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1.
Parasitol Res ; 119(11): 3595-3601, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32935162

RESUMEN

Varroosis is the disease caused by the ectoparasitic mite Varroa destructor, one of the most destructive diseases of honeybees. In Spain, there is great concern because there are many therapeutic failures after acaricide treatments intended to control varroosis outbreaks. In some of these cases it is not clear whether such failures are due to the evolution of resistance. Therefore, it is of high interest the development of methodologies to test the level of resistance in mite populations. In this work, a simple bioassay methodology was used to test whether some reports on low efficacy in different regions of Spain were in fact related to reduced Varroa sensitivity to the most used acaricides. This bioassay proved to be very effective in evaluating the presence of mites that survive after being exposed to acaricides. In the samples tested, the mortality caused by coumaphos ranged from 2 to 89%; for tau-fluvalinate, it ranged from 5 to 96%. On the other hand, amitraz caused 100% mortality in all cases. These results suggest the presence of Varroa resistant to coumaphos and fluvalinate in most of the apiaries sampled, even in those where these active ingredients were not used in the last years. The bioassay technique presented here, either alone or in combination with other molecular tools, could be useful in detecting mite populations with different sensitivity to acaricides, which is of vital interest in selecting the best management and/or acaricide strategy to control the parasite in apiaries.


Asunto(s)
Acaricidas/farmacología , Resistencia a los Insecticidas , Varroidae/efectos de los fármacos , Animales , Abejas/parasitología , Bioensayo , Cumafos/farmacología , Femenino , Infestaciones por Ácaros , Nitrilos/farmacología , Piretrinas/farmacología , España , Toluidinas/farmacología
2.
Exp Appl Acarol ; 76(1): 139-148, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30238306

RESUMEN

The ectoparasitic honey bee mite Varroa destructor Anderson & Trueman (Acari: Varroidae) is one of the major concerns for worldwide beekeeping. The use of synthetic pyrethroids for controlling the mite was among the most popular treatments until resistance evolved in the mid 1990's. In Iran, beekeepers are dealing with the parasite and they also used pyrethroids for controlling the mite for a long time. After the evolution of resistance to pyrethroids, they based mite control mostly on treatments with amitraz, organic acids and several management practices. Here we conducted a comprehensive characterization of V. destructor populations parasitizing Apis mellifera in Iran. We determined the genetic variability of mites collected from 28 localities distributed throughout the country. The haplotype of V. destructor was determined by PCR-RFLP, analyzing a fragment of the mitochondrial cox1 gene. It was found that only the Korean haplotype was present in samples from all localities. DNA fragments from cox1, atp6, cox3 and cytb mitochondrial genes were sequenced and the results showed that all samples were identical to the K1-1 or the K1-2 V. destructor haplotypes. Moreover, as it has been reported that resistance to pyrethroids in V. destructor is associated with mutations at position 925 of the voltage-gated sodium channel, a TaqMan®-based allelic discrimination assay was conducted to genotype the mites collected. The results showed that all the mites tested were homozygous for the wild-type allele and, therefore, susceptible to treatment with pyrethroids.


Asunto(s)
Acaricidas/farmacología , Resistencia a Medicamentos/genética , Variación Genética , Ácaros/efectos de los fármacos , Ácaros/genética , Piretrinas/farmacología , Animales , Proteínas de Artrópodos/genética , Abejas/parasitología , Haplotipos , Irán , Ácaros/fisiología
3.
J Invertebr Pathol ; 142: 60-67, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27756652

RESUMEN

The Vip3Ca protein, discovered in a screening of Spanish collections of Bacillus thuringiensis, was known to be toxic to Chrysodeixis chalcites, Mamestra brassicae and Trichoplusia ni. In the present study, its activity has been tested with additional insect species and we found that Cydia pomonella is moderately susceptible to this protein. Vip3Ca (of approximately 90kDa) was processed to an approximately 70kDa protein when incubated with midgut juice in all tested species. The kinetics of proteolysis correlated with the susceptibility of the insect species to Vip3Ca. The activation was faster to slower in the following order: M. brassicae (susceptible), Spodoptera littoralis (moderately susceptible), Agrotis ipsilon and Ostrinia nubilalis (slightly susceptible). Processing Vip3Ca by O. nubilalis or M. brassicae midgut juice did not significantly changed its toxicity to either insect species, indicating that the low susceptibility of O. nubilalis is not due to a problem in the midgut processing of the toxin. M. brassicae larvae fed with Vip3Ca showed binding of this toxin to the apical membrane of the midgut epithelial cells. Histopathological inspection showed sloughing of the epithelial cells with further disruption, which suggests that the mode of action of Vip3Ca is similar to that described for Vip3Aa. Biotin-labeled Vip3Ca and Vip3Aa bound specifically to M. brassicae brush border membrane vesicles and both toxins competed for binding sites. This result suggests that insects resistant to Vip3A may also be cross-resistant to Vip3C, which has implications for Insect Resistance Management (IRM).


