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M. Muniesa - One of the best experts on this subject based on the ideXlab platform.

  • f specific coliphage detection by the bluephage method
    Water Research, 2020
    Co-Authors: Daniel Toribioavedillo, Anicet R. Blanch, Julia Martindiaz, Pedro Blancopicazo, M. Muniesa
    Abstract:

    ABSTRACT F-specific coliphages have been proposed as viral indicators of fecal pollution. These intestinal phages infect cells through the F-pili of the Host Strains used for their detection, Escherichia coli HS/FAmp in the US-EPA standard method and Salmonella enterica WG49 in the ISO method. The recently designed Bluephage protocol allows the rapid detection of as low as one somatic coliphage in a working day. The current study describes a new Bluephage method designed to exclusively detect F-specific phages. It employs two new Host Strains, CB14 and CB16, which detect the same number of F-specific phages as their respective parental Strains HS and WG49. In the Bluephage method, when the strain is lysed by bacteriophage infection, the yellow medium turns blue. As low as one F-specific phage was detected in 3 to 5 hours by this approach and when the sample contained high phage concentrations, results were obtained in less than 3 hours. The F-specific Bluephage method can be used with different sample volumes and allows phage quantification by the most probable number technique. Strain CB14 performed more consistently than CB16, with comparable detection efficiency after increasing the incubation time to 50 minutes without shaking.

  • Isolation of bacteriophage Host Strains of Bacteroides species suitable for tracking sources of animal faecal pollution in water.
    Environmental microbiology, 2011
    Co-Authors: Marta Gómez-doñate, A. Payan, Anicet R. Blanch, F. Lucena, J. Jofre, Ivania Cortés, M. Muniesa
    Abstract:

    Microbial source tracking (MST) methods allow the identification of specific faecal sources. The aim is to detect the sources of faecal pollution in a water body to allow targeted, efficient and cost-effective remediation efforts in the catchment. Bacteriophages infecting selected Host Strains of Bacteroides species are used as markers to track faecal contaminants in water. By using a suitable Bacteroides Host from a given faecal origin, it is possible to specifically detect bacteriophages of this faecal origin. It can thus be used to detect specific phages of Bacteroides for MST. With this objective, we isolated several Bacteroides Strains from pig, cow and poultry faeces by applying a previously optimized methodology used to isolate the Host Strains from humans. The isolated Strains belonged to Bacteroides fragilis and Bacteroides thetaiotaomicron. These Strains, like most Bacteroides species, detected phages of the Siphoviridae morphology. Using the newly isolated Host Strains for phage enumeration in a range of samples, we showed that these detect phages in faecal sources that coincide with their own origin (70-100% of the samples), and show no detection or very low percentages of detection of phages from other animal origins (from 0 to 20% of the samples). Only Strains isolated from pig wastewater detected phages in 50% of human sewage samples. Nevertheless, those Strains detecting phages from faecal origins other than their own detected fewer phages (2-3 log₁₀ pfu·100 ml⁻¹) than the phages detected by the specific strain of the same origin. On the basis of our results, we propose that faecal source tracking with phages infecting specific Bacteroides Host Strains is a useful method for MST. In addition, the method presented here is feasible in laboratories equipped with only basic microbiological equipment, it is more rapid and cost-effective than other procedures and it does not require highly qualified staff.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and Environmental Microbiology, 2005
    Co-Authors: A. Payan, J. Ebdon, H. Taylor, C. Gantzer, J. Ottoson, G. Papageorgiou, Anicet R. Blanch, F. Lucena, J. Jofre, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe. Microbial source tracking methods are designed to enable researchers to uncover the sources of fecal pollution in a water body (19). Bacteriophages infecting Bacteroides are potential tools for microbial source tracking (4, 13, 22, 24, 26, 29). However, it is well documented that Bacteroides Host Strains vary in their ability to discriminate between phages of different sources but also that phage detection by a given Host strain varies geographically. Thus, Bacteroides fragilis strain HSP40 detects good numbers of phages in different areas of the Mediterranean region (4, 9, 10, 28, 29, 30) and in South Africa (12), but it fails to detect significant numbers of phages in Northern Europe (22) and the United States (15). In contrast, other Strains, such as RYC 2056, detect similar numbers of phages in different geographical areas but do not discriminate between the sources of fecal pollution (5, 7, 18, 22). Strains tested in the United States to date appear to behave like RYC 2056 (15). Limitations of existing source tracking methods (19, 24, 25, 26, 27), combined with the good source tracking performance of strain HSP40 in certain geographical areas (4, 9, 12, 28, 30), along with increasing information about the specificity between the animal Host and the bacteria of the Bacteroides group (11, 32) and the narrow Host ranges reported for phages infecting Bacteroides (6, 8, 16, 22, 30), prompted our search for new Bacteroides Host Strains. We describe here a rapid method for isolating and further testing Bacteroides Host Strains potentially useful for source tracking.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and environmental microbiology, 2005
    Co-Authors: A. Payan, C. Gantzer, J. Ottoson, Anicet R. Blanch, F. Lucena, J. Jofre, Huw Taylor, James Ebdon, Georgos T. Papageorgiou, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe.

