The Experts below are selected from a list of 2106 Experts worldwide ranked by ideXlab platform
Mariano Higes - One of the best experts on this subject based on the ideXlab platform.
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Nosema apis and Nosema ceranae tissue tropism in worker honey bees apis mellifera
Veterinary Pathology, 2020Co-Authors: Mariano Higes, Pilar Garciapalencia, Almudena Urbieta, Antonio Nanetti, Raquel MartinhernandezAbstract:The microsporidia Nosema apis and Nosema ceranae are major honey bee pathogens that possess different characteristics in terms of the signs they produce, as well as disease development and transmission. Although the ventricular epithelium is generally considered the target tissue, indirect observations led to speculation that N. ceranae may also target other structures, possibly explaining at least some of the differences between these 2 species. To investigate the tropism of Nosema for honey bee tissues, we performed controlled laboratory infections by orally administering doses of 50 000 or 100 000 fresh mature spores of either species. The fat body was isolated from the infected bees, as well as organs from the digestive (esophagus, ventriculus, ileum, rectum), excretory (Malpighian tubules), circulatory (aorta, heart), respiratory (thoracic tracheas), exocrine (hypopharyngeal, mandibular and labial, cephalic, thoracic salivary glands), and sensory/nervous (brain, eyes and associated nerve structures, thoracic nerve ganglia) systems. Tissues were examined by light and electron microscopy at 7, 10, and 15 days postinfection. Both Nosema species were found to infect epithelial cells and clusters of regenerative cells in the ventriculus, and while the ileum and rectum contained spores of the microsporidia in the lumen, these structures did not show overt lesions. No stages of the parasites or cellular lesions were detected in the other organs tested, confirming the high tropism of both species for the ventricular epithelium cells. Thus, these direct histopathological observations indicate that neither of these 2 Nosema species exhibit tropism for honey bee organs other than the ventriculus.
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microsporidia infection impacts the host cell s cycle and reduces host cell apoptosis
PLOS ONE, 2017Co-Authors: Raquel Martinhernandez, Mariano Higes, Aranzazu Meana, Angeles Juarranz, Soledad Sagastume, Joyce Diasalmeida, Giles E Budge, N BoonhamAbstract:Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host’s cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite’s survival within the cell.
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Nosema spp infection and its negative effects on honey bees apis mellifera iberiensis at the colony level
Veterinary Research, 2013Co-Authors: Cristina Botias, Laura Barrios, Raquel Martinhernandez, Aranzazu Meana, Mariano HigesAbstract:Nosemosis caused by the microsporidia Nosema apis and Nosema ceranae are among the most common pathologies affecting adult honey bees. N. apis infection has been associated with a reduced lifespan of infected bees and increased winter mortality, and its negative impact on colony strength and productivity has been described in several studies. By contrast, when the effects of nosemosis type C, caused by N. ceranae infection, have been analysed at the colony level, these studies have largely focused on collapse as a response to infection without addressing the potential sub-clinical effects on colony strength and productivity. Given the spread and prevalence of N. ceranae worldwide, we set out here to characterize the sub-clinical and clinical signs of N. ceranae infection on colony strength and productivity. We evaluated the evolution of 50 honey bee colonies naturally infected by Nosema (mainly N. ceranae) over a one year period. Under our experimental conditions, N. ceranae infection was highly pathogenic for honey bee colonies, producing significant reductions in colony size, brood rearing and honey production. These deleterious effects at the colony level may affect beekeeping profitability and have serious consequences on pollination. Further research is necessary to identify possible treatments or beekeeping techniques that will limit the rapid spread of this dangerous emerging disease.
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standard methods for Nosema research
Journal of Apicultural Research, 2013Co-Authors: Ingemar Fries, Mariano Higes, Raquel Martinhernandez, Yanping Chen, Mariepierre Chauzat, Vincent Doublet, Elke Genersch, Sebastian Gisder, Dino P Mcmahon, Myrsini E NatsopoulouAbstract:SummaryMethods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity t...