Asunto(s)
Proteínas Bacterianas/metabolismo , Insecticidas , Mariposas Nocturnas , Animales , Resistencia a los Insecticidas , Control Biológico de Vectores/métodos
4.
PLoS Pathog ; 8(5): e1002692, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22615559

RESUMEN

The Toxin Complex (TC) is a large multi-subunit toxin first characterized in the insect pathogens Photorhabdus and Xenorhabdus, but now seen in a range of pathogens, including those of humans. These complexes comprise three protein subunits, A, B and C which in the Xenorhabdus toxin are found in a 4:1:1 stoichiometry. Some TCs have been demonstrated to exhibit oral toxicity to insects and have the potential to be developed as a pest control technology. The lack of recognisable signal sequences in the three large component proteins hinders an understanding of their mode of secretion. Nevertheless, we have shown the Photorhabdus luminescens (Pl) Tcd complex has been shown to associate with the bacteria's surface, although some strains can also release it into the surrounding milieu. The large number of tc gene homologues in Pl make study of the export process difficult and as such we have developed and validated a heterologous Escherichia coli expression model to study the release of these important toxins. In addition to this model, we have used comparative genomics between a strain that releases high levels of Tcd into the supernatant and one that retains the toxin on its surface, to identify a protein responsible for enhancing secretion and release of these toxins. This protein is a putative lipase (Pdl1) which is regulated by a small tightly linked antagonist protein (Orf53). The identification of homologues of these in other bacteria, linked to other virulence factor operons, such as type VI secretion systems, suggests that these genes represent a general and widespread mechanism for enhancing toxin release in gram negative pathogens.


Asunto(s)
Proteínas Bacterianas/metabolismo , Sistemas de Secreción Bacterianos/fisiología , Toxinas Bacterianas/metabolismo , Lipasa/metabolismo , Manduca/microbiología , Photorhabdus/patogenicidad , Animales , Escherichia coli/genética , Escherichia coli/metabolismo , Larva/microbiología , Proteínas de la Membrana/metabolismo , Photorhabdus/metabolismo , Xenorhabdus/metabolismo , Xenorhabdus/patogenicidad
5.
J Invertebr Pathol ; 120: 1-3, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24799046

RESUMEN

Binding studies using (125)I-Cry9Ca and biotinylated-Cry1Ba proteins showed the occurrence of independent binding sites for these proteins in Ostrinia nubilalis. Our results, along with previously available binding data, indicate that combinations of Cry1A or Cry1Fa proteins with Cry1Ba and/or Cry9Ca could be a good strategy for the resistance management of O. nubilalis.


Asunto(s)
Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Mariposas Nocturnas/metabolismo , Mariposas Nocturnas/microbiología , Control Biológico de Vectores/métodos , Zea mays/microbiología , Animales , Toxinas de Bacillus thuringiensis , Sitios de Unión , Resistencia a los Insecticidas/genética , Zea mays/genética
6.
J Invertebr Pathol ; 113(1): 78-81, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23415860

RESUMEN

Vip3Aa, Vip3Ad, Vip3Ae, and Vip3Af proteins from Bacillus thuringiensis were tested for their toxicity against Spodoptera frugiperda and Agrotis ipsilon. Vip3Ad was non-toxic to the two species. Vip3Ae and Vip3Af were significantly more toxic than Vip3Aa against S. frugiperda, both as protoxins and as toxins. Against A. ipsilon, Vip3Ae protoxin was more toxic than Vip3Aa and Vip3Af protoxins. Purification by metal-chelate affinity chromatography significantly affected Vip3Ae toxicity against the two insect species.


