Education & Certifications

  • MS, Brigham Young University, Microbiology and Molecular Biology (2015)
  • BS, Brigham Young University, Molecular Biology (2014)


All Publications

  • Software-based analysis of bacteriophage genomes, physical ends, and packaging strategies BMC GENOMICS Merrill, B. D., Ward, A. T., Grose, J. H., Hope, S. 2016; 17


    Phage genome analysis is a rapidly growing field. Recurrent obstacles include software access and usability, as well as genome sequences that vary in sequence orientation and/or start position. Here we describe modifications to the phage comparative genomics software program, Phamerator, provide public access to the code, and include instructions for creating custom Phamerator databases. We further report genomic analysis techniques to determine phage packaging strategies and identification of the physical ends of phage genomes.The original Phamerator code can be successfully modified and custom databases can be generated using the instructions we provide. Results of genome map comparisons within a custom database reveal obstacles in performing the comparisons if a published genome has an incorrect complementarity or an incorrect location of the first base of the genome, which are common issues in GenBank-downloaded sequence files. To address these issues, we review phage packaging strategies and provide results that demonstrate identification of the genome start location and orientation using raw sequencing data and software programs such as PAUSE and Consed to establish the location of the physical ends of the genome. These results include determination of exact direct terminal repeats (DTRs) or cohesive ends, or whether phages may use a headful packaging strategy. Phylogenetic analysis using ClustalO and phamily circles in Phamerator demonstrate that the large terminase gene can be used to identify the phage packaging strategy and thereby aide in identifying the physical ends of the genome.Using available online code, the Phamerator program can be customized and utilized to generate databases with individually selected genomes. These databases can then provide fruitful information in the comparative analysis of phages. Researchers can identify packaging strategies and physical ends of phage genomes using raw data from high-throughput sequencing in conjunction with phylogenetic analyses of large terminase proteins and the use of custom Phamerator databases. We promote publication of phage genomes in an orientation consistent with the physical structure of the phage chromosome and provide guidance for determining this structure.

    View details for DOI 10.1186/s12864-016-3018-2

    View details for Web of Science ID 000384980300001

    View details for PubMedID 27561606

    View details for PubMedCentralID PMC5000459

  • Characterization of Five Novel Brevibacillus Bacteriophages and Genomic Comparison of Brevibacillus Phages PLOS ONE Berg, J. A., Merrill, B. D., Crockett, J. T., Esplin, K. P., Evans, M. R., Heaton, K. E., Hilton, J. A., Hyde, J. R., McBride, M. S., Schouten, J. T., Simister, A. R., Thurgood, T. L., Ward, A. T., Breakwell, D. P., Hope, S., Grose, J. H. 2016; 11 (6)


    Brevibacillus laterosporus is a spore-forming bacterium that causes a secondary infection in beehives following European Foulbrood disease. To better understand the contributions of Brevibacillus bacteriophages to the evolution of their hosts, five novel phages (Jenst, Osiris, Powder, SecTim467, and Sundance) were isolated and characterized. When compared with the five Brevibacillus phages currently in NCBI, these phages were assigned to clusters based on whole genome and proteome synteny. Powder and Osiris, both myoviruses, were assigned to the previously described Jimmer-like cluster. SecTim467 and Jenst, both siphoviruses, formed a novel phage cluster. Sundance, a siphovirus, was assigned as a singleton phage along with the previously isolated singleton, Emery. In addition to characterizing the basic relationships between these phages, several genomic features were observed. A motif repeated throughout phages Jenst and SecTim467 was frequently upstream of genes predicted to function in DNA replication, nucleotide metabolism, and transcription, suggesting transcriptional co-regulation. In addition, paralogous gene pairs that encode a putative transcriptional regulator were identified in four Brevibacillus phages. These paralogs likely evolved to bind different DNA sequences due to variation at amino acid residues predicted to bind specific nucleotides. Finally, a putative transposable element was identified in SecTim467 and Sundance that carries genes homologous to those found in Brevibacillus chromosomes. Remnants of this transposable element were also identified in phage Jenst. These discoveries provide a greater understanding of the diversity of phages, their behavior, and their evolutionary relationships to one another and to their host. In addition, they provide a foundation with which further Brevibacillus phages can be compared.

