Colon, Mexico
Colon, Mexico

Time filter

Source Type

News Article | November 8, 2016
Site: www.sciencedaily.com

A new study challenges the tenet of herpes viruses being strictly host-specific. Scientists from the Leibniz Institute for Zoo and Wildlife Research (IZW) in Germany have discovered that gammaherpesviruses switch their hosts more frequently than previously thought. In fact, bats and primates appear to be responsible for the transfer of these viruses to other mammals in many cases. The findings were published in the scientific journal mBio. For herpes, it has generally been thought that every animal has its own specific viruses and that virus and host species have co-evolved. Now, an international team of scientists led by the Leibniz-IZW discovered that herpesviruses may not conform to this commonly held view. Surprisingly, while studying a group of herpesviruses called gammaherpesviruses, the researchers demonstrated that the herpes viruses found in common vampire bats (Desmodus rotundus) and hairy-legged vampire bats (Diphylla ecaudata) were similar to those previously found in cattle. While it is known that vampire bats exclusively feed on animal blood, preferring domestic swine and cattle, since they represent an easily accessible food source, the result was somewhat unusual. Were bats being infected by viruses from their food source? To answer this question, researchers from the Leibniz-IZW worked together with the Centro Nacional de Investigación Disciplinaria en Microbiología Animal -- INIFAP; the Facultad de Medicina Veterinaria y Zootecnia of the Universidad Veracruzana; the Instituto de Biotecnología of the National Autonomous University of Mexico, the SUNY Downstate Medical Center in the USA, and the Freie Universität Berlin in Germany. Following up on the results from vampire bats, the researchers compiled the largest dataset of gammaherpesvirus sequences to date from their own sequencing data and publicly available data, including viruses from many bat species, and performed extensive analyses to determine the relationships of the viruses to one another and to their hosts. This shows that herpesviruses have frequently switched between species in the past, rather than being host specific. Most switches derived from bats, with primates being the second most common source of switches. "We speculate that bat-specific traits such as their ability to fly and a wide geographical range might have been important in promoting a virus spillover from bats to other animal groups," says Dr Marina Escalera-Zamudio, scientist at the Leibniz-IZW. After switching, herpesviruses may have adapted to their new hosts, creating the impression of host specificity. So the vampire bats were not likely infected by their food but more likely infected by other mammals in the past. Also surprisingly, vampire bats were not more prone among bats to transfer viruses, as many viruses from non-blood feeding bats also appear to have jumped. Since many viruses that cause disease in humans belong to the herpes virus family, it is important to understand their evolutionary development. "Herpes viruses establish latent life-long infections. Although they generally cause disease only in immunosuppressed individuals, they can survive largely below the radar even after infection," Escalera-Zamudio adds. Therefore, there may be even more species switches to uncover. However, only further sampling across a larger diversity of hosts will help determine the full scale of such switches. Future efforts should concentrate on clarifying the role of bats and primates for spreading these viruses.


