 44,61 a 34,33%). Para el IS, Trichoderma sp. cepa Chlorolota (64,13) y la Co-aplicacion (61,11) mostraron valores similares al Control (59,84). La co-aplicacion de ambas cepas de Trichoderma obtuvo el menor ABCPE (71,2), al mismo nivel que el Control (68,7). Sin embargo, Trichoderma sp. Chlorolota (72,1) logro el mismo ABCPE que la Co-aplicacion. El uso de Trichoderma sp. Chlorolota o su Co-aplicacion con la cepa Clombta fueron capaces de reducir la RTH en R. idaeus. EnglishABSTRACT This study aimed to evaluate the suitability of native Trichoderma strains for the biological control of Late Leaf Rust Disease (LLRD) in an organic Rubus idaeus plantation under screenhouse conditions. Four treatments were evaluated: T1) Trichoderma sp. strain Clombta; T2) Trichoderma sp. strain Chlorolota; T3) Co-application of both Trichoderma strains (Clombta + Chlorolota) and T4) Control, which consisted in the application of two biological products: Bacillus subtilis (Fungizard®) and Larrea tridentata botanic extract (CleanCrop®)]. Disease severity, disease severity index (DSI) and Area Under the Disease Progress Curve (AUDPC) were evaluated. The Co-application of Trichoderma sp. strain Chlorolota and Trichoderma sp. Clombta (from 43,44 to 35,73%) reduce the LLRD severity at the same level than the Control (from 44,61 to 34,33%). For DSI, Trichoderma sp. train Chlorolota (64,13) and the Co-application (61,11) showed similar values than those from the Control (59,84). Co-application of both Trichoderma strains showed the lowest AUDPC (71,2), at the same level that the Control (68,7). However, Trichoderma sp. Chlorolota (72,1) achieved the same AUDPC that the Co-application. The use of Trichoderma sp. Chlorolota or its Co-application with Trichoderma sp. strain Clombta was able to reduce the LLRD in R. idaeus.

The apical membrane antigen 1 (AMA-1) is a protein of the micronemes that is present in all organisms of the phylum Apicomplexa; it has been shown that AMA-1 plays an essential role for parasite invasion to target cells. It has been reported that AMA-1 is conserved among different isolates of Babesia; however, it is unknown whether the protein contains conserved B-cell epitopes and whether these epitopes are recognized by antibodies from cattle in endemic areas. In this research, using an in silico analysis, four peptides were designed containing exposed and conserved linear B-cell epitopes from the extracellular region of Babesia bovis AMA-1. The selected peptides were chemically synthesized, and then each peptide was emulsified and used to immunize two bovines per peptide. The antibodies produced against these peptides were able to recognize intra-erythrocytic parasites in an IFAT, except peptide 4, which was insoluble. The synthetic peptides were covalently fixed to the wells of an ELISA plate and incubated with sera from B. bovis naturally infected cattle. Peptides P2AMA and P3AMA were recognized by the sera of naturally infected cattle from different regions of Mexico. Statistical analysis showed that the ELISA test for peptides P2AMA and P3AMA had a concordance of 91.2% and 61.1% compared to the IFAT, a sensitivity of 94.56% and 71.74%, and a specificity of 76.19% and 14.2%, respectively. The presence of antibodies in bovine sera from endemic areas that bind to the identified peptides indicates that AMA-1 from B. bovis has conserved B-cell epitopes involved in the immune response under natural conditions. However, to propose their use as vaccine or diagnostics candidates, a further characterization of the humoral immune response elicited in cattle by these peptides is needed.

Background Babesia bovis belongs to the phylum Apicomplexa and is the major causal agent of bovine babesiosis, the most important veterinary disease transmitted by arthropods. In apicomplexan parasites, the interaction between AMA1 and RON2 is necessary for the invasion process, and it is a target for vaccine development. In B. bovis, the existence of AMA1 has already been reported; however, the presence of a homolog of RON2 is unknown. The aim of this study was to characterize RON2 in B. bovis. Results The B. bovis ron2 gene has a similar synteny with the orthologous gene in the B. bigemina genome. The entire ron2 gene was sequenced from different B. bovis strains showing > 99% similarity at the amino acid and nucleotide level among all the sequences obtained, including the characteristic CLAG domain for cytoadherence in the amino acid sequence, as is described in other Apicomplexa. The in silico transcription analysis showed similar levels of transcription between attenuated and virulent B. bovis strains, and expression of RON2 was confirmed by western blot in the B. bovis T3Bo virulent strain. Four conserved peptides, containing predicted B-cell epitopes in hydrophilic regions of the protein, were designed and chemically synthesized. The humoral immune response generated by the synthetic peptides was characterized in bovines, showing that anti-RON2 antibodies against peptides recognized intraerythrocytic merozoites of B. bovis. Only peptides P2 and P3 generated partially neutralizing antibodies that had an inhibitory effect of 28.10% and 21.42%, respectively, on the invasion process of B. bovis in bovine erythrocytes. Consistently, this effect is additive since inhibition increased to 42.09% when the antibodies were evaluated together. Finally, P2 and P3 peptides were also recognized by 83.33% and 87.77%, respectively, of naturally infected cattle from endemic areas. Conclusions The data support RON2 as a novel B. bovis vaccine candidate antigen that contains conserved B-cell epitopes that elicit partially neutralizing antibodies. Electronic supplementary material The online version of this article (10.1186/s13071-018-3164-2) contains supplementary material, which is available to authorized users.