    View details for DOI 10.1371/journal.pone.0156838

    View details for Web of Science ID 000377824800025

    View details for PubMedID 27304881

    View details for PubMedCentralID PMC4909266

  • Putative type 1 thymidylate synthase and dihydrofolate reductase as signature genes of a novel bastille-like group of phages in the subfamily Spounavirinae BMC GENOMICS Asare, P. T., Jeong, T., Ryu, S., Klumpp, J., Loessner, M. J., Merrill, B. D., Kim, K. 2015; 16


    Spounavirinae viruses have received an increasing interest as tools for the control of harmful bacteria due to their relatively broad host range and strictly virulent phenotype.In this study, we collected and analyzed the complete genome sequences of 61 published phages, either ICTV-classified or candidate members of the Spounavirinae subfamily of the Myoviridae. A set of comparative analyses identified a distinct, recently proposed Bastille-like phage group within the Spounavirinae. More importantly, type 1 thymidylate synthase (TS1) and dihydrofolate reductase (DHFR) genes were shown to be unique for the members of the proposed Bastille-like phage group, and are suitable as molecular markers. We also show that the members of this group encode beta-lactamase and/or sporulation-related SpoIIIE homologs, possibly questioning their suitability as biocontrol agents.We confirm the creation of a new genus--the "Bastille-like group"--in Spounavirinae, and propose that the presence of TS1- and DHFR-encoding genes could serve as signatures for the new Bastille-like group. In addition, the presence of metallo-beta-lactamase and/or SpoIIIE homologs in all members of Bastille-like group phages makes questionable their suitability for use in biocontrol.

    View details for DOI 10.1186/s12864-015-1757-0

    View details for Web of Science ID 000359201700001

    View details for PubMedID 26250905

    View details for PubMedCentralID PMC4528723

  • Genome Sequences of Five Additional Brevibacillus laterosporus Bacteriophages. Genome announcements Merrill, B. D., Berg, J. A., Graves, K. A., Ward, A. T., Hilton, J. A., Wake, B. N., Grose, J. H., Breakwell, D. P., Burnett, S. H. 2015; 3 (5)


    Brevibacillus laterosporus has been isolated from many different environments, including beehives, and produces compounds that are toxic to many organisms. Five B. laterosporus phages have been isolated previously. Here, we announce five additional phages that infect this bacterium, including the first B. laterosporus siphoviruses to be discovered.

    View details for DOI 10.1128/genomeA.01146-15

    View details for PubMedID 26494658

    View details for PubMedCentralID PMC4616168

  • Correction for Sheflo et al., Complete Genome Sequences of Five Brevibacillus laterosporus Bacteriophages. Genome announcements Sheflo, M. A., Gardner, A. V., Merrill, B. D., Fisher, J. N., Lunt, B. L., Breakwell, D. P., Grose, J. H., Burnett, S. H. 2015; 3 (5)

    View details for DOI 10.1128/genomeA.01113-15

    View details for PubMedID 26430035

    View details for PubMedCentralID PMC4591307

  • The Genomes, Proteomes, and Structures of Three Novel Phages That Infect the Bacillus cereus Group and Carry Putative Virulence Factors JOURNAL OF VIROLOGY Grose, J. H., Belnap, D. M., Jensen, J. D., Mathis, A. D., Prince, J. T., Merrill, B. D., Burnett, S. H., Breakwell, D. P. 2014; 88 (20): 11846-11860


    This article reports the results of studying three novel bacteriophages, JL, Shanette, and Basilisk, which infect the pathogen Bacillus cereus and carry genes that may contribute to its pathogenesis. We analyzed host range and superinfection ability, mapped their genomes, and characterized phage structure by mass spectrometry and transmission electron microscopy (TEM). The JL and Shanette genomes were 96% similar and contained 217 open reading frames (ORFs) and 220 ORFs, respectively, while Basilisk has an unrelated genome containing 138 ORFs. Mass spectrometry revealed 23 phage particle proteins for JL and 15 for Basilisk, while only 11 and 4, respectively, were predicted to be present by sequence analysis. Structural protein homology to well-characterized phages suggested that JL and Shanette were members of the family Myoviridae, which was confirmed by TEM. The third phage, Basilisk, was similar only to uncharacterized phages and is an unrelated siphovirus. Cryogenic electron microscopy of this novel phage revealed a T=9 icosahedral capsid structure with the major capsid protein (MCP) likely having the same fold as bacteriophage HK97 MCP despite the lack of sequence similarity. Several putative virulence factors were encoded by these phage genomes, including TerC and TerD involved in tellurium resistance. Host range analysis of all three phages supports genetic transfer of such factors within the B. cereus group, including B. cereus, B. anthracis, and B. thuringiensis. This study provides a basis for understanding these three phages and other related phages as well as their contributions to the pathogenicity of B. cereus group bacteria. Importance: The Bacillus cereus group of bacteria contains several human and plant pathogens, including B. cereus, B. anthracis, and B. thuringiensis. Phages are intimately linked to the evolution of their bacterial hosts and often provide virulence factors, making the study of B. cereus phages important to understanding the evolution of pathogenic strains. Herein we provide the results of detailed study of three novel B. cereus phages, two highly related myoviruses (JL and Shanette) and an unrelated siphovirus (Basilisk). The detailed characterization of host range and superinfection, together with results of genomic, proteomic, and structural analyses, reveal several putative virulence factors as well as the ability of these phages to infect different pathogenic species.

