Incorporating patient, nursing and environmental factors into antimicrobial stewardship: effects of simplifying treatment from cefuroxime to ceftriaxone.

AIM: Our antimicrobial guidelines (AGs) were changed in 2021 to recommend once-daily ceftriaxone in place of three-times-daily cefuroxime as preferred cephalosporin. This analysis sought to assess the effects of this on incidence of Clostridioides difficile infection (CDI), third-generation cephalosporin-resistant Enterobacterales (3GCR-E) and resource utilisation. METHOD: Before and after analysis of 30-day CDI and 3GCR-E incidence following receipt of cefuroxime/ceftriaxone pre- and post-AG change. Total nursing time and waste production relating to cefuroxime/ceftriaxone delivery were calculated pre- and post-change. RESULTS: CDI incidence was 0.6% pre- and 1.0% post-change (adjusted odds ratio [aOR] 1.44, p=0.07) and 3GCR-E incidence 3.5% and 3.1% (aOR 0.90, p=0.33). Mean per-quarter estimated nursing administration time decreased from 2,065 to 1,163 hours (902 nurse-hour reduction) and antibiotic-related waste generation from 1,131kg to 748kg (383kg reduction). Overall days of therapy per-quarter of cefuroxime/ceftriaxone were unchanged between periods. CONCLUSION: This simplification of our AG from a three-times-daily to a once-daily antibiotic resulted in considerable savings for our hospital (roughly 1.7 full-time equivalent nurses and over a tonne of waste yearly), with no significant increases in CDI or 3GCR-E. The impact of dosing schedules on non-antibiotic-spectrum factors, such as nursing time and resource usage, is worthy of consideration when designing AGs.

Global phylogenetic analysis of soybean dwarf virus isolates and their associations with aphid vectors and severe disease in soybeans.

Soybean dwarf virus (SbDV) was first described in Japan as an agent of severe soybean disease transmitted by the foxglove aphid, Aulacorthum solani, with separable yellowing (Y) and dwarfing (D) strains. SbDV of both Y and D genotypes were later documented in other countries. For three decades, SbDV isolates were assessed to evaluate risk to U.S. soybean production. U.S. SbDV isolates were transmitted by the pea aphid Acyrthosiphum pisum and showed limited disease in soybeans, suggesting it was not a major threat to U.S. soybean production. Here we report 21 new full-length SbDV genome sequences including those of the originally described Japanese Y and D isolates, isolates from Syria and New Zealand associated with severe disease, and 17 isolates from U.S. field collections. Using these new full-length genomes, a global phylogeny was assembled and used to revisit risk assessment based on sequence similarities, isolate pathogenicity, and vector specificity.

Introducing the Bacterial and Viral Bioinformatics Resource Center (BV-BRC): a resource combining PATRIC, IRD and ViPR.

The National Institute of Allergy and Infectious Diseases (NIAID) established the Bioinformatics Resource Center (BRC) program to assist researchers with analyzing the growing body of genome sequence and other omics-related data. In this report, we describe the merger of the PAThosystems Resource Integration Center (PATRIC), the Influenza Research Database (IRD) and the Virus Pathogen Database and Analysis Resource (ViPR) BRCs to form the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) https://www.bv-brc.org/. The combined BV-BRC leverages the functionality of the bacterial and viral resources to provide a unified data model, enhanced web-based visualization and analysis tools, bioinformatics services, and a powerful suite of command line tools that benefit the bacterial and viral research communities.

Soybean Aphid (Hemiptera: Aphididae) Feeding Behavior is Largely Unchanged by Soybean Mosaic Virus but Significantly Altered by the Beetle-Transmitted Bean Pod Mottle Virus.

The soybean aphid (Aphis glycines Matsumura) is an economically important invasive pest of soybean. In addition to damage caused by soybean aphid feeding on the phloem sap, this insect also transmits many plant viruses, including soybean mosaic virus (SMV). Previous work has shown that plant viruses can change plant host phenotypes to alter the behavior of their insect vectors to promote virus spread, known as the vector manipulation hypothesis. In this study, we used electropenetography (EPG) to examine the effects of two plant viruses on soybean aphid feeding behavior: SMV, which is transmitted by many aphid species including the soybean aphid, and bean pod mottle virus (BPMV), which is transmitted by chrysomelid and some coccinellid beetles but not aphids. These two viruses often co-occur in soybean production and can act synergistically. Surprisingly, our results showed little to no effect of SMV on soybean aphid feeding behaviors measured by EPG, but profound differences were observed in aphids feeding on BPMV-infected plants. Aphids took longer to find the vascular bundle of BPMV-infected plants, and once found, spent more time entering and conditioning the phloem than ingesting phloem sap. Interestingly, these observed alterations are similar to those of aphids feeding on insect-resistant soybean plants. The cause of these changes in feeding behavior is not known, and how they impact virus transmission and soybean aphid populations in the field will require further study.

