Successful multiple organ donation after donor brain death due to Actinomyces israelii meningitis.

The increasing gap between availability of solid organs for transplantation and the demand has led to the inclusion of donor organs that, according to current guidelines, may be discarded, some of them because of the possibility for transmission of infection to the recipients. We present the first report, to the best of our knowledge, of a case of a brain-dead donor with a localized and treated Actinomyces israelii central nervous system infection who, after a thorough evaluation, provided organs for successful transplant procedures in four recipients. There was no evidence of transmission of infection within a 6-month follow-up. Relative contraindications must be individualized in order to expand the number of real organ donors, emphasizing caution in rare causes for brain death in which patients should be thoroughly evaluated for possible donation.

Composition of the Essential Oil of Salvia ballotiflora (Lamiaceae) and Its Insecticidal Activity.

Essential oils can be used as an alternative to using synthetic insecticides for pest management. Therefore, the insectistatic and insecticidal activities of the essential oil of aerial parts of Salvia ballotiflora (Lamiaceae) were tested against the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae). The results demonstrated insecticidal and insectistatical activities against this insect pest with concentrations at 80 µg·mL(-1) resulting in 20% larval viability and 10% pupal viability. The larval viability fifty (LV50) corresponded to a concentration of 128.8 µg·mL(-1). This oil also increased the duration of the larval phase by 5.5 days and reduced the pupal weight by 29.2% withrespect to the control. The GC-MS analysis of the essential oil of S. ballotiflora showed its main components to be caryophyllene oxide (15.97%), and ß-caryophyllene (12.74%), which showed insecticidal and insectistatical activities against S. frugiperda. The insecticidal activity of ß-caryophyllene began at 80 µg·mL(-1), giving a larval viability of 25% and viability pupal of 20%. The insectistatic activity also started at 80 µg·mL(-1) reducing the pupal weight by 22.1% with respect to control. Caryophyllene oxide showed insecticidal activity at 80 µg·mL(-1) giving a larval viability of 35% and viability pupal of 20%.The insectistatic activity started at 400 µg·mL(-1) and increased the larval phase by 8.8% days with respect to control. The LV50 values for these compounds were 153.1 and 146.5 µg·mL(-1), respectively.

Edible and medicinal mushrooms (Pleurotus ostreatus, Ustilago maydis, Ganoderma lucidum) reduce endoplasmic reticulum stress and inflammation in adipose tissue of obese Wistar rats fed with a high fat plus saccharose diet.

Obesity is an increasing global public health problem. A strategy to treat obesity is the use of functional foods. Edible and medicinal mushrooms contain diverse bioactive compounds showing important antihyperlipidemic, antioxidant, and prebiotic properties. We analysed the effects of adding (10%) of Pleurotus ostreatus (Po, basidiomata), Ganoderma lucidum (Gl, basidiomata), or Ustilago maydis (Um, galls), milled, to a high fat plus saccharose diet (HFD + S) for 6 months in a model of obesity with Wistar rats. We assessed weight gain, body composition, lipid parameters, endoplasmic reticulum stress (proteins and inflammatory markers: BiP, XBP-1, JNK, p-JNK, TNF-α), and adiponectin in subcutaneous adipose tissue (SAT). The consumption of edible and medicinal mushrooms decreased weight gain (-17.2-30.1%) and fat mass (-23.7-43.1%), maintained fat-free mass, reduced levels of serum biochemical parameters (TC: -40.1-44.1%, TG: -37.7-51.6%, LDL-C: -64.5-71.1%), and prevented adipocyte hypertrophy (-30.9-36.9%) and collagen deposition (-70.9-73.7%) in SAT. Compared with the HFD + S group, mushroom consumption by Wistar rats significantly reduced the expression of proteins associated with endoplasmic reticulum stress and inflammation (BiP: -72.2-88.2%; XBP-1: -71.5-81.8%; JNK: -71.2-90.0%; p-JNK: -37.3-81.0%; TNF-α: -80.7-91.5%), whereas significantly increased adiponectin protein expression (246.4-654.2%) in SAT. These effects outperformed those obtained through the commercial lipid-lowering drug atorvastatin, contributing synergistically to prevent further obesity-related dysfunctions, such as insulin resistance derived from inflammation and ER stress in adipose tissue. Bioactive compounds from edible, functional and medicinal mushrooms represent new emerging therapies for obesity treatments using natural products.