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microsporidia infecting apis mellifera coexistence or competition is Nosema ceranae replacing Nosema apis
Environmental Microbiology, 2012Co-Authors: Raquel Martinhernandez, Cristina Botias, Aranzazu Meana, Lourdes Prieto, Encarna Garrido Bailon, Amparo Martinezsalvador, Mariano HigesAbstract:Summary Nosema ceranae has been suggested to be replacing Nosema apis in some populations of apis mellifera honeybees. However, this replacement from one to the other is not supported when studying the distribution and prevalence of both microsporidia in professional apiaries in Spanish territories (transverse study), their seasonal pattern in experimental hives with co-infection or their prevalence at individual level (either in worker bees or drones). Nevertheless, N. ceranae has shown to present a higher prevalence at all the studied levels that could indicate any advantage for its development over N. apis or that it is more adapted to Spanish conditions. Also, both microsporidia show a different pattern of preference for its development according to the prevalence in the different Spanish bioclimatic belts studied. Finally, the fact that all analyses were carried out using an Internal PCR Control (IPC) newly developed guarantees the confidence of the data extracted from the PCR analyses. This IPC provides a useful tool for laboratory detection of honeybee pathogens.
Raquel Martinhernandez - One of the best experts on this subject based on the ideXlab platform.
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Nosema apis and Nosema ceranae tissue tropism in worker honey bees apis mellifera
Veterinary Pathology, 2020Co-Authors: Mariano Higes, Pilar Garciapalencia, Almudena Urbieta, Antonio Nanetti, Raquel MartinhernandezAbstract:The microsporidia Nosema apis and Nosema ceranae are major honey bee pathogens that possess different characteristics in terms of the signs they produce, as well as disease development and transmission. Although the ventricular epithelium is generally considered the target tissue, indirect observations led to speculation that N. ceranae may also target other structures, possibly explaining at least some of the differences between these 2 species. To investigate the tropism of Nosema for honey bee tissues, we performed controlled laboratory infections by orally administering doses of 50 000 or 100 000 fresh mature spores of either species. The fat body was isolated from the infected bees, as well as organs from the digestive (esophagus, ventriculus, ileum, rectum), excretory (Malpighian tubules), circulatory (aorta, heart), respiratory (thoracic tracheas), exocrine (hypopharyngeal, mandibular and labial, cephalic, thoracic salivary glands), and sensory/nervous (brain, eyes and associated nerve structures, thoracic nerve ganglia) systems. Tissues were examined by light and electron microscopy at 7, 10, and 15 days postinfection. Both Nosema species were found to infect epithelial cells and clusters of regenerative cells in the ventriculus, and while the ileum and rectum contained spores of the microsporidia in the lumen, these structures did not show overt lesions. No stages of the parasites or cellular lesions were detected in the other organs tested, confirming the high tropism of both species for the ventricular epithelium cells. Thus, these direct histopathological observations indicate that neither of these 2 Nosema species exhibit tropism for honey bee organs other than the ventriculus.
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microsporidia infection impacts the host cell s cycle and reduces host cell apoptosis
PLOS ONE, 2017Co-Authors: Raquel Martinhernandez, Mariano Higes, Aranzazu Meana, Angeles Juarranz, Soledad Sagastume, Joyce Diasalmeida, Giles E Budge, N BoonhamAbstract:Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host’s cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite’s survival within the cell.
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Nosema spp infection and its negative effects on honey bees apis mellifera iberiensis at the colony level
Veterinary Research, 2013Co-Authors: Cristina Botias, Laura Barrios, Raquel Martinhernandez, Aranzazu Meana, Mariano HigesAbstract:Nosemosis caused by the microsporidia Nosema apis and Nosema ceranae are among the most common pathologies affecting adult honey bees. N. apis infection has been associated with a reduced lifespan of infected bees and increased winter mortality, and its negative impact on colony strength and productivity has been described in several studies. By contrast, when the effects of nosemosis type C, caused by N. ceranae infection, have been analysed at the colony level, these studies have largely focused on collapse as a response to infection without addressing the potential sub-clinical effects on colony strength and productivity. Given the spread and prevalence of N. ceranae worldwide, we set out here to characterize the sub-clinical and clinical signs of N. ceranae infection on colony strength and productivity. We evaluated the evolution of 50 honey bee colonies naturally infected by Nosema (mainly N. ceranae) over a one year period. Under our experimental conditions, N. ceranae infection was highly pathogenic for honey bee colonies, producing significant reductions in colony size, brood rearing and honey production. These deleterious effects at the colony level may affect beekeeping profitability and have serious consequences on pollination. Further research is necessary to identify possible treatments or beekeeping techniques that will limit the rapid spread of this dangerous emerging disease.