Coat protein expression strategy of maize rayado fino virus and evidence for requirement of CP1 for leafhopper transmission.

Marafiviruses, including maize rayado fino virus (MRFV) and oat blue dwarf virus (OBDV), encode two carboxy co-terminal coat proteins, CP1 and CP2, which encapsidate the genome to form icosahedral virions. While CP2 expression is expected to be solely driven from a second start codon of a subgenomic RNA under a marafibox promoter sequence, the larger CP1 with an in-frame N-terminal extension relative to CP2 could potentially be expressed either by proteolytic release from the MRFV polyprotein or from subgenomic RNA translation. We examined MRFV CP expression strategy with a series of mutations in the CP coding region and identified mutants viable and nonviable for systemic plant infection. Polyprotein expression of MRFV CP1 was minimal. Mutants blocking CP2 expression failed to establish systemic infection, while mutants depleted in CP1 exhibited systemic infection and formation of virus-like particles but lost leafhopper transmissibility, indicating that CP1 is required for leafhopper transmission.

Critical residues for proteolysis activity of maize chlorotic dwarf virus (MCDV) 3C-like protease and comparison of activity of orthologous waikavirus proteases.

Maize chlorotic dwarf virus (MCDV) encodes a 3C-like protease that cleaves the N-terminal polyprotein (R78) as previously demonstrated. Here, we examined amino acid residues required for catalytic activity of the protease, including those in the predicted catalytic triad, amino acid residues H2667, D2704, and C2798, as well as H2817 hypothesized to be important in substrate binding. These and other residues were targeted for mutagenesis and tested for proteolytic cleavage activity on the N-terminal 78 kDa MCDV-S polyprotein substrate to identify mutants that abolished catalytic activity. Mutations that altered the predicted catalytic triad residues and H2817 disrupted MCDV-S protease activity, as did mutagenesis of a conserved tyrosine residue, Y2774. The protease activity and R78 cleavage of orthologs from divergent MCDV isolates MCDV-Tn and MCDV-M1, and other waikavirus species including rice tungro spherical virus (RTSV) and bellflower vein chlorosis virus (BVCV) were also examined.

Sweat Equity: Student Scholarships in Aotearoa New Zealand's Universities.

This paper responds to calls from past and present students to increase the value of postgraduate scholarships in Aotearoa New Zealand. Here we provide context for understanding the scholarship landscape in Aotearoa, including how scholarships are understood in relation to dominant neoliberal framings of higher education and persistent inequities within the sector. We present data which provides insight into the current inequities in Summer, Masters and PhD scholarship values. The average value of PhD scholarships has remained stagnant between 2011 and 2019 resulting in the average being $11,238 less than the Living Wage in 2019. We show that the average length of time full-time PhD students take to complete their doctorates exceeds the three-year tenure of scholarships. We argue the status-quo of low scholarships, supplemented by postgraduate 'sweat', excludes people from participating in postgraduate education, preventing them and their communities from realising the public benefits that such an education can produce. We suggest that these inadequacies could be addressed through (1) raising Summer, Masters and PhD scholarships to the living wage; (2) extending tenure of PhD scholarships; and (3) reinstating the postgraduate student allowance. Supplementary Information: The online version contains supplementary material available at 10.1007/s40841-022-00244-5.

Transcriptome of the Maize Leafhopper (Dalbulus maidis) and Its Transcriptional Response to Maize Rayado Fino Virus (MRFV), Which It Transmits in a Persistent, Propagative Manner.

