bluuebunny/crossref_metadata_2025_split huggingface dataset:
A17 The effect of intra-host evolution of HIV-2 capsid on disease progression
Authors: Boswell M T , Palm A , Karlson S , Månsson F , Norrgren H , Jansson M , Medstrand P , Rowland-Jones S , Esbjornsson J 
Published: August 2019

Abstract
The human immunodeficiency virus type 2 (HIV-2) is an important cause of acquired immune deficiency syndrome (AIDS) in West Africa. The virus started circulating in humans around 1938 and has spread predominantly within West Africa with an estimated 1–2 million people being infected today. Compared with the pandemic HIV-1, HIV-2 infected people have longer AIDS-free survival times, higher CD4+ counts and lower risk of vertical and horizontal transmission. Approximately 35 per cent of HIV-2 infected individuals are classified as so-called long-term non-progressors with undetectable viral loads and limited disease progression after 10 years of follow-up. It has been shown that HIV-2 is more sensitive to the host restriction factor TRIM5α when compared with HIV-1, and this has been linked to conformational changes in the retroviral capsid. TRIM5α binds at the interface between three capsid hexamers, initiates early uncoating and proteasomal degradation. TRIM5 genotype has shown only modest effects on HIV-1 disease outcomes. HIV-2 capsid sequences bearing a specific poly-proline motif have been associated with lower viral loads and presentation of protective HLA I-restricted epitopes. The major aims of this study were to (1) determine HIV-2 capsid intra-host evolutionary rates and (2) identify residues that are affected by positive selection and that can be linked to HIV-2 viral load and disease progression in conjunction with TRIM5 genotype. The Guinea-Bissau Police cohort is unique, with decades of relatively frequent follow-up. One hundred and sixty-five patients were included for genotyping of TRIM5, 62 females and 103 males. Median age at enrolment was 52.6 years (range 30–87) and 7.9 per cent of patients had a CD4 percentage < 15 per cent at enrolment. Six of these individuals were included for amplification of HIV-2 capsid from longitudinally collected samples. Viral RNA was extracted from stored blood plasma samples and capsid of the circulating viral quasispecies was amplified, cloned, and sequenced, as previously described. Bayesian analysis will be used to determine intra-host evolutionary rates, dN/dS ratios and how these parameters associate with disease progression and TRIM5 genotype.
A29 Genetic heterogeneity of influenza A (H3N2) viruses in the United Kingdom, 2016–8
Authors: Galiano M , Miah S , Akinbami O , Gonzalez Gonoggia S , Ellis J , Zambon M 
Published: August 2019

Abstract
For the last four influenza seasons in the UK, genetic characterization of seasonal influenza viruses has shifted from single hemagglutinin (HA) and neuraminidase (NA) genes to whole genome (WG) analysis, allowing for better insight into the evolutionary dynamics of this virus. Sequences (WG or HA/NA) were obtained from >900A (H3N2) viruses sampled in the UK during influenza seasons 2016/7 and 2017/8 and the inter-seasonal period. Viral RNA was extracted from clinical samples and amplified using a multi-segment RT-PCR. Amplicons were sequenced using Nextera library preparation for Illumina MiSeq sequencing. Sequence data ????were processed using BAM-SAM tools and PHE in-house scripts. Phylogenetic analysis of the HA gene indicates that they belong to genetic group 3C.2a, which has circulated since 2014. Season 2016/7 was characterized by the emergence of cluster 3C.2a.1; further genetic heterogeneity was seen with 6 new subclusters within 3C.2a and 3C.2a.1, with predominance of those characterized by amino acid changes N121K and S144K (3C.2a) and N121K, N171K, I406K, G484E (3C.2a.1). The NA genes clustered with a similar topology to the HA. Season 2017/8 was characterized by persistence of some clades from previous season with further diversification. Three of the 3C.2a clusters continued to circulate, with predominance of clade showing T131K, R142K, and R261Q (clade 3C.2a.2). The majority of HA sequences in 3C.2a1 fall into a new subcluster which has become predominant within this subgroup, with amino acid changes E62G, K92R, and T135K (3C.2a.1b). The topology of NA and internal gene trees showed evidence of reassortment events occurring at some point between the two seasons, with group 3C.2a2 acquiring NA and some internal genes from 3C.2a1 lineage viruses. The predominance of this group during 2017–8 might be due to fitness advantage related to the new genetic constellation. Emerging viruses from group 3C.3a also have acquired genes from lineage 3C.2a1, which could be the reason for their increased frequency to 20 per cent by the end of season 2017–8. Molecular epidemiology indicates emerging genetic diversity in A(H3N2) viruses during the period of study, leading to co-circulation of variants. The frequency of circulating HA genetic groups was quite variable, with rapidly changing patterns of predominance. Evidence of reassortment events was observed which could be responsible for the rise and predominance of some clades, and might predict the emergence of other variants.
A35 The first laboratory confirmation of chikungunya outbreak in Ethiopia
Authors: Mengesha Tsegaye Mesfin , Tayachew Aadamu , Belay Desalegn , Alemu Abebe , Beyene Berhane 
Published: August 2019