  • Bacterial Host Strains that support replication of somatic coliphages
    Antonie van Leeuwenhoek, 2003
    Co-Authors: M. Muniesa, Laura Mocé-llivina, Hiroyuki Katayama, J. Jofre
    Abstract:

    Somatic coliphages detected by Escherichia coli strain WG5 have been proposed as potential indicators of water quality. Their potential replication in the water environment is considered a drawback for their use as indicators. However, the contribution of replication outside the gut to the total numbers has never been quantified. It has not been determined either the fraction of bacterial Strains that might support replication of phages detected by strain WG5 in the water environment. We examined the sensitivity of 291 Host Strains to 25 phages by streaking slants of the presumptive Host strain onto an agar layer that contains bacteriophages, which gives a total of 7275 combinations (sensitivity tests). Only a 3.02% of the tests showed sensitivity. Additionally, six environmental Strains were used as Hosts to count phages in sewage and seawater. Phages isolated on these Strains were used to infect strain WG5. The environmental Strains detected 1 log_10 fewer phages than strain WG5 in sewage and seawater. The fraction of phages that were detected by the six Strains and that also infected strain WG5 ranged from < 0.07% to < 2.0% of the total amount of bacteriophages detected by strain WG5 in the same samples. Our results confirm that less than 3% of naturally occurring Hosts support replication of phages infecting E. coli . We conclude that the contribution of replication to the number of somatic coliphages detected in the aquatic environment is negligible.

Rodney N Nagoshi - One of the best experts on this subject based on the ideXlab platform.

  • demonstration and quantification of restricted mating between fall armyworm Host Strains in field collections by snp comparisons
    Journal of Economic Entomology, 2017
    Co-Authors: Rodney N Nagoshi, S J Fleischer, Robert L Meagher
    Abstract:

    Gene introgression between related pest populations is an important component in the assessment of how rapidly economically important traits, such as pesticide resistance, can spread within a region. An example of this is provided by the noctuid moth Spodoptera frugiperda (J.E. Smith), or fall armyworm, which is composed of two 'Host Strains' that differ in their Host plant preferences. Resistance to a Bacillus thuringiensis toxin has been observed in some populations and there is concern about its spread throughout the Western Hemisphere. If this trait is easily transmitted between Strains, it would expand the range of plants affected and make control efforts more difficult. A complicating factor is that the Strains are morphologically indistinguishable and can only be identified by a small number of genetic markers. As a result, little is known about the frequency of interstrain hybridization in the wild. This study uses a novel strategy involving comparisons between two single-nucleotide polymorphisms (SNPs) to quantify the frequency of interstrain mating in field populations. The results demonstrate that hybridization between Strains is 4- to 5-fold reduced compared to that within Strains. In addition, it appears that directional interstrain mating biases observed in laboratory studies are probably not a major factor in determining the distribution of hybrid genotypes in field populations. The differential SNP technique is a significant improvement over current methods for identifying interstrain hybrids and should facilitate our understanding of fall armyworm strain and hybrid distributions in the field and the frequency of genetic exchanges between Strains.

