Nosema ceranae is a long-present and wide-spread microsporidian infection of the European honey bee (Apis mellifera) in the United States.
USDA-ARS Bee Research Laboratory, Bldg. 476, BARC-East, Beltsville, MD 20705, USA.
Honey bee samples collected between 1995 and 2007 from 12 states were examined for the presence of Nosema infections. Our results showed that Nosema ceranae is a wide-spread infection of the European honey bee, Apis mellifera in the United States. The discovery of N. ceranae in bees collected a decade ago indicates that N. ceranae was transferred from its original host, Apis cerana to A. mellifera earlier than previously recognized. The spread of N. ceranae infection in A. mellifera warrants further epidemiological studies to identify conditions that resulted in such a widespread infection.
PLoS One. 2012 ;7 (2):e32151 22384162
Swiss Bee Research Centre, Agroscope Liebefeld-Posieux Research Station ALP, Bern, Switzerland. firstname.lastname@example.org
Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies.
First Detection of Nosema ceranae, a Microsporidian Protozoa of European Honeybees (Apis mellifera) In Iran.
Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Iran.
BACKGROUND Nosemosis of European honey bee (Apis mellifera) is present in bee colonies worldwide. Until recently, Nosema apis had been regarded as the causative agent of the disease, that causes heavy economic losses in apicultures. Nosema ceranae is an emerging microsporidian parasite of European honeybees, A. mellifera, but its distribution is not well known. Previously, nosemosis in honeybees in Iran was attributed exclusively to N. apis. METHODS Six Nosema positive samples (determined from light microscopy of spores) of adult worker bees from one province of Iran (Savadkouh- Mazandaran, northern Iran) were tested to determine Nosema species using previously- developed PCR primers of the 16 S rRNA gene. As it is difficult to distinguish N. ceranae and N. apis morphologically, a PCR assay based on 16 S ribosomal RNA has been used to differentiate N. apis and N. ceranae. RESULTS Only N. ceranae was found in all samples, indicating that this species present in Iran apiaries. CONCLUSION This is the first report of N. ceranae in colonies of A. mellifera in Iran. It seems that intensive surveys are needed to determine the distribution and prevalence of N. ceranae in different regions of Iran.
USDA-ARS Bee Research Laboratory, Beltsville, MD, USA. email@example.com
Global pollinator declines have been attributed to habitat destruction, pesticide use, and climate change or some combination of these factors, and managed honey bees, Apis mellifera, are part of worldwide pollinator declines. Here we exposed honey bee colonies during three brood generations to sub-lethal doses of a widely used pesticide, imidacloprid, and then subsequently challenged newly emerged bees with the gut parasite, Nosema spp. The pesticide dosages used were below levels demonstrated to cause effects on longevity or foraging in adult honey bees. Nosema infections increased significantly in the bees from pesticide-treated hives when compared to bees from control hives demonstrating an indirect effect of pesticides on pathogen growth in honey bees. We clearly demonstrate an increase in pathogen growth within individual bees reared in colonies exposed to one of the most widely used pesticides worldwide, imidacloprid, at below levels considered harmful to bees. The finding that individual bees with undetectable levels of the target pesticide, after being reared in a sub-lethal pesticide environment within the colony, had higher Nosema is significant. Interactions between pesticides and pathogens could be a major contributor to increased mortality of honey bee colonies, including colony collapse disorder, and other pollinator declines worldwide.
Temporal analysis of the honey bee microbiome reveals four novel viruses and seasonal prevalence of known viruses, Nosema, and Crithidia.
Charles Runckel, Michelle L Flenniken, Juan C Engel, J Graham Ruby, Donald Ganem, Raul Andino, Joseph L DeRisi
Howard Hughes Medical Institute, Bethesda, Maryland, United State of America.