Abstract
Chikungunya is a viral disease (genus Alphavirus) which is transmitted to humans by infected mosquitoes—including Aedes aegypti and A. albopictus. An outbreak of febrile illness, suspected to have been caused by chikungunya, was reported in June 2016 from Dolloado district, Suuf Kebele, in the Somalia regional state of Ethiopia that borders the Mandera county of Kenya where a confirmed chikungunya outbreak was ongoing. Laboratory investigation was carried out to confirm if the outbreak in Ethiopia was caused by Chikungunya virus. Ten serum samples were collected from suspected patients visiting a health center in Suuf Kebel, who were then sent to the Nation laboratory in Ethiopian Public Health Institute. RNA was extracted from the serum samples using QIAgene RNA Mini kit, and PCR detection of dengue, chikungunya, and Zika virus nucleic acid was done using Trioplex Real-time RT-PCR Assay following the protocol from the Center for Disease Control (CDC). The Trioplex Real-time RT-PCR assay, for detection and differentiation of RNA from dengue, Chikungunya and Zika, was provided by CDC as part of the zika emergency preparedness effort. Of the nine samples tested, eight (88.88%) were found to be positive for chikungunya virus nucleic acid but negative for dengue and Zika virus nucleic acids. The median age of the affected sampled patients was 40 years, and males appear to be more affected (66.6% of sampled patients). The laboratory investigation confirmed that the outbreak was caused by chikungunya virus. Even though further molecular characterization of the positive isolates will provide more information as to the circulating genotypes and elucidate the origin of the outbreak virus, it is also possible to assume that the outbreak was an extension of the outbreak in neighboring countries in Kenya and, therefore, warrants that cross-border integration efforts to control chikungunya should be implemented by the concerned countries.
A39 Reconstruction of Ebola chains of transmission using sequence and epidemiological data
Authors: Robert A , Edmunds J , Eggo R , Henao-Restrepo A -M , Gsell P -S , Watson C H , Longini I M , Rambaut A , Camacho A , Hué S 
Published: August 2019

Abstract
Transmission trees can be established through detailed contact histories, statistical inference, phylogenetic inference, or a combination of methods. Each method has its limitations, and the extent to which they succeed in revealing a ‘true’ transmission history remains unclear. Moreover, the net value of pathogen sequencing in transmission tree reconstruction is yet to be assessed. We explored the accuracy and sensitivity to biases of a range of methods for transmission chain inference. We studied eight transmission chains determined by contact tracing, each one having more than a third of its cases sequenced (87 samples over 199 cases in total). We compared three inference methods on the selected transmission chains: (i) phylogenetic inference: the Ebola virus (EBOV) sequences derived from patients were mapped onto a dated EBOV phylogeny tree including 398 EBOV sequences sampled in Guinea between March 2014 and October 2015; (ii) statistical inference: we used the maximum likelihood framework developed by Wallinga and Teunis to infer the most likely transmitter-recipient relationships from the onset dates; (iii) combined method: we inferred probabilistic transmission events using both pathogen sequences and collection dates with the R package Outbreaker2. The cases coming from each transmission chain were mostly clustered together in the phylogenetic tree. The few misclassified cases were most likely allocated to the wrong chains of transmission because of the timing of their symptom onsets. Probabilistic transmission tree using only onset dates broadly matched the contact tracing data, but multiple potential infectors were identified for each case. The combined method showed that an a priori knowledge of the number of independent imports had an important impact on the outcome. Although cases were allocated to the correct transmission chains, discrepancies were found in identifying direct case linkage and transmission generations within a chain. Phylogenetic, epidemiological, and combined approaches for transmission chain reconstructions globally concurred in their output. Sequence data proved useful (if not necessary) to place the sampled cases in a wider context, identify transmission clusters, and misclassified cases when epidemiological chains are inferred from date of symptom onset only, and to identify links between supposedly independent chains of transmission.
A42 Next-generation sequencing to analyze multiple-strain infections, genotype distribution, and antiviral resistance in hematopoietic stem cell transplantation recipients with human cytomegalovirus infection
Authors: Dhingra A , Suárez N , Varanasi P , Zischke J , Heim A , Mischak-Weissinger E , Schulz T , Davison A , Kay-Fedorov P , Ganzenmueller T 
Published: August 2019