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standard methods for Nosema research
Journal of Apicultural Research, 2013Co-Authors: Ingemar Fries, Mariano Higes, Raquel Martinhernandez, Yanping Chen, Mariepierre Chauzat, Vincent Doublet, Elke Genersch, Sebastian Gisder, Dino P Mcmahon, Myrsini E NatsopoulouAbstract:SummaryMethods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity t...
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microsporidia infecting apis mellifera coexistence or competition is Nosema ceranae replacing Nosema apis
Environmental Microbiology, 2012Co-Authors: Raquel Martinhernandez, Cristina Botias, Aranzazu Meana, Lourdes Prieto, Encarna Garrido Bailon, Amparo Martinezsalvador, Mariano HigesAbstract:Summary Nosema ceranae has been suggested to be replacing Nosema apis in some populations of apis mellifera honeybees. However, this replacement from one to the other is not supported when studying the distribution and prevalence of both microsporidia in professional apiaries in Spanish territories (transverse study), their seasonal pattern in experimental hives with co-infection or their prevalence at individual level (either in worker bees or drones). Nevertheless, N. ceranae has shown to present a higher prevalence at all the studied levels that could indicate any advantage for its development over N. apis or that it is more adapted to Spanish conditions. Also, both microsporidia show a different pattern of preference for its development according to the prevalence in the different Spanish bioclimatic belts studied. Finally, the fact that all analyses were carried out using an Internal PCR Control (IPC) newly developed guarantees the confidence of the data extracted from the PCR analyses. This IPC provides a useful tool for laboratory detection of honeybee pathogens.
Aranzazu Meana - One of the best experts on this subject based on the ideXlab platform.
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microsporidia infection impacts the host cell s cycle and reduces host cell apoptosis
PLOS ONE, 2017Co-Authors: Raquel Martinhernandez, Mariano Higes, Aranzazu Meana, Angeles Juarranz, Soledad Sagastume, Joyce Diasalmeida, Giles E Budge, N BoonhamAbstract:Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host’s cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite’s survival within the cell.
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Nosema spp infection and its negative effects on honey bees apis mellifera iberiensis at the colony level
Veterinary Research, 2013Co-Authors: Cristina Botias, Laura Barrios, Raquel Martinhernandez, Aranzazu Meana, Mariano HigesAbstract:Nosemosis caused by the microsporidia Nosema apis and Nosema ceranae are among the most common pathologies affecting adult honey bees. N. apis infection has been associated with a reduced lifespan of infected bees and increased winter mortality, and its negative impact on colony strength and productivity has been described in several studies. By contrast, when the effects of nosemosis type C, caused by N. ceranae infection, have been analysed at the colony level, these studies have largely focused on collapse as a response to infection without addressing the potential sub-clinical effects on colony strength and productivity. Given the spread and prevalence of N. ceranae worldwide, we set out here to characterize the sub-clinical and clinical signs of N. ceranae infection on colony strength and productivity. We evaluated the evolution of 50 honey bee colonies naturally infected by Nosema (mainly N. ceranae) over a one year period. Under our experimental conditions, N. ceranae infection was highly pathogenic for honey bee colonies, producing significant reductions in colony size, brood rearing and honey production. These deleterious effects at the colony level may affect beekeeping profitability and have serious consequences on pollination. Further research is necessary to identify possible treatments or beekeeping techniques that will limit the rapid spread of this dangerous emerging disease.