The purpose of this paper is to evaluate the effect of five strains of Metarhizium anisopliae (Ma) and three strains of Isaria fumosorosea (Ifr) at a concentration of 1 × 108 colony forming units/ml applied by spraying onto bovines with controlled infestation of Haematobia irritans under stable conditions in the Mexican dry tropics. Four experiments were performed, in each of which three treatments (two fungal strains and one control) were evaluated with eight repetitions for each one, by carrying out a single application of the aqueous suspension of each strain. The animals were isolated in individual cages and direct counts of the infestation were carried out for 13 days. It was observed that strains Ma2, Ma6, Ma10, Ma14, and Ma34 caused 94–100% reduction in infestation between days 12 and 13 post-treatment, while strains Ifr19, Ifr11, and Ifr12 reduced infestation from 90% to 98% up to day 13 post-application. There was an effect in the generation of horn flies from the excrement of bovines that were treated with different strains, reducing the reproduction of subsequent generations. It was concluded that the strains of M. anisopliae and I. fumosorosea evaluated in this study can be used as biocontrol agents in infestations of H. irritans in stabled bovines.

The first objective was laboratory evaluation of the virulence of 53 Mexican isolates of fungi against larvae of Rhipicephalus (Boophilus) microplus. Thirty-three isolates of Metarhizium anisopliae var. anisopliae (Metschnickoff) Sorokin (Hypocreales: Clavicipitaceae) and 20 isolates of Isaria (Paecilomyces) fumosorosea (fumosoroseus) (Wize) (Eurotiales: Trichomaceae) were tested on 7-day-old larvae under laboratory conditions. Larvae were immersed in a suspension containing 108 conidia/mL and the CL50 values were estimated. Then, field tests were conducted to determine the efficacy of formulations of the isolate with the highest virulence. M. anisopliae (Ma 14 isolate) was formulated with four carriers: Tween, Celite, wheat bran, and Citroline (mineral oil) and applied on pasture beds of Cynodon plectostachyus (L.), at a dose of 2 × 109 CFU/m2. In the first trial, M. anisopliae was applied on plots naturally infested with larvae; in the second trial, tick populations in the experimental plots were eliminated and then re-infested with 20,000 7-day-old larvae. In the laboratory, all M. anisopliae isolates infected larvae with a mortality range between 2 and 100%; also, 13 of 20 I. fumosorosea isolates caused mortality rates between 7 and 94%. In the first field trial, 14 days post-application, conidial formulations in Celite and wheat bran caused 67.8 and 94.2% population reduction, respectively. In the second trial, the Tween formulation caused the highest larval reduction, reaching up to 61% (28 days post-application). Wheat bran formulation caused 58.3% larval reduction (21 days post-application) and was one of the most effective. The carriers and emulsifiers have a large impact on the effectiveness of conidial formulations.

El objetivo del presente estudio fue evaluar la eficacia de Metarhizium anisopliae para el control de Rhipicephalus microplus en ganado bovino infestado naturalmente. El estudio se realizó en una unidad de producción de ganado bovino ubicada en el trópico Mexicano. Se formaron dos grupos de 10 bovinos basado en el número de garrapatas R. microplus adultas y fases juveniles (larvas y ninfas). Los animales del grupo tratado (promedio de 73.4 y 27.5 garrapatas adultas y juveniles respectivamente) fueron asperjados con una mezcla de dos cepas de M. anisopliae (Ma14+Ma34) a una concentración de 1x108 conidios/ml. El grupo control (promedio de 77.7 y 24.7 garrapatas adultas y juveniles respectivamente) fue asperjado con agua+Tween80. Cada grupo recibió cuatro aplicaciones cada 14 días. En los días 0, 3, 5, 7 y 14 post-tratamiento se contó el número de garrapatas R. microplus adultas y fases juveniles. A partir de la primera aplicación del tratamiento hasta la última, los animales del grupo tratado presentaron una disminución (P0.05) en el número de garrapatas R. microplus adultas (30.9-87 %) y fases juveniles (35.8-72 %). Estos resultados demuestran que el tratamiento repetido con la mezcla de las cepas Ma14+Ma34 de M. anisopliae puede ser empleado como una alternativa para el control de infestaciones naturales de R. microplus en ganado bovino del trópico mexicano.