Abstract
Next-generation sequencing (NGS) produces comprehensive insights across the entire genome of the human cytomegalovirus (HCMV), which is an important opportunistic pathogen following hematopoietic stem cell transplantation (HSCT). To assess the clinical impact of HCMV diversity, genotype distribution, and resistance mutations, we performed NGS directly on plasma specimens from HSCT recipients with HCMV reactivation. Twenty-nine HCMV-positive plasma samples (median viral load 1.7 × 103 IU/ml) collected from a prospective allogenic HSCT recipient cohort (n = 16) between 21 and 80 days after transplantation were sequenced on an Illumina MiSeq after preparation of target-enriched sequencing libraries. Consensus HCMV genome sequences were assembled for 24 samples. The presence of multiple-strain infections and antiviral resistance mutations in genes UL54 and UL97 was determined by variant analysis. Genotype distribution was determined by specific marker analysis of several hypervariable genes (RL5A, RL6, RL12, RL13, UL1, UL9, UL11, UL73, UL74, UL120, UL146, and UL139). Associations between genomic and clinical features (e.g. graft-versus-host disease (GvHD), donor/recipient HCMV serostatus, dynamics of HCMV antigenemia, survival) were explored. Multiple infections involving up to 3 HCMV strains were detected in seven out of sixteen patients, with one patient analyzed at > 2 time points, showing a switch of the dominant HCMV population. No known antiviral resistance mutations were detected, which may be expected due to sample collection early after HSCT from patients without antiviral prophylaxis. Multiple-strain infection was associated with an earlier peak of HCMV-antigenemia (P = 0.054), but not with duration of viremia, antigenemia peak values, donor/recipient HCMV serostatus, T-cell depletion, acute or chronic GvHD, disease relapse, or reduced survival. Genotype distribution analysis revealed a potential link of one genotype of the immunomodulatory gene UL11 with GvHD incidence after HCMV reactivation. NGS of HCMV diversity directly from plasma samples, even with low viral loads, enables the acquisition of data of potential clinical interest. To identify reliable associations between clinical features and HCMV diversity, further patient cohorts with suitable sample sizes are required.
A57 An evolutionary framework to guide the hunt for human dsDNA viruses
Authors: Aghebatrafat A , Merkel K , Leendertz F , Krüger D H , Calvignac-Spencer S 
Published: August 2019

Abstract
It is becoming increasingly obvious that we only know a fraction of the human virome. The development of next-generation sequencing (NGS) technologies has dramatically increased our ability to hunt viruses. Yet, the small genomes and low copy numbers characteristic of most viruses make undirected (shotgun) hunts a relatively inefficient strategy. Here, we propose to speed-up the rate of double-stranded DNA (dsDNA) virus discovery by combining NGS with evolutionary thinking. dsDNA viruses are thought to have co-diverged with their hosts. As this applies to the hominine lineages (gorillas, humans, chimpanzees, and bonobos), it is theoretically possible to estimate the phylogenetic position of cryptic human viruses by identifying co-divergent viral lineages infecting non-human hominines. Where these lineages do not comprise a human-infecting counterpart, a yet-unknown human virus may be hiding. The first phase of this project will consist in the high-throughput characterization of dsDNA viruses (herpesviruses, papillomaviruses, and polyomaviruses) infecting wild gorillas, chimpanzees, and bonobos. For this, we will use an exhaustive collection of fecal samples (in terms of hominine species/sub-species diversity) and apply a discovery strategy combining in-solution capture and NGS. This strategy has been developed in the ancient DNA field but has a very broad applicability; it will constitute a nice addendum to the institute technical portfolio. Thanks to the massive amount of information collected, we will be able to reconstruct the evolutionary history of many dsDNA virus lineages and to identify those where a human virus would be expected but is still unknown. This will pave the way to the second phase of the project which will consist in a pre-oriented dsDNA human virus hunt based on the use of specific PCR systems implemented in multiplex. We expect that this project will generate an unprecedented amount of data on the processes at play along dsDNA virus evolution (co-divergence versus cross-species transmission), help determine the directionality, frequency, and timing of cross-species transmission events between hominines and unveil the existence of yet-to-be-discovered human viruses.
A61 Large RNA genomes: Is RNA polymerase fidelity enough?
Authors: Ferron F , Canard B 
Published: August 2019

