Genomics

Genomic imprinting, a mechanism resulting in parent-of-origin expression of genes through epigenetic regulation, intersects with a broad range of biological fields including evolution, molecular genetics and epigenetics and determinism of complex traits. Although next generation sequencing technologies enable nowadays to detect imprinted genes in a genome-wide manner, a wide spectrum of this phenomena is evaluated only in humans and mice. Here, we propose to map genes showing a parental expression bias in hypothalamus, muscle and placenta in piglets around birth using an extensive and unbiased strategy that relied on reciprocal crosses, genetics reconstruction of parental phases after imputation and statistical analyses discriminating parent-of-origin from allele-specific expression. We detected 440 unique genes with a weak to exclusive parental expression bias including 114 unique genes with an imbalance ratio above 25:75. About thirty imprinted genes are common to human and/or mice and an equivalent number is shared between tissues, suggesting an overall weak conservation landscape of genomic imprinting. Interestingly, we identified novel parent-of-origin expressed genes involved in neurodevelopmental (PITRM1, Pitrilysin Metallopeptidase 1) and fetal growth (FAM20B, Glycosaminoglycan Xylosylkinase and POU6F2, POU Class 6 Homeobox 2) functions. In addition, deeper analyses of specific loci likely highlighted lineage-specific imprinted genes such as a Zinc Finger Protein 300-like gene as well as specific imprinted isoforms of COPG2 (COPI Coat Complex Subunit Gamma 2), a gene showing conflicting data in the literature. Altogether, our results bring pig as the most comprehensively and exhaustively documented species for genomic imprinting after human and mice organisms. A weak conservation of this mechanism across species and tissues suggested a distinction between a small number of core imprinted genes and others parent-of-origin expressed genes that seemed subjected to evolutionary forces for acquiring their imprinting status either in a lineage-specific or tissue-specific manner.

Klebsiella pneumoniae is a gram-negative, encapsulated, non-motile bacterium that can cause damage to human lungs. Antibiotic resistance of this strain requires constant monitoring and for this purpose, Oxford nanopore mediated whole genome sequencing was done for a strain acquired from the pleural fluid of a diabetic patient suffering from chronic kidney disease. A genome of 5.98 MB was obtained, with 8,869 CDSs and 110 RNAs. Around 96 proteins were seen as involved in virulence, disease or defense, while 25 antibiotic resistance genes were identified. Pan-genome was inferred as open, with 12,857 and 1,303 CDSs forming respective accessory and core genome of antibiotic resistant Pakistani strains (n=168) of this species. Apart from notable antimicrobial resistance genes like beta-lactamases, a gene conferring resistance to colistin was also mined. To the best of our knowledge, this is first report of nanopore mediated long read sequencing of a hypermucoviscous virulent K. pneumoniae from Pakistan.

Pseudomonas aeruginosa, is a gram-negative bacterium causes opportunistic or nosocomial infections in immunocompromised individuals. In recent years, a steady increase in human corneal infections of P. aeruginosa has been reported with increased multi-drug resistance (MDR) or extensively drug resistance (XDR). Several non-coding sRNAs, has been identified to regulate various physiological processes in P. aeruginosa, including biofilm formation, quorum sensing. However, the regulatory mechanism of sRNAs in MDR/XDR pathways of P. aeruginosa keratitis strains is not yet studied. In this study, we identified bacterial sRNAs in publicly available P. aeruginosa keratitis genomes and investigated their regulatory role in MDR/XDR pathways using bioinformatic analysis. Totally, 46 P. aeruginosa keratitis strains from different geographical regions were included. Of 46, Eight (30%) out of Twenty-seven and Nine (52) out of Nineteen P. aeruginosa strains from India and Australia were identified as not-MDR. Whereas, 10 (38%) Indian and 9 (47%) Australian strains were identified as MDR. Eight Indian strains were identified as XDR. Out of 46 strains, 23 (50%) carried ExoU, 21(45%) carried ExoS and two (5%) strains carried both ExoU and ExoS, exotoxins for their virulence. The sRNA, SPA0021 was identified in 18 MDR/XDR and 6 not-MDR strains along with UCBPP-PA14. Interestingly, majority of the imipenem resistant P. aeruginosa keratitis strains from the present study was found to be carried SPA0023 sRNA (18 out of 30 strains). The outer membrane porin protein OprD, identified as binding target of SPA0023. Negative regulation or inactivation of OprD, reported in increased imipenem resistance in P. aeruginosa. Mutation analysis revealed that SPA0023 carrying P. aeruginosa keratitis strains contains a lesser number of amino acid changes in OprD protein than other strains. These findings indicate, imipenem resistance in SPA0023 carried strains might arose from the negative regulation or inhibition of OprD by SPA0023. However, functional studies are warranted with large number of P. aeruginosa keratitis strains to confirm the negative regulation of OprD by SPA0023 and imipenem resistance.

