Professor of Epidemiology
A molecular parasitologist and virologist, Dr. Elodie Ghedin uses genomics tools to explore host-pathogen interactions in filarial worms (which cause River Blindness and Lymphatic Filariasis) and in viral infections. Her laboratory also explores influenza virus diversity in the infected host and the respiratory tract microbiome to understand transmission dynamics.
Dr. Ghedin’s omics-based predictive modeling project aims to predict severe disease outcome of influenza to develop point of care testing, as some people are more prone to severe versus mild influenza infections. Additionally, her Zika research will be used to develop predictive models for Zika disease severity.
In the Ghedin Lab, Dr. Ghedin offers students an opportunity to study genomic characteristics of human parasites and other pathogens. The research is multidisciplinary and draws upon the tools of genomics, molecular virology, and computational biology. Some projects include the study of influenza virus evolution and emergence, the analysis of the microbiome and mycobiome (fungal microbiota) associated with the pathogenesis of lung obstruction and emphysema in HIV patients, and the characterization of endosymbiotic interactions between filarial worms and Wolbachia. Additionally, Dr. Ghedin also collaborates on the GoViral Project.
As biology and diseases are all interrelated, in her Essentials of Public Health Biology class, Dr. Ghedin teaches the importance of having a foundation in human biology in order to work in any area of public health.
BS, Biology, McGill University, Montreal, CanadaMS, Environmental Sciences, University of Quebec, Montreal, CanadaPhD, Molecular Parasitology, McGill University, Montreal, Canada
American Academy of Microbiology Fellow (2017)Kavli Frontiers of Science Fellow (2012)MacArthur Fellow (2011)Chancellor’s Distinguished Research Award (2010)
BiologyGenomicsInfectious DiseasesViral Infections
A meta-analysis of Wolbachia transcriptomics reveals a stage-specific Wolbachia transcriptional response shared across different hostsChung, M., Basting, P. J., Patkus, R. S., Grote, A., Luck, A. N., Ghedin, E., Slatko, B. E., Michalski, M., Foster, J. M., Bergman, C. M., & Dunning Hotopp, J. C.
Journal titleG3: Genes, Genomes, Genetics
Page(s)3243-3260AbstractWolbachia is a genus containing obligate, intracellular endosymbionts with arthropod and nematode hosts. Numerous studies have identified differentially expressed transcripts in Wolbachia endosymbionts that potentially inform the biological interplay between these endosymbionts and their hosts, albeit with discordant results. Here, we re-analyze previously published Wolbachia RNA-Seq transcriptomics data sets using a single workflow consisting of the most up-to-date algorithms and techniques, with the aim of identifying trends or patterns in the pan-Wolbachia transcriptional response. We find that data from one of the early studies in filarial nematodes did not allow for robust conclusions about Wolbachia differential expression with these methods, suggesting the original interpretations should be reconsidered. Across datasets analyzed with this unified workflow, there is a general lack of global gene regulation with the exception of a weak transcriptional response resulting in the upregulation of ribosomal proteins in early larval stages. This weak response is observed across diverse Wolbachia strains from both nematode and insect hosts suggesting a potential pan-Wolbachia transcriptional response during host development that diverged more than 700 million years ago.
A rapid and label-free platform for virus capture and identification from clinical samplesYeh, Y. T., Gulino, K., Zhang, Y. H., Sabestien, A., Chou, T. W., Zhou, B., Lin, Z., Albert, I., Lu, H., Swaminathan, V., Ghedin, E., & Terrones, M.
Journal titleProceedings of the National Academy of Sciences of the United States of America
Page(s)895-901AbstractEmerging and reemerging viruses are responsible for a number of recent epidemic outbreaks. A crucial step in predicting and controlling outbreaks is the timely and accurate characterization of emerging virus strains. We present a portable microfluidic platform containing carbon nanotube arrays with differential filtration porosity for the rapid enrichment and optical identification of viruses. Different emerging strains (or unknown viruses) can be enriched and identified in real time through a multivirus capture component in conjunction with surface-enhanced Raman spectroscopy. More importantly, after viral capture and detection on a chip, viruses remain viable and get purified in a microdevice that permits subsequent in-depth characterizations by various conventional methods. We validated this platform using different subtypes of avian influenza A viruses and human samples with respiratory infections. This technology successfully enriched rhinovirus, influenza virus, and parainfluenza viruses, and maintained the stoichiometric viral proportions when the samples contained more than one type of virus, thus emulating coinfection. Viral capture and detection took only a few minutes with a 70-fold enrichment enhancement; detection could be achieved with as little as 102 EID50/mL (50% egg infective dose per microliter), with a virus specificity of 90%. After enrichment using the device, we demonstrated by sequencing that the abundance of viral-specific reads significantly increased from 4.1 to 31.8% for parainfluenza and from 0.08 to 0.44% for influenza virus. This enrichment method coupled to Raman virus identification constitutes an innovative system that could be used to quickly track and monitor viral outbreaks in real time.
Cell-to-cell variation in defective virus expression and effects on host responses during influenza virus infectionWang, C., Forst, C. V., Chou, T. W., Geber, A., Wang, M., Hamou, W., Smith, M., Sebra, R., Zhang, B., Zhou, B., & Ghedin, E.