Honey bees (Apis mellifera) play a critical role in global food production as pollinators of numerous crops. Recently, honey bee populations in the United States, Canada, and Europe have suffered an unexplained increase in annual losses due to a phenomenon known as Colony Collapse Disorder (CCD). Epidemiological analysis of CCD is confounded by a relative dearth of bee pathogen field studies. To identify what constitutes an abnormal pathophysiological condition in a honey bee colony, it is critical to have characterized the spectrum of exogenous infectious agents in healthy hives over time. We conducted a prospective study of a large scale migratory bee keeping operation using high-frequency sampling paired with comprehensive molecular detection methods, including a custom microarray, qPCR, and ultra deep sequencing. We established seasonal incidence and abundance of known viruses, Nosema sp., Crithidia mellificae, and bacteria. Ultra deep sequence analysis further identified four novel RNA viruses, two of which were the most abundant observed components of the honey bee microbiome (∼10(11) viruses per honey bee). Our results demonstrate episodic viral incidence and distinct pathogen patterns between summer and winter time-points. Peak infection of common honey bee viruses and Nosema occurred in the summer, whereas levels of the trypanosomatid Crithidia mellificae and Lake Sinai virus 2, a novel virus, peaked in January.
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
Infectious fungi are among a broad group of microbial pathogens that has and continues to emerge concomitantly due to the global AIDS pandemic as well as an overall increase of patients with compromised immune systems. In addition, many pathogens have been emerging and re-emerging, causing disease in both individuals who have an identifiable immune defect and those who do not. The fungal pathogen Cryptococcus gattii can infect individuals with and without an identifiable immune defect, with a broad geographic range including both endemic areas and emerging outbreak regions. Infections in patients and animals can be severe and often fatal if untreated. We review the molecular epidemiology, population structure, clinical manifestations, and ecological niche of this emerging pathogen.
Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
Nosema ceranae is a recently described pathogen of Apis mellifera and Apis cerana. Relatively little is known about the distribution or prevalence of N. ceranae in the United States. To determine the prevalence and potential impact of this new pathogen on honey bee colonies in Virginia, over 300 hives were sampled across the state. The samples were analyzed microscopically for Nosema spores and for the presence of the pathogen using real-time PCR. Our studies indicate that N. ceranae is the dominant species in Virginia with an estimated 69.3% of hives infected. Nosema apis infections were only observed at very low levels (2.7%), and occurred only as co-infections with N. ceranae. Traditional diagnoses based on spore counts alone do not provide an accurate indication of colony infections. We found that 51.1% of colonies that did not have spores present in the sample were infected with N. ceranae when analyzed by real-time PCR. In hives that tested positive for N. ceranae, average C(T) values were used to diagnose a hive as having a low, moderate, or a heavy infection intensity. Most infected colonies had low-level infections (73%), but 11% of colonies had high levels of infection and 16% had moderate level infections. The prevalence and mean levels of infection were similar in different regions of the state.
Jerry J Bromenshenk, Colin B Henderson, Charles H Wick, Michael F Stanford, Alan W Zulich, Rabih E Jabbour, Samir V Deshpande, Patrick E McCubbin, Robert A Seccomb, Phillip M Welch, Trevor Williams, David R Firth, Evan Skowronski, Margaret M Lehmann, Shan L Bilimoria, Joanna Gress, Kevin W Wanner, Robert A Cramer Jr
Division of Biological Sciences, The University of Montana, Missoula, Montana, United States of America. firstname.lastname@example.org
BACKGROUND In 2010 Colony Collapse Disorder (CCD), again devastated honey bee colonies in the USA, indicating that the problem is neither diminishing nor has it been resolved. Many CCD investigations, using sensitive genome-based methods, have found small RNA bee viruses and the microsporidia, Nosema apis and N. ceranae in healthy and collapsing colonies alike with no single pathogen firmly linked to honey bee losses. METHODOLOGY/PRINCIPAL FINDINGS We used Mass spectrometry-based proteomics (MSP) to identify and quantify thousands of proteins from healthy and collapsing bee colonies. MSP revealed two unreported RNA viruses in North American honey bees, Varroa destructor-1 virus and Kakugo virus, and identified an invertebrate iridescent virus (IIV)(Iridoviridae) associated with CCD colonies. Prevalence of IIV significantly discriminated among strong, failing, and collapsed colonies. In addition, bees in failing colonies contained not only IIV, but also Nosema. Co-occurrence of these microbes consistently marked CCD in (1) bees from commercial apiaries sampled across the U.S. in 2006-2007,(2) bees sequentially sampled as the disorder progressed in an observation hive colony in 2008, and (3) bees from a recurrence of CCD in Florida in 2009. The pathogen pairing was not observed in samples from colonies with no history of CCD, namely bees from Australia and a large, non-migratory beekeeping business in Montana. Laboratory cage trials with a strain of IIV type 6 and Nosema ceranae confirmed that co-infection with these two pathogens was more lethal to bees than either pathogen alone. CONCLUSIONS/SIGNIFICANCE These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe, and Asia. We next need to characterize the IIV and Nosema that we detected and develop management practices to reduce honey bee losses.
