scholarly journals Pathogenic Determinants of the Mycobacterium kansasii Complex: An Unsuspected Role for Distributive Conjugal Transfer

2021 ◽  
Vol 9 (2) ◽  
pp. 348
Author(s):  
Florian Tagini ◽  
Trestan Pillonel ◽  
Claire Bertelli ◽  
Katia Jaton ◽  
Gilbert Greub
Keyword(s):  
Genomic Analysis ◽  
Comparative Genomic ◽  
Mycobacterium Kansasii ◽  
Type Vii Secretion ◽  
A Genome ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Immunosuppressed Patients ◽  
Type Vii Secretion System ◽  
Clinical Records

The Mycobacterium kansasii species comprises six subtypes that were recently classified into six closely related species; Mycobacterium kansasii (formerly M. kansasii subtype 1), Mycobacterium persicum (subtype 2), Mycobacterium pseudokansasii (subtype 3), Mycobacterium ostraviense (subtype 4), Mycobacterium innocens (subtype 5) and Mycobacterium attenuatum (subtype 6). Together with Mycobacterium gastri, they form the M. kansasii complex. M. kansasii is the most frequent and most pathogenic species of the complex. M. persicum is classically associated with diseases in immunosuppressed patients, and the other species are mostly colonizers, and are only very rarely reported in ill patients. Comparative genomics was used to assess the genetic determinants leading to the pathogenicity of members of the M. kansasii complex. The genomes of 51 isolates collected from patients with and without disease were sequenced and compared with 24 publicly available genomes. The pathogenicity of each isolate was determined based on the clinical records or public metadata. A comparative genomic analysis showed that all M. persicum, M. ostraviense, M innocens and M. gastri isolates lacked the ESX-1-associated EspACD locus that is thought to play a crucial role in the pathogenicity of M. tuberculosis and other non-tuberculous mycobacteria. Furthermore, M. kansasii was the only species exhibiting a 25-Kb-large genomic island encoding for 17 type-VII secretion system-associated proteins. Finally, a genome-wide association analysis revealed that two consecutive genes encoding a hemerythrin-like protein and a nitroreductase-like protein were significantly associated with pathogenicity. These two genes may be involved in the resistance to reactive oxygen and nitrogen species, a required mechanism for the intracellular survival of bacteria. Three non-pathogenic M. kansasii lacked these genes likely due to two distinct distributive conjugal transfers (DCTs) between M. attenuatum and M. kansasii, and one DCT between M. persicum and M. kansasii. To our knowledge, this is the first study linking DCT to reduced pathogenicity.

scholarly journals Genome Reduction and Secondary Metabolism of the Marine Sponge-Associated Cyanobacterium Leptothoe

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis
Keyword(s):  
Natural Products ◽  
Microbial Communities ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Marine Sponges ◽  
Genome Reduction ◽  
Extracellular Polysaccharides ◽  
Comparative Genomic ◽  
Symbiotic Relationships ◽  
Genes Encoding

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.

scholarly journals Genome assembly of the JD17 soybean provides a new reference genome for Comparative genomics

2021 ◽  
Author(s):  
Xinxin Yi ◽  
Jing Liu ◽  
Shengcai Chen ◽  
Hao Wu ◽  
Min Liu ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Genome Assembly ◽  
Reference Genome ◽  
De Novo ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
High Quality ◽  
Genome Wide ◽  
A Genome ◽  
Cultivated Soybean

Cultivated soybean (Glycine max) is an important source for protein and oil. Many elite cultivars with different traits have been developed for different conditions. Each soybean strain has its own genetic diversity, and the availability of more high-quality soybean genomes can enhance comparative genomic analysis for identifying genetic underpinnings for its unique traits. In this study, we constructed a high-quality de novo assembly of an elite soybean cultivar Jidou 17 (JD17) with chromsome contiguity and high accuracy. We annotated 52,840 gene models and reconstructed 74,054 high-quality full-length transcripts. We performed a genome-wide comparative analysis based on the reference genome of JD17 with three published soybeans (WM82, ZH13 and W05) , which identified five large inversions and two large translocations specific to JD17, 20,984 - 46,912 PAVs spanning 13.1 - 46.9 Mb in size, and 5 - 53 large PAV clusters larger than 500kb. 1,695,741 - 3,664,629 SNPs and 446,689 - 800,489 Indels were identified and annotated between JD17 and them. Symbiotic nitrogen fixation (SNF) genes were identified and the effects from these variants were further evaluated. It was found that the coding sequences of 9 nitrogen fixation-related genes were greatly affected. The high-quality genome assembly of JD17 can serve as a valuable reference for soybean functional genomics research.

