scholarly journals Characterization and Genomic Analysis of PALS2, a Novel Staphylococcus Jumbo Bacteriophage

2021 ◽  
Vol 12 ◽  
Author(s):  
Yoona Lee ◽  
Bokyung Son ◽  
Yoyeon Cha ◽  
Sangryeol Ryu
Keyword(s):  
Food Processing ◽  
Biocontrol Agent ◽  
Genomic Analysis ◽  
Antimicrobial Activities ◽  
Nucleotide Metabolism ◽  
Comparative Genomic ◽  
Base Pairs ◽  
Genes Encoding ◽  
Dna Replication And Repair ◽  
Bird Feces

Staphylococcus aureus is an important human pathogen that can be frequently encountered in clinical and food-processing surroundings. Among the various countermeasures, bacteriophages have been considered to be promising alternatives to antibiotics. In this study, the bacteriophage PALS2 was isolated from bird feces, and the genomic and biological characteristics of this phage were investigated. PALS2 was determined to belong to the Myoviridae family and exhibited extended host inhibition that persisted for up to 24 h with repeated bursts of 12 plaque-forming units/cell. The complete genome of PALS2 measured 268,746 base pairs (bp), indicating that PALS2 could be classified as a jumbo phage. The PALS2 genome contained 279 ORFs and 1 tRNA covering asparagine, and the majority of predicted PALS2 genes encoded hypothetical proteins. Additional genes involved in DNA replication and repair, nucleotide metabolism, and genes encoding multisubunit RNA polymerase were identified in the PALS2 genome, which is a common feature of typical jumbo phages. Comparative genomic analysis indicated that PALS2 is a phiKZ-related virus and is more similar to typical jumbo phages than to staphylococcal phages. Additionally, the effective antimicrobial activities of phage PALS2 suggest its possible use as a biocontrol agent in various clinical and food processing environments.

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 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 Virulence characterization and comparative genomics of Listeria monocytogenes sequence type 155 strains

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Eva Wagner ◽  
Andreas Zaiser ◽  
Rebekka Leitner ◽  
Narciso M. Quijada ◽  
Nadja Pracser ◽  
...  
Keyword(s):  
Food Processing ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Specific Sequence ◽  
Equal Distribution ◽  
Genetic Traits ◽  
Virulence Potential ◽  
Genetic Features ◽  
Source Category

Abstract Background Listeria (L.) monocytogenes strains show a high diversity regarding stress tolerance and virulence potential. Genome studies have mainly focused on specific sequence types (STs) predominantly associated with either food or human listeriosis. This study focused on the prevalent ST155, showing equal distribution among clinical and food isolates. We evaluated the virulence potential of 20 ST155 strains and performed comparative genomic analysis of 130 ST155 strains isolated from food, food processing environments and human listeriosis cases in different countries and years. Results The in vitro virulence assays using human intestinal epithelial Caco2 and hepatocytic HEPG2 cells showed an impaired virulence phenotype for six of the 20 selected ST155 strains. Genome analysis revealed no distinct clustering of strains from the same source category (food, food processing environment, and clinical isolates). All strains harbored an intact inlA and inlB locus, except four strains, which had an internal deletion in the inlA gene. All strains harbored LIPI-1, but prfA was present in a longer variant in six strains, all showing impaired virulence. The longer PrfA variant resulted in lower expression of inlA, inlB, and prfA, and no expression of hly and actA. Regarding stress-related gene content, SSI-1 was present, whereas qacH was absent in all strains. 34.6% of the strains harbored a plasmid. All but one ST155 plasmids showed high conservation and harbored cadA2, bcrABC, and a triphenylmethane reductase. Conclusions This study contributes to an enhanced understanding of L. monocytogenes ST155 strains, being equally distributed among isolates from humans, food, and food processing environments. The conservation of the present genetic traits and the absence of unique inherent genetic features makes these types of STs especially interesting since they are apparently equally adapted to the conditions in food processing environments, as well as in food as to the human host environment. However, a ST155-specific mutation resulting in a longer PrfA variant impaired the virulence potential of several ST155 strains.

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 Genomic analysis of a riboflavin-overproducing Ashbya gossypii mutant isolated by disparity mutagenesis

2019 ◽  
Author(s):  
Tatsuya Kato ◽  
Junya Azegami ◽  
Ami Yokomori ◽  
Hideo Dohra ◽  
Hesham A. El Enshasy ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Tca Cycle ◽  
Nucleotide Metabolism ◽  
Repair System ◽  
Ashbya Gossypii ◽  
Riboflavin Production ◽  
Dna Mismatch ◽  
Pyrimidine Nucleotide ◽  
Dna Mismatch Repair System ◽  
Genes Encoding