Issue1AbstractVirus and host factors contribute to cell-to-cell variation in viral infections and determine the outcome of the overall infection. However, the extent of the variability at the single-cell level and how it impacts virus-host interactions at a system level are not well understood. To characterize the dynamics of viral transcription and host responses, we used single-cell RNA sequencing to quantify at multiple time points the host and viral transcriptomes of human A549 cells and primary bronchial epithelial cells infected with influenza A virus. We observed substantial variability in viral transcription between cells, including the accumulation of defective viral genomes (DVGs) that impact viral replication. We show (i) a correlation between DVGs and virus-induced variation of the host transcriptional program and (ii) an association between differential inductions of innate immune response genes and attenuated viral transcription in subpopulations of cells. These observations at the single-cell level improve our understanding of the complex virus-host interplay during influenza virus infection. IMPORTANCE Defective influenza virus particles generated during viral replication carry incomplete viral genomes and can interfere with the replication of competent viruses. These defective genomes are thought to modulate the disease severity and pathogenicity of an influenza virus infection. Different defective viral genomes also introduce another source of variation across a heterogeneous cell population. Evaluating the impact of defective virus genomes on host cell responses cannot be fully resolved at the population level, requiring single-cell transcriptional profiling. Here, we characterized virus and host transcriptomes in individual influenza virus-infected cells, including those of defective viruses that arise during influenza A virus infection. We established an association between defective virus transcription and host responses and validated interfering and immunostimulatory functions of identified dominant defective viral genome species in vitro. This study demonstrates the intricate effects of defective viral genomes on host transcriptional responses and highlights the importance of capturing host-virus interactions at the single-cell level.
Characterization of antibiotic resistance and host-microbiome interactions in the human upper respiratory tract during influenza infectionZhang, L., Forst, C. V., Gordon, A., Gussin, G., Geber, A. B., Fernandez, P. J., Ding, T., Lashua, L., Wang, M., Balmaseda, A., Bonneau, R., Zhang, B., & Ghedin, E.
Issue1AbstractBackground: The abundance and diversity of antibiotic resistance genes (ARGs) in the human respiratory microbiome remain poorly characterized. In the context of influenza virus infection, interactions between the virus, the host, and resident bacteria with pathogenic potential are known to complicate and worsen disease, resulting in coinfection and increased morbidity and mortality of infected individuals. When pathogenic bacteria acquire antibiotic resistance, they are more difficult to treat and of global health concern. Characterization of ARG expression in the upper respiratory tract could help better understand the role antibiotic resistance plays in the pathogenesis of influenza-associated bacterial secondary infection. Results: Thirty-seven individuals participating in the Household Influenza Transmission Study (HITS) in Managua, Nicaragua, were selected for this study. We performed metatranscriptomics and 16S rRNA gene sequencing analyses on nasal and throat swab samples, and host transcriptome profiling on blood samples. Individuals clustered into two groups based on their microbial gene expression profiles, with several microbial pathways enriched with genes differentially expressed between groups. We also analyzed antibiotic resistance gene expression and determined that approximately 25% of the sequence reads that corresponded to antibiotic resistance genes mapped to Streptococcus pneumoniae and Staphylococcus aureus. Following construction of an integrated network of ARG expression with host gene co-expression, we identified several host key regulators involved in the host response to influenza virus and bacterial infections, and host gene pathways associated with specific antibiotic resistance genes. Conclusions: This study indicates the host response to influenza infection could indirectly affect antibiotic resistance gene expression in the respiratory tract by impacting the microbial community structure and overall microbial gene expression. Interactions between the host systemic responses to influenza infection and antibiotic resistance gene expression highlight the importance of viral-bacterial co-infection in acute respiratory infections like influenza. [MediaObject not available: See fulltext.]
Crispr-mediated transfection of brugia malayiLiu, C., Grote, A., Ghedin, E., & Unnaschid, T. R.
Journal titlePLoS neglected tropical diseases
Page(s)1-15AbstractThe application of reverse genetics in the human filarial parasites has lagged due to the diffi-cult biology of these organisms. Recently, we developed a co-culture system that permitted the infective larval stage of Brugia malayi to be transfected and efficiently develop to fecund adults. This was exploited to develop a piggyBac transposon-based toolkit that can be used to produce parasites with transgene sequences stably integrated into the parasite genome. However, the piggyBac system has generally been supplanted by Clustered Regularly Inter-spaced Short Palindromic Repeats (CRISPR) based technology, which allows precise editing of a genome. Here we report adapting the piggyBac mediated transfection system of B. malayi for CRISPR mediated knock-in insertion into the parasite genome. Suitable CRISPR insertion sites were identified in intergenic regions of the B. malayi genome. A dual reporter piggybac vector was modified, replacing the piggyBac inverted terminal repeat regions with sequences flanking the insertion site. B. malayi molting L3 were transfected with a synthetic guide RNA, the modified plasmid and the CAS9 nuclease. The transfected parasites were implanted into gerbils and allowed to develop into adults. Progeny microfilariae were recov-ered and screened for expression of a secreted luciferase reporter encoded in the plasmid. Approximately 3% of the microfilariae were found to secrete luciferase; all contained the transgenic sequences inserted at the expected location in the parasite genome. Using an adaptor mediated PCR assay, transgenic microfilariae were examined for the presence of off target insertions; no off-target insertions were found. These data demonstrate that CRISPR can be used to modify the genome of B. malayi, opening the way to precisely edit the genome of this important human filarial parasite.
Initial mapping of the new york city wastewater viromeGulino, K., Rahman, J., Badri, M., Morton, J., Bonneau, R., Bonneau, R., Bonneau, R., Ghedin, E., & Ghedin, E.
