Intraspecies Classification Research Articles

Functional Identification and Genetic Analysis of O-Antigen Gene Clusters of Food-Borne Pathogen Yersinia enterocolitica O:10 and Other Uncommon Serotypes, Further Revealing Their Virulence Profiles.

Yersinia enterocolitica is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of Y. enterocolitica, allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined. In addition to the O-antigen, several virulence factors are involved in infection and pathogenesis of Y. enterocolitica strains, and these are closely related to their biotypes, reflecting pathogenic properties. In this study, we identified the O-AGC of a Y. enterocolitica strain WL-21 of serotype O:10, and confirmed its functionality in O-antigen synthesis. Furthermore, we analyzed in silico the putative O-AGCs of uncommon serotypes, and found that the O-AGCs of Y. enterocolitica were divided into two genetic patterns: (1) O-AGC within the hemH-gsk locus, possibly synthesizing the O-antigen via the Wzx/Wzy dependent pathway, and (2) O-AGC within the dcuC-galU-galF locus, very likely assembling the O-antigen via the ABC transporter dependent pathway. By screening the virulence genes against genomes from GenBank, we discovered that strains representing different serotypes were grouped according to different virulence gene profiles, indicating strong links between serotypes and virulence markers and implying an interaction between them and the synergistic effect in pathogenicity. Our study provides a framework for further research on the origin and evolution of O-AGCs from Y. enterocolitica, as well as on differences in virulent mechanisms among distinct serotypes.

Detection and Identification of Fish Skin Health Status Referring to Four Common Diseases Based on Improved YOLOv4 Model

A primary problem affecting the sustainable development of aquaculture is fish skin diseases. In order to prevent the outbreak of fish diseases and to provide prompt treatment to avoid mass mortality of fish, it is essential to detect and identify skin diseases immediately. Based on the YOLOv4 model, coupled with lightweight depthwise separable convolution and optimized feature extraction network and activation function, the detection and identification model of fish skin disease is constructed in this study. The developed model is tested for the diseases hemorrhagic septicemia, saprolegniasis, benedeniasis, and scuticociliatosis, and applied to monitor the health condition of fish skin in deep-sea cage culture. Results show that the MobileNet3-GELU-YOLOv4 model proposed in this study has an improved learning ability, and the number of model parameters is reduced. Compared to the original YOLOv4 model, its mAP and detection speed increased by 12.39% and 19.31 FPS, respectively. The advantages of the model are its intra-species classification capability, lightweight deployment, detection accuracy, and speed, making the model more applicable to the real-time monitoring of fish skin health in a deep-sea aquaculture environment.

Phylogenetic analysis of all available monkeypox virus strains shows the close relatedness of contemporary ones

The present research aimed to evaluate the diversity of all monkeypox virus strains with a special focus on recently isolated ones by a comprehensive phylogenetic analysis of all available sequences, based on the concatenate of four viral genes. Almost all current strains from 2022 showed a high level of similarity to each other on the analyzed stretches: 218 strains shared identical sequence. Among all analyzed strains, the highest number of differences was counted compared to a RefSeq strain (Zaire-96-I-16) on the whole concatenate. Our analysis supported the distinction between Clade I (formerly Congo Basin clade), IIa and IIb (together formerly West African clade) strains and classified all 2022 strains in the last one. The high number of differences and long branch observable concerning strain Zaire-96-I-16 is most probably caused by a sequencing error. As this strain represents one of the two available reference sequences in GenBank, it is recommendable to confirm or exclude the concerning mutation. The developed method, based on four gene sequences, reflected the established whole-genome-based intraspecies classification. Although this method provides significantly less information about the strains compared to whole genome analyses, since its resolution is much lower, it still enables the rapid subspecies classification of the strains into the established clades. The genes in the analyzed concatenate are so conserved that further differentiation of contemporary strains is impossible; these strains are identical in the analyzed sections. On the other hand, since whole genome analyses are compute-intensive, the described method offers a simpler and more accessible alternative for monitoring and preliminary typing of newly sequenced monkeypox virus strains.

Accurate and fast clade assignment via deep learning and frequency chaos game representation.