Asunto(s)
Bacillus thuringiensis , Proteínas Bacterianas/farmacología , Mariposas Nocturnas , Control Biológico de Vectores , Animales , Electroforesis en Gel de Poliacrilamida
7.
Pest Manag Sci ; 79(8): 2840-2845, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36947601

RESUMEN

BACKGROUND: The parasitic mite, Varroa destructor (Anderson and Trueman), is a leading cause of honey bee colony losses around the world. Application of miticides such as amitraz are often the primary method of Varroa control in commercial beekeeping operations in the United States. It is likely that excessive and exclusive amitraz application has led to the development of amitraz resistance in Varroa. A mutation of tyrosine at amino acid position 215 to histidine (Y215H) in the ß2 -octopamine receptor was identified in putatively amitraz-resistant Varroa in the United States. This research investigated the presence of the Y215H mutation in quantitatively confirmed amitraz-resistant Varroa from the United States. RESULTS: There was a strong association of susceptible and resistant phenotypes with the corresponding susceptible and resistant genotypes respectively, and vice versa. The resistance bioassay may understate resistance levels because of the influence of environmental conditions on the outcome of the test, whereby Varroa with an amitraz-resistant genotype may appear with a susceptible phenotype. CONCLUSION: Confirmation of the Y215H mutation in the ß2 -octopamine receptor of amitraz-resistant Varroa encourages the development and validation of low-cost, high-throughput genotyping protocols to assess amitraz resistance. Resistance monitoring via genotyping will allow for large-scale passive monitoring to accurately determine the prevalence of amitraz resistance rather than directed sampling of apiaries with known resistance issues. Genotyping of Varroa for amitraz resistance early in the beekeeping season may predict late-season resistance at the colony level and provide beekeepers with enough time to develop an effective Varroa management strategy. © 2023 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.


Asunto(s)
Acaricidas , Varroidae , Animales , Abejas/genética , Estados Unidos , Varroidae/genética , Acaricidas/farmacología , Mutación
8.
Front Microbiol ; 14: 1113642, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37213513

RESUMEN

Bacillus cereus G9241 was isolated from a welder who survived a pulmonary anthrax-like disease. Strain G9241 carries two virulence plasmids, pBCX01 and pBC210, as well as an extrachromosomal prophage, pBFH_1. pBCX01 has 99.6% sequence identity to pXO1 carried by Bacillus anthracis and encodes the tripartite anthrax toxin genes and atxA, a mammalian virulence transcriptional regulator. This work looks at how the presence of pBCX01 and temperature may affect the lifestyle of B. cereus G9241 using a transcriptomic analysis and by studying spore formation, an important part of the B. anthracis lifecycle. Here we report that pBCX01 has a stronger effect on gene transcription at the mammalian infection relevant temperature of 37°C in comparison to 25°C. At 37°C, the presence of pBCX01 appears to have a negative effect on genes involved in cell metabolism, including biosynthesis of amino acids, whilst positively affecting the transcription of many transmembrane proteins. The study of spore formation showed B. cereus G9241 sporulated rapidly in comparison to the B. cereus sensu stricto type strain ATCC 14579, particularly at 37°C. The carriage of pBCX01 did not affect this phenotype suggesting that other genetic elements were driving rapid sporulation. An unexpected finding of this study was that pBFH_1 is highly expressed at 37°C in comparison to 25°C and pBFH_1 expression leads to the production of Siphoviridae-like phage particles in the supernatant of B. cereus G9241. This study provides an insight on how the extrachromosomal genetic elements in B. cereus G9241 has an influence in bacterial phenotypes.

9.
Front Microbiol ; 14: 1113562, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36937299

RESUMEN

Bacillus cereus G9241 was isolated from a Louisiana welder suffering from an anthrax-like infection. The organism carries two transcriptional regulators that have previously been proposed to be incompatible with each other in Bacillus anthracis: the pleiotropic transcriptional regulator PlcR found in most members of the Bacillus cereus group but truncated in all B. anthracis isolates, and the anthrax toxin regulator AtxA found in all B. anthracis strains and a few B. cereus sensu stricto strains. Here we report cytotoxic and hemolytic activity of cell free B. cereus G9241 culture supernatants cultured at 25°C to various eukaryotic cells. However, this is not observed at the mammalian infection relevant temperature 37°C, behaving much like the supernatants generated by B. anthracis. Using a combination of genetic and proteomic approaches to understand this unique phenotype, we identified several PlcR-regulated toxins to be secreted highly at 25°C compared to 37°C. Furthermore, results suggest that differential expression of the protease involved in processing the PlcR quorum sensing activator molecule PapR appears to be the limiting step for the production of PlcR-regulated toxins at 37°C, giving rise to the temperature-dependent hemolytic and cytotoxic activity of the culture supernatants. This study provides an insight on how B. cereus G9241 is able to "switch" between B. cereus and B. anthracis-like phenotypes in a temperature-dependent manner, potentially accommodating the activities of both PlcR and AtxA.