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microsporidia infecting apis mellifera coexistence or competition is Nosema ceranae replacing Nosema apis
Environmental Microbiology, 2012Co-Authors: Raquel Martinhernandez, Cristina Botias, Aranzazu Meana, Lourdes Prieto, Encarna Garrido Bailon, Amparo Martinezsalvador, Mariano HigesAbstract:Summary Nosema ceranae has been suggested to be replacing Nosema apis in some populations of apis mellifera honeybees. However, this replacement from one to the other is not supported when studying the distribution and prevalence of both microsporidia in professional apiaries in Spanish territories (transverse study), their seasonal pattern in experimental hives with co-infection or their prevalence at individual level (either in worker bees or drones). Nevertheless, N. ceranae has shown to present a higher prevalence at all the studied levels that could indicate any advantage for its development over N. apis or that it is more adapted to Spanish conditions. Also, both microsporidia show a different pattern of preference for its development according to the prevalence in the different Spanish bioclimatic belts studied. Finally, the fact that all analyses were carried out using an Internal PCR Control (IPC) newly developed guarantees the confidence of the data extracted from the PCR analyses. This IPC provides a useful tool for laboratory detection of honeybee pathogens.
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the effect of induced queen replacement on Nosema spp infection in honey bee apis mellifera iberiensis colonies
Environmental Microbiology, 2012Co-Authors: Cristina Botias, Laura Barrios, Pilar Garciapalencia, Raquel Martinhernandez, Aranzazu Meana, Antonio Nanetti, Joyce Dias, Maria Matabuena, Angeles Juarranz, Mariano HigesAbstract:Summary Microsporidiosis of adult honeybees caused by Nosema apis and Nosema ceranae is a common worldwide disease with negative impacts on colony strength and productivity. Few options are available to control the disease at present. The role of the queen in bee population renewal and the replacement of bee losses due to Nosema infection is vital to maintain colony homeostasis. Younger queens have a greater egg laying potential and they produce a greater proportion of uninfected newly eclosed bees to compensate for adult bee losses; hence, a field study was performed to determine the effect of induced queen replacement on Nosema infection in honey bee colonies, focusing on colony strength and honey production. In addition, the impact of long-term Nosema infection of a colony on the ovaries and ventriculus of the queen was evaluated. Queen replacement resulted in a remarkable decrease in the rates of Nosema infection, comparable with that induced by fumagillin treatment. However, detrimental effects on the overall colony state were observed due to the combined effects of stressors such as the queenless condition, lack of brood and high infection rates. The ovaries and ventriculi of queens in infected colonies revealed no signs of Nosema infection and there were no lesions in ovarioles or epithelial ventricular cells.
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comparison of the energetic stress associated with experimental Nosema ceranae and Nosema apis infection of honeybees apis mellifera
Parasitology Research, 2011Co-Authors: Raquel Martinhernandez, Cristina Botias, Laura Barrios, Aranzazu Meana, Amparo Martinezsalvador, Christopher Mayack, Mariano HigesAbstract:Nosema ceranae is a relatively new and widespread parasite of the western honeybee apis mellifera that provokes a new form of nosemosis. In comparison to Nosema apis, which has been infecting the honeybee for much longer, N. ceranae seems to have co-evolved less with this host, causing a more virulent disease. Given that N. apis and N. ceranae are obligate intracellular microsporidian parasites, needing host energy to reproduce, energetic stress may be an important factor contributing to the increased virulence observed. Through feeding experiments on caged bees, we show that both mortality and sugar syrup consumption were higher in N. ceranae-infected bees than in N. apis-infected and control bees. The mortality and sugar syrup consumption are also higher in N. apis-infected bees than in controls, but are less than in N. ceranae-infected bees. With both microsporidia, mortality and sugar syrup consumption increased in function of the increasing spore counts administered for infection. The differences in energetic requirements between both Nosema spp. confirm that their metabolic patterns are not the same, which may depend critically on host–parasite interactions and, ultimately, on host pathology. The repercussions of this increased energetic stress may even explain the changes in host behavior due to starvation, lack of thermoregulatory capacity, or higher rates of trophallaxis, which might enhance transmission and bee death.
Zachary Y. Huang - One of the best experts on this subject based on the ideXlab platform.
