Metagenomic and functional analysis of hindgut microbiota of a wood-feeding higher termite.

From the standpoints of both basic research and biotechnology, there is considerable interest in reaching a clearer understanding of the diversity of biological mechanisms employed during lignocellulose degradation. Globally, termites are an extremely successful group of wood-degrading organisms and are therefore important both for their roles in carbon turnover in the environment and as potential sources of biochemical catalysts for efforts aimed at converting wood into biofuels. Only recently have data supported any direct role for the symbiotic bacteria in the gut of the termite in cellulose and xylan hydrolysis. Here we use a metagenomic analysis of the bacterial community resident in the hindgut paunch of a wood-feeding 'higher' Nasutitermes species (which do not contain cellulose-fermenting protozoa) to show the presence of a large, diverse set of bacterial genes for cellulose and xylan hydrolysis. Many of these genes were expressed in vivo or had cellulase activity in vitro, and further analyses implicate spirochete and fibrobacter species in gut lignocellulose degradation. New insights into other important symbiotic functions including H2 metabolism, CO2-reductive acetogenesis and N2 fixation are also provided by this first system-wide gene analysis of a microbial community specialized towards plant lignocellulose degradation. Our results underscore how complex even a 1-microl environment can be.

Isolation of Fungi and Bacteria Associated with the Guts of Tropical Wood-Feeding Coleoptera and Determination of Their Lignocellulolytic Activities.

The guts of beetle larvae constitute a complex system where relationships among fungi, bacteria, and the insect host occur. In this study, we collected larvae of five families of wood-feeding Coleoptera in tropical forests of Costa Rica, isolated fungi and bacteria from their intestinal tracts, and determined the presence of five different pathways for lignocellulolytic activity. The fungal isolates were assigned to three phyla, 16 orders, 24 families, and 40 genera; Trichoderma was the most abundant genus, detected in all insect families and at all sites. The bacterial isolates were assigned to five phyla, 13 orders, 22 families, and 35 genera; Bacillus, Serratia, and Pseudomonas were the dominant genera, present in all the Coleopteran families. Positive results for activities related to degradation of wood components were determined in 65% and 48% of the fungal and bacterial genera, respectively. Our results showed that both the fungal and bacterial populations were highly diverse in terms of number of species and their phylogenetic composition, although the structure of the microbial communities varied with insect host family and the surrounding environment. The recurrent identification of some lignocellulolytic-positive inhabitants suggests that particular microbial groups play important roles in providing nutritional needs for the Coleopteran host.

Genetic diversity of Costa Rican populations of the rice planthopper Tagosodes orizicolus (Homoptera: Delphacidae).

Tagosodes orizicolus (Homoptera: Delphacidae) is one of the main constraints of the rice production in the Neotropics. This planthopper produces severe damages as a phloem feeder, causes mechanical injury during oviposition and vectors the rice hoja blanca virus (RHBV). The main objective of this study was to determine the genetic diversity of T. orizicolus populations from three rice growing regions of Costa Rica, using RAPDs. Individuals from Guanacaste, Parrita, San Carlos and Cali-Colombia, as outgroup, were analyzed using the random primers. Phenetic relationships revealed that the Costa Rican populations were clearly separated from Cali-Colombia, sharing less than 25% similarity. Costa Rican populations were divided into two main branches separated at 30% similarity. The first branch included Guanacaste and San Carlos and the second displayed Parrita. In relation to similarity indexes within groups, the Guanacaste cluster showed the highest (over 50%) and Cali-Colombia was the most diverse (28%). The correspondence analysis confirmed the clusters of the phenogram and showed close interactions between the Parrita and San Carlos populations. The genetic separation observed could be the result of the geographic isolation among populations, but it could also be explained by the infection with the rickettsia Wolbachia pipientis. This bacterium causes cytoplasmic incompatibility in its host, which results in non-viable progeny when infected males mate with non-infected females, or when insects hosting different strains of Wolbachia mate. Then, a search for Wolbachia in previously described populations of T orizicolus was initiated. The presence of the bacteria was analyzed by PCR with 16S rDNA-specific primers for Wolbachia. The PCR analyses revealed infections of 86% in the population of San Carlos, 96% in Guanacaste, 37% in Parrita and 100% in Cali-Colombia. Crosses between individuals of T. orizicolus from Parrita and Guanacaste were performed for testing cytoplasmic incompatibility. When infected males were crossed with non-infected females within the same population, a significant reduction in progeny number was obtained as well as when crosses between infected individuals belonging to different populations were performed. These experiments showed cytoplasmic incompatibility not only caused by the presence of Wolbachia within the population, but also by the presence of different strains of the bacteria between populations.