Detection of Bacillus cereus sensu lato Isolates Posing Potential Health Risks in Mexican Chili Powder.

The potential presence of spore-forming bacteria related to the Bacillus cereus group in Mexican chili powder elaborated from Capsicum annuum L. is of commercial and clinical interest, because chili powder is an essential spice in the Mexican diet and in diets around the globe. To facilitate detection and isolation of members of this group of spore-forming bacteria from Mexican chili powder samples, we identified colonies that grew on agar medium selective for Bacillus cereus sensu lato, supplemented with polymyxin B (10 µg/mL) and ampicillin (10 to 100 µg/mL). The presumptive B. cereus (s.l.) isolates were tested using a tRNACys-PCR-based approach and the results identified species related phylogenetically to B. cereus, B. thuringiensis, and B. toyonensis. Their toxigenic potential was assessed by serological tests to detect enterotoxins (Nhe and Hbl) and by PCR targeting the hemolysin BL (hbl) component C (hblC) and non-hemolytic enterotoxin component A (nheA). The antibiotic profiles of the isolates showed a high resistance to ß-lactams (100% of the isolates), trimethoprim-sulfamethoxazole (100%), tetracycline (90%), erythromycin (77%), clindamycin (74%), and chloramphenicol (42%). Our results indicate the presence of B. cereus s.l. with toxigenic characteristics in Mexican chili powder. Because of the potential for these organisms to cause disease through their production of various toxins, and resistance to antibiotics, we recommend that a microbiological risk assessment must be considered in the Mexican regulatory requirements.

Effect of Salicylic Acid in the Yield of Ricinine in Ricinus communis under Greenhouse Condition.

Castor bean (Ricinus communis) seeds contain ricinine, an alkaloid with insecticidal and insectistatic activities. Elicitation with salicylic acid (SA) has proven to stress R. communis and might modify the ricinine concentration. The aim of this study was to evaluate the concentration of ricinine in the bagasse of seeds from R. communis elicited with exogenous SA under greenhouse conditions. Plants were grown and divided into five groups, which were sprayed with SA and drench with 50 mL 60 days after sowing with concentrations of SA (0, 100, 300, 600 and 900 µM). Clusters were mixed and separated according to the treatment, and dried. The seeds were ground, the oil was extracted by Soxhlet with hexane, and then the bagasse was extracted with methanol. Ricinine was determined by HPLC. Elicitation did not change the plant height or diameter; the control group had 9.17 µg mL-1 of ricinine; and the concentrations followed a hormesis curve with the peak at 300 µM of SA that had a ricinine concentration of 18.25 µg mL-1. Elicitation with SA might be a cost-effective technique to increase ricinine from R. communis bagasse.

Synovial sarcoma involving the calcaneus and plantar compartment of the foot: a case report.

Synovial sarcoma arising in the foot is a rare finding. We report a 64-year-old female with synovial sarcoma involving the calcaneus and central plantar compartment. The patient presented with a 2-year history of painful heel with soft tissue mass presentation 21 months after initial pain. We performed an incisional biopsy with frozen section; histopathology was consistent with synovial sarcoma.

A great diversity of Amerindian mitochondrial DNA ancestry is present in the Mexican mestizo population.