The corn leafhopper (Dalbulus maidis) is an important vector of maize rayado fino virus (MRFV), a positive-strand RNA (+ssRNA) marafivirus which it transmits in a persistent propagative manner. The interaction of D. maidis with MRFV, including infection of the insect and subsequent transmission to new plants, is not well understood at the molecular level. To examine the leafhopper-virus interaction, a D. maidis transcriptome was assembled and differences in transcript abundance between virus-exposed and naive D. maidis were examined at two time points (4 h and 7 days) post exposure to MRFV. The D. maidis transcriptome contained 56,116 transcripts generated from 1,727,369,026 100-nt paired-end reads from whole adult insects. The transcriptome of D. maidis shared highest identity and most orthologs with the leafhopper Graminella nigrifrons (65% of transcripts had matches with E values of <10-5) versus planthoppers Sogatella furcifera (with 23% of transcript matches below the E value cutoff) and Peregrinus maidis (with 21% transcript matches below the E value cutoff), as expected based on taxonomy. D. maidis expressed genes in the Toll, Imd, and Jak/Stat insect immune signaling pathways, RNA interference (RNAi) pathway genes, prophenoloxidase-activating system pathways, and immune recognition protein-encoding genes such as peptidoglycan recognition proteins (PGRPs), antimicrobial peptides, and other effectors. Statistical analysis (performed by R package DESeq2) identified 72 transcripts at 4 h and 67 at 7 days that were significantly responsive to MRFV exposure. Genes expected to be favorable for virus propagation, such as protein synthesis-related genes and genes encoding superoxide dismutase, were significantly upregulated after MRFV exposure. IMPORTANCE The transcriptome of the corn leafhopper, D. maidis, revealed conserved biochemical pathways for immunity and discovered transcripts responsive to MRFV-infected plants at two time points, providing a basis for functional identification of genes that either limit or promote the virus-vector interaction. Compared to other hopper species and the propagative plant viruses they transmit, D. maidis shared 15 responsive transcripts with S. furcifera (to southern rice black-streaked dwarf virus [SRBSDV]), one with G. nigrifrons (to maize fine streak virus [MFSV]), and one with P. maidis (to maize mosaic virus [MMV]), but no virus-responsive transcripts identified were shared among all four hopper vector species.

Simultaneous gene expression and multi-gene silencing in Zea mays using maize dwarf mosaic virus.

BACKGROUND: Maize dwarf mosaic virus (MDMV), a member of the genus Potyvirus, infects maize and is non-persistently transmitted by aphids. Several plant viruses have been developed as tools for gene expression and gene silencing in plants. The capacity of MDMV for both gene expression and gene silencing were examined. RESULTS: Infectious clones of an Ohio isolate of MDMV, MDMV OH5, were obtained, and engineered for gene expression only, and for simultaneous marker gene expression and virus-induced gene silencing (VIGS) of three endogenous maize target genes. Single gene expression in single insertion constructs and simultaneous expression of green fluorescent protein (GFP) and silencing of three maize genes in a double insertion construct was demonstrated. Constructs with GFP inserted in the N-terminus of HCPro were more stable than those with insertion at the N-terminus of CP in our study. Unexpectedly, the construct with two insertion sites also retained insertions at a higher rate than single-insertion constructs. Engineered MDMV expression and VIGS constructs were transmissible by aphids (Rhopalosiphum padi). CONCLUSIONS: These results demonstrate that MDMV-based vector can be used as a tool for simultaneous gene expression and multi-gene silencing in maize.

Maize Yellow Mosaic Virus Interacts with Maize Chlorotic Mottle Virus and Sugarcane Mosaic Virus in Mixed Infections, But Does Not Cause Maize Lethal Necrosis.

A maize-infecting polerovirus, variously named maize yellow dwarf virus RMV2 (MYDV RMV2), MYDV-like, and maize yellow mosaic virus (MaYMV), is frequently found in mixed infections in plants also infected with maize chlorotic mottle virus (MCMV) and sugarcane mosaic virus (SCMV), known to synergistically cause maize lethal necrosis (MLN). MaYMV was discovered in deep sequencing studies precipitated by recent MLN emergence and is prevalent at global locations with MLN, but its role in or contribution to disease was not known. We examined how MaYMV impacted disease development in mixed infections with MCMV, SCMV, and both MCMV and SCMV compared with mock-inoculated plants. Results demonstrated that MaYMV symptoms included stunting as well as leaf reddening in single and mixed infections. MaYMV did not recapitulate MLN synergistic disease in double infections in which either MCMV or SCMV was missing (MaYMV + MCMV or MaYMV + SCMV), but did significantly enhance stunting in mixed infections and suppressed titers of both MCMV and SCMV in double infections. Interestingly, MaYMV strongly suppressed the SCMV-induced titer increase of MCMV in triple infections, but MLN symptoms still occurred with the reduced MCMV titer. These data indicate the potential disease impact of this newly discovered ubiquitous maize virus, alone and in the context of MLN.