Since the beginning of the coronavirus disease 2019 pandemic, there has been an explosion of sequencing of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, making it the most widely sequenced virus in the history. Several databases and tools have been created to keep track of genome sequences and variants of the virus; most notably, the GISAID platform hosts millions of complete genome sequences, and it is continuously expanding every day. A challenging task is the development of fast and accurate tools that are able to distinguish between the different SARS-CoV-2 variants and assign them to a clade. In this article, we leverage the frequency chaos game representation (FCGR) and convolutional neural networks (CNNs) to develop an original method that learns how to classify genome sequences that we implement into CouGaR-g, a tool for the clade assignment problem on SARS-CoV-2 sequences. On a testing subset of the GISAID, CouGaR-g achieved an $96.29\%$ overall accuracy, while a similar tool, Covidex, obtained a $77,12\%$ overall accuracy. As far as we know, our method is the first using deep learning and FCGR for intraspecies classification. Furthermore, by using some feature importance methods, CouGaR-g allows to identify k-mers that match SARS-CoV-2 marker variants. By combining FCGR and CNNs, we develop a method that achieves a better accuracy than Covidex (which is based on random forest) for clade assignment of SARS-CoV-2 genome sequences, also thanks to our training on a much larger dataset, with comparable running times. Our method implemented in CouGaR-g is able to detect k-mers that capture relevant biological information that distinguishes the clades, known as marker variants. The trained models can be tested online providing a FASTA file (with 1 or multiple sequences) at https://huggingface.co/spaces/BIASLab/sars-cov-2-classification-fcgr. CouGaR-g is also available at https://github.com/AlgoLab/CouGaR-g under the GPL.

Full genome characterization of porcine circovirus type 3 isolates reveals the existence of two distinct groups of virus strains

BackgroundThe occurrence of the novel porcine circovirus type 3 (PCV3) was reported from the Americas, Asia and Europe. Although this virus was detected in association with various clinical syndromes in pigs, its role as possible swine pathogen remains unclear. PCV3 was detected with high prevalence in Polish farms, but to date no genome sequences were available from European PCV3 strains.MethodsWe collected 1060 serum samples from piglets at the age of 20–24 weeks from 53 farms distributed all over Germany. PCV3 DNA was detected using a real-time PCR and subsequently complete PCV3 genome sequences were obtained after multiply primed rolling circle amplification and sequencing of overlapping PCR products. Phylogenetic analysis was performed by neighbor-joining method and maximum likelihood method.ResultsWe obtained 15 complete PCV3 genome sequences as well as nine partial sequences including the putative ORFs 1, 2 and 3 from PCV3 viremic animals in German pig farms. Phylogenetic analysis of these German as well as 30 full genome sequences received from GenBank divided the PCV3 strains into two main groups and several subclusters. Furthermore, we were able to define group specific amino acid patterns in open reading frame 1 and 2.ConclusionPCV3 is distributed with high prevalence in German pig industry. Phylogenetic analysis revealed two clearly separated groups of PCV3 strains, which might be considered as PCV3 genotypes. Specific nucleotide and amino acid marker positions may serve for easy and fast intraspecies classification and genotyping of PCV3 strains. No correlation between PCV3 variants with their geographical origin was evident. We found the same diversity of PCV3 strains in Germany as in other countries. We hypothesize that PCV3 is not a newly emerging virus in the German pig population. Future studies will have to show, if PCV3 genotype specific biological properties are evident.

Lipid and protein fingerprinting for Fusarium oxysporum f. sp. cubense strain-level classification.

Banana is one of the most popular fruits in the world but has been substantially impaired by Panama disease in the last years. Fusarium oxysporum f. sp. cubense (Foc) is the causal agent and colonizes banana cultivars from many subgroups with different aggressiveness levels, often leading to plant death while compromising new crops in infested areas. This study has evaluated the ability of MALDI-MS protein and lipid fingerprinting to provide intraspecies classification of Foc isolates and to screen biomolecules related to host-pathogen relationship. The MS data, when inspected via partial least square discriminant analysis (PLS-DA), distinguished the isolates by aggressiveness as well as by specific location and host. Although both lipids and proteins show discriminating tendencies, these differences were more clearly perceived via the protein profiles. Considering that Cavendish cultivar is the more resistant option to endure Foc presence in the field, the lipids and proteins related to this subgroup might have an important role in pathogen adaptation. This study reports a new application of MALDI-MS for the analysis of a banana pathogen with intraspecies classification ability. Graphical abstract MALDI-MS classified Foc isolates by aggressiveness level on banana revealing the additional influence of location and host cultivar on the expression of lipids and proteins.