Issue3AbstractBacteriophages are abundant members of all microbiomes studied to date, influencing microbial communities through interactions with their bacterial hosts. Despite their functional importance and ubiquity, phages have been underexplored in urban environments compared to their bacterial counterparts. We profiled the viral communities in New York City (NYC) wastewater using metagenomic data collected in November 2014 from 14 wastewater treatment plants. We show that phages accounted for the largest viral component of the sewage samples and that specific virus communities were associated with local environmental conditions within boroughs. The vast majority of the virus sequences had no homology matches in public databases, forming an average of 1,700 unique virus clusters (putative genera). These new clusters contribute to elucidating the overwhelming proportion of data that frequently goes unidentified in viral metagenomic studies. We assigned potential hosts to these phages, which appear to infect a wide range of bacterial genera, often outside their presumed host. We determined that infection networks form a modular-nested pattern, indicating that phages include a range of host specificities, from generalists to specialists, with most interactions organized into distinct groups. We identified genes in viral contigs involved in carbon and sulfur cycling, suggesting functional importance of viruses in circulating pathways and gene functions in the wastewater environment. In addition, we identified virophage genes as well as a nearly complete novel virophage genome. These findings provide an understanding of phage abundance and diversity in NYC wastewater, previously uncharacterized, and further examine geographic patterns of phagehost association in urban environments. Importance: Wastewater is a rich source of microbial life and contains bacteria, viruses, and other microbes found in human waste as well as environmental runoff sources. As part of an effort to characterize the New York City wastewater metagenome, we profiled the viral community of sewage samples across all five boroughs of NYC and found that local sampling sites have unique sets of viruses. We focused on bacteriophages, or viruses of bacteria, to understand how they may influence the microbial ecology of this system. We identified several new clusters of phages and successfully associated them with bacterial hosts, providing insight into virus-host interactions in urban wastewater. This study provides a first look into the viral communities present across the wastewater system in NYC and points to their functional importance in this environment.
Modeling the metabolic interplay between a parasitic worm and its bacterial endosymbiont allows the identification of novel drug targetsCurran, D. M., Grote, A., Nursimulu, N., Geber, A., Voronin, D., Jones, D. R., Ghedin, E., & Parkinson, J.
Page(s)1-28AbstractThe filarial nematode Brugia malayi represents a leading cause of disability in the developing world, causing lymphatic filariasis in nearly 40 million people. Currently available drugs are not well-suited to mass drug administration efforts, so new treatments are urgently required. One potential vulnerability is the endosymbiotic bacteria Wolbachia—present in many filariae— which is vital to the worm. Genome scale metabolic networks have been used to study prokaryotes and protists and have proven valuable in identifying therapeutic targets, but have only been applied to multicellular eukaryotic organisms more recently. Here, we present iDC625, the first compartmentalized metabolic model of a parasitic worm. We used this model to show how metabolic pathway usage allows the worm to adapt to different environments, and predict a set of 102 reactions essential to the survival of B. malayi. We validated three of those reactions with drug tests and demonstrated novel antifilarial properties for all three compounds.
Nearly complete genome sequence of Brugia malayi strain FR3Tracey, A., Foster, J. M., Paulini, M., Grote, A., Mattick, J., Tsai, Y. C., Chung, M., Cotton, J. A., Clark, T. A., Geber, A., Holroyd, N., Korlach, J., Libro, S., Lustigman, S., Michalski, M. L., Rogers, M. B., Twaddle, A., Dunning Hotopp, J. C., Dunning Hotopp, J. C., Dunning Hotopp, J. C., Berriman, M., Ghedin, E., & Ghedin, E.
Journal titleMicrobiology Resource Announcements
Issue24AbstractLymphatic filariasis affects ∼120 million people and can result in elephantiasis and hydrocele. Here, we report the nearly complete genome sequence of the best-studied causative agent of lymphatic filariasis, Brugia malayi. The assembly contains four autosomes, an X chromosome, and only eight gaps but lacks a contiguous sequence for the known Y chromosome.
Prediction pipeline for discovery of regulatory motifs associated with brugia Malayi moltingGrote, A., Li, Y., Liu, C., Voronin, D., Geber, A., Lustigman, S., Unnasch, T. R., Welch, L., & Ghedin, E.
Journal titlePLoS neglected tropical diseases
Page(s)1-16AbstractFilarial nematodes can cause debilitating diseases in humans. They have complicated life cycles involving an insect vector and mammalian hosts, and they go through a number of developmental molts. While whole genome sequences of parasitic worms are now avail-able, very little is known about transcription factor (TF) binding sites and their cognate transcription factors that play a role in regulating development. To address this gap, we developed a novel motif prediction pipeline, Emotif Alpha, that integrates ten different motif discovery algorithms, multiple statistical tests, and a comparative analysis of conserved elements between the filarial worms Brugia malayi and Onchocerca volvulus, and the free-liv-ing nematode Caenorhabditis elegans. We identified stage-specific TF binding motifs in B. malayi, with a particular focus on those potentially involved in the L3-L4 molt, a stage important for the establishment of infection in the mammalian host. Using an in vitro molting sys-tem, we tested and validated three of these motifs demonstrating the accuracy of the motif prediction pipeline.
Quantifying between-host transmission in influenza virus infectionsJohnson, K. E., & Ghedin, E.