Polymorphism and recombination for rDNA in the putatively asexual microsporidian Nosema ceranae, a pathogen of honeybees.
Universidad San Pablo-CEU, Biology Department, 28668 Montepríncipe, Spain.
Summary Nosema ceranae is currently one of the major pathogens of honeybees, related to the worldwide colony losses phenomenon. The genotyping of strains based on ribosomal DNA (rDNA) can be misleading if the repeated units are not identical. The analysis of cloned rDNA fragments containing the intergenic spacer (IGS) and part of the rDNA small-subunit (SSU) gene, from N. ceranae isolates from different European and Central Asia populations, revealed a high diversity of sequences. The variability involved single-nucleotide polymorphisms and insertion/deletions, resulting in 79 different haplotypes. Two sequences from the same isolate could be as different as any pair of sequences from different samples; in contrast, identical haplotypes were also found in very different geographical origins. Consequently, haplotypes cannot be organized in a consistent phylogenetic tree, clearly indicating that rDNA is not a reliable marker for the differentiation of N. ceranae strains. The results indicate that recombination between different sequences may produce new variants, which is quite surprising in microsporidia, usually considered to have an asexual mode of reproduction. The diversity of sequences and their geographical distribution indicate that haplotypes of different lineages may occasionally be present in a same cell and undergo homologue recombination, therefore suggesting a sexual haplo-diploid cycle.
School of Environmental Sciences, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1.
Correct identification of the microsporidia, Nosema apis and Nosema ceranae, is key to the study and control of Nosema disease of honey bees (Apis mellifera). A rapid DNA extraction method combined with multiplex PCR to amplify the 16S rRNA gene with species-specific primers was compared with a previously published assay requiring spore-germination buffer and a DNA extraction kit. When the spore germination-extraction kit method was used, 10 or more bees were required to detect the pathogens, whereas the new extraction method made it possible to detect the pathogens in single bees. Approx. 4-8 times better detection of N. ceranae was found with the new method compared to the spore germination-extraction kit method. In addition, the time and cost required to process samples was lower with the proposed method compared to using a kit. Using the new DNA extraction method, a spore quantification procedure was developed using a triplex PCR involving co-amplifying the N. apis and N. ceranae 16S rRNA gene with the ribosomal protein gene, RpS5, from the honey bee. The accuracy of this semi-quantitative PCR was determined by comparing the relative band intensities to the number of spores per bee determined by microscopy for 23 samples, and a high correlation (R(2)=0.95) was observed. This method of Nosema spore quantification revealed that spore numbers as low as 100 spores/bee could be detected by PCR. The new semi-quantitative triplex PCR assay is more sensitive, economical, rapid, simple, and reliable than previously published standard PCR-based methods for detection of Nosema and will be useful in laboratories where real-time PCR is not available.
Institute for Bee Research, Friedrich-Engels-Str. 32, 16540 Hohen Neuendorf, Germany. email@example.com
Managed honey bees are the most important commercial pollinators of those crops which depend on animal pollination for reproduction and which account for 35% of the global food production. Hence, they are vital for an economic, sustainable agriculture and for food security. In addition, honey bees also pollinate a variety of wild flowers and, therefore, contribute to the biodiversity of many ecosystems. Honey and other hive products are, at least economically and ecologically rather, by-products of beekeeping. Due to this outstanding role of honey bees, severe and inexplicable honey bee colony losses, which have been reported recently to be steadily increasing, have attracted much attention and stimulated many research activities. Although the phenomenon "decline of honey bees" is far from being finally solved, consensus exists that pests and pathogens are the single most important cause of otherwise inexplicable colony losses. This review will focus on selected bee pathogens and parasites which have been demonstrated to be involved in colony losses in different regions of the world and which, therefore, are considered current threats to honey bees and beekeeping.
Other papers by authors:
PLoS One. 2012 ;7 (8):e43562 22927991
R Scott Cornman, David R Tarpy, Yanping Chen, Lacey Jeffreys, Dawn Lopez, Jeffery S Pettis, Dennis Vanengelsdorp, Jay D Evans
Bee Research Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland, United States of America.
Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees.
Differential expression of immune genes of adult honey bee (Apis mellifera) after inoculated by Nosema ceranae.
Bee Protection Center, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Nosema ceranae is a microsporidium parasite infecting adult honey bees (Apis mellifera) and is known to affects at both the individual and colony level. In this study, the expression levels were measured for four antimicrobial peptide encoding genes that are associated with bee humoral immunity (defensin, abaecin, apidaecin, and hymenoptaecin), eater gene which is a transmembrane protein involved cellular immunity and gene encoding female-specific protein (vitellogenin) in honey bees when inoculated by N. ceranae. The results showed that four of these genes, defensin, abaecin, apidaecin and hymenoptaecin were significantly down-regulated 3 and 6days after inoculations. Additionally, antimicrobial peptide expressions did not significantly differ between control and inoculated bees after 12days post inoculation. Moreover, our results revealed that the mRNA levels of eater and vitellogenin did not differ significantly following N. ceranae inoculation. Therefore, in this study we reaffirmed that N. ceranae infection induces host immunosuppression.
Dennis Vanengelsdorp, Jay D Evans, Claude Saegerman, Chris Mullin, Eric Haubruge, Bach Kim Nguyen, Maryann Frazier, Jim Frazier, Diana Cox-Foster, Yanping Chen, Robyn Underwood, David R Tarpy, Jeffery S Pettis
Pennsylvania Department of Agriculture, Harrisburg, PA, USA.
BACKGROUND Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. METHODS AND PRINCIPAL FINDINGS Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. CONCLUSIONS/SIGNIFICANCE This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.
Yanping Chen, Jay D Evans, Liang Zhou, Humberto Boncristiani, Kiyoshi Kimura, Tieguang Xiao, A M Litkowski, Jeffery S Pettis
USDA-ARS, Bee Research Laboratory, Beltsville, MD 20705, USA. firstname.lastname@example.org
Globalization has provided opportunities for parasites/pathogens to cross geographic boundaries and expand to new hosts. Recent studies showed that Nosema ceranae, originally considered a microsporidian parasite of Eastern honey bees, Apis cerana, is a disease agent of nosemosis in European honey bees, Apis mellifera, along with the resident species, Nosema apis. Further studies indicated that disease caused by N. ceranae in European honey bees is far more prevalent than that caused by N. apis. In order to gain more insight into the epidemiology of Nosema parasitism in honey bees, we conducted studies to investigate infection of Nosema in its original host, Eastern honey bees, using conventional PCR and duplex real time quantitative PCR methods. Our results showed that A. cerana was infected not only with N. ceranae as previously reported [Fries, I., Feng, F., Silva, A.D., Slemenda, S.B., Pieniazek, N.J., 1996. Nosema ceranae n. sp.(Microspora, Nosematidae), morphological and molecular characterization of a microsporidian parasite of the Asian honey bee Apis cerana (Hymenoptera, Apidae). Eur. J. Protistol. 32, 356-365], but also with N. apis. Both microsporidia produced single and mixed infections. Overall and at each location alone, the prevalence of N. ceranae was higher than that of N. apis. In all cases of mixed infections, the number of N. ceranae gene copies (corresponding to the parasite load) significantly out numbered those of N. apis. Phylogenetic analysis based on a variable region of small subunit ribosomal RNA (SSUrRNA) showed four distinct clades of N. apis and five clades of N. ceranae and that geographical distance does not appear to influence the genetic diversity of Nosema populations. The results from this study demonstrated that duplex real-time qPCR assay developed in this study is a valuable tool for quantitative measurement of Nosema and can be used to monitor the progression of microsprodian infections of honey bees in a timely and cost efficient manner.
PLoS One. 2012 ;7 (11):e47955 23144838
Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China.