Phylogenetic Relationship of Indonesian Water Yam (Dioscorea alata L.) Cultivars Based on DNA Marker Using ITS-rDNA Analysis

Research on genetic diversity and intra-species classification of Indonesian Dioscorea alata L. based on morphological characters has been done, and the result shows that there are 4 sub-groups of green cultivars group, and 5 sub-groups of purplish-red cultivars group. The objectives of this study are to determine the phylogenetic relationship cultivars of D. alata Indonesia compared to D. bulbifera as nearest species as well as 3 cultivars from GenBank. The young leaves of 18 water yam cultivar accessions were collected from Java, Madura, South Sumatera, South Kalimantan, Centre Celebes (Sulawesi), Ternate, West Papua, and Nusa Tenggara islands of Indonesia. DNA Isolation was conducted using Phytopure reagent. DNA amplification was conducted using thermocycler, predenaturation at 95 oC 5 minutes, denaturation at 95 oC 1 minutes, annealing at 60 oC 3 minutes, and elongation at 72 oC 2 minutes along with 30 cycles. The PCR products were electrophoresed in 1.5% agarose and visualized under UV transiluminator. Fifty-five µl of PCR products with positive targeted band between 700-800 bp were sent to 1st Base Singapore for purification and sequencing of 18S, ITS-1, 5.8S, ITS-2, and 28S rDNA. The DNA sequences were compared and aligned by BioEdit program (version 7.0.5.2) and MEGA programs. Comparison of entire sequences of the tested samples were aligned by software ClustalW (version 1.83). Phylogenetic trees were based on hierarchical clustering of the alignments of 18S, ITS-1, 5.8S, ITS-2, and 28S rDNA and produced by Neigbor-Joining using MEGA 5 software of the bootstrap values (1000 replicates). The study result shows that D. alata cultivars have high genetic variability on ITS-1, 5.8S, and ITS-2 rDNA region. Groups of green and purplish red cultivars formed based on morphological characters are not formed based on ITS-rDNA markers. Sub-groups were formed based on ITS-rDNA molecular markers derived from both the green and purplish-red cultivar groups. This result revealed that two cultivar groups are not similar with RAPD and morphological characters.

VARIABILITY AND INTRASPECIES CLASSIFICATION OF PUMKIN (Cucurbita moschata (Duch. ex Lam.) Duch. ex Poir.) BASED ON MORPHOLOGICAL CHARACTERS

<p>Pumpkin (C. moschata) is minor cultivated plant has morphological variability, that is. important data illustrate the genetic variability. Morphological variation data of of pumpkin can be used for intraspecies classification and conservation. The relationship of cultivar groups of pumpkin also as important data for pumpkin cultivation. The objectives of this study are to determine variability and intraspecies classification of pumpkin in Yogyakarta and around area based on morphological characters. Cultivar accession are collected from Yogyakarta, and Kopeng also Salatiga central Java as operational taxonomic units (OTU’s). Character scoring based on IPGRI of pumpkin with soft modification. Morphological similarity is calculated based on presence and absence characters, and cluster analysis is conducted by UPGMA method to create dendrogram to determine morphological variability and intraspecies classification of pumpkin based on morphological similarity. The result study shows, that there are 3 fruit shapes, namely giant, globular, and oblong with lobes or not. Pumpkin also has yellow and orange colors fruit flesh. The taste of fruit flesh are sweet or not. Based on Dendrogram pumpkin is classified into 3 group cultivars: lowland group with standard fruit shape, highland with standard fruit shape, and giant cultivar groups. Morphological variability of pumpkin in Yogyakarta and around areas indicate on fruit shape, fruit size, fruit color, and taste of fruit flesh, with morphological similarity coefficient 0,55-0,88.</p><p><br /><strong>Keywords</strong>: C. moschata, cultivar, morphological variability, intraspecies classification, phenetic relationship.</p>

A system to automatically classify and name any individual genome-sequenced organism independently of current biological classification and nomenclature.

A broadly accepted and stable biological classification system is a prerequisite for biological sciences. It provides the means to describe and communicate about life without ambiguity. Current biological classification and nomenclature use the species as the basic unit and require lengthy and laborious species descriptions before newly discovered organisms can be assigned to a species and be named. The current system is thus inadequate to classify and name the immense genetic diversity within species that is now being revealed by genome sequencing on a daily basis. To address this lack of a general intra-species classification and naming system adequate for today’s speed of discovery of new diversity, we propose a classification and naming system that is exclusively based on genome similarity and that is suitable for automatic assignment of codes to any genome-sequenced organism without requiring any phenotypic or phylogenetic analysis. We provide examples demonstrating that genome similarity-based codes largely align with current taxonomic groups at many different levels in bacteria, animals, humans, plants, and viruses. Importantly, the proposed approach is only slightly affected by the order of code assignment and can thus provide codes that reflect similarity between organisms and that do not need to be revised upon discovery of new diversity. We envision genome similarity-based codes to complement current biological nomenclature and to provide a universal means to communicate unambiguously about any genome-sequenced organism in fields as diverse as biodiversity research, infectious disease control, human and microbial forensics, animal breed and plant cultivar certification, and human ancestry research.