Seafloor Incubation Experiment with Deep-Sea Hydrothermal Vent Fluid Reveals Effect of Pressure and Lag Time on Autotrophic Microbial Communities.

Depressurization and sample processing delays may impact the outcome of shipboard microbial incubations of samples collected from the deep sea. To address this knowledge gap, we developed a remotely operated vehicle (ROV)-powered incubator instrument to carry out and compare results from in situ and shipboard RNA stable isotope probing (RNA-SIP) experiments to identify the key chemolithoautotrophic microbes and metabolisms in diffuse, low-temperature venting fluids from Axial Seamount. All the incubations showed microbial uptake of labeled bicarbonate primarily by thermophilic autotrophic Epsilonbacteraeota that oxidized hydrogen coupled with nitrate reduction. However, the in situ seafloor incubations showed higher abundances of transcripts annotated for aerobic processes, suggesting that oxygen was lost from the hydrothermal fluid samples prior to shipboard analysis. Furthermore, transcripts for thermal stress proteins such as heat shock chaperones and proteases were significantly more abundant in the shipboard incubations, suggesting that depressurization induced thermal stress in the metabolically active microbes in these incubations. Together, the results indicate that while the autotrophic microbial communities in the shipboard and seafloor experiments behaved similarly, there were distinct differences that provide new insight into the activities of natural microbial assemblages under nearly native conditions in the ocean.IMPORTANCE Diverse microbial communities drive biogeochemical cycles in Earth's ocean, yet studying these organisms and processes is often limited by technological capabilities, especially in the deep ocean. In this study, we used a novel marine microbial incubator instrument capable of in situ experimentation to investigate microbial primary producers at deep-sea hydrothermal vents. We carried out identical stable isotope probing experiments coupled to RNA sequencing both on the seafloor and on the ship to examine thermophilic, microbial autotrophs in venting fluids from an active submarine volcano. Our results indicate that microbial communities were significantly impacted by the effects of depressurization and sample processing delays, with shipboard microbial communities being more stressed than seafloor incubations. Differences in metabolism were also apparent and are likely linked to the chemistry of the fluid at the beginning of the experiment. Microbial experimentation in the natural habitat provides new insights into understanding microbial activities in the ocean.

First report of cDNA clone-launched infection of maize plants with the polerovirus maize yellow mosaic virus (MaYMV).

An East African isolate of the maize-associated polerovirus, maize yellow mosaic virus (MaYMV) was previously shown to cause leaf reddening on singly infected maize plants (Zea mays). Here we describe the construction of a full-length infectious clone of an East African isolate and, for the first time, show infectivity of clone-derived transcripts in the primary host, maize, through vascular puncture inoculation (VPI), as well as in the dicotyledonous research model plant species, Nicotiana benthamiana, through agrobacterium inoculation. Characteristic leaf reddening symptoms were observed in a subset of maize plants inoculated with clone-derived transcripts, and infection was confirmed by RT-PCR and Northern blot analyses. In N. benthamiana plants, infections were entirely asymptomatic even at high virus titers, as was also reported for the cloned Chinese isolate. In this study, however, we demonstrated that N. benthamiana can serve as a clone launching platform for maize infection, as VPI of sap of infected N. benthamiana plants into maize kernels resulted in infection and the typical red leaf symptoms. We further demonstrated that the cloned East African isolate virus was aphid transmissible to maize, with experimental transmission rates up to 97 %, comparable to that shown previously for the native virus. Interestingly, our data additionally showed a definitive correlation of leaf reddening symptoms with increased expression of chalcone synthase, thus suggesting upregulation of the flavonoid biosynthesis pathway as the molecular basis for symptom induction in maize. As the first report of experimental infection of maize with transcripts from a cloned polerovirus, this work constitutes a breakthrough for studies on molecular maize-polerovirus-aphid interactions.

