scholarly journals Pan-genome Analyses of 3 Strains of Inonotus obliquus and Prediction of Polysaccharide and Terpenoid Genes

2021 ◽  
Vol 16 (11) ◽  
pp. 1934578X2110609
Author(s):  
Xiaofan Guo ◽  
Shouming Wang

Inonotus obliquus is a rare, edible and medicinal fungus that is widely used as a remedy for various diseases. Its main bioactive substances are polysaccharides and terpenoids. In this study, we characterized and investigated the pan-genome of three strains of I. obliquus. The genome sizes of JL01, HE, and NBRC8681 were 32.04, 29.04, and 31.78 Mb, respectively. There were 6 543 core gene families and 6 197 accessory gene families among the three strains, with 14 polysaccharide-related core gene families and seven accessory gene families. For terpenoids, there were 13 core gene families and 17 accessory gene families. Pan-genome sequencing of I. obliquus has improved our understanding of biological characteristics related to the biosynthesis of polysaccharides and terpenoids at the molecular level, which in turn will enable us to increase the production of polysaccharides and terpenoids by this mushroom.

2019 ◽  
Vol 7 (11) ◽  
pp. 487
Author(s):  
Samrat Ghosh ◽  
Aditya Narayan Sarangi ◽  
Mayuri Mukherjee ◽  
Swati Bhowmick ◽  
Sucheta Tripathy

Lactobacillus paracasei are diverse Gram-positive bacteria that are very closely related to Lactobacillus casei, belonging to the Lactobacillus casei group. Due to extreme genome similarities between L. casei and L. paracasei, many strains have been cross placed in the other group. We had earlier sequenced and analyzed the genome of Lactobacillus paracasei Lbs2, but mistakenly identified it as L. casei. We re-analyzed Lbs2 reads into a 2.5 MB genome that is 91.28% complete with 0.8% contamination, which is now suitably placed under L. paracasei based on Average Nucleotide Identity and Average Amino Acid Identity. We took 74 sequenced genomes of L. paracasei from GenBank with assembly sizes ranging from 2.3 to 3.3 MB and genome completeness between 88% and 100% for comparison. The pan-genome of 75 L. paracasei strains hold 15,945 gene families (21,5232 genes), while the core genome contained about 8.4% of the total genes (243 gene families with 18,225 genes) of pan-genome. Phylogenomic analysis based on core gene families revealed that the Lbs2 strain has a closer relationship with L. paracasei subsp. tolerans DSM20258. Finally, the in-silico analysis of the L. paracasei Lbs2 genome revealed an important pathway that could underpin the production of thiamin, which may contribute to the host energy metabolism.


Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 686
Author(s):  
Poonam Sharma ◽  
Sushim K. Gupta ◽  
John B. Barrett ◽  
Lari M. Hiott ◽  
Tiffanie A. Woodley ◽  
...  

Enterococcus cecorum is an emerging avian pathogen, particularly in chickens, but can be found in both diseased (clinical) and healthy (non-clinical) poultry. To better define differences between E. cecorum from the two groups, whole-genome sequencing (WGS) was used to identify and compare antimicrobial resistance genes as well as the pan-genome among the isolates. Eighteen strains selected from our previous study were subjected to WGS using Illumina MiSeq and comparatively analyzed. Assembled contigs were analyzed for resistance genes using ARG-ANNOT. Resistance to erythromycin was mediated by ermB, ermG, and mefA, in clinical isolates and ermB and mefA, in non-clinical isolates. Lincomycin resistance genes were identified as linB, lnuB, lnuC, and lnuD with lnuD found only in non-clinical E. cecorum; however, lnuB and linB were found in only one clinical isolate. For both groups of isolates, kanamycin resistance was mediated by aph3-III, while tetracycline resistance was conferred by tetM, tetO, and tetL. No mutations or known resistance genes were found for isolates resistant to either linezolid or chloramphenicol, suggesting possible new mechanisms of resistance to these drugs. A comparison of WGS results confirmed that non-clinical isolates contained more resistance genes than clinical isolates. The pan-genome of clinical and non-clinical isolates resulted in 3651 and 4950 gene families, respectively, whereas the core gene sets were comprised of 1559 and 1534 gene families in clinical and non-clinical isolates, respectively. Unique genes were found more frequently in non-clinical isolates than clinical. Phylogenetic analysis of the isolates and all the available complete and draft genomes showed no correlation between healthy and diseased poultry. Additional genomic comparison is required to elucidate genetic factors in E. cecorum that contribute to disease in poultry.


2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Amjad Ali ◽  
Anam Naz ◽  
Siomar C Soares ◽  
Marriam Bakhtiar ◽  
Sandeep Tiwari ◽  
...  

Helicobacter pyloriis a human gastric pathogen implicated as the major cause of peptic ulcer and second leading cause of gastric cancer (~70%) around the world. Conversely, an increased resistance to antibiotics and hindrances in the development of vaccines againstH. pyloriare observed. Pan-genome analyses of the global representativeH. pyloriisolates consisting of 39 complete genomes are presented in this paper. Phylogenetic analyses have revealed close relationships among geographically diverse strains ofH. pylori. The conservation among these genomes was further analyzed by pan-genome approach; the predicted conserved gene families (1,193) constitute ~77% of the averageH. pylorigenome and 45% of the global gene repertoire of the species. Reverse vaccinology strategies have been adopted to identify and narrow down the potential core-immunogenic candidates. Total of 28 nonhost homolog proteins were characterized as universal therapeutic targets againstH. pyloribased on their functional annotation and protein-protein interaction. Finally, pathogenomics and genome plasticity analysis revealed 3 highly conserved and 2 highly variable putative pathogenicity islands in all of theH. pylorigenomes been analyzed.


Author(s):  
Gulinigaer Anwaier ◽  
Cong Wen ◽  
Yi-ni Caoili ◽  
Rong Qi

: As a medicinal fungus, Inonotus obliquus (IO) has been widely used in the treatment of cancer and digestive system diseases. Despite the progress that has been made in the studies of IO and its active compounds, their applications in other important clinical diseases, such as cardiovascular diseases, which are major global issues with limited treatment strategies, are seldom reported. This review summarizes the separation and purification methods of chemical components of IO, the advances in their applications, and research progress on the pharmacological effects and related mechanisms of IO in disease prevention. This review will help researchers and clinicians to further understand the pharmacological functions and mechanisms of IO and its active components, which may extend their medical applications in the prevention and treatment of other diseases in addition to tumors and digestive system diseases in the near future.


2020 ◽  
Vol 12 (11) ◽  
pp. 2002-2014
Author(s):  
Ling-Ling Yang ◽  
Zhao Jiang ◽  
Yan Li ◽  
En-Tao Wang ◽  
Xiao-Yang Zhi

Abstract Rhizobia are soil bacteria capable of forming symbiotic nitrogen-fixing nodules associated with leguminous plants. In fast-growing legume-nodulating rhizobia, such as the species in the family Rhizobiaceae, the symbiotic plasmid is the main genetic basis for nitrogen-fixing symbiosis, and is susceptible to horizontal gene transfer. To further understand the symbioses evolution in Rhizobiaceae, we analyzed the pan-genome of this family based on 92 genomes of type/reference strains and reconstructed its phylogeny using a phylogenomics approach. Intriguingly, although the genetic expansion that occurred in chromosomal regions was the main reason for the high proportion of low-frequency flexible gene families in the pan-genome, gene gain events associated with accessory plasmids introduced more genes into the genomes of nitrogen-fixing species. For symbiotic plasmids, although horizontal gene transfer frequently occurred, transfer may be impeded by, such as, the host’s physical isolation and soil conditions, even among phylogenetically close species. During coevolution with leguminous hosts, the plasmid system, including accessory and symbiotic plasmids, may have evolved over a time span, and provided rhizobial species with the ability to adapt to various environmental conditions and helped them achieve nitrogen fixation. These findings provide new insights into the phylogeny of Rhizobiaceae and advance our understanding of the evolution of symbiotic nitrogen fixation.


2021 ◽  
Vol 15 (8) ◽  
pp. e0009665
Author(s):  
Shuai Xu ◽  
Zhenpeng Li ◽  
Yuanming Huang ◽  
Lichao Han ◽  
Yanlin Che ◽  
...  

Nocardia is a complex and diverse genus of aerobic actinomycetes that cause complex clinical presentations, which are difficult to diagnose due to being misunderstood. To date, the genetic diversity, evolution, and taxonomic structure of the genus Nocardia are still unclear. In this study, we investigated the pan-genome of 86 Nocardia type strains to clarify their genetic diversity. Our study revealed an open pan-genome for Nocardia containing 265,836 gene families, with about 99.7% of the pan-genome being variable. Horizontal gene transfer appears to have been an important evolutionary driver of genetic diversity shaping the Nocardia genome and may have caused historical taxonomic confusion from other taxa (primarily Rhodococcus, Skermania, Aldersonia, and Mycobacterium). Based on single-copy gene families, we established a high-accuracy phylogenomic approach for Nocardia using 229 genome sequences. Furthermore, we found 28 potentially new species and reclassified 16 strains. Finally, by comparing the topology between a phylogenomic tree and 384 phylogenetic trees (from 384 single-copy genes from the core genome), we identified a novel locus for inferring the phylogeny of this genus. The dapb1 gene, which encodes dipeptidyl aminopeptidase BI, was far superior to commonly used markers for Nocardia and yielded a topology almost identical to that of genome-based phylogeny. In conclusion, the present study provides insights into the genetic diversity, contributes a robust framework for the taxonomic classification, and elucidates the evolutionary relationships of Nocardia. This framework should facilitate the development of rapid tests for the species identification of highly variable species and has given new insight into the behavior of this genus.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Isaiah Paolo A. Lee ◽  
Cheryl P. Andam

Abstract Background Cronobacter sakazakii is an emerging opportunistic bacterial pathogen known to cause neonatal and pediatric infections, including meningitis, necrotizing enterocolitis, and bacteremia. Multiple disease outbreaks of C. sakazakii have been documented in the past few decades, yet little is known of its genomic diversity, adaptation, and evolution. Here, we analyzed the pan-genome characteristics and phylogenetic relationships of 237 genomes of C. sakazakii and 48 genomes of related Cronobacter species isolated from diverse sources. Results The C. sakazakii pan-genome contains 17,158 orthologous gene clusters, and approximately 19.5% of these constitute the core genome. Phylogenetic analyses reveal the presence of at least ten deep branching monophyletic lineages indicative of ancestral diversification. We detected enrichment of functions involved in proton transport and rotational mechanism in accessory genes exclusively found in human-derived strains. In environment-exclusive accessory genes, we detected enrichment for those involved in tryptophan biosynthesis and indole metabolism. However, we did not find significantly enriched gene functions for those genes exclusively found in food strains. The most frequently detected virulence genes are those that encode proteins associated with chemotaxis, enterobactin synthesis, ferrienterobactin transporter, type VI secretion system, galactose metabolism, and mannose metabolism. The genes fos which encodes resistance against fosfomycin, a broad-spectrum cell wall synthesis inhibitor, and mdf(A) which encodes a multidrug efflux transporter were found in nearly all genomes. We found that a total of 2991 genes in the pan-genome have had a history of recombination. Many of the most frequently recombined genes are associated with nutrient acquisition, metabolism and toxin production. Conclusions Overall, our results indicate that the presence of a large accessory gene pool, ability to switch between ecological niches, a diverse suite of antibiotic resistance, virulence and niche-specific genes, and frequent recombination partly explain the remarkable adaptability of C. sakazakii within and outside the human host. These findings provide critical insights that can help define the development of effective disease surveillance and control strategies for Cronobacter-related diseases.


2019 ◽  
Vol 95 (1130) ◽  
pp. 686.3-686
Author(s):  
Mark Caulfield

The UK 100,000 Genomes Project has focussed on transforming genomic medicine in the National Health Service using whole genome sequencing in rare disease, cancer and infection. Genomics England partnering with the NHS established 13 Genomic Medicine Centres, the NHS whole genome sequencing centre and the Genomics England Clinical Interpretation Partnership (3337 researchers from 24 countries). We sequenced the 100,000th genome on the 5th December 2019 and completed an initial analysis for participants in July 2019. Alongside these genomes we have assembled a longitudinal life course dataset for research and diagnosis including 2.6 billion clinical data points for the 3000 plus researchers to work on to drive up the value of the genomes for direct healthcare. In parallel we have partnered the NHS to establish one of the world’s most advanced Genomic Medicine Service where we re-evaluated 300,000 genomic tests and upgraded 25% of tests to newer technologies with an annual review. The Department of Health have announced the ambition to undertake 5 million genome analyses over the next 5 years focused on new areas tractable to health gain.


2015 ◽  
Vol 53 (8) ◽  
pp. 2622-2631 ◽  
Author(s):  
Jane F. Turton ◽  
Laura Wright ◽  
Anthony Underwood ◽  
Adam A. Witney ◽  
Yuen-Ting Chan ◽  
...  

Whole-genome sequencing (WGS) was carried out on 87 isolates of sequence type 111 (ST-111) of Pseudomonas aeruginosa collected between 2005 and 2014 from 65 patients and 12 environmental isolates from 24 hospital laboratories across the United Kingdom on an Illumina HiSeq instrument. Most isolates (73) carried VIM-2, but others carried IMP-1 or IMP-13 (5) or NDM-1 (1); one isolate had VIM-2 and IMP-18, and 7 carried no metallo-beta-lactamase (MBL) gene. Single nucleotide polymorphism analysis divided the isolates into distinct clusters; the NDM-1 isolate was an outlier, and the IMP isolates and 6/7 MBL-negative isolates clustered separately from the main set of 73 VIM-2 isolates. Within the VIM-2 set, there were at least 3 distinct clusters, including a tightly clustered set of isolates from 3 hospital laboratories consistent with an outbreak from a single introduction that was quickly brought under control and a much broader set dominated by isolates from a long-running outbreak in a London hospital likely seeded from an environmental source, requiring different control measures; isolates from 7 other hospital laboratories in London and southeast England were also included. Bayesian evolutionary analysis indicated that all the isolates shared a common ancestor dating back ∼50 years (1960s), with the main VIM-2 set separating approximately 20 to 30 years ago. Accessory gene profiling revealed blocks of genes associated with particular clusters, with some having high similarity (≥95%) to bacteriophage genes. WGS of widely found international lineages such as ST-111 provides the necessary resolution to inform epidemiological investigations and intervention policies.


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