  • Differential Feeding of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains on Meridic and Natural Diets
    Annals of the Entomological Society of America, 2012
    Co-Authors: Robert L Meagher, Rodney N Nagoshi
    Abstract:

    ABSTRACT Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is composed of two sympatric, morphologically identical Host Strains (corn and rice) that differ in their distribution on different Host plants. This suggests possible strain specificity in the use of Host plants. However, although feeding studies published since 1987 have reported such developmental differences, the results were often contradictory, making generalizations about strain-specific physiological traits problematic. Here, we tested whether more consistent results could be obtained using several genetically characterized colonies when assayed in the same laboratory. We also assessed whether a commonly used meridic diet was more favorable to one strain and the potential this might have on altering the behavior of artificially raised colonies. Corn and rice strain colonies were characterized by cytochrome oxidase I (COI) strain markers and were subjected to feeding studies using corn (Zea mays L.), stargrass (Cyn...

  • genetic characterization of fall armyworm lepidoptera noctuidae Host Strains in argentina
    Journal of Economic Entomology, 2012
    Co-Authors: Rodney N Nagoshi, Gabriela M Murua, Mirian M Hayroe, Laura M Juarez, Eduardo Willink, Robert L Meagher
    Abstract:

    ABSTRACT Fall armyworm is a major economic pest throughout the Western Hemisphere. Previous studies of populations in the southern United States, Brazil, and the Caribbean demonstrated the existence of two morphologically identical but genetically distinct Host Strains that can only be distinguished using genetic markers, including polymorphisms in the mitochondrial Cytochrome Oxidase I (COI) gene and in the Z-chromosome linked Triose phosphate isomerase (Tpi) gene. The Strains differ in some physiological and behavioral characteristics, most notably their preference for different plant Hosts, but are capable of hybridizing in the laboratory and in the field. These traits suggest that the Strains are in the process of divergence, which may or may not be hemispheric in scope. The objective of this study was to determine whether the two Strains are present in Argentina. It was found that the strain-diagnostic haplotypes of the COI and Tpi genes subdivided the Argentina population into two major groups. Each...

  • Genetic characterization of fall armyworm (Lepidoptera: Noctuidae) Host Strains in Argentina.
    Journal of economic entomology, 2012
    Co-Authors: Rodney N Nagoshi, Eduardo Willink, M. Gabriela Murúa, Mirian M. Hay-roe, M. Laura Juárez, Robert L Meagher
    Abstract:

    Fall armyworm is a major economic pest throughout the Western Hemisphere. Previous studies of populations in the southern United States, Brazil, and the Caribbean demonstrated the existence of two morphologically identical but genetically distinct Host Strains that can only be distinguished using genetic markers, including polymorphisms in the mitochondrial Cytochrome Oxidase I (COI) gene and in the Z-chromosome linked Triose phosphate isomerase (Tpi) gene. The Strains differ in some physiological and behavioral characteristics, most notably their preference for different plant Hosts, but are capable of hybridizing in the laboratory and in the field. These traits suggest that the Strains are in the process of divergence, which may or may not be hemispheric in scope. The objective of this study was to determine whether the two Strains are present in Argentina. It was found that the strain-diagnostic haplotypes of the COI and Tpi genes subdivided the Argentina population into two major groups. Each group displayed biases in their distribution among different Host plants that were generally consistent with expected strain behavior. The overall results indicated that Argentina fall armyworm exhibit similar genetics and behavior to populations in the rest of the hemisphere. In addition, the Argentina populations had comparable haplotype frequencies to those from Brazil and Texas, consistent with possible interactions with these fall armyworm groups, but appeared to have had minimal exchanges with those from Puerto Rico or Florida.