There are limited data on mitochondrial DNA (mtDNA) variation in the Mexican mestizo population. To examine the genetic diversity and matrilineal ancestry, the full mtDNA hypervariable regions I and II were sequenced in 270 unrelated mestizos from different regions of Mexico. A total of 202 different haplotypes were identified and the haplotype diversity was 0.9945. Amerindian haplotypes predominated in the sample with a proportion of 93.3%, followed by European (6.0%) and African haplotypes (0.7%). The frequency of the Amerindian haplogroups A2, B2, C1 and D1 was 51.1, 17.8, 18.5 and 5.9%, respectively. The frequency of Amerindian haplogroups was higher in the central region than in Mexico City, whereas it was the contrary for European haplogroups. This difference was accounted principally by the high frequency of B2 haplotypes in the central region. The minimum spanning network, the mismatch distribution and Tajima's D neutrality test suggest a population expansion for each Amerindian haplogroup, which could be initiated more recently for haplogroups A2 and D1. The present knowledge combined with other nuclear genetic markers will be essential in future association studies to correct for genetic substructure in mestizo populations.

Epidemiology and diagnosis of pleural tuberculosis in a low incidence country with high rate of immigrant population: A retrospective study.

BACKGROUND: The confirmatory diagnosis of pleural tuberculosis (pTB) remains challenging. The aim of this study was to describe the clinical and epidemiological characteristics of pTB patients and assess the yield of different diagnostic procedures in a low burden country with a high rate of immigrant population. METHODS: All adult patients with pTB between 2007 and 2014 were studied retrospectively. RESULTS: One hundred and three out of 843 patients with tuberculosis had pTB. Fifty-three (54.1%) were male, and the median age was 45years (range 18-87years). Fifty-two (50.49%) patients were immigrants. A confirmed diagnosis was reached in 16 patients (15.5%) by microbiological studies of pleural effusion. Lung involvement was demonstrated by sputum smear microscopy in 13/49 (26.5%), sputum GeneXpert MTB/RIF test in 13/20 (65%), and sputum culture in 16/37 (43.2%). High-resolution computed tomography (CT) showed lung involvement in 47.7% of the patients. The cure rate was 91.3% at the 1-year follow-up. Three patients died, all of them within the first month after diagnosis. CONCLUSIONS: The detection of lung involvement increased by two-fold when lung CT was used; this correlated with the likelihood of finding a positive microbiological result on sputum sample testing. Pleural microbiological studies had a low diagnostic yield, and sputum could have a complementary role.

Fine needle aspiration of pulmonary adiaspiromycosis: a case report.

BACKGROUND: Pulmonary adiaspiromycosis is a common disease of many species of wild rodents and occasionally of humans, caused by the inhalation of spores of the fungus Chrysosporium parvum var crescens (Emmonsia crescens). CASE: A 74-year-old female with pulmonary adiaspiromycosis was diagnosed by radiologically guided lung fine needle aspiration (FNA). The specimen showed intracellular and extracellular 100-300 microm conidia with a distinct thick, trilaminar wall, which was positive for Gomori-methenamine silver and periodic acid-Schiff stain. The background consisted of a granulomatous process. CONCLUSION: FNA is an effective method of diagnosing pulmonary adiaspiromycosis, and pathologists need to be aware of the characteristic features of this unusual opportunistic fungal infection.

Cat scratch disease in Medellín, Colombia.

Cat scratch disease (CSD) is the most common zoonosis transmitted by household animals. There is limited data on the epidemiology and clinical presentation of this disease in Colombia. The typical presentation includes subacute or chronic lymph node infection following inoculation of Bartonella henselae bacilli through a cat scratch. Cats have a B. henselae seroprevalence as high as 90%. Here, we report the case of a preschool boy from a rural area of Antioquia, Colombia, who presented with chronic lymphadenopathy in the right axilla. Other important infectious etiologies were ruled out, and confirmation was made with the Warthin Starry stain of a lymph node biopsy. We also discuss the most important aspects of the diagnosis, treatment and prevention of the disease.