News Article | November 8, 2016
Site: phys.org

A new study challenges the tenet of herpes viruses being strictly host-specific. Scientists from the Leibniz Institute for Zoo and Wildlife Research (IZW) in Germany have discovered that gammaherpesviruses switch their hosts more frequently than previously thought. In fact, bats and primates appear to be responsible for the transfer of these viruses to other mammals in many cases. The findings were published in the scientific journal "mBio". For herpes, it has generally been thought that every animal has its own specific viruses and that virus and host species have co-evolved. Now, an international team of scientists led by the Leibniz-IZW discovered that herpesviruses may not conform to this commonly held view. Surprisingly, while studying a group of herpesviruses called gammaherpesviruses, the researchers demonstrated that the herpes viruses found in common vampire bats (Desmodus rotundus) and hairy-legged vampire bats (Diphylla ecaudata) were similar to those previously found in cattle. While it is known that vampire bats exclusively feed on animal blood, preferring domestic swine and cattle, since they represent an easily accessible food source, the result was somewhat unusual. Were bats being infected by viruses from their food source? To answer this question, researchers from the Leibniz-IZW worked together with the Centro Nacional de Investigación Disciplinaria en Microbiología Animal - INIFAP; the Facultad de Medicina Veterinaria y Zootecnia of the Universidad Veracruzana; the Instituto de Biotecnología of the National Autonomous University of Mexico, the SUNY Downstate Medical Center in the USA, and the Freie Universität Berlin in Germany. Following up on the results from vampire bats, the researchers compiled the largest dataset of gammaherpesvirus sequences to date from their own sequencing data and publicly available data, including viruses from many bat species, and performed extensive analyses to determine the relationships of the viruses to one another and to their hosts. This shows that herpesviruses have frequently switched between species in the past, rather than being host specific. Most switches derived from bats, with primates being the second most common source of switches. "We speculate that bat-specific traits such as their ability to fly and a wide geographical range might have been important in promoting a virus spillover from bats to other animal groups," says Dr Marina Escalera-Zamudio, scientist at the Leibniz-IZW. After switching, herpesviruses may have adapted to their new hosts, creating the impression of host specificity. So the vampire bats were not likely infected by their food but more likely infected by other mammals in the past. Also surprisingly, vampire bats were not more prone among bats to transfer viruses, as many viruses from non-blood feeding bats also appear to have jumped. Since many viruses that cause disease in humans belong to the herpes virus family, it is important to understand their evolutionary development. "Herpes viruses establish latent life-long infections. Although they generally cause disease only in immunosuppressed individuals, they can survive largely below the radar even after infection," Escalera-Zamudio adds. Therefore, there may be even more species switches to uncover. However, only further sampling across a larger diversity of hosts will help determine the full scale of such switches. Future efforts should concentrate on clarifying the role of bats and primates for spreading these viruses. Explore further: Virus in bats homologous to retroviruses in rodents and primates More information: Escalera-Zamudio M, et al. (2016): Bats, primates, and the evolutionary origins and diversification of mammalian gammaherpesviruses. mBio, DOI: 10.1128/mBio.01425-16


We evaluated the efficacy of the biorational insecticides azadirachtin and spinetoram, as well as the neonicotinoid thiametoxam, the organophosphates chlorpyrifos and malathion, and the pyrethroid-cyhalothrin against the pepper weevil, Anthonomus eugenii Cano, in a field of jalapeo pepper, Capsicum annuum L., in South-Central Chihuahua. Thiametoxam and chlorpyrifos had an impact on the reduction of this pest as many as five days after application. Also, we evaluated the insecticide rotation effect of Treatment 1 (spinetoram → chlorpyrifos → chlorpyrifos → thiametoxam) and Treatment 2 (thiametoxam → chlorpyrifos → chlorpyrifos → thiametoxam) where both treatments suppressed populations of this insect. Treatment 1 had the fewest fallen fruits.


Figueroa-Viramontes U.,INIFAP | Delgado J.A.,U.S. Department of Agriculture | Cueto-Wong J.A.,National Research Center Disciplinaria en Relacion Agua Suelo Planta Atmosfera | Nunez-Hernandez G.,INIFAP | And 2 more authors.
Agriculture, Ecosystems and Environment | Year: 2011

Although nitrogen inputs to agricultural fields are necessary for global food sustainability, they present a major nutrient management challenge, because nitrogen inputs can increase nitrogen losses to the environment, which can negatively impact water quality across key surface and groundwater resources. The need to evaluate the potential risk of nitrogen losses for a given forage type, management scenario, and field quickly and easily can be met with new tools that assist in environmental risk assessment. An example is the Mexico Nitrogen Index: this new tool aims to help its users quickly evaluate the risk of nitrogen loss for a given field under a given set of management practices. The objective of this study was to evaluate the accuracy of the Mexico Nitrogen Index in ranking the risk of nitrogen loss for a given field under a given set of management practices. To perform this evaluation, data for several different management scenarios were collected and entered into the Mexico Nitrogen Index. The capability of the Index to assess the fate and transport of nitrogen and to rank the risk of nitrogen loss was evaluated by comparing predicted soil residual nitrate and forage nitrogen uptake with observed values. Nitrogen fate and transport were accurately predicted under many different scenarios (P< 0.001); for example, the Index was successful in accurately predicting higher potential risk for nitrogen loss for scenarios with excessive nitrogen applications. It was concluded that the Mexico Nitrogen Index can accurately perform these risk assessments and that it has the potential to facilitate communication between scientists, extension personnel and farmers about the effects different management practices may have on nitrogen losses. © 2011.