  • Effects of Cyanogenic Plants on Fitness in Two Host Strains of the Fall Armyworm (Spodoptera frugiperda)
    Journal of Chemical Ecology, 2011
    Co-Authors: Robert L Meagher, Rodney N Nagoshi
    Abstract:

    The generalist moth, Spodoptera frugiperda (J. E. Smith) consists of two genetic subgroups (Host Strains) that differ in their distribution among Host plant species. The corn strain prefers crop plants such as corn, sorghum, and cotton, while the rice strain is found in small grasses such as Cynodon spp. and rice. Little is known about the physiological factors that drive this Host preference. Here, we report a feeding study with natural Host plants and an artificial diet containing cyanide. We found that corn, two Cynodon spp. (bermudagrass C. dactylon (L.) Persoon, ‘NuMex Sahara’, and stargrass C. nlemfuensis var. nlemfuensis Vanderyst, ‘Florona’), and a hybrid between bermudagrass and stargrass, ‘Tifton 85’, exhibited differences in the concentration of the cyanogenic precursors or cyanogenic potential (HCNp) and the release of hydrogen cyanide per unit time or cyanogenic capacity (HCNc). Corn plants released low levels of hydrogen cyanide, while stargrass had greater HCNp/HCNc than bermudagrass and ‘Tifton 85’. Feeding studies showed that corn strain larvae experienced higher mortality than the rice strain when fed stargrass or artificial diet supplemented with cyanide. Also, corn strain larvae excreted higher levels of cyanogenic compounds than the rice strain when fed Cynodon spp. These differences in excretion suggest potential disparities in cyanide metabolism between the two Strains. We hypothesize that differences in the susceptibility to cyanide levels in various Host plants could play a role in driving strain divergence and what appears to be the incipient speciation of this moth.

J. Jofre - One of the best experts on this subject based on the ideXlab platform.

  • Isolation of bacteriophage Host Strains of Bacteroides species suitable for tracking sources of animal faecal pollution in water.
    Environmental microbiology, 2011
    Co-Authors: Marta Gómez-doñate, A. Payan, Anicet R. Blanch, F. Lucena, J. Jofre, Ivania Cortés, M. Muniesa
    Abstract:

    Microbial source tracking (MST) methods allow the identification of specific faecal sources. The aim is to detect the sources of faecal pollution in a water body to allow targeted, efficient and cost-effective remediation efforts in the catchment. Bacteriophages infecting selected Host Strains of Bacteroides species are used as markers to track faecal contaminants in water. By using a suitable Bacteroides Host from a given faecal origin, it is possible to specifically detect bacteriophages of this faecal origin. It can thus be used to detect specific phages of Bacteroides for MST. With this objective, we isolated several Bacteroides Strains from pig, cow and poultry faeces by applying a previously optimized methodology used to isolate the Host Strains from humans. The isolated Strains belonged to Bacteroides fragilis and Bacteroides thetaiotaomicron. These Strains, like most Bacteroides species, detected phages of the Siphoviridae morphology. Using the newly isolated Host Strains for phage enumeration in a range of samples, we showed that these detect phages in faecal sources that coincide with their own origin (70-100% of the samples), and show no detection or very low percentages of detection of phages from other animal origins (from 0 to 20% of the samples). Only Strains isolated from pig wastewater detected phages in 50% of human sewage samples. Nevertheless, those Strains detecting phages from faecal origins other than their own detected fewer phages (2-3 log₁₀ pfu·100 ml⁻¹) than the phages detected by the specific strain of the same origin. On the basis of our results, we propose that faecal source tracking with phages infecting specific Bacteroides Host Strains is a useful method for MST. In addition, the method presented here is feasible in laboratories equipped with only basic microbiological equipment, it is more rapid and cost-effective than other procedures and it does not require highly qualified staff.