Abstract Background: Ashbya gossypii naturally overproduces riboflavin and has been utilized for industrial riboflavin production. To improve riboflavin production, various approaches have been developed. In this study, to investigate the change in metabolism of a riboflavin-overproducing mutant, namely, the W122032 strain (MT strain) that was isolated by disparity mutagenesis, genomic analysis was carried out. Results: In the genomic analysis, 33 homozygous and 1377 heterozygous mutations were detected. Among these heterozygous mutations, the proportion of mutated reads in each gene was different, ranging from 21 to 75%. These results suggest that the MT strain exhibits a mixture of diploidy, triploidy and tetraploidy, or contains multiple nuclei containing different mutations. We tried to isolate haploid spores from the MT strain to prove it ploidy, but these spores were never isolated. This result indicate MT strain does not produce its spores. Homozygous and heterozygous mutations were found in genes encoding enzymes involved in amino acid metabolism, the TCA cycle, purine and pyrimidine nucleotide metabolism and the DNA mismatch repair system. Especially, genes encoding enzymes in mitochondria had many homozygous and heterozygous mutations intensively. These results suggest that the overproduction of riboflavin in the MT strain may be associated with mitochondrial dysfunction. Conclusion: This study provides new insights into riboflavin production in A. gossypii and the usefulness of disparity mutagenesis for the creation of new types of mutants for metabolic engineering.

scholarly journals Comparative Genomic Analysis of the Biotechnological Potential of the Novel Species Pseudomonas wadenswilerensis CCOS 864T and Pseudomonas reidholzensis CCOS 865T

Diversity ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 204
Author(s):  
Dominik Rutz ◽  
David Frasson ◽  
Martin Sievers ◽  
Jochen Blom ◽  
Fabio Rezzonico ◽  
...  
Keyword(s):  
New Species ◽  
Plant Pathogens ◽  
Draft Genome ◽  
Genomic Analysis ◽  
Yield Potential ◽  
Comparative Genomic ◽  
Genomic Features ◽  
Two New Species ◽  
Genes Encoding ◽  
Potential Applications

In recent years, the use of whole-cell biocatalysts and biocatalytic enzymes in biotechnological applications originating from the genus Pseudomonas has greatly increased. In 2014, two new species within the Pseudomonas putida group were isolated from Swiss forest soil. In this study, the high quality draft genome sequences of Pseudomonas wadenswilerensis CCOS 864T and Pseudomonas reidholzensis CCOS 865T were used in a comparative genomics approach to identify genomic features that either differed between these two new species or to selected members of the P. putida group. The genomes of P. wadenswilerensis CCOS 864T and P. reidholzensis CCOS 865T were found to share genomic features for the degradation of aromatic compounds or the synthesis of secondary metabolites. In particular, genes encoding for biocatalytic relevant enzymes belonging to the class of oxidoreductases, proteases and isomerases were found, that could yield potential applications in biotechnology. Ecologically relevant features revealed that both species are probably playing an important role in the degradation of soil organic material, the accumulation of phosphate and biocontrol against plant pathogens.

scholarly journals Genome-guided analysis allows the identification of novel physiological traits in Trichococcus species

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Nikolaos Strepis ◽  
Henry D. Naranjo ◽  
Jan Meier-Kolthoff ◽  
Markus Göker ◽  
Nicole Shapiro ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Genomic Analysis ◽  
Single Species ◽  
The Other ◽  
Physiological Traits ◽  
Comparative Genomic ◽  
C Protein ◽  
Wide Range ◽  
Genes Encoding ◽  
Type Strains

Abstract Background The genus Trichococcus currently contains nine species: T. flocculiformis, T. pasteurii, T. palustris, T. collinsii, T. patagoniensis, T. ilyis, T. paludicola, T. alkaliphilus, and T. shcherbakoviae. In general, Trichococcus species can degrade a wide range of carbohydrates. However, only T. pasteurii and a non-characterized strain of Trichococcus, strain ES5, have the capacity of converting glycerol to mainly 1,3-propanediol. Comparative genomic analysis of Trichococcus species provides the opportunity to further explore the physiological potential and uncover novel properties of this genus. Results In this study, a genotype-phenotype comparative analysis of Trichococcus strains was performed. The genome of Trichococcus strain ES5 was sequenced and included in the comparison with the other nine type strains. Genes encoding functions related to e.g. the utilization of different carbon sources (glycerol, arabinan and alginate), antibiotic resistance, tolerance to low temperature and osmoregulation could be identified in all the sequences analysed. T. pasteurii and Trichococcus strain ES5 contain a operon with genes encoding necessary enzymes for 1,3-PDO production from glycerol. All the analysed genomes comprise genes encoding for cold shock domains, but only five of the Trichococcus species can grow at 0 °C. Protein domains associated to osmoregulation mechanisms are encoded in the genomes of all Trichococcus species, except in T. palustris, which had a lower resistance to salinity than the other nine studied Trichococcus strains. Conclusions Genome analysis and comparison of ten Trichococcus strains allowed the identification of physiological traits related to substrate utilization and environmental stress resistance (e.g. to cold and salinity). Some substrates were used by single species, e.g. alginate by T. collinsii and arabinan by T. alkaliphilus. Strain ES5 may represent a subspecies of Trichococcus flocculiformis and contrary to the type strain (DSM 2094T), is able to grow on glycerol with the production of 1,3-propanediol.

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