    View details for DOI 10.1128/JVI.01364-14

    View details for Web of Science ID 000342688000020

    View details for PubMedID 25100842

    View details for PubMedCentralID PMC4178739

  • Characterization of Paenibacillus larvae bacteriophages and their genomic relationships to firmicute bacteriophages BMC GENOMICS Merrill, B. D., Grose, J. H., Breakwell, D. P., Burnett, S. H. 2014; 15


    Paenibacillus larvae is a Firmicute bacterium that causes American Foulbrood, a lethal disease in honeybees and is a major source of global agricultural losses. Although P. larvae phages were isolated prior to 2013, no full genome sequences of P. larvae bacteriophages were published or analyzed. This report includes an in-depth analysis of the structure, genomes, and relatedness of P. larvae myoviruses Abouo, Davis, Emery, Jimmer1, Jimmer2, and siphovirus phiIBB_Pl23 to each other and to other known phages.P. larvae phages Abouo, Davies, Emery, Jimmer1, and Jimmer2 are myoviruses with ~50 kbp genomes. The six P. larvae phages form three distinct groups by dotplot analysis. An annotated linear genome map of these six phages displays important identifiable genes and demonstrates the relationship between phages. Sixty phage assembly or structural protein genes and 133 regulatory or other non-structural protein genes were identifiable among the six P. larvae phages. Jimmer1, Jimmer2, and Davies formed stable lysogens resistant to superinfection by genetically similar phages. The correlation between tape measure protein gene length and phage tail length allowed identification of co-isolated phages Emery and Abouo in electron micrographs. A Phamerator database was assembled with the P. larvae phage genomes and 107 genomes of Firmicute-infecting phages, including 71 Bacillus phages. Phamerator identified conserved domains in 1,501 of 6,181 phamilies (only 24.3%) encoded by genes in the database and revealed that P. larvae phage genomes shared at least one phamily with 72 of the 107 other phages. The phamily relationship of large terminase proteins was used to indicate putative DNA packaging strategies. Analyses from CoreGenes, Phamerator, and electron micrograph measurements indicated Jimmer1, Jimmer2, Abouo and Davies were related to phages phiC2, EJ-1, KC5a, and AQ113, which are small-genome myoviruses that infect Streptococcus, Lactobacillus, and Clostridium, respectively.This paper represents the first comparison of phage genomes in the Paenibacillus genus and the first organization of P. larvae phages based on sequence and structure. This analysis provides an important contribution to the field of bacteriophage genomics by serving as a foundation on which to build an understanding of the natural predators of P. larvae.

    View details for DOI 10.1186/1471-2164-15-745

    View details for Web of Science ID 000341790000001

    View details for PubMedID 25174730

    View details for PubMedCentralID PMC4168068

  • Genome Sequences of Three Novel Bacillus cereus Bacteriophages. Genome announcements Grose, J. H., Jensen, J. D., Merrill, B. D., Fisher, J. N., Burnett, S. H., Breakwell, D. P. 2014; 2 (1)


    The Bacillus cereus group is an assemblage of highly related firmicute bacteria that cause a variety of diseases in animals, including insects and humans. We announce three high-quality, complete genome sequences of bacteriophages we isolated from soil samples taken at the bases of fruit trees in Utah County, Utah. While two of the phages (Shanette and JL) are highly related myoviruses, the bacteriophage Basilisk is a siphovirus.

    View details for DOI 10.1128/genomeA.01118-13

    View details for PubMedID 24459255

    View details for PubMedCentralID PMC3900887

  • Genome sequences of five b1 subcluster mycobacteriophages. Genome announcements Breakwell, D. P., Barrus, E. Z., Benedict, A. B., Brighton, A. K., Fisher, J. N., Gardner, A. V., Kartchner, B. J., Ladle, K. C., Lunt, B. L., Merrill, B. D., Morrell, J. D., Burnett, S. H., Grose, J. H. 2013; 1 (6)


    Mycobacteriophages infect members of the Mycobacterium genus in the phylum Actinobacteria and exhibit remarkable diversity. Genome analysis groups the thousands of known mycobacteriophages into clusters, of which the B1 subcluster is currently the third most populous. We report the complete genome sequences of five additional members of the B1 subcluster.

    View details for DOI 10.1128/genomeA.00968-13

    View details for PubMedID 24285667

    View details for PubMedCentralID PMC3869329

  • Complete Genome Sequences of Five Paenibacillus larvae Bacteriophages. Genome announcements Sheflo, M. A., Gardner, A. V., Merrill, B. D., Fisher, J. N., Lunt, B. L., Breakwell, D. P., Grose, J. H., Burnett, S. H. 2013; 1 (6)


    Paenibacillus larvae is a pathogen of honeybees that causes American foulbrood (AFB). We isolated bacteriophages from soil containing bee debris collected near beehives in Utah. We announce five high-quality complete genome sequences, which represent the first completed genome sequences submitted to GenBank for any P. larvae bacteriophage.

    View details for DOI 10.1128/genomeA.00668-13

    View details for PubMedID 24233582

    View details for PubMedCentralID PMC3828306