Uncovering the cultivable microbial diversity of costa rican beetles and its ability to break down plant cell wall components.

Coleopterans are the most diverse insect order described to date. These organisms have acquired an array of survival mechanisms through their evolution, including highly efficient digestive systems. Therefore, the coleopteran intestinal microbiota constitutes an important source of novel plant cell wall-degrading enzymes with potential biotechnological applications. We isolated and described the cultivable fungi, actinomycetes and aerobic eubacteria associated with the gut of larvae and adults from six different beetle families colonizing decomposing logs in protected Costa Rican ecosystems. We obtained 611 isolates and performed phylogenetic analyses using the ITS region (fungi) and 16S rDNA (bacteria). The majority of fungal isolates belonged to the order Hypocreales (26% of 169 total), while the majority of actinomycetes belonged to the genus Streptomyces (86% of 241 total). Finally, we isolated 201 bacteria spanning 19 different families belonging into four phyla: Firmicutes, α, ß and γ-proteobacteria. Subsequently, we focused on microbes isolated from Passalid beetles to test their ability to degrade plant cell wall polymers. Highest scores in these assays were achieved by a fungal isolate (Anthostomella sp.), two Streptomyces and one Bacillus bacterial isolates. Our study demonstrates that Costa Rican beetles harbor several types of cultivable microbes, some of which may be involved in symbiotic relationships that enable the insect to digest complex polymers such as lignocellulose.

Seroprevalencia y serotipificación de leptospirosis canina en el municipio de Buenaventura (Valle del Cauca) / Seroprevalence and serotypification of canine leptospirosis in Buenaventura (Valle del cauca)

El presente estudio tuvo como objetivo verificar la infección con serovares de Leptospira spp. en caninos con propietario en Buenaventura, Valle del Cauca, Colombia. Las muestras de suero fueron tomadas de 100 caninos y fueron probadas con los serogrupos de Leptospira interrogans: Bataviae, Mini, Autumnalis, Canicola, Shermani, Icterohaemorrhagiae, Cynopteri, Australis, Celledonis, Grippotyphosa, Hebdomadis, Javanica, Manhao, Pomona, Pyrogenes, Sejroe, Tarassovi y Ballum, usando la técnica de aglutinación microscópica. La prevalencia de anticuerpos anti-Leptospira contra uno o más serovares fue del 31%. Los serovares s frecuentes fueron icterohaemorrhagiae (38,7%), autumnalis (19,4%) y australis (12,9%). Se presentaron coaglutinaciones en el 6,5% de los sueros positivos. Estos resultados sugieren que los caninos evaluados son reservorios de Leptospiras sp patógenas, potenciales para leptospirosis en Buenaventura, siendo necesario implementar medidas preventivas y estudiar la epidemiología de la enfermedad en esta ciudad.

This study aimed to verify Leptospira spp. serovars infections in dogs with owner in Buenaventura, Valle del Cauca, Colombia. Serum samples were collected from 100 dogs and tested against serogroups of Leptospira interrogans: Bataviae, Mini, Autumnalis, Canicola, Shermani, Icterohaemorrhagiae, Cynopteri, Australis, Celledonis, Grippotyphosa, Hebdomadis, Javanica, Manhao, Pomona, Pyrogenes, Sejroe, Tarassovi and Ballum, using the microscopic agglutination test. Prevalence of anti-Leptospira antibodies against one or more serovars was 31%. The most frequent servars were icterohaemorrhagiae (38.7%), autumnalis (19.4%) and australis (12.9%). Co-agluttinations were presented in 6.5% sera samples. These results suggested that dogs are potential reservoirs of pathogen Leptospiras sp, potential of leptospirosis in Buenaventura and underscored the need to implement preventive measures and study the epidemiology of this disease in this city.