Pathogens and parasites represent significant threats to the health and well-being of honeybee species that are key pollinators of agricultural crops and flowers worldwide. We conducted a nationwide survey to determine the occurrence and prevalence of pathogens and parasites in Asian honeybees, Apis cerana, in China. Our study provides evidence of infections of A. cerana by pathogenic Deformed wing virus (DWV), Black queen cell virus (BQCV), Nosema ceranae, and C. bombi species that have been linked to population declines of European honeybees, A. mellifera, and bumble bees. However, the prevalence of DWV, a virus that causes widespread infection in A. mellifera, was low, arguably a result of the greater ability of A. cerana to resist the ectoprasitic mite Varroa destructor, an efficient vector of DWV. Analyses of microbial communities from the A. cerana digestive tract showed that Nosema infection could have detrimental effects on the gut microbiota. Workers infected by N. ceranae tended to have lower bacterial quantities, with these differences being significant for the Bifidobacterium and Pasteurellaceae bacteria groups. The results of this nationwide screen show that parasites and pathogens that have caused serious problems in European honeybees can be found in native honeybee species kept in Asia. Environmental changes due to new agricultural practices and globalization may facilitate the spread of pathogens into new geographic areas. The foraging behavior of pollinators that are in close geographic proximity likely have played an important role in spreading of parasites and pathogens over to new hosts. Phylogenetic analyses provide insights into the movement and population structure of these parasites, suggesting a bidirectional flow of parasites among pollinators. The presence of these parasites and pathogens may have considerable implications for an observed population decline of Asian honeybees.
Phylogenetic analysis of Nosema ceranae isolated from European and Asian honeybees in Northern Thailand.
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
Nosema ceranae was found to infect four different host species including the European honeybee (A. mellifera) and the Asian honeybees (Apis florea, A. cerana and Apis dorsata) collected from apiaries and forests in Northern Thailand. Significant sequence variation in the polar tube protein (PTP1) gene of N. ceranae was observed with N. ceranae isolates from A. mellifera and A. cerana, they clustered into the same phylogenetic lineage. N. ceranae isolates from A. dorsata and A. florea were grouped into two other distinct clades. This study provides the first elucidation of a genetic relationship among N. ceranae strains isolated from different host species and demonstrates that the N. ceranae PTP gene was shown to be a suitable and reliable marker in revealing genetic relationships within species.
Weighing risk factors associated with bee colony collapse disorder by classification and regression tree analysis.
Dennis VanEngelsdorp, Niko Speybroeck, Jay D Evans, Bach Kim Nguyen, Chris Mullin, Maryann Frazier, Jim Frazier, Diana Cox-Foster, Yanping Chen, David R Tarpy, Eric Haubruge, Jeffrey S Pettis, Claude Saegerman
Bureau of Plant Industry, Pennsylvania Department of Agriculture, 2301 North Cameron St., Harrisburg PA 17110, USA.
Colony collapse disorder (CCD), a syndrome whose defining trait is the rapid loss of adult worker honey bees, Apis mellifera L., is thought to be responsible for a minority of the large overwintering losses experienced by U.S. beekeepers since the winter 2006-2007. Using the same data set developed to perform a monofactorial analysis (PloS ONE 4: e6481, 2009), we conducted a classification and regression tree (CART) analysis in an attempt to better understand the relative importance and interrelations among different risk variables in explaining CCD. Fifty-five exploratory variables were used to construct two CART models: one model with and one model without a cost of misclassifying a CCD-diagnosed colony as a non-CCD colony. The resulting model tree that permitted for misclassification had a sensitivity and specificity of 85 and 74%, respectively. Although factors measuring colony stress (e.g., adult bee physiological measures, such as fluctuating asymmetry or mass of head) were important discriminating values, six of the 19 variables having the greatest discriminatory value were pesticide levels in different hive matrices. Notably, coumaphos levels in brood (a miticide commonly used by beekeepers) had the highest discriminatory value and were highest in control (healthy) colonies. Our CART analysis provides evidence that CCD is probably the result of several factors acting in concert, making afflicted colonies more susceptible to disease. This analysis highlights several areas that warrant further attention, including the effect of sublethal pesticide exposure on pathogen prevalence and the role of variability in bee tolerance to pesticides on colony survivorship.
Varroa destructor is an effective vector of Israeli acute paralysis virus in the honeybee, Apis mellifera.
Gennaro Di Prisco, Francesco Pennacchio, Emilio Caprio, Humberto F Boncristiani Jr, Jay D Evans, Yanping Chen
Dipartimento di Entomologia e Zoologia Agraria Filippo Silvestri, Universita' degli Studi di Napoli Federico II, Via Universita' n.100, 80055 Portici, Napoli, Italy.