  • Evaluation of Escherichia coli Host strain CB390 for simultaneous detection of somatic and F-specific coliphages.
    Applied and environmental microbiology, 2007
    Co-Authors: Carolina Guzmán, F. Lucena, Laura Mocé-llivina, J. Jofre
    Abstract:

    Escherichia coli WG5, the strain recommended by the International Organization for Standardization (ISO) to detect somatic coliphages, was transformed to F+ by introducing the plasmid Famp, which rendered it capable of simultaneously detecting both somatic and F-specific coliphages. Indeed, this strain, CB390, proved as effective in detecting similar numbers of phages as the sum of somatic and F-specific bacteriophages detected by the Host Strains recommended by both the ISO and the U.S. Environmental Protection Agency standardized methods.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and Environmental Microbiology, 2005
    Co-Authors: A. Payan, J. Ebdon, H. Taylor, C. Gantzer, J. Ottoson, G. Papageorgiou, Anicet R. Blanch, F. Lucena, J. Jofre, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe. Microbial source tracking methods are designed to enable researchers to uncover the sources of fecal pollution in a water body (19). Bacteriophages infecting Bacteroides are potential tools for microbial source tracking (4, 13, 22, 24, 26, 29). However, it is well documented that Bacteroides Host Strains vary in their ability to discriminate between phages of different sources but also that phage detection by a given Host strain varies geographically. Thus, Bacteroides fragilis strain HSP40 detects good numbers of phages in different areas of the Mediterranean region (4, 9, 10, 28, 29, 30) and in South Africa (12), but it fails to detect significant numbers of phages in Northern Europe (22) and the United States (15). In contrast, other Strains, such as RYC 2056, detect similar numbers of phages in different geographical areas but do not discriminate between the sources of fecal pollution (5, 7, 18, 22). Strains tested in the United States to date appear to behave like RYC 2056 (15). Limitations of existing source tracking methods (19, 24, 25, 26, 27), combined with the good source tracking performance of strain HSP40 in certain geographical areas (4, 9, 12, 28, 30), along with increasing information about the specificity between the animal Host and the bacteria of the Bacteroides group (11, 32) and the narrow Host ranges reported for phages infecting Bacteroides (6, 8, 16, 22, 30), prompted our search for new Bacteroides Host Strains. We describe here a rapid method for isolating and further testing Bacteroides Host Strains potentially useful for source tracking.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and environmental microbiology, 2005
    Co-Authors: A. Payan, C. Gantzer, J. Ottoson, Anicet R. Blanch, F. Lucena, J. Jofre, Huw Taylor, James Ebdon, Georgos T. Papageorgiou, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe.

  • Bacterial Host Strains that support replication of somatic coliphages
    Antonie van Leeuwenhoek, 2003
    Co-Authors: M. Muniesa, Laura Mocé-llivina, Hiroyuki Katayama, J. Jofre
    Abstract:

    Somatic coliphages detected by Escherichia coli strain WG5 have been proposed as potential indicators of water quality. Their potential replication in the water environment is considered a drawback for their use as indicators. However, the contribution of replication outside the gut to the total numbers has never been quantified. It has not been determined either the fraction of bacterial Strains that might support replication of phages detected by strain WG5 in the water environment. We examined the sensitivity of 291 Host Strains to 25 phages by streaking slants of the presumptive Host strain onto an agar layer that contains bacteriophages, which gives a total of 7275 combinations (sensitivity tests). Only a 3.02% of the tests showed sensitivity. Additionally, six environmental Strains were used as Hosts to count phages in sewage and seawater. Phages isolated on these Strains were used to infect strain WG5. The environmental Strains detected 1 log_10 fewer phages than strain WG5 in sewage and seawater. The fraction of phages that were detected by the six Strains and that also infected strain WG5 ranged from < 0.07% to < 2.0% of the total amount of bacteriophages detected by strain WG5 in the same samples. Our results confirm that less than 3% of naturally occurring Hosts support replication of phages infecting E. coli . We conclude that the contribution of replication to the number of somatic coliphages detected in the aquatic environment is negligible.