Estudio seroepidemiológico de la leptospirosis humana en el departamento del Valle del Cauca, Colombia / Seroepidemiological situation of human leptospirosis in Valle del Cauca, Colombia

OBJETIVO: confirmar serológicamente la ocurrencia de leptospirosis humana en casos presuntivos procedentes del departamento del Valle del Cauca, estudiar variables clínico-epidemiológicas asociadas a la enfermedad e identificar los serogrupos de Leptospira más prevalentes en la región. MÉTODOS: se analizaron 150 muestras séricas colectadas en fase aguda, de casos con sospecha clínica y con riesgo epidemiológico de leptospirosis. Fueron evaluadas mediante hemoaglutinación indirecta y microaglutinación tomando como criterio de confirmación de la enfermedad la presencia de un título por microaglutinación mayor o igual que 1:800. Se analizaron datos epidemiológicos de interés así como síntomas y signos presentados en cada caso. RESULTADOS: las técnicas serológicas empleadas permitieron definir 31 casos confirmados (20,6 por ciento) y 16 casos probables (10,6 por ciento). Icterohaemorrhagie fue el serogrupo de mayor reactividad serológica tanto en casos confirmados como probables. Los síntomas más comunes fueron fiebre (89,3 por ciento), cefalea (86,7 por ciento) y mialgias (77,3 por ciento). Síntomas de leptospirosis severa como ictericia e insuficiencia renal fueron observados en 36 por ciento y 6,7 por ciento de los casos, respectivamente. Cerca de 70 por ciento de los casos confirmados o probables procedía de zonas urbanas y 85 por ciento resultó de hombres con un promedio de edad de 40 años. Los factores de riesgo más frecuentes fueron la exposición a roedores o animales domésticos (95,7 por ciento) y aguas potencialmente contaminadas (36,2 por ciento). CONCLUSIONES: los resultados del presente estudio sugieren que la leptospirosis constituye un problema de salud pública en el Valle del Cauca, región suroccidental de Colombia(AU)

OBJECTIVE: to serologically confirm the occurrence of human leptospirosis in presumptive cases from the department of Valle del Cauca in Colombia, to study clinical-epidemiological data associated to the disease and to find out the most prevalent leptospiral serogroups. METHOD: a total of 150 serum samples collected during the acute phase from clinically suspected patients of having leptospirosis were analyzed. Samples were evaluated by indirect hemagglutination and microagglutination tests, taking a microagglutination titer equal to or greater than 1:800 as definition of confirmed case. Epidemiological data as well as symptoms and signs of interest were analyzed. RESULTS: these serological techniques allowed defining 31 confirmed cases (20.6 percent) and 16 probable cases (10.6 percent). Icterohaemorrhagiae was the serogroup with the higher serological reactivity in both confirmed and probable cases. Most common symptoms were fever (89.3 percent), headaches (86.7 percent) and myalgias (77.3 percent). Symptoms of severe leptospirosis like jaundice and renal failure were observed in 36 percent and 6.7 percent of cases, respectively. About 70 percent of confirmed or probable cases came from urban areas and 85 percent of them were men aged 40 years as average. The epidemiological risk factors were exposure to rats and domestic animal (95.7 percent) and potentially contaminated water (36.2 percent). CONCLUSIONS: the results of the present study suggest that leptospirosis is a public health problem in Valle del Cauca, a region located on the south west of the country(AU)

Estudio seroepidemiológico de la leptospirosis humana en el departamento del Valle del Cauca, Colombia / Seroepidemiological situation of human leptospirosis in Valle del Cauca, Colombia

OBJETIVO: confirmar serológicamente la ocurrencia de leptospirosis humana en casos presuntivos procedentes del departamento del Valle del Cauca, estudiar variables clínico-epidemiológicas asociadas a la enfermedad e identificar los serogrupos de Leptospira más prevalentes en la región. MÉTODOS: se analizaron 150 muestras séricas colectadas en fase aguda, de casos con sospecha clínica y con riesgo epidemiológico de leptospirosis. Fueron evaluadas mediante hemoaglutinación indirecta y microaglutinación tomando como criterio de confirmación de la enfermedad la presencia de un título por microaglutinación mayor o igual que 1:800. Se analizaron datos epidemiológicos de interés así como síntomas y signos presentados en cada caso. RESULTADOS: las técnicas serológicas empleadas permitieron definir 31 casos confirmados (20,6 por ciento) y 16 casos probables (10,6 por ciento). Icterohaemorrhagie fue el serogrupo de mayor reactividad serológica tanto en casos confirmados como probables. Los síntomas más comunes fueron fiebre (89,3 por ciento), cefalea (86,7 por ciento) y mialgias (77,3 por ciento). Síntomas de leptospirosis severa como ictericia e insuficiencia renal fueron observados en 36 por ciento y 6,7 por ciento de los casos, respectivamente. Cerca de 70 por ciento de los casos confirmados o probables procedía de zonas urbanas y 85 por ciento resultó de hombres con un promedio de edad de 40 años. Los factores de riesgo más frecuentes fueron la exposición a roedores o animales domésticos (95,7 por ciento) y aguas potencialmente contaminadas (36,2 por ciento). CONCLUSIONES: los resultados del presente estudio sugieren que la leptospirosis constituye un problema de salud pública en el Valle del Cauca, región suroccidental de Colombia.

