scholarly journals Comparative genomics of the black rot pathogen Xanthomonas campestris pv. campestris and non-pathogenic co-inhabitant Xanthomonas melonis from Trinidad reveal unique pathogenicity determinants and secretion system profiles

PeerJ ◽  
2022 ◽  
Vol 9 ◽  
pp. e12632
Author(s):  
Stephen D. B. Jr. Ramnarine ◽  
Jayaraj Jayaraman ◽  
Adesh Ramsubhag
Keyword(s):  
Xanthomonas Campestris ◽  
Bacterial Species ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Caribbean Region ◽  
Future Research ◽  
Comparative Genomic ◽  
Black Rot ◽  
Cell Wall Degrading Enzymes

Black-rot disease caused by the phytopathogen Xanthomonas campestris pv. campestris (Xcc) continues to have considerable impacts on the productivity of cruciferous crops in Trinidad and Tobago and the wider Caribbean region. While the widespread occurrence of resistance of Xcc against bactericidal agrochemicals can contribute to the high disease burdens, the role of virulence and pathogenicity features of local strains on disease prevalence and severity has not been investigated yet. In the present study, a comparative genomic analysis was performed on 6 pathogenic Xcc and 4 co-isolated non-pathogenic Xanthomonas melonis (Xmel) strains from diseased crucifer plants grown in fields with heavy chemical use in Trinidad. Native isolates were grouped into two known and four newly assigned ribosomal sequence types (rST). Mobile genetic elements were identified which belonged to the IS3, IS5 family, Tn3 transposon, resolvases, and tra T4SS gene clusters. Additionally, exogenous plasmid derived sequences with origins from other bacterial species were characterised. Although several instances of genomic rearrangements were observed, native Xcc and Xmel isolates shared a significant level of structural homology with reference genomes, Xcc ATCC 33913 and Xmel CFBP4644, respectively. Complete T1SS hlyDB, T2SS, T4SS vir and T5SS xadA, yapH and estA gene clusters were identified in both species. Only Xmel strains contained a complete T6SS but no T3SS. Both species contained a complex repertoire of extracellular cell wall degrading enzymes. Native Xcc strains contained 37 T3SS and effector genes but a variable and unique profile of 8 avr, 4 xop and 1 hpa genes. Interestingly, Xmel strains contained several T3SS effectors with low similarity to references including avrXccA1 (~89%), hrpG (~73%), hrpX (~90%) and xopAZ (~87%). Furthermore, only Xmel genomes contained a CRISPR-Cas I-F array, but no lipopolysaccharide wxc gene cluster. Xmel strains were confirmed to be non-pathogenic by pathogenicity assays. The results of this study will be useful to guide future research into virulence mechanisms, agrochemical resistance, pathogenomics and the potential role of the co-isolated non-pathogenic Xanthomonas strains on Xcc infections.

scholarly journals Comparative Genomic Analysis Reveals Habitat-Specific Genes and Regulatory Hubs within the Genus Novosphingobium

mSystems ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Roshan Kumar ◽  
Helianthous Verma ◽  
Shazia Haider ◽  
Abhay Bajaj ◽  
Utkarsh Sood ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Core Genome ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Genomic Analysis ◽  
Specific Protein ◽  
Comparative Genomic ◽  
Ecological Groups ◽  
Functional And Phylogenetic Diversity

ABSTRACT This study highlights the significant role of the genetic repertoire of a microorganism in the similarity between Novosphingobium strains. The results suggest that the phylogenetic relationships were mostly influenced by metabolic trait enrichment, which is possibly governed by the microenvironment of each microbe’s respective niche. Using core genome analysis, the enrichment of a certain set of genes specific to a particular habitat was determined, which provided insights on the influence of habitat on the distribution of metabolic traits for Novosphingobium strains. We also identified habitat-specific protein hubs, which suggested delineation of Novosphingobium strains based on their habitat. Examining the available genomes of ecologically diverse bacterial species and analyzing the habitat-specific genes are useful for understanding the distribution and evolution of functional and phylogenetic diversity in the genus Novosphingobium. Species belonging to the genus Novosphingobium are found in many different habitats and have been identified as metabolically versatile. Through comparative genomic analysis, we identified habitat-specific genes and regulatory hubs that could determine habitat selection for Novosphingobium spp. Genomes from 27 Novosphingobium strains isolated from diverse habitats such as rhizosphere soil, plant surfaces, heavily contaminated soils, and marine and freshwater environments were analyzed. Genome size and coding potential were widely variable, differing significantly between habitats. Phylogenetic relationships between strains were less likely to describe functional genotype similarity than the habitat from which they were isolated. In this study, strains (19 out of 27) with a recorded habitat of isolation, and at least 3 representative strains per habitat, comprised four ecological groups—rhizosphere, contaminated soil, marine, and freshwater. Sulfur acquisition and metabolism were the only core genomic traits to differ significantly in proportion between these ecological groups; for example, alkane sulfonate (ssuABCD) assimilation was found exclusively in all of the rhizospheric isolates. When we examined osmolytic regulation in Novosphingobium spp. through ectoine biosynthesis, which was assumed to be marine habitat specific, we found that it was also present in isolates from contaminated soil, suggesting its relevance beyond the marine system. Novosphingobium strains were also found to harbor a wide variety of mono- and dioxygenases, responsible for the metabolism of several aromatic compounds, suggesting their potential to act as degraders of a variety of xenobiotic compounds. Protein-protein interaction analysis revealed β-barrel outer membrane proteins as habitat-specific hubs in each of the four habitats—freshwater (Saro_1868), marine water (PP1Y_AT17644), rhizosphere (PMI02_00367), and soil (V474_17210). These outer membrane proteins could play a key role in habitat demarcation and extend our understanding of the metabolic versatility of the Novosphingobium species. IMPORTANCE This study highlights the significant role of a microorganism’s genetic repertoire in structuring the similarity between Novosphingobium strains. The results suggest that the phylogenetic relationships were mostly influenced by metabolic trait enrichment, which is possibly governed by the microenvironment of each microbe’s respective niche. Using core genome analysis, the enrichment of a certain set of genes specific to a particular habitat was determined, which provided insights on the influence of habitat on the distribution of metabolic traits in Novosphingobium strains. We also identified habitat-specific protein hubs, which suggested delineation of Novosphingobium strains based on their habitat. Examining the available genomes of ecologically diverse bacterial species and analyzing the habitat-specific genes are useful for understanding the distribution and evolution of functional and phylogenetic diversity in the genus Novosphingobium.

scholarly journals Whole Genome Sequencing Based Taxonomic Classification, and Comparative Genomic Analysis of Potentially Human Pathogenic Enterobacter spp. Isolated from Chlorinated Wastewater in the North West Province, South Africa

2021 ◽  
Vol 9 (9) ◽  
pp. 1928
Author(s):  
Tawanda E. Maguvu ◽  
Cornelius C. Bezuidenhout
Keyword(s):  
Bacterial Species ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Comparative Genomic Analysis ◽  
Taxonomic Classification ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Human Pathogens ◽  
Wastewater Treatment Process ◽  
North West

Comparative genomics, in particular, pan-genome analysis, provides an in-depth understanding of the genetic variability and dynamics of a bacterial species. Coupled with whole-genome-based taxonomic analysis, these approaches can help to provide comprehensive, detailed insights into a bacterial species. Here, we report whole-genome-based taxonomic classification and comparative genomic analysis of potential human pathogenic Enterobacter hormaechei subsp. hoffmannii isolated from chlorinated wastewater. Genome Blast Distance Phylogeny (GBDP), digital DNA-DNA hybridization (dDDH), and average nucleotide identity (ANI) confirmed the identity of the isolates. The algorithm PathogenFinder predicted the isolates to be human pathogens with a probability of greater than 0.78. The potential pathogenic nature of the isolates was supported by the presence of biosynthetic gene clusters (BGCs), aerobactin, and aryl polyenes (APEs), which are known to be associated with pathogenic/virulent strains. Moreover, analysis of the genome sequences of the isolates reflected the presence of an arsenal of virulence factors and antibiotic resistance genes that augment the predictions of the algorithm PathogenFinder. The study comprehensively elucidated the genomic features of pathogenic Enterobacter isolates from wastewaters, highlighting the role of wastewaters in the dissemination of pathogenic microbes, and the need for monitoring the effectiveness of the wastewater treatment process.