Complex subsurface hydrothermal fluid mixing at a submarine arc volcano supports distinct and highly diverse microbial communities.

Hydrothermally active submarine volcanoes are mineral-rich biological oases contributing significantly to chemical fluxes in the deep sea, yet little is known about the microbial communities inhabiting these systems. Here we investigate the diversity of microbial life in hydrothermal deposits and their metagenomics-inferred physiology in light of the geological history and resulting hydrothermal fluid paths in the subsurface of Brothers submarine volcano north of New Zealand on the southern Kermadec arc. From metagenome-assembled genomes we identified over 90 putative bacterial and archaeal genomic families and nearly 300 previously unknown genera, many potentially endemic to this submarine volcanic environment. While magmatically influenced hydrothermal systems on the volcanic resurgent cones of Brothers volcano harbor communities of thermoacidophiles and diverse members of the superphylum "DPANN," two distinct communities are associated with the caldera wall, likely shaped by two different types of hydrothermal circulation. The communities whose phylogenetic diversity primarily aligns with that of the cone sites and magmatically influenced hydrothermal systems elsewhere are characterized predominately by anaerobic metabolisms. These populations are probably maintained by fluids with greater magmatic inputs that have interacted with different (deeper) previously altered mineral assemblages. However, proximal (a few meters distant) communities with gene-inferred aerobic, microaerophilic, and anaerobic metabolisms are likely supported by shallower seawater-dominated circulation. Furthermore, mixing of fluids from these two distinct hydrothermal circulation systems may have an underlying imprint on the high microbial phylogenomic diversity. Collectively our results highlight the importance of considering geologic evolution and history of subsurface processes in studying microbial colonization and community dynamics in volcanic environments.

Building a global genomics observatory: Using GEOME (the Genomic Observatories Metadatabase) to expedite and improve deposition and retrieval of genetic data and metadata for biodiversity research.

Genetic data represent a relatively new frontier for our understanding of global biodiversity. Ideally, such data should include both organismal DNA-based genotypes and the ecological context where the organisms were sampled. Yet most tools and standards for data deposition focus exclusively either on genetic or ecological attributes. The Genomic Observatories Metadatabase (GEOME: geome-db.org) provides an intuitive solution for maintaining links between genetic data sets stored by the International Nucleotide Sequence Database Collaboration (INSDC) and their associated ecological metadata. GEOME facilitates the deposition of raw genetic data to INSDCs sequence read archive (SRA) while maintaining persistent links to standards-compliant ecological metadata held in the GEOME database. This approach facilitates findable, accessible, interoperable and reusable data archival practices. Moreover, GEOME enables data management solutions for large collaborative groups and expedites batch retrieval of genetic data from the SRA. The article that follows describes how GEOME can enable genuinely open data workflows for researchers in the field of molecular ecology.

Temperature-gradient incubation isolates multiple competitive species from a single environmental sample.

High-throughput sequencing has allowed culture-independent investigation into a wide variety of microbiomes, but sequencing studies still require axenic culture experiments to determine ecological roles, confirm functional predictions and identify useful compounds and pathways. We have developed a new method for culturing and isolating multiple microbial species with overlapping ecological niches from a single environmental sample, using temperature-gradient incubation. This method was more effective than standard serial dilution-to-extinction at isolating methanotrophic bacteria. It also highlighted discrepancies between culture-dependent and -independent techniques; 16S rRNA gene amplicon sequencing of the same sample did not accurately reflect cultivatable strains using this method. We propose that temperature-gradient incubation could be used to separate out and study previously 'unculturable' strains, which co-exist in both natural and artificial environments.

Engineering Maize rayado fino virus for virus-induced gene silencing.