10.
Sci Rep ; 13(1): 9825, 2023 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-37330528

RESUMEN

Interleukin (IL)-33 is a broad-acting alarmin cytokine that can drive inflammatory responses following tissue damage or infection and is a promising target for treatment of inflammatory disease. Here, we describe the identification of tozorakimab (MEDI3506), a potent, human anti-IL-33 monoclonal antibody, which can inhibit reduced IL-33 (IL-33red) and oxidized IL-33 (IL-33ox) activities through distinct serum-stimulated 2 (ST2) and receptor for advanced glycation end products/epidermal growth factor receptor (RAGE/EGFR complex) signalling pathways. We hypothesized that a therapeutic antibody would require an affinity higher than that of ST2 for IL-33, with an association rate greater than 107 M-1 s-1, to effectively neutralize IL-33 following rapid release from damaged tissue. An innovative antibody generation campaign identified tozorakimab, an antibody with a femtomolar affinity for IL-33red and a fast association rate (8.5 × 107 M-1 s-1), which was comparable to soluble ST2. Tozorakimab potently inhibited ST2-dependent inflammatory responses driven by IL-33 in primary human cells and in a murine model of lung epithelial injury. Additionally, tozorakimab prevented the oxidation of IL-33 and its activity via the RAGE/EGFR signalling pathway, thus increasing in vitro epithelial cell migration and repair. Tozorakimab is a novel therapeutic agent with a dual mechanism of action that blocks IL-33red and IL-33ox signalling, offering potential to reduce inflammation and epithelial dysfunction in human disease.


Asunto(s)
Inflamación , Proteína 1 Similar al Receptor de Interleucina-1 , Ratones , Humanos , Animales , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Inflamación/metabolismo , Interleucina-33/metabolismo , Citocinas/metabolismo , Receptores ErbB/metabolismo , Transducción de Señal
11.
Emergencias ; 35(1): 31-38, 2023 02.
Artículo en Inglés, Español | MEDLINE | ID: mdl-36756914

RESUMEN

OBJECTIVES: To evaluate the impact of a quality-of-care improvement program implemented in emergency departments (EDs) in a Spanish autonomous community with the aim of reducing the use of unrecommended drugs when treating infants for acute bronchiolitis. MATERIAL AND METHODS: Before-after quasi-experimental intervention study. We retrospectively included infants aged 12 months or less who were treated for acute bronchiolitis in 24 Spanish national health system hospital EDs in December during 2 epidemic periods: in 2018, before implementing the program, and in 2019, after implementation. Data collected included epidemiologic information, clinical and care details, and clinical course. The program consisted of providing informative material and training sessions before the epidemic period started. RESULTS: A total of 7717 episodes (4007 in 2018 and 2710 in 2019) were identified. Epidemiologic and clinical characteristics did not differ between the 2 periods. ED use of the following treatments decreased between the 2 periods: salbutamol, from 29.4% (95% CI, 28.8%-30.8%) in 2018 to 10.6% (95% CI, 9.6%-11.6%) in 2019; epinephrine from 6.0% (95% CI, 5.3%-6.8%) to 0.9% (95% CI, 0.7%-1.3%); and hypertonic saline solution fell from 8.2% (95% CI, 7.3%-9.1%) to 2.1% (95% CI, 1.7%-2.6%) (P.001, all comparisons). Prescriptions for salbutamol on discharge fell from 38.7% (95% CI, 36.9%-40.4%) to 10.6% (95% CI, 9.6%-11.6%) (P.001). Admissions and readmissions did not change, and the median time (interquartile range) spent in the ED fell from 81 (44-138) minutes to 66 (37-127) minutes (P.001). CONCLUSION: The quality-of-care improvement initiative was able to decrease the number of unrecommended therapeutic interventions for acute bronchiolitis. However, we identified great variations between EDs, suggesting that training and assessment of impact should continue.