Casique-Valdes R.,Antonio Narro Agrarian Autonomous University | Reyes-Martinez A.Y.,Antonio Narro Agrarian Autonomous University | Sanchez-Pena S.R.,Antonio Narro Agrarian Autonomous University | Bidochka M.J.,Brock University | Lopez-Arroyo J.I.,INIFAP
Florida Entomologist | Year: 2011

This report confirms the identification of Mexican strains of Hirsutella citriformis isolated from Asian citrus psyllid, Diaphorina citri. Two H. citriformis strains were pathogenic to adults of D. citri and adults of the potato psyllid, Bactericera cockerelli. Copyright © 2011 BioOne All rights reserved.


Ortega A.L.,INIFAP
Archives of Agronomy and Soil Science | Year: 2011

The permanent bed planting system for wheat (Triticum aestivum L.) production has recently received additional attention. Studies using hard red spring wheat (cultivar Nahuatl F2000) were conducted at two locations in central Mexico. The studies included the installation of three furrow diking treatments, two granular N timing treatments and three foliar N rates applied at the end of anthesis. The objective was to evaluate the effect of these factors on wheat grain yield, yield components and grain N in a wheat-maize (Zea maize L.) rotation with residues of both crops left as stubble. Results indicated that diking in alternate furrows increased both grain yield and the final number of spikes per m 2. The split application of N fertilizer enhanced the number of spikes per m 2 and grain N uptake, but the effect on grain yield was inconsistent. Similarly, grain protein increased with the foliar application of 6 kg N ha -1, depending upon the maximum temperature within the 10 days following anthesis. The normalized difference vegetative index (NDVI) readings collected at four growth stages were generally higher for the split N application than for the basal N application at planting. Grain N uptake was associated to NDVI readings collected after anthesis. © 2011 Taylor & Francis.


Bautista-Cruz A.,National Polytechnic Institute of Mexico | Del Castillo R.F.,National Polytechnic Institute of Mexico | Etchevers-Barra J.D.,Colegio de Mexico | Gutierrez-Castorena M.D.C.,Colegio de Mexico | Baez A.,INIFAP
Forest Ecology and Management | Year: 2012

Through slash-and-burn techniques, vast areas formerly occupied by tropical montane cloud forest (TMCF) in Mexico have been converted into croplands and secondary forest of different ages. Despite the dramatic changes in soil properties and processes detected during cropping and forest regeneration, no attempts have been made to develop soil quality indicators (SQI) to assist in the assessment of soil conditions during such changes. SQI are considered to be essential in evaluating plans of forest restoration or management; as such, the objectives of this study were to (i) select soil properties that can be used as SQI during forest regeneration for abandoned crop fields in a TMCF area managed under the slash-and-burn method; and (ii) examine the ecological significance of stand age for function-based interpretations of the selected SQI. To this end, the soil properties of three adjacent chronosequences in El Rincón, Sierra Norte, Southern Mexico were analyzed. Each chronosequence consisted of ordered series of five stands of different age after abandonment: a cornfield and adjacent forests of ~15 (incipient forest), ~45 (young forest), ~75 (mature forest), and≥100 (old-growth forest) years after abandonment. The soil properties of undisturbed old-growth forest stands were used as a reference. After inspection of principal component analysis results and control charts, the following soil properties were chosen as SQI in TMCF areas: soil organic carbon, pH, plant-available P, O horizon thickness and exchangeable Al 3+. The selected SQI displayed different rates of change during forest regeneration. Soil organic carbon had a fast recovery rate and, therefore, a greater ability to return to its original level after disturbance. In contrast, O horizon thickness, soil pH, plant-available P, and exchangeable Al 3+ showed a slow rate of change during the fallow period. SQI did not always change linearly nor improve with the age of the forest. The highest exchangeable Al 3+ concentration was detected in 45-year-old forests, suggesting that at this forest age, soil become an important filter against Al 3+ sensitive species, potentially affecting vegetation composition. Considering the slow recovery rate of some SQI, we estimate that fallow periods of at least 100years are required in order to reach good soil quality in TMCF ecosystems. Management practices should therefore consider the maintenance of forest of different ages spanning at least 100years in the landscape. Doing so would achieve more sustainable management practices by allowing a relatively continuous recovery of the ecosystem without prolonged interruptions of land utilization. © 2012 Elsevier B.V.