Abstract
Large-genome Nidoviruses and Nidovirus-like viruses reside at the current boundary of largest RNA genome sizes. They code for an unusually large number of gene products matching that of small DNA viruses (e.g. DNA bacteriophages). The order of appearance and distribution of enzyme genes along various virus families (e.g. helicase and ExoN) may be seen as an evolutionary marker in these large RNA genomes lying at the genome size boundary. A positive correlation exists between (+)RNA virus genome sizes and the presence of the RNA helicase and the ExoN domains. Although the mechanistic basis of the presence of the helicase is still unclear, the role of the ExoN activity has been linked to the existence of an RNA synthesis proofreading system. In large Nidovirales, ExoN is bound to a processive replicative RNA-dependent RNA polymerase (RdRp) and corrects mismatched bases during viral RNA synthesis. Over the last decade, a view of the overall process has been refined in Coronaviruses, and in particular in our lab (Ferron et al., PNAS, 2018). We have identified genetic markers of large RNA genomes that we wish to use to data-mine currently existing metagenomic datasets. We have also initiated a collaboration to sequence and explore new viromes that will be searched according to these criteria. Likewise, we have a collection of purified viral RdRps that are currently being used to generate RNA synthesis products that will be compared to existing NGS datasets of cognate viruses. We will be able to have an idea about how much genetic diversity is possibly achievable by viral RdRp (‘tunable fidelity’) versus the detectable diversity (i.e. after selection in the infected cell) that is actually produced.
A65 Characterization of endolysin gene of bacteriophages infecting Listeria spp. isolated from dairy industry wastewater
Authors: Fernández Blanco , Barrios M E , Cammarata R V , Torres C , Mbayed V A 
Published: August 2019

Abstract
Bacteriophages and their endolysins, enzymes that degrade the cell walls of bacteria, are emerging as alternative tools to detect and inhibit growth of pathogen bacteria. Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a serious invasive disease that affects both humans and a wide range of animals. Listeria spp. are ubiquitous in the dairy farm environment and could be present in dairy-processing plants and wastewater. All Listeria-specific bacteriophages found to date are members of the Caudovirales, of the Siphoviridae or Myoviridae families. Myophages infecting Listeria have been recently classified by the ICTV in the Spounavirinae subfamily, as well as in the P100 virus genus. The aim of this work was to isolate Listeria spp. bacteriophages and their endolysin codifying genes from wastewater of a dairy industry. Wastewater with and without treatment was sampled during the course of a year, and isolation of bacteriophages was performed after an enrichment step using as hosts L. innocua, L. ivanovii, and L. monocytogenes serotypes 1/2a, 1/2b, and 4b. Bacteriophages infecting L. innocua and L. ivanovii were isolated (n = 24) from 3 out of 12 samples. Bacteriophages were purified, and the host range was determined using spot test and EOP against five collection strains and several field isolates of Listeria spp. Two bacteriophages of narrow and broad host range, vB_Lino_VEfB7, and vB_Liva_VAfA18, were selected for further characterization. High titer stocks of bacteriophages were purified by centrifugation with ammonium acetate, and morphological information on the purified bacteriophages was obtained by negative staining and transmission electronic microscopy. Their morphology, size, and contractile tails indicated that these bacteriophages belonged to the Myoviridae family. Bacteriophage genomes were extracted using phenol-chloroform, followed by ethanol precipitation, and tested by digestion with RNAsa A and DNAse I. RFLP was performed, digesting genomes with restriction enzymes HindIII and NcoI. Consistent with the morphological findings, bacteriophages contained dsDNA genomes but showed different RFLP patterns. A PCR designed to amplify conserved domains of endolysins—PGRP and CwlA—was applied to characterize this gene. Another PCR was designed to amplify the complete endolysin gene, and the complete sequence of this gene was obtained and analyzed. Substitution model selection and a maximum likelihood phylogenetic tree of the endolysin gene was carried out using IQ-Tree software. The sequences of the endolysin gene indicated that the codified enzyme is an N-acetyl-muramoyl-L-alanine amidase, related to A511 and P100 species of the recently described P100virus genus. Further evolutionary analyses are needed to evaluate their belonging to this species or their taxonomy within this genus.
Is Treetop Skidding Effective in Reducing Fuel Loading?
Authors: Tesch Steven D. , Lysne David H. 
Published: August 2019