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 Role of Hypermutability in the Evolution of the Genus Oenococcus

2007 ◽  
Vol 190 (2) ◽  
pp. 564-570 ◽  
Author(s):  
Angela M. Marcobal ◽  
David A. Sela ◽  
Yuri I. Wolf ◽  
Kira S. Makarova ◽  
David A. Mills
Keyword(s):  
Lactic Acid ◽  
Leuconostoc Mesenteroides ◽  
Genomic Analysis ◽  
Oenococcus Oeni ◽  
Mutation Rates ◽  
Comparative Genomic ◽  
Allelic Polymorphism ◽  
Resistant Strains ◽  
High Level

ABSTRACT Oenococcus oeni is an alcohol-tolerant, acidophilic lactic acid bacterium primarily responsible for malolactic fermentation in wine. A recent comparative genomic analysis of O. oeni PSU-1 with other sequenced lactic acid bacteria indicates that PSU-1 lacks the mismatch repair (MMR) genes mutS and mutL. Consistent with the lack of MMR, mutation rates for O. oeni PSU-1 and a second oenococcal species, O. kitaharae, were higher than those observed for neighboring taxa, Pediococcus pentosaceus and Leuconostoc mesenteroides. Sequence analysis of the rpoB mutations in rifampin-resistant strains from both oenococcal species revealed a high percentage of transition mutations, a result indicative of the lack of MMR. An analysis of common alleles in the two sequenced O. oeni strains, PSU-1 and BAA-1163, also revealed a significantly higher level of transition substitutions than were observed in other Lactobacillales species. These results suggest that the genus Oenococcus is hypermutable due to the loss of mutS and mutL, which occurred with the divergence away from the neighboring Leuconostoc branch. The hypermutable status of the genus Oenococcus explains the observed high level of allelic polymorphism among known O. oeni isolates and likely contributed to the unique adaptation of this genus to acidic and alcoholic environments.

scholarly journals Interaction of two strongly divergent archaellins stabilizes the structure of the Halorubrum archaellum

2019 ◽  
Author(s):  
Mikhail G. Pyatibratov ◽  
Alexey S. Syutkin ◽  
Tessa E.F. Quax ◽  
Tatjana N. Melnik ◽  
R. Thane Papke ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Genomic Analysis ◽  
Halophilic Archaea ◽  
Amino Acid Sequences ◽  
Comparative Genomic ◽  
Low Salinity ◽  
Additional Stabilization ◽  
External Conditions ◽  
Thermal Stability Of