OBJETIVO: Evaluar el impacto de una iniciativa de mejora realizada en los servicios de urgencias (SU) de una comunidad autónoma para reducir el uso de fármacos no recomendados en lactantes con bronquiolitis aguda (BA). METODO: Estudio cuasi-experimental analítico del tipo "antes y después de una intervención". Se incluyeron de forma retrospectiva todas las BA en niños # 12 meses atendidas en los SU de 24 hospitales públicos durante el mes de diciembre de dos periodos epidémicos: 2018 (preintervención) y 2019 (postintervención). Se recogieron variables epidemiológicas, clínicas, asistenciales y evolutivas. La intervención consistió en difundir material informativo y realizar actividades formativas previas al periodo epidémico. RESULTADOS: Se incluyeron 7.717 episodios (2018: 4.007 y 2019: 3.710). No existieron diferencias en las características epidemiológicas y clínicas. El empleo de salbutamol en los SU descendió del 29,4% [intervalo de confianza del 95% (IC 95%): 28,8-30,8] en 2018 al 10,6% (IC 95%: 9,6-11,6) en 2019 (p 0,001), el de adrenalina del 6,0% (IC 95%: 5,3-6,8) al 0,9% (IC 95%: 0,7-1,3) y el de suero salino hipertónico del 8,2% (IC 95%: 7,3-9,1) al 2,1% (IC 95%: 1,7-2,6) (p 0,001). La prescripción al alta de salbutamol se redujo del 38,7% (IC 95%: 36,9-40,4) al 10,6% (IC 95%: 9,6-11,6) (p 0,001). La tasa de ingreso y la tasa de readmisión no cambiaron y la mediana de tiempo de estancia en los SU se redujo 81 minutos [rango intercuartil (RIC) 44-138] a 66 (RIQ: 37-127) (p 0,001). CONCLUSIONES: La iniciativa de mejora ha conseguido disminuir la tasa de intervenciones terapéuticas no indicadas en BA. Sin embargo, existe una gran variabilidad entre los diferentes SU por lo que la estrategia y la medición de su impacto deben mantenerse en el tiempo.


Asunto(s)
Bronquiolitis , Humanos , Lactante , Estudios Retrospectivos , Enfermedad Aguda , Bronquiolitis/tratamiento farmacológico , Servicio de Urgencia en Hospital , Albuterol/uso terapéutico
12.
Appl Environ Microbiol ; 78(11): 4048-50, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22447600

RESUMEN

Cry1Fa insecticidal protein was successfully radiolabeled with (125)I-Na. Specific binding to brush border membrane vesicles was shown for the lepidopteran species Ostrinia nubilalis, Spodoptera frugiperda, Spodoptera exigua, Helicoverpa armigera, Heliothis virescens, and Plutella xylostella. Homologous competition assays were performed to obtain equilibrium binding parameters (K(d) [dissociation constant] and R(t) [concentration of binding sites]) for these six insect species.


Asunto(s)
Bacillus thuringiensis/metabolismo , Proteínas Bacterianas/metabolismo , Sistema Digestivo/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Radioisótopos de Yodo/metabolismo , Lepidópteros/metabolismo , Animales , Toxinas de Bacillus thuringiensis , Sitios de Unión , Sistema Digestivo/ultraestructura , Lepidópteros/clasificación , Microvellosidades/metabolismo , Especificidad de la Especie , Spodoptera/metabolismo , Vesículas Transportadoras/metabolismo
13.
Appl Environ Microbiol ; 78(18): 6759-61, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22773634

RESUMEN

Previous studies reported "mode 1" Bacillus thuringiensis resistance in a colony of diamondback moths (NO-QA), and recently, this resistance has been mapped to an ABC transporter (ABCC2) locus. We report the lack of binding of Cry1Fa to insects derived from this colony and compare our data with those from other insects with ABCC2-associated resistance.


Asunto(s)
Resistencia a Medicamentos , Lepidópteros/efectos de los fármacos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Mutación , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas , Endotoxinas , Proteínas Hemolisinas , Lepidópteros/genética , Microvellosidades/efectos de los fármacos , Microvellosidades/genética , Proteína 2 Asociada a Resistencia a Múltiples Medicamentos , Unión Proteica
14.
Appl Environ Microbiol ; 78(19): 7163-5, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22865065

RESUMEN

Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 µg/cm(2).