Journal titleCold Spring Harbor perspectives in medicine
Page(s)1-15AbstractThe error-prone replication and life cycle of influenza virus generate a diverse set of genetic variants. Transmission between hosts strictly limits both the number of virus particles and the genetic diversity of virus variants that reach a new host and establish an infection. This sharp reduction in the virus population at transmission––the transmission bottleneck––is significant to the evolution of influenza virus and to its epidemic and pandemic potential. This review describes transmission bottlenecks and their effect on the diversity and evolution of influenza virus. It also reviews the methods for calculating and predicting bottleneck sizes and high-lights the host and viral determinants of influenza transmissibility.
Sex chromosome evolution in parasitic nematodes of humansFoster, J. M., Grote, A., Mattick, J., Tracey, A., Tsai, Y. C., Chung, M., Cotton, J. A., Clark, T. A., Geber, A., Holroyd, N., Korlach, J., Li, Y., Libro, S., Lustigman, S., Michalski, M. L., Paulini, M., Rogers, M. B., Teigen, L., Twaddle, A., Welch, L., Berriman, M., Dunning Hotopp, J. C., & Ghedin, E.
Journal titleNature communications
Issue1AbstractSex determination mechanisms often differ even between related species yet the evolution of sex chromosomes remains poorly understood in all but a few model organisms. Some nematodes such as Caenorhabditis elegans have an XO sex determination system while others, such as the filarial parasite Brugia malayi, have an XY mechanism. We present a complete B. malayi genome assembly and define Nigon elements shared with C. elegans, which we then map to the genomes of other filarial species and more distantly related nematodes. We find a remarkable plasticity in sex chromosome evolution with several distinct cases of neo-X and neo-Y formation, X-added regions, and conversion of autosomes to sex chromosomes from which we propose a model of chromosome evolution across different nematode clades. The phylum Nematoda offers a new and innovative system for gaining a deeper understanding of sex chromosome evolution.
Age-Related Pathology Associated with H1N1 A/California/07/2009 Influenza Virus InfectionBissel, S. J., Carter, C. E., Wang, G., Johnson, S. K., Lashua, L. P., Kelvin, A. A., Wiley, C. A., Ghedin, E., & Ross, T. M.
Journal titleAmerican Journal of Pathology
Page(s)2389-2399AbstractInfluenza virus infection causes a spectrum of diseases, ranging from mild upper respiratory tract infection to severe lower respiratory tract infection, that can lead to diffuse alveolar damage, interstitial and airspace inflammation, or acute respiratory failure. Mechanisms instructing disease severity are not completely understood, but host, viral, and bacterial factors influence disease outcome. With age being one host factor associated with a higher risk of severe influenza, we investigated regional pulmonary distribution and severity of pneumonia after 2009 H1N1 influenza virus infection in newly weaned, adult, and aged ferrets to better understand age-dependent susceptibility and pathology. Aged ferrets exhibited greater weight loss and higher rates of mortality than adult ferrets, whereas most newly weaned ferrets did not lose weight but had a lack of weight gain. Newly weaned ferrets exhibited minimal pneumonia, whereas adult and aged ferrets had a spectrum of pneumonia severity. Influenza virus–induced pneumonia peaked earliest in adult ferrets, whereas aged ferrets had delayed presentation. Bronchial severity differed among groups, but bronchial pathology was comparable among all cohorts. Alveolar infection was strikingly different among groups. Newly weaned ferrets had little alveolar cell infection. Adult and aged ferrets had alveolar infection, but aged ferrets were unable to clear infection. These different age-related pneumonia and infection patterns suggest therapeutic strategies to treat influenza should be tailored contingent on age.
Development and characterization of a reverse-genetics system for influenza D virusYu, J., Liu, R., Zhou, B., Chou, T. W., Ghedin, E., Sheng, Z., Gao, R., Zhai, S. L., Wang, D., & Lia, F.
Journal titleJournal of virology
Issue21AbstractInfluenza D virus (IDV) of the Orthomyxoviridae family has a wide host range and a broad geographical distribution. Recent IDV outbreaks in swine along with serological and genetic evidence of IDV infection in humans have raised concerns regarding the zoonotic potential of this virus. To better study IDV at the molecular level, a reverse-genetics system (RGS) is urgently needed, but to date, no RGS had been described for IDV. In this study, we rescued the recombinant influenza D/swine/Oklahoma/1314/2011 (D/OK) virus by using a bidirectional seven-plasmid-based system and further characterized rescued viruses in terms of growth kinetics, replication stability, and receptor-binding capacity. Our results collectively demonstrated that RGS-derived viruses resembled the parental viruses for these properties, thereby supporting the utility of this RGS to study IDV infection biology. In addition, we developed an IDV minigenome replication assay and identified the E697K mutation in PB1 and the L462F mutation in PB2 that directly affected the activity of the IDV ribonucleoprotein (RNP) complex, resulting in either attenuated or replication-incompetent viruses. Finally, by using the minigenome replication assay, we demonstrated that a single nucleotide polymorphism at position 5 of the 3= conserved noncoding region in IDV and influenza C virus (ICV) resulted in the inefficient cross-recognition of the heterotypic promoter by the viral RNP complex. In conclusion, we successfully developed a minigenome replication assay and a robust reverse-genetics system that can be used to further study replication, tropism, and pathogenesis of IDV. IMPORTANCE Influenza D virus (IDV) is a new type of influenza virus that uses cattle as the primary reservoir and infects multiple agricultural animals. Increased outbreaks in pigs and serological and genetic evidence of human infection have raised concerns about potential IDV adaptation in humans. Here, we have developed a plasmid-based IDV reverse-genetics system that can generate infectious viruses with replication kinetics similar to those of wild-type viruses following transfection of cultured cells. Further characterization demonstrated that viruses rescued from the described RGS resembled the parental viruses in biological and receptor-binding properties. We also developed and validated an IDV minireplicon reporter system that specifically measures viral RNA polymerase activity. In summary, the reverse-genetics system and minireplicon reporter assay described in this study should be of value in identifying viral determinants of cross-species transmission and pathogenicity of novel influenza D viruses.