Robert L Meagher - One of the best experts on this subject based on the ideXlab platform.

  • Assessing the Use of Wing Morphometrics to Identify Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Field Collections
    Journal of economic entomology, 2019
    Co-Authors: Kira L Nagoshi, Sandra A. Allan, Robert L Meagher
    Abstract:

    The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricultural pest in the Western Hemisphere, has recently become established in Africa and Asia. This highly polyphagous species has potential to economically harm multiple crops. Contributing to this Host range are two fall armyworm populations historically called ‘Host Strains’ that differ in Host specificity. Understanding behaviors of the two Strains is crucial to effective management of this pest. A major difficulty in such studies is that Strains have long been considered morphologically indistinguishable, with molecular markers the only reliable means of identification. However, studies of fall armyworm in Colombia reported strain differences in wing morphology sufficiently large to potentially provide a more economical alternative method to determine strain. This study tested whether a similar phenotypic difference was present in Florida populations using geometric morphometric analysis of 15 anatomical landmarks on forewings of 182 specimens from three habitats associated with different Host plants. Principle component and linear discriminant analyses identified significant differences in wing size and shape in comparison of Strains from different habitats, but not between Strains within the same habitat. Data indicate that apparent strain distinctions in wing phenotype are most likely a secondary consequence of differences in developmental growth patterns on different Host plants combined with strain-biased Host choice. Furthermore, Florida specimens showed much larger phenotypic overlap than observed for Strains from Colombia. Together these findings suggest that wing morphology is probably not a reliable indicator of strain identity in field populations where different Host plants are available.

  • demonstration and quantification of restricted mating between fall armyworm Host Strains in field collections by snp comparisons
    Journal of Economic Entomology, 2017
    Co-Authors: Rodney N Nagoshi, S J Fleischer, Robert L Meagher
    Abstract:

    Gene introgression between related pest populations is an important component in the assessment of how rapidly economically important traits, such as pesticide resistance, can spread within a region. An example of this is provided by the noctuid moth Spodoptera frugiperda (J.E. Smith), or fall armyworm, which is composed of two 'Host Strains' that differ in their Host plant preferences. Resistance to a Bacillus thuringiensis toxin has been observed in some populations and there is concern about its spread throughout the Western Hemisphere. If this trait is easily transmitted between Strains, it would expand the range of plants affected and make control efforts more difficult. A complicating factor is that the Strains are morphologically indistinguishable and can only be identified by a small number of genetic markers. As a result, little is known about the frequency of interstrain hybridization in the wild. This study uses a novel strategy involving comparisons between two single-nucleotide polymorphisms (SNPs) to quantify the frequency of interstrain mating in field populations. The results demonstrate that hybridization between Strains is 4- to 5-fold reduced compared to that within Strains. In addition, it appears that directional interstrain mating biases observed in laboratory studies are probably not a major factor in determining the distribution of hybrid genotypes in field populations. The differential SNP technique is a significant improvement over current methods for identifying interstrain hybrids and should facilitate our understanding of fall armyworm strain and hybrid distributions in the field and the frequency of genetic exchanges between Strains.

  • Differential Feeding of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains on Meridic and Natural Diets
    Annals of the Entomological Society of America, 2012
    Co-Authors: Robert L Meagher, Rodney N Nagoshi
    Abstract:

    ABSTRACT Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is composed of two sympatric, morphologically identical Host Strains (corn and rice) that differ in their distribution on different Host plants. This suggests possible strain specificity in the use of Host plants. However, although feeding studies published since 1987 have reported such developmental differences, the results were often contradictory, making generalizations about strain-specific physiological traits problematic. Here, we tested whether more consistent results could be obtained using several genetically characterized colonies when assayed in the same laboratory. We also assessed whether a commonly used meridic diet was more favorable to one strain and the potential this might have on altering the behavior of artificially raised colonies. Corn and rice strain colonies were characterized by cytochrome oxidase I (COI) strain markers and were subjected to feeding studies using corn (Zea mays L.), stargrass (Cyn...