scholarly journals Characterization of a blaNDM-1-Bearing IncHI5-Like Plasmid From Klebsiella pneumoniae of Infant Origin

2021 ◽  
Vol 11 ◽  
Author(s):  
Ziyi Liu ◽  
Ruifei Chen ◽  
Poshi Xu ◽  
Zhiqiang Wang ◽  
Ruichao Li
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Genetic Composition ◽  
Carbapenem Resistant ◽  
Antimicrobial Resistance Genes ◽  
Genes Encoding ◽  
History Of ◽  
Core Genes

The spread of plasmid-mediated carbapenem-resistant clinical isolates is a serious threat to global health. In this study, an emerging NDM-encoding IncHI5-like plasmid from Klebsiella pneumoniae of infant patient origin was characterized, and the plasmid was compared to the available IncHI5-like plasmids to better understand the genetic composition and evolution of this emerging plasmid. Clinical isolate C39 was identified as K. pneumoniae and belonged to the ST37 and KL15 serotype. Whole genome sequencing (WGS) and analysis revealed that it harbored two plasmids, one of which was a large IncHI5-like plasmid pC39-334kb encoding a wide variety of antimicrobial resistance genes clustered in a single multidrug resistance (MDR) region. The blaNDM-1 gene was located on a ΔISAba125-blaNDM-1-bleMBL-trpF-dsbC structure. Comparative genomic analysis showed that it shared a similar backbone with four IncHI5-like plasmids and the IncHI5 plasmid pNDM-1-EC12, and these six plasmids differed from typical IncHI5 plasmids. The replication genes of IncHI5-like plasmids shared 97.06% (repHI5B) and 97.99% (repFIB-like) nucleotide identity with those of IncHI5 plasmids. Given that pNDM-1-EC12 and all IncHI5-like plasmids are closely related genetically, the occurrence of IncHI5-like plasmid is likely associated with the mutation of the replication genes of pNDM-1-EC12-like IncHI5 plasmids. All available IncHI5-like plasmids harbored 262 core genes encoding replication and maintenance functions and carried distinct MDR regions. Furthermore, 80% of them (4/5) were found in K. pneumoniae from Chinese nosocomial settings. To conclude, this study expands our knowledge of the evolution history of IncHI5-like plasmids, and more attention should be paid to track the evolution pathway of them among clinical, animal, and environmental settings.

scholarly journals Brassica carinata genome characterization clarifies U’s triangle model of evolution and polyploidy in Brassica

2021 ◽  
Author(s):  
Xiaoming Song ◽  
Yanping Wei ◽  
Dong Xiao ◽  
Ke Gong ◽  
Pengchuan Sun ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Agronomic Traits ◽  
Repetitive Sequences ◽  
Genomic Analysis ◽  
Brassica Species ◽  
Brassica Carinata ◽  
Comparative Genomic ◽  
Ethiopian Mustard ◽  
A Genome ◽  
Genome Triplication

Abstract Ethiopian mustard (Brassica carinata) in the Brassicaceae family possesses many excellent agronomic traits. Here, the high-quality genome sequence of B. carinata is reported. Characterization revealed a genome anchored to 17 chromosomes with a total length of 1.087 Gb and an N50 scaffold length of 60 Mb. Repetitive sequences account for approximately 634 Mb or 58.34% of the B. carinata genome. Notably, 51.91% of 97,149 genes are confined to the terminal 20% of chromosomes as a result of the expansion of repeats in pericentromeric regions. Brassica carinata shares one whole-genome triplication event with the five other species in U’s triangle, a classic model of evolution and polyploidy in Brassica. Brassica carinata was deduced to have formed ∼0.047 Mya, which is slightly earlier than B. napus but later than B. juncea. Our analysis indicated that the relationship between the two subgenomes (BcaB and BcaC) is greater than that between other two tetraploid subgenomes (BjuB and BnaC) and their respective diploid parents. RNA-seq datasets and comparative genomic analysis were used to identify several key genes in pathways regulating disease resistance and glucosinolate metabolism. Further analyses revealed that genome triplication and tandem duplication played important roles in the expansion of those genes in Brassica species. With the genome sequencing of B. carinata completed, the genomes of all six Brassica species in U’s triangle are now resolved. The data obtained from genome sequencing, transcriptome analysis, and comparative genomic efforts in this study provide valuable insights into the genome evolution of the six Brassica species in U’s triangle.