Global phylogeography and ancient evolution of the widespread human gut virus crAssphageEdwards, R. A., Vega, A. A., Norman, H. M., Ohaeri, M., Levi, K., Dinsdale, E. A., Cinek, O., Aziz, R. K., McNair, K., Barr, J. J., Bibby, K., Brouns, S. J., Cazares, A., De Jonge, P. A., Desnues, C., Díaz Muñoz, S. L., Fineran, P. C., Kurilshikov, A., Lavigne, R., Mazankova, K., McCarthy, D. T., Nobrega, F. L., Reyes Muñoz, A., Tapia, G., Trefault, N., Tyakht, A. V., Vinuesa, P., Wagemans, J., Zhernakova, A., Aarestrup, F. M., Ahmadov, G., Alassaf, A., Anton, J., Asangba, A., Billings, E. K., Cantu, V. A., Carlton, J. M., Cazares, D., Cho, G. S., Condeff, T., Cortés, P., Cranfield, M., Cuevas, D. A., De La Iglesia, R., Decewicz, P., Doane, M. P., Dominy, N. J., Dziewit, L., Elwasila, B. M., Eren, A. M., Franz, C., Fu, J., Garcia-Aljaro, C., Ghedin, E., Gulino, K. M., Haggerty, J. M., Head, S. R., Hendriksen, R. S., Hill, C., Hyöty, H., Ilina, E. N., Irwin, M. T., Jeffries, T. C., Jofre, J., Junge, R. E., Kelley, S. T., Khan Mirzaei, M., Kowalewski, M., Kumaresan, D., Leigh, S. R., Lipson, D., Lisitsyna, E. S., Llagostera, M., Maritz, J. M., Marr, L. C., McCann, A., Molshanski-Mor, S., Monteiro, S., Moreira-Grez, B., Morris, M., Mugisha, L., Muniesa, M., Neve, H., Nguyen, N. P., Nigro, O. D., Nilsson, A. S., O’Connell, T., Odeh, R., Oliver, A., Piuri, M., Prussin, A. J., Qimron, U., Quan, Z. X., Rainetova, P., Ramírez-Rojas, A., Raya, R., Reasor, K., Rice, G. A., Rossi, A., Santos, R., Shimashita, J., Stachler, E. N., Stene, L. C., Strain, R., Stumpf, R., Torres, P. J., Twaddle, A., Ugochi Ibekwe, M. A., Villagra, N., Wandro, S., White, B., Whiteley, A., Whiteson, K. L., Wijmenga, C., Zambrano, M. M., Zschach, H., & Dutilh, B. E.
Journal titleNature Microbiology
Page(s)1727-1736AbstractMicrobiomes are vast communities of microorganisms and viruses that populate all natural ecosystems. Viruses have been considered to be the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared with that of other environments. Here, we investigate the origin, evolution and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboration, we obtained DNA sequences of crAssphage from more than one-third of the world’s countries and showed that the phylogeography of crAssphage is locally clustered within countries, cities and individuals. We also found fully colinear crAssphage-like genomes in both Old-World and New-World primates, suggesting that the association of crAssphage with primates may be millions of years old. Finally, by exploiting a large cohort of more than 1,000 individuals, we tested whether crAssphage is associated with bacterial taxonomic groups of the gut microbiome, diverse human health parameters and a wide range of dietary factors. We identified strong correlations with different clades of bacteria that are related to Bacteroidetes and weak associations with several diet categories, but no significant association with health or disease. We conclude that crAssphage is a benign cosmopolitan virus that may have coevolved with the human lineage and is an integral part of the normal human gut virome.
Microbial composition of the human nasopharynx varies according to influenza virus type and vaccination statusDing, T., Song, T., Zhou, B., Geber, A., Ma, Y., Zhang, L., Volk, M., Kapadia, S. N., Jenkins, S. G., Salvatore, M., & Ghedin, E.
Issue4AbstractFactors that contribute to enhanced susceptibility to severe bacterial disease after influenza virus infection are not well defined but likely include the microbiome of the respiratory tract. Vaccination against influenza, while having variable effectiveness, could also play a role in microbial community stability. We collected nasopharyngeal samples from 215 individuals infected with influenza A/H3N2 or influenza B virus and profiled the microbiota by target sequencing of the 16S rRNA gene. We identified signature taxonomic groups by performing linear discriminant analysis and effective size comparisons (LEfSe) and defined bacterial community types using Dirichlet multinomial mixture (DMM) models. Influenza infection was shown to be significantly associated with microbial composition of the nasopharynx according to the virus type and the vaccination status of the patient. We identified four microbial community types across the combined cohort of influenza patients and healthy individuals with one community type most representative of the influenza virus-infected group. We also identified microbial taxa for which relative abundance was significantly higher in the unvaccinated elderly group; these taxa include species known to be associated with pneumonia. IMPORTANCE Our results suggest that there is a significant association between the composition of the microbiota in the nasopharynx and the influenza virus type causing the infection. We observe that vaccination status, especially in more senior individuals, also has an association with the microbial community profile. This indicates that vaccination against influenza, even when ineffective to prevent disease, could play a role in controlling secondary bacterial complications.