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M: Physiological and behavioral changes in honey bees (apis mellifera) induced by Nosema ceranae infection. PLoS One 2013
2016Co-Authors: Mike Goblirsch, Zachary Y. Huang, Marla SpivakAbstract:Persistent exposure to mite pests, poor nutrition, pesticides, and pathogens threaten honey bee survival. In healthy colonies, the interaction of the yolk precursor protein, vitellogenin (Vg), and endocrine factor, juvenile hormone (JH), functions as a pacemaker driving the sequence of behaviors that workers perform throughout their lives. Young bees perform nursing duties within the hive and have high Vg and low JH; as older bees transition to foraging, this trend reverses. Pathogens and parasites can alter this regulatory network. For example, infection with the microsporidian, Nosema apis, has been shown to advance behavioral maturation in workers. We investigated the effects of infection with a recent honey bee pathogen on physiological factors underlying the division of labor in workers. Bees infected with N. ceranae were nearly twice as likely to engage in precocious foraging and lived 9 days less, on average, compared to controls. We also show that Vg transcript was low, while JH titer spiked, in infected nurse-aged bees in cages. This pattern of expression is atypical and the reverse of what would be expected for healthy, non-infected bees. Disruption of the basic underpinnings of temporal polyethism due to infection may be a contributing factor to recent high colony mortality, as workers may lose flexibility in their response to colony demands
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comparative virulence and competition between Nosema apis and Nosema ceranae in honey bees apis mellifera
Journal of Invertebrate Pathology, 2015Co-Authors: Meghan O Milbrath, Leellen F. Solter, David R. Tarpy, Toan Van Tran, Wei Fong Huang, Frank R Lawrence, Zachary Y. HuangAbstract:Abstract Honey bees (apis mellifera) are infected by two species of microsporidia: Nosema apis and Nosema ceranae. Epidemiological evidence indicates that N. ceranae may be replacing N. apis globally in A. mellifera populations, suggesting a potential competitive advantage of N. ceranae. Mixed infections of the two species occur, and little is known about the interactions among the host and the two pathogens that have allowed N. ceranae to become dominant in most geographical areas. We demonstrated that mixed Nosema species infections negatively affected honey bee survival (median survival = 15–17 days) more than single species infections (median survival = 21 days and 20 days for N. apis and N. ceranae, respectively), with median survival of control bees of 27 days. We found similar rates of infection (percentage of bees with active infections after inoculation) for both species in mixed infections, with N. apis having a slightly higher rate (91% compared to 86% for N. ceranae). We observed slightly higher spore counts in bees infected with N. ceranae than in bees infected with N. apis in single microsporidia infections, especially at the midpoint of infection (day 10). Bees with mixed infections of both species had higher spore counts than bees with single infections, but spore counts in mixed infections were highly variable. We did not see a competitive advantage for N. ceranae in mixed infections; N. apis spore counts were either higher or counts were similar for both species and more N. apis spores were produced in 62% of bees inoculated with equal dosages of the two microsporidian species. N. ceranae does not, therefore, appear to have a strong within-host advantage for either infectivity or spore growth, suggesting that direct competition in these worker bee mid-guts is not responsible for its apparent replacement of N. apis.
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infectivity and virulence of Nosema ceranae and Nosema apis in commercially available north american honey bees
Journal of Invertebrate Pathology, 2015Co-Authors: Wei-fone Huang, Leellen F. Solter, Katherine A Aronstein, Zachary Y. HuangAbstract:Nosema ceranae infection is ubiquitous in western honey bees, apis mellifera, in the United States and the pathogen has apparently replaced Nosema apis in colonies nationwide. Displacement of N. apis suggests that N. ceranae has competitive advantages but N. ceranae was significantly less infective and less virulent than N. apis in commercially available lineages of honey bees in studies conducted in Illinois and Texas. At 5 days post eclosion, the most susceptible age of adult bees tested, the mean ID50 for N. apis was 359 spores compared to 3217 N. ceranae spores, a nearly 9-fold difference. Infectivity of N. ceranae was also lower than N. apis for 24-h and 14-day worker bees. N. ceranae was less infective than reported in studies using European strains of honey bees, while N. apis infectivity, tested in the same cohort of honey bees, corresponded to results reported globally from 1972 to 2010. Mortality of worker bees was similar for both pathogens at a dosage of 50 spores and was not different from the uninfected controls, but was significantly higher for N. apis than N. ceranae at dosages ⩾500 spores. Our results provide comparisons for evaluating research using different ages of bees and pathogen dosages and clarify some controversies. In addition, comparisons among studies suggest that the mixed lineages of US honey bees may be less susceptible to N. ceranae infections than are European bees or that the US isolates of the pathogen are less infective and less virulent than European isolates.