Morphologic spectrum of immunohistochemically characterized clear cell carcinoma of the ovary: a study of 155 cases.

Establishing a diagnosis of ovarian clear cell carcinoma (O-CCC) can be subject to significant interobserver variation. Accurately diagnosing this tumor is important because of its chemoresistance and reported association with Lynch syndrome. The spectrum of the morphologic features of O-CCC has not been well described in a series composed of immunohistochemically characterized cases. A total of 155 cases diagnosed as O-CCC were retrieved from the files of 3 institutions to analyze architectural and cytologic features. The immunohistochemical features of these cases have been reported earlier. A comprehensive list of features was recorded, including, but not limited to, architectural patterns, nuclear appearance, cytoplasmic characteristics, and mitotic index. Between 1 and 13 slides were available for review for each case. The cases were divided into 2 groups based on morphologic characteristics, those with features shared by the large majority (the first group, n=138) and those that showed unusual characteristics (second group, n=17). Tumors in the first group typically showed a mixture of architectural patterns, the most frequent being papillary and tubulocystic. Papillae, usually small and round and lacking hierarchical branching and tufting or stratification of more than 3 cells, were present at least focally in almost 3 of 4 cases. The cell shape was predominantly cuboidal, not columnar. Nuclear pleomorphism and prominent nucleoli were frequently present, but never diffusely. Clear cytoplasm was found in nearly every case and hobnail cells were common. Mitoses exhibited a range from 0 to 13 with an average of 3 to 4 per 10 high power fields. The second group of tumors showed numerous unusual morphologic characteristics, despite the presence of clear cytoplasm, including those typically seen in other ovarian epithelial tumors, such as serous and endometrioid carcinoma. Eighty-nine percent of tumors from the first group showed the expected "O-CCC immunophenotype" [hepatocyte nuclear factor (HNF) positive, and estrogen receptor (ER), progesterone receptor (PR), Wilms tumor 1 (WT1) and p53 negative], whereas 4% of tumors showed HNF positivity along with focal ER or PR expression. Seven percent of tumors were not immunoreactive with these markers. Twenty-nine percent of tumors in the second group showed the O-CCC immunophenotype, whereas 24% of tumors were p53 positive, 5% of tumors were WT1 positive, and the remaining cases were negative for all markers. Ninety-seven percent (112 of 117) of HNF-positive tumors in this series were classical O-CCC. Therefore, O-CCC has characteristic morphologic features and a specific, if not unique, immunophenotype in the vast majority of the cases. Clear cell-rich tumors with features that depart from the classical morphologic appearances described herein should suggest the possibility of an alternative diagnosis.

Reading and interpretation of chest X-ray in adults with community-acquired pneumonia.

INTRODUCTION: Traditional reading of chest X-rays usually has a low prognostic value and poor agreement. OBJECTIVE: This study aimed to determine the interobserver and intraobserver agreement using two reading formats in patients with community-acquired pneumonia, and to explore their association with etiology and clinical outcomes. METHODS: A pulmonologist and a radiologist, who were blind to clinical data, interpreted 211 radiographs using a traditional analysis format (type and location of pulmonary infiltrates and pleural findings), and a quantitative analysis (pulmonary damage categorized from 0 to 10). For both, the interobserver and intraobserver agreement was estimated (Kappa statistic and intraclass correlation coefficient). The latter was assessed in a subsample of 25 radiographs three months after the initial reading. Finally, the observers made a joint reading to explore its prognostic usefulness via multivariate analysis. RESULTS: Seventy-four chest radiographs were discarded due to poor quality. With the traditional reading, the mean interobserver agreement was moderate (0.43). It was considered good when the presence of pleural effusion, and the location of the infiltrates in the right upper lobe and both lower lobes, were evaluated; moderate for multilobar pneumonia; and poor for the type of infiltrates. The mean intraobserver agreement for each reviewer was 0.71 and 0.5 respectively. The quantitative reading had an agreement between good and excellent (interobserver 0.72, intraobserver 0.85 and 0.61). Radiological findings were neither associated to a specific pathogen nor to mortality. CONCLUSION: In patients with pneumonia, the interpretation of the chest X-ray, especially the smallest of details, depends solely on the reader.