Abstract
In an attempt to reduce fuel loading during commercial thinning in a mixed-conifer forest, treetops were left attached to logs that were skidded to a landing for bucking and top disposal. Designated skidtrails were used to minimize residual stand damage and soil compaction. In a comparison with conventional logging procedures, treetop skidding did not decrease skidding productivity or increase damage to residual crop trees, but neither did it significantly reduce fuels. Whole-tree skidding, which would remove lower limbs, may be necessary to reduce unacceptable fire hazard. West. J. Appl. For. 1:13-15, Jan. 1986
Potential for Expansion of the Special Forest Products Industry in the Northern Rockies
Authors: Schlosser William E. , Blatner Keith A. , Schuster Ervin G. , Carroll Matthew S. 
Published: August 2019

Abstract
The special forest products industry has the potential of making substantial contributions to the troubled forest-based economies of the Northern Rockies. Comprised of floral greens, Christmas ornamentals, wild edible mushrooms, other edibles and medicinals, and Pacific yew segments, the industry has the potential to provide both full-time and part-time employment on a nearly year-round basis. The region's natural resource base and available labor supply seem well-suited to developing special forest products firms. The existing transportation system and business environment is also well suited to expansion of this industry. West. J. Appl. For. 10(4):138-143.
The Role of Uneven-Aged Silviculture in the Context of Ecosystem Management
Authors: Guldin James M. 
Published: August 2019

Abstract
The role of uneven-aged silviculture in an ecosystem management context is established using three elements. A review of succession and disturbance theory establishes an ecological basis for the method. The economic and social basis for the method is derived from comparisons of yields and economics, and discussion of social aspects. The adaptive management context is developed by reviewing four classic case studies, drawing on past successes and failures of the method. Overall the case is made that widespread application of uneven-aged silviculture under ecosystem management carries both potential and risk, and that the trade-offs expand rather than limit future silvicultural options. West. J. Appl. For. 11(1):4-12.
Stem Characteristics on the Lower Log of 35-Year-Old Western Redcedar Grown at Several Spacings
Authors: DeBell Jeffrey D. , Gartner Barbara L. 
Published: August 2019

Abstract
Information on stem characteristics of western redcedar (Thuja plicata) grown in managed stands is quite limited. Stem characteristics are important because they influence the quality of logs and lumber produced. We measured branch diameter, number of branches, taper, and fluting severity on the first 5m log of stems grown at spacings of 1.8 to 4.6 m in a 35-yr-old spacing trial on the University of British Columbia Research Forest. Average branch diameter increased from 15 mm to 25 mm as tree spacing increased from 1.8 m to 4.6 m. Number of branches per unit of stem length was unaffected by spacing. Trees at wider spacings tended to be more tapered and have more butt swell than those at narrower spacings. At wider spacings, more trees showed fluting, and that fluting was more severe than at narrower spacings. However, most trees had no fluting or only mild fluting even at the 4.6 m spacing. Branch diameter, taper, and fluting were all related to stem diameter. Smaller diameter stems tended to have smaller branches, less taper, and were less likely to have severe fluting than large diameter stems. Branch diameter was larger at wider spacings even for trees of the same stem diameter. West. J. Appl. For. 12(1):9-14.