Pyruvate produced by Brugia spp. via glycolysis is essential for maintaining the mutualistic association between the parasite and its endosymbiont, WolbachiaVoronin, D., Schnall, E., Grote, A., Jawahar, S., Ali, W., Unnasch, T. R., Ghedin, E., & Lustigman, S.
Journal titlePLoS Pathogens
Issue9AbstractHuman parasitic nematodes are the causative agents of lymphatic filariasis (elephantiasis) and onchocerciasis (river blindness), diseases that are endemic to more than 80 countries and that consistently rank in the top ten for the highest number of years lived with disability. These filarial nematodes have evolved an obligate mutualistic association with an intracellular bacterium, Wolbachia, a symbiont that is essential for the successful development, reproduction, and survival of adult filarial worms. Elimination of the bacteria causes adult worms to die, making Wolbachia a primary target for developing new interventional tools to combat filariases. To further explore Wolbachia as a promising indirect macrofilaricidal drug target, the essential cellular processes that define the symbiotic Wolbachia-host interactions need to be identified. Genomic analyses revealed that while filarial nematodes encode all the enzymes necessary for glycolysis, Wolbachia does not encode the genes for three glycolytic enzymes: hexokinase, 6-phosphofructokinase, and pyruvate kinase. These enzymes are necessary for converting glucose into pyruvate. Wolbachia, however, has the full complement of genes required for gluconeogenesis starting with pyruvate, and for energy metabolism via the tricarboxylic acid cycle. Therefore, we hypothesized that Wolbachia might depend on host glycolysis to maintain a mutualistic association with their parasitic host. We did conditional experiments in vitro that confirmed that glycolysis and its end-product, pyruvate, sustain this symbiotic relationship. Analysis of alternative sources of pyruvate within the worm indicated that the filarial lactate dehydrogenase could also regulate the local intracellular concentration of pyruvate in proximity to Wolbachia and thus help control bacterial growth via molecular interactions with the bacteria. Lastly, we have shown that the parasite's pyruvate kinase, the enzyme that performs the last step in glycolysis, could be a potential novel anti-filarial drug target. Establishing that glycolysis is an essential component of symbiosis in filarial worms could have a broader impact on research focused on other intracellular bacteria-host interactions where the role of glycolysis in supporting intracellular survival of bacteria has been reported.
Reply to ‘Reconciling disparate estimates of viral genetic diversity during human influenza infections’Poon, L. L., Song, T., Wentworth, D. E., Holmes, E. C., Greenbaum, B. D., Peiris, J. S., Cowling, B. J., & Ghedin, E. In Nature Genetics.
Taxonomy of the order Mononegavirales: second update 2018Maes, P., Amarasinghe, G. K., Ayllón, M. A., Basler, C. F., Bavari, S., Blasdell, K. R., Briese, T., Brown, P. A., Bukreyev, A., Balkema-Buschmann, A., Buchholz, U. J., Chandran, K., Crozier, I., De Swart, R. L., Dietzgen, R. G., Dolnik, O., Domier, L. L., Drexler, J. F., Dürrwald, R., Dundon, W. G., Duprex, W. P., Dye, J. M., Easton, A. J., Fooks, A. R., Formenty, P. B., Fouchier, R. A., Freitas-Astúa, J., Ghedin, E., Griffiths, A., Hewson, R., Horie, M., Hurwitz, J. L., Hyndman, T. H., Jiāng, D., Kobinger, G. P., Kondō, H., Kurath, G., Kuzmin, I. V., Lamb, R. A., Lee, B., Leroy, E. M., Lǐ, J., Marzano, S. Y. L., Mühlberger, E., Netesov, S. V., Nowotny, N., Palacios, G., Pályi, B., Pawęska, J. T., Payne, S. L., Rima, B. K., Rota, P., Rubbenstroth, D., Simmonds, P., Smither, S. J., Song, Q., Song, T., Spann, K., Stenglein, M. D., Stone, D. M., Takada, A., Tesh, R. B., Tomonaga, K., Tordo, N., Towner, J. S., Van Den Hoogen, B., Vasilakis, N., Wahl, V., Walker, P. J., Wang, D., Wang, L. F., Whitfield, A. E., Williams, J. V., Yè, G., Zerbini, F. M., Zhang, Y. Z., & Kuhn, J. H.
Journal titleArchives of Virology
Page(s)1233-1244AbstractIn October 2018, the order Mononegavirales was amended by the establishment of three new families and three new genera, abolishment of two genera, and creation of 28 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).
Comparison of the nasopharynx microbiome between influenza and non-influenza cases of severe acute respiratory infections: A pilot studyBorges, L. G. D. A., Giongo, A., Pereira, L. D. M., Trindade, F. J., Gregianini, T. S., Campos, F. S., Ghedin, E., & Da Veiga, A. B. G.
Journal titleHealth Science Reports
Issue6AbstractAims: Influenza A virus (IAV) can cause severe acute respiratory infection (SARI), and disease outcome may be associated with changes in the microbiome of the nasopharynx. This is a pilot study to characterize the microbiome of the nasopharynx in patients hospitalized with SARI, infected and not infected by IAV. Methods and Results: Using target sequencing of the 16S rRNA gene, we assessed the bacterial community of nasopharyngeal aspirate samples and compared the microbiome of patients infected with IAV with the microbiome of patients who were negative for IAV. We observed differences in the relative abundance of Proteobacteria and Firmicutes between SARI patients, with Streptococcus being enriched and Pseudomonas underrepresented in IAV patients compared with patients who were not infected with IAV. Conclusion: Pseudomonas taxon seems to be in high frequency on the nasopharynx of SARI patients with non-IAV infection and might present a negative association with Streptococcus taxon. Microbial profile appears to be different between SARI patients infected or not infected with IAV.