Maize rayado fino virus (MRFV) is the type species of the genus Marafivirus in the family Tymoviridae. It infects maize (Zea mays), its natural host, to which it is transmitted by leafhoppers including Dalbulus maidis and Graminella nigrifrons in a persistent-propagative manner. The MRFV monopartite RNA genome encodes a precursor polyprotein that is processed into replication-associated proteins. The genome is encapsidated by two carboxy co-terminal coat proteins, CP1 and CP2. Cloned MRFV can be readily transmitted to maize by vascular puncture inoculation (VPI), and such virus systems that can be used in maize are valuable to examine plant gene function by gene silencing. However, the efficacy of marafiviruses for virus-induced gene silencing (VIGS) has not been investigated to date. To this end, MRFV genomic loci were tested for their potential to host foreign insertions without attenuating virus viability. This was done using infectious MRFV clones engineered to carry maize phytoene desaturase (PDS) gene fragments (ZmPDS) at various genomic regions. Several MRFV-PDS constructs were generated and tested for infectivity and VIGS in maize. This culminated in identification of the helicase/polymerase (HEL/POL) junction as a viable insertion site that preserved virus infectivity, as well as several sites at which sequence insertion caused loss of virus infectivity. Transcripts of viable constructs, carrying PDS inserts in the HEL/POL junction, induced stable local and systemic MRFV symptoms similar to wild-type infections, and triggered PDS VIGS initiating in veins and spreading into both inoculated and noninoculated leaves. These constructs were remarkably stable, retaining inserted sequences for at least four VPI passages while maintaining transmissibility by D. maidis. Our data thus identify the MRFV HEL/POL junction as an insertion site useful for gene silencing in maize.

A Recently Discovered Maize Polerovirus Causes Leaf Reddening Symptoms in Several Maize Genotypes and is Transmitted by Both the Corn Leaf Aphid (Rhopalosiphum maidis) and the Bird Cherry-Oat Aphid (Rhopalosiphum padi).

A maize-infecting polerovirus variously named maize yellow dwarf virus RMV2 (MYDV-RMV2) and maize yellow mosaic virus (MaYMV) has been discovered and previously described in East Africa, Asia, and South America. It was identified in virus surveys in these locations instigated by outbreaks of maize lethal necrosis (MLN), known to be caused by coinfections of unrelated maize chlorotic mottle virus (MCMV) and any of several maize-infecting potyviruses, and was often found in coinfections with MLN viruses. Although sequenced in many locations globally and named for symptoms of related or coinfecting viruses, and with an infectious clone reported that experimentally infects Nicotiana benthamiana, rudimentary biological characterization of MaYMV in maize, including insect vector(s) and symptoms in single infections, has not been reported until now. We report isolation from other viruses and leaf tip reddening symptoms in several maize genotypes, along with transmission by two aphids, Rhopalosiphum padi and Rhopalosiphum maidis. This is important information distinguishing this virus and demonstrating that in single infections it causes symptoms distinct from those of potyviruses or MCMV in maize, and identification of vectors provides an important framework for determination of potential disease impact and management.

Fundamental Aspects of Plant Viruses-An Overview on Focus Issue Articles.

Given the importance of and rapid research progress in plant virology in recent years, this Focus Issue broadly emphasizes advances in fundamental aspects of virus infection cycles and epidemiology. This Focus Issue comprises three review articles and 18 research articles. The research articles cover broad research areas on the identification of novel viruses, the development of detection methods, reverse genetics systems and functional genomics for plant viruses, vector and seed transmission studies, viral population studies, virus-virus interactions and their effect on vector transmission, and management strategies of viral diseases. The three review articles discuss recent developments in application of prokaryotic clustered regularly interspaced short palindromic repeats/CRISPR-associated genes (CRISPR/Cas) technology for plant virus resistance, mixed viral infections and their role in disease synergism and cross-protection, and viral transmission by whiteflies. The following briefly summarizes the articles appearing in this Focus Issue.

Maize lethal necrosis viruses and other maize viruses in Rwanda.

Maize lethal necrosis (MLN) is emergent in East Africa, first reported in 2011 in Kenya, and is devastating to maize production in the region. MLN is caused by coinfection of maize with the emergent maize chlorotic mottle virus (MCMV) and any of several maize-infecting potyviruses endemic in East Africa and worldwide. Here, we examined the distribution of MCMV and sugarcane mosaic virus (SCMV), the major viruses contributing to MLN in Rwanda. These and other viruses in maize across Rwanda were further characterized by deep sequencing. When identified, MCMV had high titres and minimal sequence variability, whereas SCMV showed moderate titres and high sequence variability. Deep sequencing also identified maize streak virus and other maize-associated viruses, including a previously described polerovirus, maize yellow mosaic virus, and barley yellow dwarf virus, diverse maize-associated totiviruses, maize-associated pteridovirus, Zea mays chrysovirus 1, and a maize-associated betaflexivirus. Detection of each virus was confirmed in maize samples by reverse transcription polymerase chain reaction.