scholarly journals A genome-annotated bacterial collection of the barley rhizosphere microbiota

2021 ◽  
Author(s):  
Senga Robertson-Albertyn ◽  
Federico Concas ◽  
Lynn H Brown ◽  
Jamie N Orr ◽  
James C Abbott ◽  
...  
Keyword(s):  
Plant Growth ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Strain Specificity ◽  
Bacterial Microbiota ◽  
A Genome ◽  
Plant Growth Promoting ◽  
Plant Microbiota ◽  
Growth Promoting

ABSTRACTWe generated a bacterial collection from the rhizosphere of cultivated barley (Hordeum vulgare L. ssp. vulgare) to assess taxonomic distribution of culturable members of the barley microbiota and their plant growth-promoting potential. From this we retrieved strains belonging to the dominant phyla of the plant microbiota— Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria—and gathered evidence they code for functional genes implicated in nitrogen fixation, hydrogen cyanide channels and phosphate solubilisation. Here we present an initial comparative genomic analysis of the collection revealing that plant growth-promoting potential of the culturable barley bacterial microbiota appears to have a relatively broad phylogenetic base while retaining some strain-specificity.

scholarly journals Characterization of Novel Erwinia amylovora Jumbo Bacteriophages from Eneladusvirus Genus

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1373
Author(s):  
Sang Guen Kim ◽  
Sung Bin Lee ◽  
Sib Sankar Giri ◽  
Hyoun Joong Kim ◽  
Sang Wha Kim ◽  
...  
Keyword(s):  
Genome Size ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Gc Content ◽  
Genomic Analysis ◽  
Open Reading Frames ◽  
Comparative Genomic ◽  
Limited Information ◽  
High Sequence Similarity ◽  
A Genome

Jumbo phages, which have a genome size of more than 200 kb, have recently been reported for the first time. However, limited information is available regarding their characteristics because few jumbo phages have been isolated. Therefore, in this study, we aimed to isolate and characterize other jumbo phages. We performed comparative genomic analysis of three Erwinia phages (pEa_SNUABM_12, pEa_SNUABM_47, and pEa_SNUABM_50), each of which had a genome size of approximately 360 kb (32.5% GC content). These phages were predicted to harbor 546, 540, and 540 open reading frames with 32, 34, and 35 tRNAs, respectively. Almost all of the genes in these phages could not be functionally annotated but showed high sequence similarity with genes encoded in Serratia phage BF, a member of Eneladusvirus. The detailed comparative and phylogenetic analyses presented in this study contribute to our understanding of the diversity and evolution of Erwinia phage and the genus Eneladusvirus.

scholarly journals Identification of Genetic Bases ofVibrio fluvialisSpecies-Specific Biochemical Pathways and Potential Virulence Factors by Comparative Genomic Analysis

2014 ◽  
Vol 80 (6) ◽  
pp. 2029-2037 ◽  
Author(s):  
Xin Lu ◽  
Weili Liang ◽  
Yunduan Wang ◽  
Jialiang Xu ◽  
Jun Zhu ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Type Vi Secretion System ◽  
Biochemical Tests ◽  
Regulatory Pathways ◽  
Vibrio Fluvialis ◽  
Genes Encoding ◽  
Genetic Mechanisms

ABSTRACTVibrio fluvialisis an important food-borne pathogen that causes diarrheal illness and sometimes extraintestinal infections in humans. In this study, we sequenced the genome of a clinicalV. fluvialisstrain and determined its phylogenetic relationships with otherVibriospecies by comparative genomic analysis. We found that the closest relationship was betweenV. fluvialisandV. furnissii, followed by those withV. choleraeandV. mimicus. Moreover, based on genome comparisons and gene complementation experiments, we revealed genetic mechanisms of the biochemical tests that differentiateV. fluvialisfrom closely related species. Importantly, we identified a variety of genes encoding potential virulence factors, including multiple hemolysins, transcriptional regulators, and environmental survival and adaptation apparatuses, and the type VI secretion system, which is indicative of complex regulatory pathways modulating pathogenesis in this organism. The availability ofV. fluvialisgenome sequences may promote our understanding of pathogenic mechanisms for this emerging pathogen.