  • genetic characterization of fall armyworm lepidoptera noctuidae Host Strains in argentina
    Journal of Economic Entomology, 2012
    Co-Authors: Rodney N Nagoshi, Gabriela M Murua, Mirian M Hayroe, Laura M Juarez, Eduardo Willink, Robert L Meagher
    Abstract:

    ABSTRACT Fall armyworm is a major economic pest throughout the Western Hemisphere. Previous studies of populations in the southern United States, Brazil, and the Caribbean demonstrated the existence of two morphologically identical but genetically distinct Host Strains that can only be distinguished using genetic markers, including polymorphisms in the mitochondrial Cytochrome Oxidase I (COI) gene and in the Z-chromosome linked Triose phosphate isomerase (Tpi) gene. The Strains differ in some physiological and behavioral characteristics, most notably their preference for different plant Hosts, but are capable of hybridizing in the laboratory and in the field. These traits suggest that the Strains are in the process of divergence, which may or may not be hemispheric in scope. The objective of this study was to determine whether the two Strains are present in Argentina. It was found that the strain-diagnostic haplotypes of the COI and Tpi genes subdivided the Argentina population into two major groups. Each...

  • Genetic characterization of fall armyworm (Lepidoptera: Noctuidae) Host Strains in Argentina.
    Journal of economic entomology, 2012
    Co-Authors: Rodney N Nagoshi, Eduardo Willink, M. Gabriela Murúa, Mirian M. Hay-roe, M. Laura Juárez, Robert L Meagher
    Abstract:

    Fall armyworm is a major economic pest throughout the Western Hemisphere. Previous studies of populations in the southern United States, Brazil, and the Caribbean demonstrated the existence of two morphologically identical but genetically distinct Host Strains that can only be distinguished using genetic markers, including polymorphisms in the mitochondrial Cytochrome Oxidase I (COI) gene and in the Z-chromosome linked Triose phosphate isomerase (Tpi) gene. The Strains differ in some physiological and behavioral characteristics, most notably their preference for different plant Hosts, but are capable of hybridizing in the laboratory and in the field. These traits suggest that the Strains are in the process of divergence, which may or may not be hemispheric in scope. The objective of this study was to determine whether the two Strains are present in Argentina. It was found that the strain-diagnostic haplotypes of the COI and Tpi genes subdivided the Argentina population into two major groups. Each group displayed biases in their distribution among different Host plants that were generally consistent with expected strain behavior. The overall results indicated that Argentina fall armyworm exhibit similar genetics and behavior to populations in the rest of the hemisphere. In addition, the Argentina populations had comparable haplotype frequencies to those from Brazil and Texas, consistent with possible interactions with these fall armyworm groups, but appeared to have had minimal exchanges with those from Puerto Rico or Florida.

F. Lucena - One of the best experts on this subject based on the ideXlab platform.

  • Isolation of bacteriophage Host Strains of Bacteroides species suitable for tracking sources of animal faecal pollution in water.
    Environmental microbiology, 2011
    Co-Authors: Marta Gómez-doñate, A. Payan, Anicet R. Blanch, F. Lucena, J. Jofre, Ivania Cortés, M. Muniesa
    Abstract:

    Microbial source tracking (MST) methods allow the identification of specific faecal sources. The aim is to detect the sources of faecal pollution in a water body to allow targeted, efficient and cost-effective remediation efforts in the catchment. Bacteriophages infecting selected Host Strains of Bacteroides species are used as markers to track faecal contaminants in water. By using a suitable Bacteroides Host from a given faecal origin, it is possible to specifically detect bacteriophages of this faecal origin. It can thus be used to detect specific phages of Bacteroides for MST. With this objective, we isolated several Bacteroides Strains from pig, cow and poultry faeces by applying a previously optimized methodology used to isolate the Host Strains from humans. The isolated Strains belonged to Bacteroides fragilis and Bacteroides thetaiotaomicron. These Strains, like most Bacteroides species, detected phages of the Siphoviridae morphology. Using the newly isolated Host Strains for phage enumeration in a range of samples, we showed that these detect phages in faecal sources that coincide with their own origin (70-100% of the samples), and show no detection or very low percentages of detection of phages from other animal origins (from 0 to 20% of the samples). Only Strains isolated from pig wastewater detected phages in 50% of human sewage samples. Nevertheless, those Strains detecting phages from faecal origins other than their own detected fewer phages (2-3 log₁₀ pfu·100 ml⁻¹) than the phages detected by the specific strain of the same origin. On the basis of our results, we propose that faecal source tracking with phages infecting specific Bacteroides Host Strains is a useful method for MST. In addition, the method presented here is feasible in laboratories equipped with only basic microbiological equipment, it is more rapid and cost-effective than other procedures and it does not require highly qualified staff.

  • Evaluation of Escherichia coli Host strain CB390 for simultaneous detection of somatic and F-specific coliphages.
    Applied and environmental microbiology, 2007
    Co-Authors: Carolina Guzmán, F. Lucena, Laura Mocé-llivina, J. Jofre
    Abstract:

    Escherichia coli WG5, the strain recommended by the International Organization for Standardization (ISO) to detect somatic coliphages, was transformed to F+ by introducing the plasmid Famp, which rendered it capable of simultaneously detecting both somatic and F-specific coliphages. Indeed, this strain, CB390, proved as effective in detecting similar numbers of phages as the sum of somatic and F-specific bacteriophages detected by the Host Strains recommended by both the ISO and the U.S. Environmental Protection Agency standardized methods.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and Environmental Microbiology, 2005
    Co-Authors: A. Payan, J. Ebdon, H. Taylor, C. Gantzer, J. Ottoson, G. Papageorgiou, Anicet R. Blanch, F. Lucena, J. Jofre, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe. Microbial source tracking methods are designed to enable researchers to uncover the sources of fecal pollution in a water body (19). Bacteriophages infecting Bacteroides are potential tools for microbial source tracking (4, 13, 22, 24, 26, 29). However, it is well documented that Bacteroides Host Strains vary in their ability to discriminate between phages of different sources but also that phage detection by a given Host strain varies geographically. Thus, Bacteroides fragilis strain HSP40 detects good numbers of phages in different areas of the Mediterranean region (4, 9, 10, 28, 29, 30) and in South Africa (12), but it fails to detect significant numbers of phages in Northern Europe (22) and the United States (15). In contrast, other Strains, such as RYC 2056, detect similar numbers of phages in different geographical areas but do not discriminate between the sources of fecal pollution (5, 7, 18, 22). Strains tested in the United States to date appear to behave like RYC 2056 (15). Limitations of existing source tracking methods (19, 24, 25, 26, 27), combined with the good source tracking performance of strain HSP40 in certain geographical areas (4, 9, 12, 28, 30), along with increasing information about the specificity between the animal Host and the bacteria of the Bacteroides group (11, 32) and the narrow Host ranges reported for phages infecting Bacteroides (6, 8, 16, 22, 30), prompted our search for new Bacteroides Host Strains. We describe here a rapid method for isolating and further testing Bacteroides Host Strains potentially useful for source tracking.

  • Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water
    Applied and environmental microbiology, 2005
    Co-Authors: A. Payan, C. Gantzer, J. Ottoson, Anicet R. Blanch, F. Lucena, J. Jofre, Huw Taylor, James Ebdon, Georgos T. Papageorgiou, M. Muniesa
    Abstract:

    Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides Host Strains are needed for different geographic areas. A feasible method for isolating Bacteroides Host Strains for phages present in human fecal material is described. Useful Strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe.