scholarly journals Comparative genomics of Exiguobacterium reveals what makes a cosmopolitan bacterium

2020 ◽  
Author(s):  
De-Chao Zhang ◽  
Zhaolu Zhu ◽  
Xudong Li ◽  
Ziyu Guan ◽  
Jinshui Zheng
Keyword(s):  
Large Scale ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Adaptive Strategy ◽  
Adaptation Strategy ◽  
Wide Distribution ◽  
Comparative Genomic ◽  
Cosmopolitan Distribution ◽  
Group I ◽  
Wide Range

ABSTRACTAlthough the adaptation strategies of bacteria to specific environmental conditions are widely reported, fewer studies have addressed how microbe with cosmopolitan distribution adapted to diverse habitats. Exiguobacterium is a versatile genus whose members have been commonly found in great variety of habitats. To understand the mechanism behind the universally of Exiguobacterium, we isolated 103 strains from diverse environments, and performed large-scale metabolic and adaptive ability tests. We found that the capacities of survival in a wide range of temperature, salinity and pH are common for most Exiguobacterium members. According to the core genome based phylogeny and ANI analysis, 26 putative species including 13 putative new ones were identified and two genetic groups were classified as Group I and II. Comparative genomic analysis revealed that Exiguobacterium members can not only utilize a variety of complex polysaccharides and proteins that are ubiquitous in both terrestrial and marine environments, but also have a number of chaperonins and transporters which could support them to survive in different extreme environments. In addition, we found that the species from Group I can be found in more diverse environments with larger genome size compared to those of Group II. Twenty-five transporter families involved in transport of organic or inorganic substrates and environments stresses resistance were predicted to be enriched in Group I strains. This study provided the comprehensive insight into general genetic basis of the cosmopolitan distribution of a bacteria genus and deciphered putative determinants behind the ecological difference of different groups belonging to the same genus.IMPORTANCEThe wide distribution characteristics make Exiguobacterium a valuable model for studying adaptive strategy of bacteria adapted to multiple habitats. In this study, we found that comprehensive capacity of diverse polysaccharides utilization and environmental stress resistance is the important basis for survival, and selective expansion of transporters is an evolution and adaptation strategy for extensive distribution. Our findings are significant for understanding the adaptation and evolution mechanisms of cosmopolitan bacteria and explaining the vital genomic traits that facilitate niches adaptation.

scholarly journals Comparative Genomic Analysis of Bacillus thuringiensis Reveals Molecular Adaptations to Copper Tolerance

2018 ◽  
Author(s):  
Low Yi Yik ◽  
Grace Joy Wei Lie Chin ◽  
Collin Glen Joseph ◽  
Kenneth Francis Rodrigues
Keyword(s):  
Bacillus Thuringiensis ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Copper Resistance ◽  
Copper Tolerance ◽  
Contaminated Site ◽  
Comparative Genomic ◽  
Wide Range ◽  
Almost All

ABSTRACTBacillus thuringiensis is a type of Gram positive and rod shaped bacterium that is found in a wide range of habitats. Despite the intensive studies conducted on this bacterium, most of the information available are related to its pathogenic characteristics, with only a limited number of publications mentioning its ability to survive in extreme environments. Recently, a B. thuringiensis MCMY1 strain was successfully isolated from a copper contaminated site in Mamut Copper Mine, Sabah. This study aimed to conduct a comparative genomic analysis by using the genome sequence of MCMY1 strain published in GenBank (PRJNA374601) as a target genome for comparison with other available B. thuringiensis genomes at the GenBank. Whole genome alignment, Fragment all-against-all comparison analysis, phylogenetic reconstruction and specific copper genes comparison were applied to all forty-five B. thuringiensis genomes to reveal the molecular adaptation to copper tolerance. The comparative results indicated that B. thuringiensis MCMY1 strain is closely related to strain Bt407 and strain IS5056. This strain harbors almost all available copper genes annotated from the forty-five B. thuringiensis genomes, except for the gene for Magnesium and cobalt efflux protein (CorC) which plays an indirect role in reducing the oxidative stress that caused by copper and other metal ions. Furthermore, the findings also showed that the Copper resistance gene family, CopABCDZ and its repressor (CsoR) are conserved in almost all sequenced genomes but the presence of the genes for Cytoplasmic copper homeostasis protein (CutC) and CorC across the sample genomes are highly inconsonant. The variation of these genes across the B. thuringiensis genomes suggests that each strain may have adapted to their specific ecological niche. However, further investigations will be need to support this preliminary hypothesis.

scholarly journals Complete Genome Sequence of Escherichia Coli Strain S9922 Isolated from Meningitis in Calf and Comparative Genomic Analysis with Other E. Coli Pathotypes

2021 ◽  
Author(s):  
Beibei Li ◽  
Jingjing Ren ◽  
Xun Ma ◽  
Qian Qin ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cluster Analysis ◽  
Large Scale ◽  
Virulent Strain ◽  
Evolutionary Relationship ◽  
Intestinal Flora ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
E Coli ◽  
Wide Range

Abstract Background: Extraintestinal pathogenic Escherichia coli (ExPEC) exists in the normal intestinal flora, but can invade and colonize extraintestinal sites and cause a wide range of infections. Genomic analysis of ExPEC has mainly focused on isolates of human, poultry and pig. In recent years, some large-scale dairy farms in Xinjiang broke out cases characterized by neurological symptoms and acute death in newborn calves. To better understand the genomic attributes underlying the pathogenicity of bovine-source ExPEC, a highly virulent strain, which named E. coli S9922 was isolated from cerebral effusion in a calf that died of meningitis, was sequenced and analyzed.Results: Using single-molecule sequencing technology on PacBio and then assembled, the genes were predicted and annotated. The whole genome of E.coli S9922 was consisted of a chromosome and three plasmids containing 5055 genes, and the total length was 5269374 bp and the average G+C content was 50.82%. In addition, 291 host-, 204 virulence-, and 185 resistance-related genes, and 182 T3SS effector proteins were found by comparison with related databases. Comparison of this genome to 16 representative strains of pathogenic E.coli genomic sequences showed that E.coli S9922 had the greatest co-linearity with E.coli 90-9272. In addition, Core genes obtained by cluster analysis of E.coli S9922 homologous genes were classified, a total of 2570, 2780, and 2188 genes were obtained via COG, KEGG, and GO comparisons, respectively. The unique genes identified by homologous cluster analysis were classified 204, 550, 239 genes in COG, KEGG, and GO comparisons, respectively. Evolutionary tree analysis revealed a close evolutionary relationship between E.coli S9922 and E.coli 90-9272, and a distant relationship between E.coli S9922 and UTI89.Conclusions: The study provide dgenomics of E.coli S9922 strain from the cattle that had died of meningitis. It enriched the genome data of E.coli and laid a theoretical foundation for further experimental study of ExPEC. Comparative genomics analysis showed that E.coli S9922 had a close evolutionary relationship with E.coli 90-9272, but far from that of UTI89.

scholarly journals Comparative genomic analysis of Methanimicrococcus blatticola provides insights into host adaptation in archaea and the evolution of methanogenesis

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Courtney M. Thomas ◽  
Najwa Taib ◽  
Simonetta Gribaldo ◽  
Guillaume Borrel
Keyword(s):  
Gut Microbiota ◽  
Large Scale ◽  
Genomic Analysis ◽  
Host Adaptation ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Methyl Branch ◽  
Mechanisms Of Adaptation ◽  
Hydrogenotrophic Methanogens ◽  
Almost All

AbstractOther than the Methanobacteriales and Methanomassiliicoccales, the characteristics of archaea that inhabit the animal microbiome are largely unknown. Methanimicrococcus blatticola, a member of the Methanosarcinales, currently reunites two unique features within this order: it is a colonizer of the animal digestive tract and can only reduce methyl compounds with H2 for methanogenesis, a increasingly recognized metabolism in the archaea and whose origin remains debated. To understand the origin of these characteristics, we have carried out a large-scale comparative genomic analysis. We infer the loss of more than a thousand genes in M. blatticola, by far the largest genome reduction across all Methanosarcinales. These include numerous elements for sensing the environment and adapting to more stable gut conditions, as well as a significant remodeling of the cell surface components likely involved in host and gut microbiota interactions. Several of these modifications parallel those previously observed in phylogenetically distant archaea and bacteria from the animal microbiome, suggesting large-scale convergent mechanisms of adaptation to the gut. Strikingly, M. blatticola has lost almost all genes coding for the H4MPT methyl branch of the Wood–Ljungdahl pathway (to the exception of mer), a phenomenon never reported before in any member of Class I or Class II methanogens. The loss of this pathway illustrates one of the evolutionary processes that may have led to the emergence of methyl-reducing hydrogenotrophic methanogens, possibly linked to the colonization of organic-rich environments (including the animal gut) where both methyl compounds and hydrogen are abundant.

scholarly journals Insights into the Metabolism and Evolution of the Genus Acidiphilium, a Typical Acidophile in Acid Mine Drainage

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Liangzhi Li ◽  
Zhenghua Liu ◽  
Min Zhang ◽  
Delong Meng ◽  
Xueduan Liu ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Evolutionary History ◽  
Mine Drainage ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Metabolic Potential ◽  
Ecological Functions ◽  
History Of

ABSTRACT Here, we report three new Acidiphilium genomes, reclassified existing Acidiphilium species, and performed the first comparative genomic analysis on Acidiphilium in an attempt to address the metabolic potential, ecological functions, and evolutionary history of the genus Acidiphilium. In the genomes of Acidiphilium, we found an abundant repertoire of horizontally transferred genes (HTGs) contributing to environmental adaption and metabolic expansion, including genes conferring photosynthesis (puf, puh), CO2 assimilation (rbc), capacity for methane metabolism (mmo, mdh, frm), nitrogen source utilization (nar, cyn, hmp), sulfur compound utilization (sox, psr, sqr), and multiple metal and osmotic stress resistance capacities (czc, cop, ect). Additionally, the predicted donors of horizontal gene transfer were present in a cooccurrence network of Acidiphilium. Genome-scale positive selection analysis revealed that 15 genes contained adaptive mutations, most of which were multifunctional and played critical roles in the survival of extreme conditions. We proposed that Acidiphilium originated in mild conditions and adapted to extreme environments such as acidic mineral sites after the acquisition of many essential functions. IMPORTANCE Extremophiles, organisms that thrive in extreme environments, are key models for research on biological adaption. They can provide hints for the origin and evolution of life, as well as improve the understanding of biogeochemical cycling of elements. Extremely acidophilic bacteria such as Acidiphilium are widespread in acid mine drainage (AMD) systems, but the metabolic potential, ecological functions, and evolutionary history of this genus are still ambiguous. Here, we sequenced the genomes of three new Acidiphilium strains and performed comparative genomic analysis on this extremely acidophilic bacterial genus. We found in the genomes of Acidiphilium an abundant repertoire of horizontally transferred genes (HTGs) contributing to environmental adaption and metabolic ability expansion, as indicated by phylogenetic reconstruction and gene context comparison. This study has advanced our understanding of microbial evolution and biogeochemical cycling in extreme niches.

scholarly journals A large scale, multiple genome comparison of acidophilic Archaea (pH ≤ 5.0) extends our understanding of oxidative stress responses in polyextreme environments

2021 ◽  
Author(s):  
Gonzalo Neira ◽  
Eva Vergara ◽  
Diego Nahuel Cortez ◽  
David S. Holmes
Keyword(s):  
Oxidative Stress ◽  
Stress Responses ◽  
Large Scale ◽  
Genomic Analysis ◽  
Low Ph ◽  
Genome Comparison ◽  
Comparative Genomic ◽  
Acidophilic Bacteria ◽  
Acidophilic Archaea ◽  
Oxidative Stress Responses

Acidophilic Archaea thrive in anaerobic and aerobic low pH environments (<pH 5) rich in dissolved heavy metals that exacerbate stress caused by the production of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (·OH) and superoxide (O2·−). ROS react with lipids, proteins and nucleic acids causing oxidative stress and damage that can lead to cell death. Herein, genes and mechanisms potentially involved in ROS mitigation are predicted in over 200 genomes of acidophilic Archaea with sequenced genomes. These organisms can be subjected to simultaneous multiple stresses such as high temperature, high salinity, low pH and high heavy metal loads. Some of the topics addressed include: (1) the phylogenomic distribution of these genes and what can this tell us about the evolution of these mechanisms in acidophilic Archaea; (2) key differences in genes and mechanisms used by acidophilic versus non-acidophilic Archaea and between acidophilic Archaea and acidophilic Bacteria and (3) how comparative genomic analysis predicts novel genes or pathways involved in oxidative stress responses in Archaea and possible Horizontal Gene Transfer (HGT) events.

scholarly journals In SilicoTyping and Comparative Genomic Analysis of IncFIIKPlasmids and Insights into the Evolution of Replicons, Plasmid Backbones, and Resistance Determinant Profiles

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Dexi Bi ◽  
Jiayi Zheng ◽  
Jun-Jie Li ◽  
Zi-Ke Sheng ◽  
Xingchen Zhu ◽  
...  
Keyword(s):  
Large Scale ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Epidemiological Studies ◽  
Genome Comparison ◽  
Comparative Genomic ◽  
Content Type ◽  
Bacterial Plasmid ◽  
Phylogeny And Evolution ◽  
Sequence Types

ABSTRACTIncFIIKplasmids are associated with the acquisition and dissemination of multiple-antimicrobial resistance inKlebsiella pneumoniaeand often encountered in clinical isolates of this species. Since the phylogeny and evolution of IncFIIKplasmids remain unclear, here we performed large-scalein silicotyping and comparative analysis of these plasmids in publicly available bacterial/plasmid genomes. IncFIIKplasmids are prevalent inK. pneumoniae, being found in 69% of sequenced genomes, covering 66% of sequenced STs (sequence types), but sparse in otherEnterobacteriaceae. IncFIIKreplicons have three lineages. One IncFIIKallele could be found in distinctK. pneumoniaeSTs, highlighting the lateral genetic flow of IncFIIKplasmids. A set of 77 IncFIIKplasmids with full sequences were further analyzed. A pool of 327 antibiotic resistance genes or remnants were annotated in 75.3% of these plasmids. Plasmid genome comparison reiterated that they often contain other replicons belonging to IncFIA, IncFIB, IncFIIYp, IncFIIpCRY, IncR, IncL, and IncN groups and that they share a conserved backbone featuring an F-like conjugation module that has divergent components responsible for regulation and mating pair stabilization. Further epidemiological studies of IncFIIKplasmids are required due to the sample bias ofK. pneumoniaegenomes in public databases. This study provides insights into the evolution and structures of IncFIIKplasmids.

scholarly journals Phylogeny and Population Structure of Brown Rot- and Moko Disease-Causing Strains of Ralstonia solanacearum Phylotype II

2012 ◽  
Vol 78 (7) ◽  
pp. 2367-2375 ◽  
Author(s):  
G. Cellier ◽  
B. Remenant ◽  
F. Chiroleu ◽  
P. Lefeuvre ◽  
P. Prior
Keyword(s):  
Population Structure ◽  
Ralstonia Solanacearum ◽  
Brown Rot ◽  
Phylogeographic Structure ◽  
Diagnostic Tools ◽  
Comparative Genomic ◽  
Content Type ◽  
Pathogenic Variants ◽  
Group I ◽  
Wide Range