The aim of the present study was to evaluate the effect of Metarhizium anisopliae to control Rhipicephalus microplus under laboratory and field conditions (larvae on vegetation) in the Mexican tropics. In the laboratory study, Ma34, Ma14 and a mixture of Ma34+Ma14 strains of M. anisopliae were evaluated for their control of the adult and larval stages of R. microplus, using the adult and larval immersion test respectively. The reproductive efficiency index of engorged females was determined in the treated and control groups. In the adults, the Ma34 and MA14 strains both produced an efficacy of 100% on engorged females at 1 x 10(8), 1 x 10(7) and 1 x 10(6)conidia/ml; however, only Ma34 killed 100% at 1 x 10(6)conidia/ml dose. The mixture of both strains (Ma34+Ma14) produced an efficacy of 100% on engorged females at 1 x 10(8)conidia/ml. R. microplus engorged females treated with Ma34 and a mixture of strains Ma34 and Ma14 reduced egg oviposition by 55.5% and 39.1% respectively compared to treated controls (P

El objetivo del trabajo fue estudiar la fl uctuación poblacional de H. irritans en un hato de ganado bovino en el municipio de Tecomán, Colima, México. El hato fue visitado semanalmente de marzo de 2003 a mayo de 2004; en cada ocasión se seleccionaron al azar diez animales para estimar la infestación mediante el método de visualización directa. Se registró la temperatura y la humedad relativa (HR) diariamente. Se describió la fl uctuación poblacional presentada y se identifi caron los periodos y picos poblacionales. Se realizó un análisis de correlación de Pearson (P 0.05) entre la temperatura y la HR, con los valores promedio del número de moscas por animal para cada uno de los periodos poblacionales. La infestación por H. irritans fue fl uctuante, pero con presencia de moscas durante todo el año; los momentos de mayor infestación se observaron en verano, al presentarse dos picos poblacionales, con 236 y 120 moscas/animal; la actividad en otoño e invierno también fl uctuó; se incrementó en primavera, durante la cual se observó un pico poblacional, tanto al inicio del estudio (156 moscas/animal) como al fi nal (323 moscas/animal). Para el primer periodo poblacional se encontró un coefi ciente de correlación signifi cativo (0.93) con la temperatura, algo similar ocurrió para el cuarto periodo (–0.57); no fue posible detectar coefi cientes signifi cativos en otros periodos poblacionales para los factores climáticos en estudio.

The efficacy of Metarhizium anisopliae on the control of Boophilus microplus in cattle infested naturally in the Mexican tropics was evaluated. The study was carried out on a ranch in Veracruz, Mexico. Twenty steers were randomly allocated into two groups of 10 cattle. Animals were naturally infested with B. microplus. Animals in the treated group were sprayed with M. anisopliae (strain Ma34) at a concentration of 1x10(8)conidia/ml every 15 days (four treatments). The other group remained as untreated control. Standard engorged female ticks were recorded on days 0, 1, 3, 5, 7 and 14 post-treatment. From the second application treatment (day 7) to the end of the experiment, animals in the treated group had lower tick infestation (P0.05) with an efficacy of 40.0-91.2%. The results demonstrate the efficacy of repeated treatment with M. anisopiae (Ma34 strain) to control natural infestation of engorged female B. microplus on cattle in the Mexican tropics.

The susceptibility of the egg, pupa, and adult of Haematobia irritans (L.) (Diptera: Muscidae) to isolates of the fungi Metarhizium anisopliae (Metsch.) Sor., Beauveria bassiana (Bals.) Vuill., and Paecilomyces fumosoroseus (Wize) Brown and Smith, was evaluated under laboratory conditions. Groups of 20 eggs than 4 h old, pupae less than 48h old and adults were sprayed with a conidial suspension of each isolate. Eggs, pupae and adults of horn fly were susceptible to these entomopathogenic fungi. For treated eggs, the isolates Ma3, Ma 15, Ma25, Pfr1, and Pfr8 reduced adult emergence to 3.8% to 6.3% in comparison with the control (72%). The mortality of pupae infected by the isolates Ma2, Ma25, and Pfr10 ranged between 50% and 71.3%. Mortality of adults after treatment with the isolates Ma6, Ma 10, Ma 14, Ma 15, Pfr 1, Pfr 9, Pfr 10, Pfr 11, and Pfr12 were higher than 90%. The isolate Ma6 produced the lowest LC(50) against adult horn flies (8.08times 10(2)conidia/ml). These findings supported the hypotheses that isolates of M. anisopliae, and P. fumosoroseus are pathogenic against the different biological stages of horn flies by reducing adult emergence when applied on groups of eggs and pupae, and producing mortality when applied to adults.