Asunto(s)
Bacillus thuringiensis/genética , Proteínas Bacterianas/genética , Animales , Bacillus thuringiensis/aislamiento & purificación , Proteínas Bacterianas/toxicidad , ADN Bacteriano/química , ADN Bacteriano/genética , Larva/efectos de los fármacos , Lepidópteros/efectos de los fármacos , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , España , Análisis de Supervivencia
15.
Prev Med Rep ; 28: 101879, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35813400

RESUMEN

Depression is more frequent in women, affecting the early stages of child development. This study aimed to determine the association between maternal depression and self-regulation of emotions and behaviors in Peruvian children under five years. A cross-sectional analytical study of data collected by the 2019 Demographic and Family Health Survey (ENDES) was conducted. The outcome variable was emotion and behavior regulation in children aged 24 to 59 months, and exposure was the presence of depression in women aged 15 to 49 years during the 14 days prior to the survey using the Patient Health Questionnaire (PHQ-9). A generalized linear model of the binomial family was used for reporting crude prevalence ratios and adjusted. The overall prevalence of children who did not self-regulate their emotions and behaviors was 68.8%, while 3.8% of the mothers had moderate depressive symptoms and 2.2% severe symptoms. Regarding the association of interest, moderate and severe depressive symptoms of mothers decreased the probability of children regulating emotions and behaviors in the first model, whereas in the second model, an association was only found with severe depressive symptoms. In conclusion, children of mothers with moderate and severe depressive symptoms had a lower probability of self-regulating their emotions and behaviors. Therefore, it is necessary to develop maternal education, nutritional and social support programs and mental health strategies from the first level of care aimed at reducing social, economic and child factors to reduce the risk of depression in mothers and low early childhood development, which could reduce the risk of developing mental health disorders in adolescence and adulthood.

16.
Insects ; 12(1)2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33406622

RESUMEN

Varroa destructor is an ectoparasitic mite causing devastating damages to honey bee colonies around the world. Its impact is considered a major factor contributing to the significant seasonal losses of colonies recorded every year. Beekeepers usually rely on a reduced set of acaricides to manage the parasite, usually the pyrethroids tau-fluvalinate or flumethrin, the organophosphate coumaphos, and the formamidine amitraz. However, the evolution of resistance in the mite populations is leading to an unsustainable scenario with almost no alternatives to reach an adequate control of the mite. Here, we present the results from the first large-scale and extensive monitoring of the susceptibility to acaricides in the Comunitat Valenciana, one of the most prominent apicultural regions in Spain. Our ultimate goal is to provide beekeepers with timely information to help them decide what would be the best alternative for a long-term control of the mites in their apiaries. Our data show that there is a significant variation in the expected efficacy of coumaphos and pyrethroids across the region, indicating the presence of a different ratio of resistant individuals to these acaricides in each population. On the other hand, the expected efficacy of amitraz was more consistent, though slightly below the expected efficacy according to the label.

17.
Appl Environ Microbiol ; 75(7): 2236-7, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19181834

RESUMEN

Vip3Aa, Vip3Af, Cry1Ab, and Cry1Fa were tested for their toxicities and binding interactions. Vip3A proteins were more toxic than Cry1 proteins. Binding assays showed independent specific binding sites for Cry1 and Vip3A proteins. Cry1Ab and Cry1Fa competed for the same binding sites, whereas Vip3Aa competed for those of Vip3Af.


Asunto(s)
Bacillus thuringiensis/fisiología , Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Tracto Gastrointestinal/microbiología , Proteínas Hemolisinas/metabolismo , Spodoptera/microbiología , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/toxicidad , Endotoxinas/toxicidad , Proteínas Hemolisinas/toxicidad , Larva/efectos de los fármacos , Dosificación Letal Mediana , Unión Proteica
18.
J Invertebr Pathol ; 100(2): 131-3, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19041324

RESUMEN

The microlepidopteran Prays oleae is one of the main insect pests causing significant crop losses in the Mediterranean olive groves. Bacillus thuringiensis based insecticides are being successfully used to minimize the impact of the second and third generations of this pest. However, because of its very small size and difficulty of rearing, very few studies have been carried out to determine the potency and mode of action of B. thuringiensis Cry proteins in this insect. In this study, Cry1Ac, Cry1Ca, and Cry1Fa proteins were shown to be toxic to third instar larvae of P. oleae. Furthermore, binding assays with (125)I-Cry1Ac and brush border membrane vesicles from midguts of last-instar larvae showed specific binding sites for Cry1Ac that are shared, with low affinity, by Cry1Ca and Cry1Fa.