The Israeli acute paralysis virus (IAPV) is a significant marker of honeybee colony collapse disorder (CCD). In the present work, we provide the first evidence that Varroa destructor is IAPV replication-competent and capable of vectoring IAPV in honeybees. The honeybees became infected with IAPV after exposure to Varroa mites that carried the virus. The copy number of IAPV in bees was positively correlated with the density of Varroa mites and time period of exposure to Varroa mites. Further, we showed that the mite-virus association could possibly reduce host immunity and therefore promote elevated levels of virus replication. This study defines an active role of Varroa mites in IAPV transmission and sheds light on the epidemiology of IAPV infection in honeybees.
Effective gene silencing in a microsporidian parasite associated with honeybee (Apis mellifera) colony declines.
Nitzan Paldi, Eitan Glick, Maayan Oliva, Yaron Zilberberg, Lucie Aubin, Jeffery Pettis, Yanping Chen, Jay D Evans
Beeologics Inc., 11800 SW 77th Ave., Miami, Florida 33156, USA.
Honeybee colonies are vulnerable to parasites and pathogens ranging from viruses to vertebrates. An increasingly prevalent disease of managed honeybees is caused by the microsporidian Nosema ceranae. Microsporidia are basal fungi and obligate parasites with much-reduced genomic and cellular components. A recent genome-sequencing effort for N. ceranae indicated the presence of machinery for RNA silencing in this species, suggesting that RNA interference (RNAi) might be exploited to regulate Nosema gene expression within bee hosts. Here we used controlled laboratory experiments to show that double-stranded RNA homologous to specific N. ceranae ADP/ATP transporter genes can specifically and differentially silence transcripts encoding these proteins. This inhibition also affects Nosema levels and host physiology. Gene silencing could be mediated solely by Nosema or in concert with known systemic RNAi mechanisms in their bee hosts. These results are novel for the microsporidia and provide a possible avenue for controlling a disease agent implicated in severe honeybee colony losses. Moreover, since microsporidia are pathogenic in several known veterinary and human diseases, this advance may have broader applications in the future for disease control.
R Scott Cornman, Yan Ping Chen, Michael C Schatz, Craig Street, Yan Zhao, Brian Desany, Michael Egholm, Stephen Hutchison, Jeffery S Pettis, W Ian Lipkin, Jay D Evans
USDA-ARS Bee Research Lab, Beltsville, Maryland, United States of America.
Recent steep declines in honey bee health have severely impacted the beekeeping industry, presenting new risks for agricultural commodities that depend on insect pollination. Honey bee declines could reflect increased pressures from parasites and pathogens. The incidence of the microsporidian pathogen Nosema ceranae has increased significantly in the past decade. Here we present a draft assembly (7.86 MB) of the N. ceranae genome derived from pyrosequence data, including initial gene models and genomic comparisons with other members of this highly derived fungal lineage. N. ceranae has a strongly AT-biased genome (74% A+T) and a diversity of repetitive elements, complicating the assembly. Of 2,614 predicted protein-coding sequences, we conservatively estimate that 1,366 have homologs in the microsporidian Encephalitozoon cuniculi, the most closely related published genome sequence. We identify genes conserved among microsporidia that lack clear homology outside this group, which are of special interest as potential virulence factors in this group of obligate parasites. A substantial fraction of the diminutive N. ceranae proteome consists of novel and transposable-element proteins. For a majority of well-supported gene models, a conserved sense-strand motif can be found within 15 bases upstream of the start codon; a previously uncharacterized version of this motif is also present in E. cuniculi. These comparisons provide insight into the architecture, regulation, and evolution of microsporidian genomes, and will drive investigations into honey bee-Nosema interactions.
Latest similar papers:
SkinCare Physicians, Chestnut Hill, MA, USA. email@example.com
There are currently more than 20 FDA-approved fillers in the United States (U.S.), noteworthy considering that it was only six years ago that the first hyaluronic acid filler was approved. The pace of development of filler substances in the last few years has been extremely rapid. The authors review the development, advantages, and disadvantages of fillers currently available in the U.S.