Fungi stabilize connectivity in the lung and skin microbial ecosystemsTipton, L., Müller, C. L., Kurtz, Z. D., Huang, L., Kleerup, E., Morris, A., Bonneau, R., & Ghedin, E.
Issue1AbstractBackground: No microbe exists in isolation, and few live in environments with only members of their own kingdom or domain. As microbiome studies become increasingly more interested in the interactions between microbes than in cataloging which microbes are present, the variety of microbes in the community should be considered. However, the majority of ecological interaction networks for microbiomes built to date have included only bacteria. Joint association inference across multiple domains of life, e.g., fungal communities (the mycobiome) and bacterial communities, has remained largely elusive. Results: Here, we present a novel extension of the SParse InversE Covariance estimation for Ecological ASsociation Inference (SPIEC-EASI) framework that allows statistical inference of cross-domain associations from targeted amplicon sequencing data. For human lung and skin micro- and mycobiomes, we show that cross-domain networks exhibit higher connectivity, increased network stability, and similar topological re-organization patterns compared to single-domain networks. We also validate in vitro a small number of cross-domain interactions predicted by the skin association network. Conclusions: For the human lung and skin micro- and mycobiomes, our findings suggest that fungi play a stabilizing role in ecological network organization. Our study suggests that computational efforts to infer association networks that include all forms of microbial life, paired with large-scale culture-based association validation experiments, will help formulate concrete hypotheses about the underlying biological mechanisms of species interactions and, ultimately, help understand microbial communities as a whole.
Measuring associations between the microbiota and repeated measures of continuous clinical variables using a lasso-penalized generalized linear mixed modelTipton, L., Cuenco, K. T., Huang, L., Greenblatt, R. M., Kleerup, E., Sciurba, F., Duncan, S. R., Donahoe, M. P., Morris, A., & Ghedin, E.
Journal titleBioData Mining
Issue1AbstractBackground: Human microbiome studies in clinical settings generally focus on distinguishing the microbiota in health from that in disease at a specific point in time. However, microbiome samples may be associated with disease severity or continuous clinical health indicators that are often assessed at multiple time points. While the temporal data from clinical and microbiome samples may be informative, analysis of this type of data can be problematic for standard statistical methods. Results: To identify associations between microbiota and continuous clinical variables measured repeatedly in two studies of the respiratory tract, we adapted a statistical method, the lasso-penalized generalized linear mixed model (LassoGLMM). LassoGLMM can screen for associated clinical variables, incorporate repeated measures of individuals, and address the large number of species found in the microbiome. As is common in microbiome studies, when the number of variables is an order of magnitude larger than the number of samples LassoGLMM can be imperfect in its variable selection. We overcome this limitation by adding a pre-screening step to reduce the number of variables evaluated in the model. We assessed the use of this adapted two-stage LassoGLMM for its ability to determine which microbes are associated with continuous repeated clinical measures. We found associations (retaining a non-zero coefficient in the LassoGLMM) between 10 laboratory measurements and 43 bacterial genera in the oral microbiota, and between 2 cytokines and 3 bacterial genera in the lung. We compared our associations with those identified by the Wilcoxon test after dichotomizing our outcomes and identified a non-significant trend towards differential abundance between high and low outcomes. Our two-step LassoGLMM explained more of the variance seen in the outcome of interest than other variants of the LassoGLMM method. Conclusions: We demonstrated a method that can account for the large number of genera detected in microbiome studies and repeated measures of clinical or longitudinal studies, allowing for the detection of strong associations between microbes and clinical measures. By incorporating the design strengths of repeated measurements and a prescreening step to aid variable selection, our two-step LassoGLMM will be a useful analytic method for investigating relationships between microbes and repeatedly measured continuous outcomes.
Profiling the airway in the macaque model of tuberculosis reveals variable microbial dysbiosis and alteration of community structureCadena, A. M., Ma, Y., Ding, T., Bryant, M., Maiello, P., Geber, A., Lin, P. L., Flynn, J. L., & Ghedin, E.
Issue1AbstractBackground: The specific interactions of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), and the lung microbiota in infection are entirely unexplored. Studies in cancer and other infectious diseases suggest that there are important exchanges occurring between host and microbiota that influence the immunological landscape. This can result in alterations in immune regulation and inflammation both locally and systemically. To assess whether Mtb infection modifies the lung microbiome, and identify changes in microbial abundance and diversity as a function of pulmonary inflammation, we compared infected and uninfected lung lobe washes collected serially from 26 macaques by bronchoalveolar lavage over the course of infection. Results: We found that Mtb induced an initial increase in lung microbial diversity at 1 month post infection that normalized by 5 months of infection across all macaques. Several core genera showed global shifts from baseline and throughout infection. Moreover, we identified several specific taxa normally associated with the oral microbiome that increased in relative abundance in the lung following Mtb infection, including SR1, Aggregatibacter, Leptotrichia, Prevotella, and Campylobacter. On an individual macaque level, we found significant heterogeneity in both the magnitude and duration of change within the lung microbial community that was unrelated to lung inflammation and lobe involvement as seen by positron emission tomography/computed tomography (PET/CT) imaging. By comparing microbial interaction networks pre- and post-infection using the predictive algorithm SPIEC-EASI, we observe that extra connections are gained by Actinomycetales, the order containing Mtb, in spite of an overall reduction in the number of interactions of the whole community post-infection, implicating Mtb-driven ecological reorganization within the lung. Conclusions: This study is the first to probe the dynamic interplay between Mtb and host microbiota longitudinally and in the macaque lung. Our findings suggest that Mtb can alter the microbial landscape of infected lung lobes and that these interactions induce dysbiosis that can disrupt oral-airway boundaries, shift overall lung diversity, and modulate specific microbial relationships. We also provide evidence that this effect is heterogeneous across different macaques. Overall, however, the changes to the airway microbiota after Mtb infection were surprisingly modest, despite a range of Mtb-induced pulmonary inflammation in this cohort of macaques.
