species demarcation
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2021 ◽  
Author(s):  
Yuliya V Zakalyukina ◽  
Ilya A Osterman ◽  
Jacqueline Wolf ◽  
Meina Neumann-Schaal ◽  
Imen Nouioui ◽  
...  

Abstract An actinobacterial strain A23T, isolated from adult ant Camponotus vagus collected in Ryazan region (Russia) and established as tetracenomycin X producer, was subjected to a polyphasic taxonomic study. Morphological characteristics of this strain included well-branched substrate mycelium and aerial hyphae fragmented into rod-shaped elements. Phylogenetic analyses based on 16S rRNA gene and genome sequences showed that strain A23T was most closely related to Amycolatopsis pretoriensis DSM 44654T (99.9%). Average nucleotide identity and digital DNA–DNA hybridization values between the genome sequences of isolate A23T and its closest relative, Amycolatopsis pretoriensis DSM 44654T, were 39.5% and 88.6%, which were below the 70% and 95-96% cut-off point recommended for bacterial species demarcation, respectively. The genome size of the isolate A23T is 10,560,374 bp with a DNA G+C content of 71.2 mol%. The whole-organism hydrolysates contain arabinose and galactose as main diagnostic sugars as well as ribose and rhamnose. It contained MK-9(H4) as the predominant menaquinone and iso-C16:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major cellular fatty acids. Based on the phenotypic, genomic and phylogenetic data, isolate A23T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis camponoti sp. nov. is proposed, and the type strain is A23T (=DSM 111725T =VKM 2882T).


Author(s):  
Simona Kraberger ◽  
Tanja Opriessnig ◽  
Vladimir Celer ◽  
Fabrizio Maggi ◽  
Hiroaki Okamoto ◽  
...  

2021 ◽  
Vol 25 (04) ◽  
pp. 859-862
Author(s):  
Muhammad Shafiq Shahid

Cucumber (Cucumis sativus; family Cucurbitaceae) plants exhibiting begomovirus-like symptoms such as yellowing, mosaics and stunting were studied using cloning, sequencing, Species Demarcation Tool followed by phylogenetic clustering. The complete genome of DNA-A showed maximum sequence identity of 98.7% with the corresponding DNA-A of an isolate from “Iran” strain of Watermelon chlorotic stunt virus (WmCSV). The DNA-B displayed 97.5% nt identity with the component of DNA-B of WmCSV from Iran, too. Our results confirmed that yellowing and mosaic symptoms of cucumber are associated with a bipartite begomovirus (WmCSV). This study is the first characterization of WmCSV in association with described symptoms in cucumber from Oman. © 2021 Friends Science Publishers


Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 576 ◽  
Author(s):  
Jessica Coertse ◽  
Marike Geldenhuys ◽  
Kevin le Roux ◽  
Wanda Markotter

Lagos bat virus (LBV), one of the 17 accepted viral species of the Lyssavirus genus, was the first rabies-related virus described in 1956. This virus is endemic to the African continent and is rarely encountered. There are currently four lineages, although the observed genetic diversity exceeds existing lyssavirus species demarcation criteria. Several exposures to rabid bats infected with LBV have been reported; however, no known human cases have been reported to date. This review provides the history of LBV and summarizes previous knowledge as well as new detections. Genetic diversity, pathogenesis and prevention are re-evaluated and discussed.


2021 ◽  
pp. 079160352199995
Author(s):  
Corey Lee Wrenn

In the early middle ages, a community of Irish monks constructed a monastery outpost on the lonely Skellig Michael just offshore of County Kerry. These skelligs served as a mysterious boundary land where the known met the unknown, the worldly wrangled with the spiritual, and the very parameters of humanity itself were brought into question. Amid a period of great transition in Irish society, the monks willfully abandoned the luxuries of developing Western civilization on the mainland (and on the continent more broadly) to test their endurance through religious asceticism on a craggy island more suitable to birds than bipeds. This article reimagines the Skellig Michael experiment as a liminal space, one that troubles premodern efforts to disassociate from animality in an era when “human” and “animal” were malleable concepts. As Western society transitioned from animist paganism to anthropocentric Christianity and Norman colonial control, the Skellig Michael outpost (which survived into the 1300s) offered a point of permeability that invites a critical rethinking of early Irish custom. This article applies theories of liminality and Critical Animal studies to address the making of “human” and “animal” in the march to “civilization,” arguing that species demarcation and the establishment of anthroparchy has been central to the process.


Author(s):  
Yan Wu ◽  
Chun Tao Gu

In the present study, the taxonomic positions of five strains (C, 17-2, LMG 10779T, LMG 18969 and LMG 11483) of Leuconostoc pseudomesenteroides were re-evaluated by a polyphasic approach, including the analyses of 16S rRNA, pheS and rpoA gene sequences, cellular fatty acids, average nucleotide and amino acid identities (ANI and AAI), digital DNA–DNA hybridization (dDDH), and phenotypic features. Based on rpoA sequence analysis, the five strains and L. pseudomesenteroides LMG 11482T were divided into two groups: strains C, LMG 10779T and LMG 18969; strains 17-2, LMG 11483 and LMG 11482T. Each of the two groups had almost identical rpoA sequences. The rpoA sequence similarity between strain LMG 10779T and L. pseudomesenteroides LMG 11482T was 95.6 %. Strains LMG 11483 and 17-2 had 98.1 and 97.2 % ANI values, 83.5 and 73.2 % dDDH values, and a 97.0 % AAI value with L. pseudomesenteroides LMG 11482T, greater than the threshold for species demarcation, indicating that strains LMG 11483 and 17-2 belong to L. pseudomesenteroides . Strains LMG 18969 and C shared 97.1 and 98.2 % ANI values, 73.4 and 83.2 % dDDH values, and 96.9 and 96.6 % AAI values with strain LMG 10779T, greater than the threshold for species demarcation, indicating that strains LMG 10779T, LMG 18969 and C represent the same species. The ANI, dDDH and AAI values between strain LMG 10779T and the type strains of phylogenetically related species were 75.2–92.5, 20.0–48.2 and 75.3–93.9 %, respectively, below the thresholds for species demarcation, indicating that strain LMG 10779T represents a novel species within the genus Leuconostoc . On the basis of the results presented here, (i) strains 17-2 and LMG 11483 belong to L. pseudomesenteroides , and (ii) strains LMG 10779T, LMG 18969 and C are considered to represent a novel species within the genus Leuconostoc , for which the name Leuconostoc falkenbergense sp. nov. is proposed with the type strain LMG 10779T (=CCUG 27119T).