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physiological and behavioral changes in honey bees apis mellifera induced by Nosema ceranae infection
PLOS ONE, 2013Co-Authors: Mike Goblirsch, Zachary Y. Huang, Marla SpivakAbstract:Persistent exposure to mite pests, poor nutrition, pesticides, and pathogens threaten honey bee survival. In healthy colonies, the interaction of the yolk precursor protein, vitellogenin (Vg), and endocrine factor, juvenile hormone (JH), functions as a pacemaker driving the sequence of behaviors that workers perform throughout their lives. Young bees perform nursing duties within the hive and have high Vg and low JH; as older bees transition to foraging, this trend reverses. Pathogens and parasites can alter this regulatory network. For example, infection with the microsporidian, Nosema apis, has been shown to advance behavioral maturation in workers. We investigated the effects of infection with a recent honey bee pathogen on physiological factors underlying the division of labor in workers. Bees infected with N. ceranae were nearly twice as likely to engage in precocious foraging and lived 9 days less, on average, compared to controls. We also show that Vg transcript was low, while JH titer spiked, in infected nurse-aged bees in cages. This pattern of expression is atypical and the reverse of what would be expected for healthy, non-infected bees. Disruption of the basic underpinnings of temporal polyethism due to infection may be a contributing factor to recent high colony mortality, as workers may lose flexibility in their response to colony demands.
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pollen nutrition affects honey bee stress resistance
Terrestrial Arthropod Reviews, 2012Co-Authors: Zachary Y. HuangAbstract:The honey bee, apis, is perhaps the most beneficial insect to humans because most of our fruits and vegetables depend on them for pollination. Yet these iconic insects have been plagued by many types of stresses. This paper reviews many lines of evidence pointing to the importance of pollen nutrition in honey bee health. In laboratory studies that used caged honey bees, poor pollen nutrition led to a reduction of worker bees’ resistance to the microsporidian, Nosema apis, an increase of bee’s sensitivity to pesticides, and an increased titer of bee virus. On the other hand, polyfloral pollen made bees more resistant to stresses by enhancing their immune related enzyme activities. At the colony level, good pollen nutrition increased honey bee’s resistance to Nosema ceranae or the ectoparasitic mite, Varroa destructor. The effects of both transportation and habitat changes on honey bees seem most likely mediated via decreased diversity, or amount, of pollen to the colonies. Pollen nutrition, therefore, might work together with other factors in reducing the bees’ resistance and exacerbate the effects of viruses, pesticides, or parasites, eventually resulting in Colony Collapse Disorder. Besides paying attention to all of these other factors, pollen nutrition should be an important focus in the future for maintaining healthy bee colonies.
Ingemar Fries - One of the best experts on this subject based on the ideXlab platform.
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Characteristics of Nosema ceranae infection in Serbian honey bee colonies
Apidologie, 2013Co-Authors: Jevrosima Stevanovic, Nada Lakic, Ingemar Fries, Predrag Simeunovic, Bojan Gajic, Dejan Radovic, Zoran StanimirovicAbstract:The incidence, symptoms and consequences of Nosema ceranae infection were monitored in 200 honey bee colonies in Serbia over 5 years (2008–2012) to reveal if they display characteristics described for nosemosis type C. Continual high frequency of N. ceranae-positive colonies was recorded within each study year, ranging from 73 to 98 %. A seasonal pattern in N. ceranae incidence was observed over 4 years (2008–2011). Symptoms traditionally attributed to Nosema apis infection were observed in the majority of N. ceranae-infected colonies, both among surviving and those that died. These symptoms could not serve as predictive markers for colony losses, as they were significantly more frequently observed among surviving colonies in 2010, 2011 and 2012. No clear association between N. ceranae infection and colony losses was affirmed neither during the winter nor during the summer season. Thus, N. ceranae infection in Serbian bees do not fit the characteristics for nosemosis type C.