Nesidioblastosis: hipoglucemia hiperinsulinémica persistente en la infancia / Nesidioblastosis: persistent hyperinsulinemic hypoglycemia in the childhood

Se presentan 2 casos clínicos de recién nacidas que, entre otros síntomas, presentaron cifras bajas de glucemia mantenidas (menores 2,2 mmol/L), por lo que fueron evaluadas en el Servicio de Endocrinología del Hospital Provincial Pediátrico Docente "Eduardo Agramonte Piña" de Camagüey, donde se les diagnosticó nesidioblastosis -- hipoglucemia neonatal persistente --. En una de las pacientes el tratamiento médico resultó favorable, pero en la otra fue necesario realizar la pancreatectomía subtotal. Actualmente ambas afectadas reciben esquemas terapéuticos adecuados a sus necesidades clínicas.

Two case reports of female newborns are presented who, among other symptoms, presented with low concentrations of maintained glucemia (lower than 2,2 mmol/L), so they were evaluated in the Endocrinology Service of "Eduardo Agramonte Piña" Teaching Pediatric Provincial Hospital in Camagüey, where they were diagnosed nesidioblastosis -- persistent neonatal hypoglycemia --. In one of the patients the medical treatment was favorable, but in the other it was necessary to carry out a subtotal pancreatectomy. At present both patients receive therapeutic schedules adjusted to their clinical needs.

Reading and interpretation of chest X-ray in adults with community-acquired pneumonia

INTRODUCTION: Traditional reading of chest X-rays usually has a low prognostic value and poor agreement. OBJECTIVE: This study aimed to determine the interobserver and intraobserver agreement using two reading formats in patients with community-acquired pneumonia, and to explore their association with etiology and clinical outcomes. METHODS: A pulmonologist and a radiologist, who were blind to clinical data, interpreted 211 radiographs using a traditional analysis format (type and location of pulmonary infiltrates and pleural findings), and a quantitative analysis (pulmonary damage categorized from 0 to 10). For both, the interobserver and intraobserver agreement was estimated (Kappa statistic and intraclass correlation coefficient). The latter was assessed in a subsample of 25 radiographs three months after the initial reading. Finally, the observers made a joint reading to explore its prognostic usefulness via multivariate analysis. RESULTS: Seventy-four chest radiographs were discarded due to poor quality. With the traditional reading, the mean interobserver agreement was moderate (0.43). It was considered good when the presence of pleural effusion, and the location of the infiltrates in the right upper lobe and both lower lobes, were evaluated; moderate for multilobar pneumonia; and poor for the type of infiltrates. The mean intraobserver agreement for each reviewer was 0.71 and 0.5 respectively. The quantitative reading had an agreement between good and excellent (interobserver 0.72, intraobserver 0.85 and 0.61). Radiological findings were neither associated to a specific pathogen nor to mortality. CONCLUSION: In patients with pneumonia, the interpretation of the chest X-ray, especially the smallest of details, depends solely on the reader.

Impacto de una estrategia educativa estomatológica dirigida a pacientes diabéticos tipo 1 en edad pediátrica / Impact of an odontology educational strategy directed to diabetic patients type 1 in pediatric age