2020 ◽  
Vol 165 (12) ◽  
pp. 2999-3002
Author(s):  
Jean-Sébastien Reynard ◽  
Justine Brodard ◽  
Eric Remoliff ◽  
Marie Lefebvre ◽  
Olivier Schumpp ◽  
...  

Abstract We report the genome sequence of a putative new foveavirus infecting non-cultivated Vitis vinifera, tentatively named “grapevine foveavirus A” (GFVA). This virus was identified by high-throughput sequencing analysis of a European wild Vitis collected in Switzerland. Phylogenetic analysis revealed that this virus clustered with known grapevine virus T (GVT) isolates but was clearly distinct from any of them. If considering the International Committee of Taxonomy of Viruses (ICTV)-suggested foveavirus species demarcation criterion based on sequence similarity in the replicase gene/protein, this virus should be considered a member of a new species closely related to GVT. On the other hand, comparison of capsid gene/protein sequences using the same criteria indicates that GFVA is at the border of species demarcation. Whether this virus represents a highly divergent GVT isolate or a member of a distinct but closely related species is discussed.


Plant Disease ◽  
2020 ◽  
Vol 104 (5) ◽  
pp. 1318-1327
Author(s):  
Chih-Hung Huang ◽  
Chia-Hsing Tai ◽  
Nabin Sharma ◽  
Chia-Hung Chao ◽  
Chung-Jan Chang ◽  
...  

A new begomovirus, tentatively named hibiscus yellow vein leaf curl virus (HYVLCV), was identified in Hibiscus rosa-sinensis plants showing symptoms of leaf curl, yellow vein, and vein enation on the undersides of the leaf in Taiwan. Sequence analysis of the full-length HYVLCV genome from the rolling cycle amplicon revealed a genome of 2,740 nucleotides that contains six open reading frames and a conserved sequence (5′-TAATATTAC-3′) commonly found in geminiviral genomes. HYVLCV shares the highest nucleotide identity (88.8%) with cotton leaf curl Multan virus (CLCuMuV) genome, which is lower than the criteria (91%) set for species demarcation in the genus Begomovirus. No begomoviral DNA-B was detected; however, a begomovirus-associated DNA betasatellite (DNA-β) was detected. The DNA-β (1,355 nucleotides) shares the highest nucleotide identity (78.6%) with malvastrum yellow vein betasatellite (MaYVB). Because the identity is slightly higher than the criteria (78%) set for the species demarcation threshold for a distinct DNA-β species, the DNA-β of HYVLCV reported in this study is considered the same species of MaYVB and tentatively named MaYVB-Hib. An expected 1,498-bp fragment was amplified with two HYVLCV-specific primers from 10 of 11 field-collected samples. Four independent amplicons were sequenced, revealing 100% nucleotide identity with the HYVLCV genome. Agroinoculation of a dimer of the infectious monopartite genome alone to Nicotiana benthamiana resulted in mild symptoms at 28 days postinoculation (dpi); coagroinoculation with the DNA-β satellite resulted in severe symptoms at 12 dpi. HYVLCV could be transmitted to healthy H. rosa-sinensis by grafting, resulting in yellow vein symptoms at 30 dpi.


2020 ◽  
Vol 8 (2) ◽  
pp. 309 ◽  
Author(s):  
Jarryd M. Boath ◽  
Sudip Dakhal ◽  
Thi Thu Hao Van ◽  
Robert J. Moore ◽  
Chaitali Dekiwadia ◽  
...  

The Cedecea genus is comprised of six rarely isolated species within the Enterobacteriaceae family. Representatives are Gram-negative motile bacilli, and are typically oxidase-negative, lipase-positive and resistant to colistin and cephalothin. In this study, a putative novel Cedecea species (designated strain ZA_0188T), isolated from the koala hindgut, was characterised using a polyphasic taxonomic approach. Maximum average nucleotide identity (ANI) and 16S ribosomal RNA (rRNA) similarity scores well below thresholds of species demarcation were reported, at 81.1% and 97.9%, respectively. Multilocus phylogenetic analysis indicated strain ZA_0188T was most similar to but divergent from recognised Cedecea species. The isolate’s genomic G+C content was determined as 53.0 mol%, >1% lower than previously reported in Cedecea. Phenotypically, strain ZA_0188T was distinct from recognised Cedecea species such as colistin- and cephalothin-sensitive, lipase-, sorbitol-, sucrose-, and Voges-Proskauer-negative, and melibiose-, arabinose-, arginine-, and rhamnose-positive. In preliminary experiments, strain ZA_0188T exhibited cellulase activity and high-level tolerance to eucalyptus oil compared to other enteric species surveyed. Collectively, these findings suggest that strain ZA_0188T represents a novel enteric species, for which the name Cedecea colo is proposed.


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