Molecular typing of Yersinia pestis

Techniques for differentiating single bacterial isolates into intraspecies clusters corresponding to subspecies, biovars, and natural foci are reviewed. The techniques under consideration are reproducible under different laboratory settings. A version of the intraspecies classification of Y. pestis that is in harmony with the International Code of Nomencláture of Bacteria is suggested.

Identification of Chinese Medicinal Fungus Cordyceps sinensis by PCR-Single-Stranded Conformation Polymorphism and Phylogenetic Relationship

Fungi belonging to the Cordyceps species have long been used as food and herbal medicines in Asia and are especially popular as commercially available powdered supplements. Despite this acceptance and use, little is known of the phylogenetic relationships of the genus. Presently, the neighbor-joining method based on the ITS1, 5.8S rRNA, and ITS2 regions was used to construct a phylogenetic tree of 17 Cordyceps isolates. Five major groups were evident. Cordyceps sinensis was less closely related to 15 Cordyceps species but shared a closer relationship with Cordyceps agriota. PCR-single-stranded conformational polymorphism was applied to differentiate seven Cordyceps isolates: five were different from those used to construct the phylogenetic tree, based on differences in the internal spacer 2 (ITS2). The length of ITS2, amplified by primers 5.8SR and ITS4, vary between 334 and 400 bp. This segment could be used for intraspecies classification or detection of mutations and represents potential novel means of identification of this fungal genus in herbal medicines and in quality control applications in the fermentation industry.

Antigenic and Molecular Characterization of Yersinia ruckeri Proposal for a New Intraspecies Classification

The serological and molecular properties of a group of 17 Yersinia ruckeri strains isolated from cultured rainbow trout in Spain were compared with a total of 36 collection strains isolated from fish in other geographic areas. The serological relationship among isolates, as well as the study of their antigenic determinants (LPS and membrane proteins) allow to propose a new serotyping scheme with four O-serotypes (from O1 to O4). Moreover, serotypes O1 and O2 were divided in two and three groups respectively based mainly on minor differences observed in LPS and membrane protein profiles. The patterns obtained in the analysis of the LPS and proteins present in the extracellular products also support the serological scheme proposed. The strains showed a great genetic homogeneity, displaying similar DNA fingerprint patterns regardless of their serotype. In contrast, only the serotype O1 isolates harbour a plasmid of about 50 MDa, while the strains of the other serotypes presented no extrachromosomical DNA or only small plasmids (less than 10 MDa). © 1993, Gustav Fischer Verlag, Stuttgart · New York. All rights reserved.

Correlation between ribosomal DNA polymorphism and electrophoretic enzyme polymorphism in Yersinia

Ribosomal DNA (rDNA) polymorphism was compared with electrophoretic enzyme polymorphism for the intra- and interspecies differentiation of Yersinia enterocolitica, Y. pseudotuberculosis, Y. intermedia, Y. aldovae, Y. frederiksenii and Y. kristensenii. DNA from 90 strains previously classified into six zymotypes (Y. enterocolitica and Y. frederiksenii) and into distinct enzyme electrophoretic patterns (the four other species) was digested with EcoRI or HindIII and analysed by Southern blotting. The six species were clearly differentiated from each other. In Y. enterocolitica, the subclassification of biotype 1 into zymotypes 1A and 1B was also reflected in the rDNA and the four other bio-zymotypes gave four different classes of restriction pattern. In Y. frederiksenii, both EcoRI and HindIII gave five distinct riboclasses which correlated with the zymotypes. In the four other species, the phenotype polymorphism appeared to be better correlated with the restriction fragment length polymorphism data in some enzymes than others. The data demonstrate that the inter- and intraspecies classification by rDNA polymorphism using two restriction enzymes is similar to that based on electrophoretic enzyme polymorphism. The analysis could be refined for taxonomic and epidemiological purposes by using other restriction enzymes.

Epicuticular wax constituents of North American and European Euphorbia esula biotypes

The epicuticular leaf wax of four North American and one Austrian Euphorbia esula biotypes was examined as a potential source of chemotaxonomic information relative to intraspecies classification. Analysis (GC and GC/MS) shows general similarity of wax constituent character among all biotypes but differences in specific component yields between the North American and Austrian biotypes. Distinctive variation in occurrence of five triterpenes (α- and β-amyrin, δ-amyrenone, 24-methylenecycloartenol and lupeyl acetate) was observed between the North American and Austrian biotypes.