Muchas investigaciones muestran la relación existente entre las enfermedades sistémicas y las buco dentales. La diabetes mellitus es un problema mundial del que Cuba no escapa. El gran dilema es la posibilidad de originar complicaciones cuando no se cumple con el control de la enfermedad, dentro de ellas, la periodontopatía. Objetivo: evaluar el impacto de una estrategia educativa en pacientes diabéticos tipo 1 en edad pediátrica, con gingivitis crónica. Método: según el análisis y alcance de los resultados se realizó un estudio cuasi experimental (ensayo de intervención comunitaria), en el Policlínico de Especialidades Pediátricas de la provincia de Camagüey, entre enero y julio de 2008. El universo estuvo constituido por los 54 pacientes diabéticos entre 8 y 19 años registrados en el Programa provincial de atención al niño y adolescente diabéticos. La muestra coincidió con el universo. Se tuvieron en cuenta variables como nivel de información, higiene bucal, estado de salud gingival. Se compararon los resultados antes de realizar la intervención con los obtenidos a corto y a mediano plazo. Resultados: inicialmente el nivel de información se evaluó de mal en el 57,4 % de los pacientes. A mediano plazo el 68,6 % fue evaluado de bien. La higiene bucal fue buena en el 8 % de los pacientes al inicio, pasados 18 meses la evaluación de bien se extendió al 70,4 %. Al año y medio el 50 % no padecía enfermedad gingival. Conclusiones: se constató que el impacto, pasado 18 meses de aplicada la estrategia, fue positivo.

Many researches show the relationship between systemic and buccodental diseases. Diabetes mellitus is a global problem and Cuba is no exception. The dilemma is the possibility to cause complications when does not comply with the control of the disease inside them, periodontopathy. Objective: to assess the impact of an educational strategy in patients with diabetes type 1 in pediatric age with chronic gingivitis. Method: according to the analysis and the scope of results a quasi-experimental study was conducted (Community intervention trial), at the General Hospital of pediatric specialties in the province of Camagüey, from January to July 2008. The universe was made up of 54 diabetic patients between 8 and 19 years, registered in the provincial programme of care for diabetic children and adolescents. The sample coincided with the universe. Variables as: level of information, oral hygiene, and gingival health status were considered. The results were compared before making the intervention with those obtained in the short and medium term. Results: initially the level of information was evaluated of wrong in 57.4 % of patients. At medium term 68.6 % was rated of good. Oral hygiene was good in 8 % of patients at the beginning, after 18 months evaluation of well spread to 70.4 %. To one year and a half the 50 % was not suffering from gingival disease. Conclusions: it was found that the impact, after 18 months of being applied the strategy, was positive.

A randomized, double-blinded comparison of thoracic epidural ropivacaine, ropivacaine/fentanyl, or bupivacaine/fentanyl for postthoracotomy analgesia.

UNLABELLED: Epidural ropivacaine has not been compared with bupivacaine for postthoracotomy analgesia. Eighty patients undergoing elective lung surgery were randomized in a double-blinded manner to receive one of three solutions for high thoracic epidural analgesia. A continuous epidural infusion of 0.1 mL. kg(-1). h(-1) of either 0.2% ropivacaine, 0.15% ropivacaine/fentanyl 5 micro g/mL, or 0.1% bupivacaine/fentanyl 5 micro g/mL was started at admission to the intensive care unit. We assessed pain scores (rest and spirometry), IV morphine consumption, spirometry, hand grip strength, PaCO(2), heart rate, blood pressure, respiratory rate, and side effects (sedation, nausea, vomiting, and pruritus) for 48 h. Thoracic epidural ropivacaine/fentanyl provided adequate pain relief similar to bupivacaine/fentanyl during the first 2 postoperative days after posterolateral thoracotomy. The use of plain 0.2% ropivacaine was associated with worse pain control during spirometry, larger consumption of IV morphine, and increased incidence of postoperative nausea and vomiting. Morphine requirements were larger in the ropivacaine group, with no differences between bupivacaine/fentanyl and ropivacaine/fentanyl groups. Patients in the ropivacaine group experienced more pain and performed worse in spirometry than patients who received epidural fentanyl. There was no significant difference in motor block. We conclude that epidural ropivacaine/fentanyl offers no clinical advantage compared with bupivacaine/fentanyl for postthoracotomy analgesia. IMPLICATIONS: Thoracic epidural ropivacaine/fentanyl provided adequate pain relief and similar analgesia to bupivacaine/fentanyl during the first 2 postoperative days after posterolateral thoracotomy. Plain 0.2% ropivacaine was associated with worse pain control and an increased incidence of postoperative nausea and vomiting. We conclude that epidural ropivacaine/fentanyl offers no clinical advantage compared with bupivacaine/fentanyl for postthoracotomy analgesia.