Research Unit Biochemistry Macromolecular and Genetic, Faculty of Sciences Gafsa, Zarroug City, 2112, Gafsa, Tunisia. firstname.lastname@example.org
Nine different species of scorpions can be recognized from more than 5000 samples collected from different areas in Libya: Leiurus quinquestriatus, Androctonus bicolor, Androctonus australis, Androctonus amoreuxi, Buthacus leptochelys, Buthus occitanus, Buthacus arenicola, Orthochirus innesi and Scorpio maurus. The geographical occurrence showed that Leiurus quinquestriatus seems to be restricted to the Southern areas. On the contrary, Buthus occitanus was found in the costal regions. Other species such as Androctonus were widely spread in all regions. Buthacus Leptochelys, Orthochirus innesi and Scorpio maurus were found, in the East (Aujlah, Jalu), the South (Wadi-Atbah) and the Western cost of Libya respectively.
Proteomic characterization of royal jelly proteins in Chinese (Apis cerana cerana) and European (Apis mellifera) honeybees.
School of Life Sciences, Xiamen University, Xiamen 361005, China.
In this study, the proteins contained in royal jelly (RJ) derived from Chinese and European honeybees have been analyzed in detail and compared. Remarkable differences were found in the heterogeneity of major royal jelly proteins (MRJPs), MRJP2 and MRJP3, in terms of molecular weight and isoelectric points between the two species of RJ. MRJP2 and MRJP3 produced by Chinese honeybee are less polymorphic than those produced by European honeybee. This study is a contribution to the description of the royal jelly proteome.
[Nosema ceranae (Eukaryota: Fungi: Microsporea)--a new parasite of western honey bee Apis mellifera L].
Szkoła Głowna Gospodarstwa Wiejskiego, Wydział Medycyny Weterynaryjnej, Katedra Nauk Klinicznych, Choroby Owadów Uzytkowych, ul. Ciszewskigo 8, 02-786 Warszawa.
Nosema ceranae was discovered in Apis cerana, Eastern honeybee first. Until recently A. cerana has been considered the only host to this parasite. A few years ago N. ceranae was recorded in honey bee Apis mellifera. It appeared that N. ceranae is more pathogenic for A. mellifera than Nosema apis. This parasite can cause significant losses in bee colonies. Bees die without symptoms observed in nosemosis caused by N. apis such as diarrhea.
Africanized and European honey bee (Apis mellifera) populations showed quantitative differences in colony defensive behavior. Africanized bees responded faster and in much larger numbers than European honey bees and produced 8.2 and 5.9 times as many stings during two different experiments. Times to react to alarming stimuli were negatively correlated with the number of bees responding and to the total number of stings. The number of bees responding was significantly correlated to the total number of stings only for the Africanized population.
The author uses data on household heads from the Public Use Sample of the 1950 U.S. census to analyze the relationship between household income and the probability of suburban residence. The results indicate that "slightly less than half of population suburbanization between 1950 and 1980 can be attributed to rising household incomes."
Department of Microbiology, National Institute of Public Health, Tokyo, Japan. email@example.com
Rotavirus was examined in 818 diarrheal stool samples collected in Karachi, Pakistan, from 1990 to 1997. Rotavirus was detected in 112 samples (13.7%). The predominant serotypes were G1 and G4 and G3 was not detected. The predominant type changed between years. Rotavirus was found in all seasons and most infections were found in children aged less than 2 years.
Africanized honey bees (Hymenoptera: Apidae) have a greater fidelity to sunflowers than European bees.
Area de Producción Apícola, Facultad de Ciencias Veterinarias, Universidad Nacional de la Provincia de Buenos Aires, Argentina.
A study of sunflower, Helianthus annuus L., pollen collection by Africanized and European honey bees, Apis mellifera L., was conducted in a hybrid seed production field in Argentina. Africanized honey bees collected significantly larger proportions of sunflower pollen than did European honey bees. The result suggests that Africanized bees would be more efficient for commercial sunflower seed production.
Influenza virus infections regularly increase serious morbidity and mortality in the United States. From 1972 to 1985, between 10,000 and 40,000 deaths were attributed to influenza each year. More than 90% of these deaths were individuals 65 years or older.
Department of Orthodontics, University Dental School, Graz, Austria.
A comparison between occlusal deviations in the permanent dentition in the skulls of 94 19th century and 157 present-day Austrian males was made by means of the PAR Index. It was found that the contemporary dentitions showed significantly higher malocclusion scores than the 19th century sample (weighted PAR Index 11.79 and 6.62, respectively). The results show that secular changes in malocclusion have occurred during the last 100 years.