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standard methods for Nosema research
Journal of Apicultural Research, 2013Co-Authors: Ingemar Fries, Mariano Higes, Raquel Martinhernandez, Yanping Chen, Mariepierre Chauzat, Vincent Doublet, Elke Genersch, Sebastian Gisder, Dino P Mcmahon, Myrsini E NatsopoulouAbstract:SummaryMethods are described for working with Nosema apis and Nosema ceranae in the field and in the laboratory. For fieldwork, different sampling methods are described to determine colony level infections at a given point in time, but also for following the temporal infection dynamics. Suggestions are made for how to standardise field trials for evaluating treatments and disease impact. The laboratory methods described include different means for determining colony level and individual bee infection levels and methods for species determination, including light microscopy, electron microscopy, and molecular methods (PCR). Suggestions are made for how to standardise cage trials, and different inoculation methods for infecting bees are described, including control methods for spore viability. A cell culture system for in vitro rearing of Nosema spp. is described. Finally, how to conduct different types of experiments are described, including infectious dose, dose effects, course of infection and longevity t...
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comparative virulence of Nosema ceranae and Nosema apis in individual european honey bees
Veterinary Parasitology, 2010Co-Authors: Eva Forsgren, Ingemar FriesAbstract:Nosema apis and Nosema ceranae are intracellular microsporidian parasites infecting the midgut epithelial cells of adult honey bees. N. ceranae was considered to be restricted to the Asian honey bee, apis cerana, but is nowadays a parasite found also in the European honey bee (apis mellifera) across most of the world. Recent surveys and experimental work suggest that N. ceranae is a serious threat to the global beekeeping industry. It has been suggested that N. ceranae induces significantly higher mortality in honey bees than N. apis, but little is known about their comparative virulence. In this study, we used in vivo infection experiments to study the two parasites' different virulence (i.e. multiplication rate and infectivity). A qPCR was developed to elucidate within host competition between the two parasites using mixed infections. The outcome of the experiments indicates minor differences in infectious dose and multiplication rate between the two species. Moreover, the mortality caused by N. ceranae was not significantly higher than for N. apis and N. ceranae appeared to have no competitive advantage within host.
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Nosema ceranae in european honey bees apis mellifera
Journal of Invertebrate Pathology, 2010Co-Authors: Ingemar FriesAbstract:Nosema ceranae is a microsporidian parasite described from the Asian honey bee, apis cerana. The parasite is cross-infective with the European honey bee, apis mellifera. It is not known when or where N. ceranae first infected European bees, but N. ceranae has probably been infecting European bees for at least two decades. N. ceranae appears to be replacing Nosema apis, at least in some populations of European honey bees. This replacement is an enigma because the spores of the new parasite are less durable than those of N. apis. Virulence data at both the individual bee and at the colony level are conflicting possibly because the impact of this parasite differs in different environments. The recent advancements in N. ceranae genetics, with a draft assembly of the N. ceranae genome available, are discussed and the need for increased research on the impacts of this parasite on European honey bees is emphasized.
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Nosema ceranae has infected apis mellifera in europe since at least 1998 and may be more virulent than Nosema apis
Apidologie, 2007Co-Authors: Robert J Paxton, Julia Klee, Seppo Korpela, Ingemar FriesAbstract:Nosema ceranae, a microsporidian formerly regarded as confined to its Asiatic host apis cerana, has recently been shown to parasitise apis mellifera and to have spread throughout most of the world in the past few years. Using a temporal sequence of N = 28 Nosema isolates from Finland from 1986–2006, we now find (i) that N. ceranae has been present in Europe since at least 1998 and (ii) that it has increased in frequency across this time period relative to Nosema apis, possibly leading to higher mean spore loads per bee. We then present results of a single laboratory infection experiment in which we directly compare the virulence of N. apis with N. ceranae. Though lacking replication, our results suggest (iii) that both parasites build up to equal numbers per bee by day 14 post infection but that (iv) N. ceranae induces significantly higher mortality relative to N. apis.