SUMMARYThe archaellum is a unique motility structure that has only functional similarity to its bacterial counterpart, the flagellum. Archaellar filaments consist of thousands of copies of the protein protomer archaellin. Most euryarchaeal genomes encode multiple homologous archaellins. The role of these multiple archaellin genes remains unclear. Halophilic archaea from the genus Halorubrum possess two archaellin genes, flaB1 and flaB2. Amino acid sequences of the corresponding protein products are extraordinarily diverged (identity of ∼ 40%). To clarify roles for each archaellin, we compared archaella from two natural Halorubrum lacusprofundi strains: the DL18 strain, which possesses both archaellin genes, and the type strain ACAM 34 whose genome contains the flaB2 gene only. Both strains synthesize functional archaella; however, the DL18 strain, where both archaellins are present in comparable amounts, is more motile. In addition, we expressed these different Hrr. lacusprofundi archaellins in a Haloferax volcanii strain from which the endogenous archaellin genes were deleted. Three Hfx. volcanii strains expressing Hrr. lacusprofundi archaellins flaB1, flaB2 or flaB1-flaB2 produced archaellum filaments consisting of only one (FlaB1 or FlaB2) or both (FlaB1/B2) archaellins. All three recombinant Hfx. volcanii strains were motile, although there were profound differences in the efficiency of motility. The recombinant filaments resemble the natural filaments of Hrr. lacusprofundi. Electron microscopy showed that FlaB1 FlaB2-archaella look like typical supercoiled filaments, while with the shape of the FlaB1- and FlaB2-archaella is more variable. Both native and recombinant FlaB1 FlaB2-filaments have greater thermal stability and are more resistant to low salinity stress than single-component filaments. This shows that thermal stability of archaellins depends on the presence of both archaellin types, indicating a close interaction between these subunits in the supramolecular structure. Functional helical Hrr. lacusprofundi archaella can be composed of either single archaellin: FlaB2 or FlaB1; however, the two divergent archaellin subunits in combination provide additional stabilization to the archaellum structure and thus adaptation to a wider range of external conditions. A comparative genomic analysis of archaellins suggests that the described combination of divergent archaellins is not restricted to Hrr. lacusprofundi, but is occurring also in organisms from other haloarchaeal genera.

scholarly journals Enhanced copper-resistance gene repertoire in Alteromonas macleodii strains isolated from copper-treated marine coatings

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257800
Author(s):  
Kathleen Cusick ◽  
Ane Iturbide ◽  
Pratima Gautam ◽  
Amelia Price ◽  
Shawn Polson ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Markov Models ◽  
Bacterial Species ◽  
Genomic Analysis ◽  
Copper Resistance ◽  
Comparative Genomic ◽  
Gene Repertoire ◽  
Ship Hulls ◽  
Multiple Copies ◽  
Alteromonas Macleodii

Copper is prevalent in coastal ecosystems due to its use as an algaecide and as an anti-fouling agent on ship hulls. Alteromonas spp. have previously been shown to be some of the early colonizers of copper-based anti-fouling paint but little is known about the mechanisms they use to overcome this initial copper challenge. The main models of copper resistance include the Escherichia coli chromosome-based Cue and Cus systems; the plasmid-based E. coli Pco system; and the plasmid-based Pseudomonas syringae Cop system. These were all elucidated from strains isolated from copper-rich environments of agricultural and/or enteric origin. In this work, copper resistance assays demonstrated the ability of Alteromonas macleodii strains CUKW and KCC02 to grow at levels lethal to other marine bacterial species. A custom database of Hidden Markov Models was designed based on proteins from the Cue, Cus, and Cop/Pco systems and used to identify potential copper resistance genes in CUKW and KCC02. Comparative genomic analyses with marine bacterial species and bacterial species isolated from copper-rich environments demonstrated that CUKW and KCC02 possess genetic elements of all systems, oftentimes with multiple copies, distributed throughout the chromosome and mega-plasmids. In particular, two copies of copA (the key player in cytoplasmic detoxification), each with its own apparent MerR-like transcriptional regulator, occur on a mega-plasmid, along with multiple copies of Pco homologs. Genes from both systems were induced upon exposure to elevated copper levels (100 μM– 3 mM). Genomic analysis identified one of the merR-copA clusters occurs on a genomic island (GI) within the plasmid, and comparative genomic analysis found that either of the merR-copA clusters, which also includes genes coding for a cupredoxin domain-containing protein and an isoprenylcysteine methyltransferase, occurs on a GI across diverse bacterial species. These genomic findings combined with the ability of CUKW and KCC02 to grow in copper-challenged conditions are couched within the context of the genome flexibility of the Alteromonas genus.

scholarly journals Comparative genomics: Dominant coral-bacterium Endozoicomonas acroporae metabolizes dimethylsulfoniopropionate (DMSP)