OBJECTIVE: to serologically confirm the occurrence of human leptospirosis in presumptive cases from the department of Valle del Cauca in Colombia, to study clinical-epidemiological data associated to the disease and to find out the most prevalent leptospiral serogroups. METHOD: a total of 150 serum samples collected during the acute phase from clinically suspected patients of having leptospirosis were analyzed. Samples were evaluated by indirect hemagglutination and microagglutination tests, taking a microagglutination titer equal to or greater than 1:800 as definition of confirmed case. Epidemiological data as well as symptoms and signs of interest were analyzed. RESULTS: these serological techniques allowed defining 31 confirmed cases (20.6 percent) and 16 probable cases (10.6 percent). Icterohaemorrhagiae was the serogroup with the higher serological reactivity in both confirmed and probable cases. Most common symptoms were fever (89.3 percent), headaches (86.7 percent) and myalgias (77.3 percent). Symptoms of severe leptospirosis like jaundice and renal failure were observed in 36 percent and 6.7 percent of cases, respectively. About 70 percent of confirmed or probable cases came from urban areas and 85 percent of them were men aged 40 years as average. The epidemiological risk factors were exposure to rats and domestic animal (95.7 percent) and potentially contaminated water (36.2 percent). CONCLUSIONS: the results of the present study suggest that leptospirosis is a public health problem in Valle del Cauca, a region located on the south west of the country.

Genetic diversity of Costa Rican populations of the rice planthopper Tagosodes orizicolus (Homoptera: Delphacidae)

Tagosodes orizicolus (Homoptera: Delphacidae) is one of the main constraints of the rice production in the Neotropics. This planthopper produces severe damages as a phloem feeder, causes mechanical injury during oviposition and vectors the rice hoja blanca virus (RHBV). The main objective of this study was to determine the genetic diversity of T. orizicolus populations from three rice growing regions of Costa Rica, using RAPDs. Individuals from Guanacaste, Parrita, San Carlos and Cali-Colombia, as outgroup, were analyzed using the random primers. Phenetic relationships revealed that the Costa Rican populations were clearly separated from Cali-Colombia, sharing less than 25% similarity. Costa Rican populations were divided into two main branches separated at 30% similarity. The first branch included Guanacaste and San Carlos and the second displayed Parrita. In relation to similarity indexes within groups, the Guanacaste cluster showed the highest (over 50%) and Cali-Colombia was the most diverse (28%). The correspondence analysis confirmed the clusters of the phenogram and showed close interactions between the Parrita and San Carlos populations. The genetic separation observed could be the result of the geographic isolation among populations, but it could also be explained by the infection with the rickettsia Wolbachia pipientis. This bacterium causes cytoplasmic incompatibility in its host, which results in non-viable progeny when infected males mate with non-infected females, or when insects hosting different strains of Wolbachia mate. Then, a search for Wolbachia in previously described populations of T orizicolus was initiated. The presence of the bacteria was analyzed by PCR with 16S rDNA-specific primers for Wolbachia. The PCR analyses revealed infections of 86% in the population of San Carlos, 96% in Guanacaste, 37% in Parrita and 100% in Cali-Colombia. Crosses between individuals of T. orizicolus from Parrita and Guanacaste were performed for testing...

La familia en México. Guía sobre derechos, deberes y obligaciones / The family in Mexico. Guide on rigths and obligations

Se estudia el concepto y las características de la familia, su función social y los tipos de familias existentes; asimismo, describe la relación entre los derechos humanos y la familia, y se oborda la violencia intrafamiliar, sus causas y repercusiones. Contenido: Presentación. 1.- Importancia de la familia; 2.- Derechos humanos y familia; 3.- Derechos, deberes y obligaciones de los miembros de la familia; 4.- Violencia intrafamiliar; 5.- Directorio de instituciones públicas que brindan asistencia a la familia.