ABSTRACTThe ancient soilborne plant vascular pathogenRalstonia solanacearumhas evolved and adapted to cause severe damage in an unusually wide range of plants. In order to better describe and understand these adaptations, strains with very similar lifestyles and host specializations are grouped into ecotypes. We used comparative genomic hybridization (CGH) to investigate three particular ecotypes in the American phylotype II group: (i) brown rot strains from phylotypes IIB-1 and IIB-2, historically known as race 3 biovar 2 and clonal; (ii) new pathogenic variants from phylotype IIB-4NPB that lack pathogenicity for banana but can infect many other plant species; and (iii) Moko disease-causing strains from phylotypes IIB-3, IIB-4, and IIA-6, historically known as race 2, that cause wilt on banana, plantain, andHeliconiaspp. We compared the genomes of 72R. solanacearumstrains, mainly from the three major ecotypes of phylotype II, using a newly developed pangenomic microarray to decipher their population structure and gain clues about the epidemiology of these ecotypes. Strain phylogeny and population structure were reconstructed. The results revealed a phylogeographic structure within brown rot strains, allowing us to distinguish European outbreak strains of Andean and African origins. The pangenomic CGH data also demonstrated that Moko ecotype IIB-4 is phylogenetically distinct from the emerging IIB-4NPB strains. These findings improved our understanding of the epidemiology of important ecotypes in phylotype II and will be useful for evolutionary analyses and the development of new DNA-based diagnostic tools.

scholarly journals Comparative genomic analysis of Polypodiaceae chloroplasts reveals fine structural features and dynamic insertion sequences

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shanshan Liu ◽  
Zhen Wang ◽  
Yingjuan Su ◽  
Ting Wang
Keyword(s):  
Large Scale ◽  
Structural Evolution ◽  
Genomic Analysis ◽  
Structural Features ◽  
Comparative Genomic ◽  
Insertion Sequences ◽  
Strand Breaks ◽  
Genomic Structural Variation ◽  
Organizational Stability ◽  
Dispersed Repeats

Abstract Background Comparative chloroplast genomics could shed light on the major evolutionary events that established plastomic diversity among closely related species. The Polypodiaceae family is one of the most species-rich and underexplored groups of extant ferns. It is generally recognized that the plastomes of Polypodiaceae are highly notable in terms of their organizational stability. Hence, no research has yet been conducted on genomic structural variation in the Polypodiaceae. Results The complete plastome sequences of Neolepisorus fortunei, Neolepisorus ovatus, and Phymatosorus cuspidatus were determined based on next-generation sequencing. Together with published plastomes, a comparative analysis of the fine structure of Polypodiaceae plastomes was carried out. The results indicated that the plastomes of Polypodiaceae are not as conservative as previously assumed. The size of the plastomes varies greatly in the Polypodiaceae, and the large insertion fragments present in the genome could be the main factor affecting the genome length. The plastome of Selliguea yakushimensis exhibits prominent features including not only a large-scale IR expansion exceeding several kb but also a unique inversion. Furthermore, gene contents, SSRs, dispersed repeats, and mutational hotspot regions were identified in the plastomes of the Polypodiaceae. Although dispersed repeats are not abundant in the plastomes of Polypodiaceae, we found that the large insertions that occur in different species are mobile and are always adjacent to repeated hotspot regions. Conclusions Our results reveal that the plastomes of Polypodiaceae are dynamic molecules, rather than constituting static genomes as previously thought. The dispersed repeats flanking insertion sequences contribute to the repair mechanism induced by double-strand breaks and are probably a major driver of structural evolution in the plastomes of Polypodiaceae.

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