Gandarilla-Pacheco F.L.,Autonomous University of Nuevo León | Galan-Wong L.J.,Autonomous University of Nuevo León | Lopez-Arroyo J.I.,INIFAP | Rodriguez-Guerra R.,INIFAP | Quintero-Zapata I.,Autonomous University of Nuevo León
Florida Entomologist | Year: 2013

Huanglongbing (HLB), considered one of the most lethal diseases of citrus worldwide, has reached the main areas of Mexican lime (Citrus latifolia Tanaka) fruit production on the Pacific coast of México. Growers have initiated intensive use of insecticides in order to control populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), the vector of the pathogen, 'Candidatus Liberibacter asiaticus' associated with huanglongbing. Presently, costs of insecticides and the side effects of their use are major concerns, because they could impair the management strategy against the vector; and thus, ecologically and economically viable alternatives to conventional insecticides are required in the short term. Therefore the goal of this study was to evaluate the pathogenicity of 27 native isolates and 3 strains of entomopathogenic fungi and determine their potential as biological control agents of D. citri by using 2 different bioassay methods. Bioassays were performed under laboratory conditions (26 ±2 °C, 60 ±5% RH and 16:8 h L:D) by exposing adult insects to a concentration of 1 × 10 8 conidia per milliliter using 2 different application methods, i.e., spraying the spores onto the citrus seedlings and spraying the spores directly onto the adult psyllids. The results showed that by direct spraying the adults, HIB-24 (B. bassiana) and HIB-32 (I. fumosorosea) isolates showed the highest mortality (60.66%). Regarding spraying of the seedlings, HIB-19 (I. fumosorosea) showed the highest percentage of mortality (62.02%). The results from this study demonstrate potential for using entomopathogenic fungi in the management of D. citri in México.


During the 2005 Spring-Summer growing cycle, three experiments were established in Ursulo Galvan, Ver., Mexico, to determine the best time of application of the herbicide amicarbazone in irrigated sugarcane, and the susceptibility of the three main varieties grown in this state to this herbicide. In one experiment, weed control of amicarbazone at 0.7, 1.05 and 1.4 kg ha-1 applied at four stages (pre-emergence before germination irrigation, pre-emergence after germination irrigation, early post-emergence and late post-emergence) was evaluated. In the other experiments, the toxicity of amicarbazone at 0, 0.7, 1.4 and 2.1 kg ha-1 was evaluated when applied at pre-emergence and post-emergence on sugarcane varieties Mex 69-290, CP 72-2086 and 79 Mex-431. Amaranthus lividus was better controlled with post-emergence applications of amicarbazone, starting at 0.7 kg ha-1. Control of Guinea grass (Megathyrsus maximus) was low with amicarbazone at all stages. In pre-emergence applications, amicarbazone up to 2.1 kg ha-1 was highly selective to all varieties evaluated, whereas when applied in post-emergence, it caused slight toxicity to the three sugarcane varieties, increasing as the dose increased. However, the damages disappeared between 30 and 45 days after application, without causing a permanent reduction in plant height.


Gandarilla-Pacheco F.L.,Autonomous University of Nuevo León | Lopez-Arroyo J.I.,INIFAP | Galan-Wong L.J.,Autonomous University of Nuevo León | Quintero-Zapata I.,Autonomous University of Nuevo León
Southwestern Entomologist | Year: 2013

The aim of this study was to evaluate the pathogenicity and virulence of 16 native isolates and three collection strains of three species of entomopathogenic fungi that may have the potential for affecting Asian citrus psyllid nymphs, Diaphorina citri Kuwayama (Hemiptera: Liviidae), by developing an effective methodology for their evaluation. Bioassays were conducted in a laboratory using shoots of Citrus aurantium L., infested with second to fifth instar D. citri nymphs placed in Petri dishes and sprayed with 1 × 10 8 conidia mL-1 suspensions of the entomopathogenic fungi Beauveria bassiana, Isaria fumosorosea, and Metarhizium brunneum. Infested insects were incubated in a growth chamber at 26 ± 2°C, 60 ± 5% relative humidity, and 16:8 lightdark hours. The results showed that/. fumosorosea Pfr-612 strain scored the highest mortality (84.2%), while the isolate HIB-14 of B. bassiana induced the development of mycosis more effectively on psyllid nymphs.

Loading INIFAP collaborators
Loading INIFAP collaborators