Asunto(s)
Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Insecticidas/metabolismo , Mariposas Nocturnas/metabolismo , Animales , Toxinas de Bacillus thuringiensis , Sitios de Unión , Larva/metabolismo , Mariposas Nocturnas/crecimiento & desarrollo , Control Biológico de Vectores
19.
J Basic Microbiol ; 49(2): 152-7, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18798173

RESUMEN

Four collections comprising 507 strains of Bacillus thuringiensis have been analysed in this study. A different ecological origin characterizes each collection. Collection No. 1 was established from soil, dust, and grain samples from Spanish agricultural and non-cultivated soil, silos, and mills. Collection No. 2 is the result of a screening in olive-crop related environments in Spain. Collection No. 3 is made up of strains isolated from potato-growing areas in Bolivia. Collection No. 4 has been generated for this study and includes strains collected from diverse types of samples belonging to several habitats from Spain and Mexico. Crystal morphologies and cry1A and cry2 gene content were assessed for all isolates from each collection. In the 507 strains, the most common crystal morphology was bipyramidal crystals. Frequencies of cry1A and cry2 genes were 61.5% and 59.2%, respectively, and there was a strong correlation between the occurrence of cry1A and cry2 genes.


Asunto(s)
Bacillus thuringiensis/genética , Bacillus thuringiensis/aislamiento & purificación , Proteínas Bacterianas/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Toxinas de Bacillus thuringiensis , Bolivia , ADN Bacteriano/genética , Ecología , Microbiología Ambiental , Geografía , México , España
20.
Rev Peru Med Exp Salud Publica ; 36(2): 288-295, 2019.
Artículo en Español | MEDLINE | ID: mdl-31460643

RESUMEN

The challenge of Universal Health Coverage (UHC) led countries to make greater efforts to increase the proportion of population protected, to define and expand their benefit plans, and to provide financial resources to support payment for the benefits provided. The implementation of the health insurance policy in our country has allowed reaching important milestones, evidencing, however, an insufficient effect on timely access and on meeting the health needs of a large portion of the population. In this article we begin by highlighting the main advances and limitations in the process towards a UHC, guding the development of the pending agenda, based on the proposals issued by international organizations aimed at improving health systems globally. The pending challenges include efforts to involve and articulate the various actors in the task at hand of redesigning healthcare processes, strengthening the ethical dimension of their practice, as well as promoting citizen participation in the generation of a high-quality health system that would facilitate effective and timely access to health services. This requires the adoption of measures that extend to the entire health system, based on a shared vision and led by those responsible for its execution and governance.


El desafío de la Cobertura Universal en Salud (CUS) orientó a los países a desplegar sus mayores esfuerzos en la ampliación de la proporción de población protegida, la delimitación y ampliación de sus planes de beneficios, así como en la provisión de recursos financieros que permitan respaldar el pago de las prestaciones brindadas. En nuestro país, a través de la implementación de la política de aseguramiento en salud, ha sido posible arribar a importantes logros, evidenciando, sin embargo, un insuficiente efecto en el acceso oportuno y en la satisfacción de las necesidades de salud de gran parte de la población. En el presente artículo partimos por destacar los principales avances y limitaciones en el proceso hacia una CUS, orientando el desarrollo de la agenda pendiente, sobre la base de los planteamientos emitidos por Organizaciones Internacionales que apuntan hacia una mejora de los sistemas de salud a nivel global. Los desafíos pendientes incluyen esfuerzos de involucramiento y articulación de los diversos actores, en la tarea de rediseñar los procesos de atención, fortalecer la dimensión ética de su ejercicio, así como promover la participación ciudadana en la generación de un sistema de salud de alta calidad, que permita un acceso efectivo y oportuno a servicios de salud; ello obliga a adoptar medidas que alcancen a todo el sistema de salud, orientadas en una visión compartida y liderada por los responsables de su conducción y gobierno.


Asunto(s)
Atención a la Salud/organización & administración , Calidad de la Atención de Salud , Cobertura Universal del Seguro de Salud , Atención a la Salud/normas , Política de Salud , Humanos , Perú , Guías de Práctica Clínica como Asunto
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