scholarly journals Complete Genomes of Symbiotic Cyanobacteria Clarify the Evolution of Vanadium-Nitrogenase

2019 ◽  
Vol 11 (7) ◽  
pp. 1959-1964 ◽  
Author(s):  
Jessica M Nelson ◽  
Duncan A Hauser ◽  
José A Gudiño ◽  
Yessenia A Guadalupe ◽  
John C Meeks ◽  
...  
Keyword(s):  
Sequence Divergence ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
16S Rrna Sequence ◽  
Plant Microbe Interaction ◽  
Complete Genomes ◽  
Genes Encoding ◽  
Long Read ◽  
Vanadium Nitrogenase ◽  
Conserved Gene

Abstract Plant endosymbiosis with nitrogen-fixing cyanobacteria has independently evolved in diverse plant lineages, offering a unique window to study the evolution and genetics of plant–microbe interaction. However, very few complete genomes exist for plant cyanobionts, and therefore little is known about their genomic and functional diversity. Here, we present four complete genomes of cyanobacteria isolated from bryophytes. Nanopore long-read sequencing allowed us to obtain circular contigs for all the main chromosomes and most of the plasmids. We found that despite having a low 16S rRNA sequence divergence, the four isolates exhibit considerable genome reorganizations and variation in gene content. Furthermore, three of the four isolates possess genes encoding vanadium (V)-nitrogenase (vnf), which is uncommon among diazotrophs and has not been previously reported in plant cyanobionts. In two cases, the vnf genes were found on plasmids, implying possible plasmid-mediated horizontal gene transfers. Comparative genomic analysis of vnf-containing cyanobacteria further identified a conserved gene cluster. Many genes in this cluster have not been functionally characterized and would be promising candidates for future studies to elucidate V-nitrogenase function and regulation.

scholarly journals Investigating the Relatedness of Enteroinvasive Escherichia coli to Other E. coli and Shigella Isolates by Using Comparative Genomics

2016 ◽  
Vol 84 (8) ◽  
pp. 2362-2371 ◽  
Author(s):  
Tracy H. Hazen ◽  
Susan R. Leonard ◽  
Keith A. Lampel ◽  
David W. Lacher ◽  
Anthony T. Maurelli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Analysis ◽  
Host Cells ◽  
Comparative Genomic ◽  
Virulence Plasmid ◽  
Phylogenomic Analysis ◽  
Content Type ◽  
E Coli ◽  
Associated Proteins ◽  
Human Illness

EnteroinvasiveEscherichia coli(EIEC) is a unique pathovar that has a pathogenic mechanism nearly indistinguishable from that ofShigellaspecies. In contrast to isolates of the fourShigellaspecies, which are widespread and can be frequent causes of human illness, EIEC causes far fewer reported illnesses each year. In this study, we analyzed the genome sequences of 20 EIEC isolates, including 14 first described in this study. Phylogenomic analysis of the EIEC genomes demonstrated that 17 of the isolates are present in three distinct lineages that contained only EIEC genomes, compared to reference genomes from each of theE. colipathovars andShigellaspecies. Comparative genomic analysis identified genes that were unique to each of the three identified EIEC lineages. While many of the EIEC lineage-specific genes have unknown functions, those with predicted functions included a colicin and putative proteins involved in transcriptional regulation or carbohydrate metabolism.In silicodetection of theShigellavirulence plasmid (pINV), which is essential for the invasion of host cells, demonstrated that a form of pINV was present in nearly all EIEC genomes, but the Mxi-Spa-Ipa region of the plasmid that encodes the invasion-associated proteins was absent from several of the EIEC isolates. The comparative genomic findings in this study support the hypothesis that multiple EIEC lineages have evolved independently from multiple distinct lineages ofE. colivia the acquisition of theShigellavirulence plasmid and, in some cases, theShigellapathogenicity islands.

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