2019 ◽  
Author(s):  
Kshitij Tandon ◽  
Pei-Wen Chiang ◽  
Chih-Ying Lu ◽  
Naohisa Wada ◽  
Shan-Hua Yang ◽  
...  
Keyword(s):  
Sole Carbon Source ◽  
Genomic Analysis ◽  
Sulfur Cycle ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
High Quality ◽  
Coa Transferase ◽  
Complete Genomes ◽  
Central Carbon

AbstractDominant coral-associated Endozoicomonas bacteria species are hypothesized to play a role in the coral-sulfur cycle by metabolizing Dimethylsulfoniopropionate (DMSP) into Dimethylsulfide (DMS); however, no sequenced genome to date harbors genes for this process. In this study, we assembled high-quality (>95% complete) genomes of strains of a recently added species Endozoicomonas acroporae (Acr-14T, Acr-1 and Acr-5) isolated from the coral Acropora muricata and performed comparative genomic analysis on genus Endozoicomonas. We identified the first DMSP CoA-transferase/lyase—a dddD gene homolog found in all E. acroporae strains—and functionally characterized bacteria capable of metabolizing DMSP into DMS via the DddD cleavage pathway using RT-qPCR and gas chromatography (GC). Furthermore, we demonstrated that E. acroporae strains can use DMSP as the sole carbon source and have genes arranged in an operon-like manner to link DMSP metabolism to the central carbon cycle. This study confirms the role of Endozoicomonas in the coral sulfur cycle.

scholarly journals Web-Based Genome Analysis of Bacterial Meningitis Pathogens for Public Health Applications Using the Bacterial Meningitis Genomic Analysis Platform (BMGAP)

2020 ◽  
Vol 11 ◽  
Author(s):  
Sean A. Buono ◽  
Reagan J. Kelly ◽  
Nadav Topaz ◽  
Adam C. Retchless ◽  
Hideky Silva ◽  
...  
Keyword(s):  
Public Health ◽  
Bacterial Meningitis ◽  
Sensitivity And Specificity ◽  
Genome Analysis ◽  
Bacterial Species ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Public Health Response ◽  
Analysis Platform

Effective laboratory-based surveillance and public health response to bacterial meningitis depends on timely characterization of bacterial meningitis pathogens. Traditionally, characterizing bacterial meningitis pathogens such as Neisseria meningitidis (Nm) and Haemophilus influenzae (Hi) required several biochemical and molecular tests. Whole genome sequencing (WGS) has enabled the development of pipelines capable of characterizing the given pathogen with equivalent results to many of the traditional tests. Here, we present the Bacterial Meningitis Genomic Analysis Platform (BMGAP): a secure, web-accessible informatics platform that facilitates automated analysis of WGS data in public health laboratories. BMGAP is a pipeline comprised of several components, including both widely used, open-source third-party software and customized analysis modules for the specific target pathogens. BMGAP performs de novo draft genome assembly and identifies the bacterial species by whole-genome comparisons against a curated reference collection of 17 focal species including Nm, Hi, and other closely related species. Genomes identified as Nm or Hi undergo multi-locus sequence typing (MLST) and capsule characterization. Further typing information is captured from Nm genomes, such as peptides for the vaccine antigens FHbp, NadA, and NhbA. Assembled genomes are retained in the BMGAP database, serving as a repository for genomic comparisons. BMGAP’s species identification and capsule characterization modules were validated using PCR and slide agglutination from 446 bacterial invasive isolates (273 Nm from nine different serogroups, 150 Hi from seven different serotypes, and 23 from nine other species) collected from 2017 to 2019 through surveillance programs. Among the validation isolates, BMGAP correctly identified the species for all 440 isolates (100% sensitivity and specificity) and accurately characterized all Nm serogroups (99% sensitivity and 98% specificity) and Hi serotypes (100% sensitivity and specificity). BMGAP provides an automated, multi-species analysis pipeline that can be extended to include additional analysis modules as needed. This provides easy-to-interpret and validated Nm and Hi genome analysis capacity to public health laboratories and collaborators. As the BMGAP database accumulates more genomic data, it grows as a valuable resource for rapid comparative genomic analyses during outbreak investigations.

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