Efecto de la adición de zeolita (clinoptilolita y modernita) en un andosol sobre el ambiente químico edáfico y el crecimiento de avena / Effect of zeolite (clinoptilolite and mordentite) amended andosols on soil chemical environment and growth of oat

Entre las zeolitas, la clinoptilolita y la mordenita se distinguen por su utilidad en la agricultura, debido a que al entrar en contacto con el amonio del medio lo retienen en su estructura interna y externa, funcionando entonces como un fertilizante nitrogenado de lenta liberación. Se estudió el efecto de la zeolita ZCU (clinoptilolita y mordenita) en la producción de biomasa vegetal y el ambiente químico del suelo, empleando la avena como cultivo indicador. Se evaluaron cinco concentraciones de ZCU en suelo (0, 5, 10, 20 y 30 por ciento peso base seca del suelo) y un tratamiento adicional preparado solo con ZCU. Las variables evaluadas fueron biomasa aérea y de raíces, pH y capacidad de intercambio catiónico (CIC), NH4+ sustrato y NO3-l lixiviado. La aplicación de ZCU tuvo un efecto positivo sobre la producción de la biomasa aérea y de raíces y modificó el ambiente químico edáfico en sus valores de pH y CIC. La aplicación de ZCU provocó una menor acumulación de NO3- lixiviado en relación a la cantidad de NH4+ en sustrato. Los resultados apoyan que la ZCU tiene capacidad para adsorber amonio y aminorar el proceso de nitrificación.

Tiroides lingual en el niño: a propósito de un caso y su revisión en la literatura / Lingual thyroid in the child: case presentation and its review in the literature

Se hace la presentación de un caso de tiroides lingual en una niña de cinco años de edad atendida en el Hospital Provincial Pediátrico de Camagüey, entidad rara en la práctica pediátrica, lo cual nos ha permitido indagar sobre algunos aspectos de interés en esta enfermedad en los niños y sus características clínicas, anatomopatológicas y conducta a seguir

Mecanismo de acción de los hongos entomopatógenos / Mechanism of action of entomopathogenic fungi

Los hongos entomopatógenos tienen un gran potencial como agentes de control, ya que constituyen un grupo con más de 750 especies que al dispersarse en el ambiente provocan infecciones fúngicas en las poblaciones de insectos. Estos hongos inician su proceso infectivo cuando las esporas son retenidas en la superficie del integumento, donde se inicia la formación del tubo germinativo, comenzando el hongo a excretar enzimas como las proteasas, quitinasas, quitobiasas, lipasas y lipooxigenasas. Estas enzimas degradan la cutícula del insecto y coadyuvan con el proceso de penetración por presión mecánica iniciado por el apresorio, que es una estructura especializada formada en el tubo germinativo. Una vez dentro del insecto, el hongo se desarrolla como cuerpos hifales que se van diseminando a través del hemocele e invaden diversos tejidos musculares, cuerpos grasos, tubos de Malpighi, mitocondrias y hemocitos, ocasionando la muerte del insecto después de 3 a 14 días de iniciada la infección. Una vez muerto el insecto y ya agotados muchos de los nutrientes, el hongo inicia un crecimiento micelar e invade todos los órganos del hospedero. Finalmente, las hifas penetran la cutícula desde el interior del insecto y emergen a la superficie, donde en condiciones ambientales apropiadas inician la formación de nuevas esporas