Taxonomy of the order Mononegavirales: update 2018Amarasinghe, G. K., Aréchiga Ceballos, N. G., Banyard, A. C., Basler, C. F., Bavari, S., Bennett, A. J., Blasdell, K. R., Briese, T., Bukreyev, A., Caì, Y., Calisher, C. H., Campos Lawson, C., Chandran, K., Chapman, C. A., Chiu, C. Y., Choi, K. S., Collins, P. L., Dietzgen, R. G., Dolja, V. V., Dolnik, O., Domier, L. L., Dürrwald, R., Dye, J. M., Easton, A. J., Ebihara, H., Echevarría, J. E., Fooks, A. R., Formenty, P. B., Fouchier, R. A., Freuling, C. M., Ghedin, E., Goldberg, T. L., Hewson, R., Horie, M., Hyndman, T. H., Jiāng, D., Kityo, R., Kobinger, G. P., Kondō, H., Koonin, E. V., Krupovic, M., Kurath, G., Lamb, R. A., Lee, B., Leroy, E. M., Maes, P., Maisner, A., Marston, D. A., Mor, S. K., Müller, T., Mühlberger, E., Ramírez, V. M. N., Netesov, S. V., Ng, T. F. F., Nowotny, N., Palacios, G., Patterson, J. L., Pawęska, J. T., Payne, S. L., Prieto, K., Rima, B. K., Rota, P., Rubbenstroth, D., Schwemmle, M., Siddell, S., Smither, S. J., Song, Q., Song, T., Stenglein, M. D., Stone, D. M., Takada, A., Tesh, R. B., Thomazelli, L. M., Tomonaga, K., Tordo, N., Towner, J. S., Vasilakis, N., Vázquez-Morón, S., Verdugo, C., Volchkov, V. E., Wahl, V., Walker, P. J., Wang, D., Wang, L. F., Wellehan, J. F., Wiley, M. R., Whitfield, A. E., Wolf, Y. I., Yè, G., Zhāng, Y. Z., & Kuhn, J. H.
Journal titleArchives of Virology
Page(s)2283-2294AbstractIn 2018, the order Mononegavirales was expanded by inclusion of 1 new genus and 12 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.
Tropheryma whipplei colonization in HIVinfected individuals is not associated with lung function or inflammationQin, S., Clausen, E., Nouraie, S. M., Kingsley, L., McMahon, D., Kleerup, E., Huang, L., Ghedin, E., Greenblatt, R. M., & Morris, A.
Journal titlePloS one
Issue10AbstractStudies demonstrate that Tropheryma whipplei (T. whipplei) is present in the lungs of healthy individuals without acute respiratory symptoms or acute respiratory infection and is more common in the lungs of HIV-infected individuals and in smokers. The impact of T. whipplei colonization in the lung on local inflammation and pulmonary dysfunction in HIVinfected individuals is currently unknown. In this study, we performed specific polymerase chain reaction (PCR) and sequencing for T. whipplei in bronchoalveolar lavage (BAL) and induced sputum (IS) samples in 76 HIV-infected participants from three clinical sites. Pulmonary function and proinflammatory cytokine and chemokine levels in BAL were measured. Frequency of T. whipplei in either BAL or IS was 43.4%. The sensitivity and specificity of IS compared to BAL for detection of T. whipplei was 92.3% and 84.2%, respectively, and isolates of T. whipplei in the BAL and IS in the same subject shared genetic identity. Pulmonary function measures were not associated with T. whipplei colonization, and proinflammatory cytokine and chemokine levels in BAL and plasma as well as percentages of inflammatory cells in BAL and IS were not higher in colonized individuals. Overall, these results indicate that T. whipplei colonization in the lung is common, but may not be associated with decreased pulmonary function or inflammation in HIV-infected individuals.
Characterization of five unclassified orthobunyaviruses (Bunyaviridae) from Africa and the AmericasRogers, M. B., Gulino, K. M., Tesh, R. B., Cui, L., Fitch, A., Unnasch, T. R., Popov, V. L., Travassos Da Rosa, A. P., Guzman, H., Carrera, J. P., Vasilakis, N., & Ghedin, E.
Journal titleJournal of General Virology
Page(s)2258-2266AbstractThe Bunyaviridae family is made up of a diverse range of viruses, some of which cause disease and are a cause for concern in human and veterinary health. Here, we report the genomic and antigenic characterization of five previously uncharacterized bunyaviruses. Based on their ultrastructure, antigenic relationships and phylogenomic relationships, the five viruses are classified as members of the Orthobunyavirus genus. Three are viruses in the California encephalitis virus serogroup and are related to Trivittatus virus; the two others are most similar to the Mermet virus in the Simbu serogroup, and to the Tataguine virus, which is not currently assigned to a serogroup. Each of these five viruses was pathogenic to newborn mice, indicating their potential to cause illness in humans and other animals.