BackgroundPneumococcal genomes are highly dynamic with varying core genome sizes. The genotype classification system, Global Pneumococcal Sequence Clusters, identified patterns within genotype and antibiotic resistance. Few genotypes like GPSC10 are frequently associated with antimicrobial resistance and high rates of non-vaccine serotypes. ObjectiveTo identify and annotate the differences in the core genomes of major GPSC in India, and construct and analyse the Indian Pneumococcal Pangenome (IPPG). MethodsUsing existing dataset from the Global Pneumococcal Sequencing Project, 618 strains were included. The most frequent GPSCs: GPSC1, GOSC2, GPSC8, GPSC9 and GPSC10 were analyzed separately. Pangenomes were constructed using Panaroo with tuning the family threshold parameter. Differences in protein clusters were identified using Orthovenn3 webserver. Functional annotations were performed by eggNOG, Uniprot and STRING database searches. ResultsThe IPPG core genome size (1615 genes) was similar to those reported previously, with similar distribution of metabolic categories across the five GPSC types. The GPSC10 (1619 genes) and GPSC1 (1909 genes) had the lowest and highest core genome sizes respectively, and these core genomes possessed genes encoding for macrolide and tetracycline resistance. Virulence genes ply, psaA, pce (cbpE), pavA, nanB, lytA, and hysA are detected among all the core genomes. ConclusionsThere is a genotype specific variation within the core genomes of major GPSCs in India. The presence of antibiotic resistance genes among GPSC1 and GPSC10 core genomes explain widespread drug resistance due to these genotypes. The core virulence genes identified among all the genotypes indicate conserved pathogenesis mechanisms, and can be targets for vaccine development or therapy.

Leptospirosis is an emerging zoonotic and neglected disease across the world causing huge loss of life and economy. The disease is caused by Leptospira of which 605 sequenced genomes representing 72 species are available in RefSeq database. A comparative genomics approach based on Average Amino acid Identity (AAI), Average Nucleotide Identity (ANI), and Insilco DNA-DNA hybridization provide insight that taxonomic and evolutionary position of few genomes needs to be changed and reclassified. Clustering on the basis of AAI of core and pan-genome contradict clustering pattern on basis of ANI into 4 clusters. Amino acid identity based hierarchical clustering clearly established 3 clusters of Leptospira correlating with level of virulence. Whole genome tree supported three cluster classifications and grouped Leptospira into three clades termed as pathogenic, intermediate and saprophytic. Leptospira genus consist of diverse species and exist in heterogeneous environment, it contains relatively large and closed core genome of 1038 genes. Analysis provided pan genome remains open with 20822 genes. COG analysis revealed that mobilome related genes were found mainly in pan-genome of pathogenic clade. Clade specific genes mined in the study can be used as marker for determining clade and associating level of virulence of any new Leptospira species. Many known Leptospira virulent genes were absent in set of 78 virulent factors mined using Virulence Factor database. A deep search approach provided a repertoire of 496 virulent genes in pan-genome. Further validation of virulent genes will help in accurately targeting pathogenic Leptospira and controlling leptospirosis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/426470v2_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@104babborg.highwire.dtl.DTLVardef@17f727dorg.highwire.dtl.DTLVardef@35a6c1org.highwire.dtl.DTLVardef@56fd53_HPS_FORMAT_FIGEXP M_FIG C_FIG

Withdrawal StatementThe authors have withdrawn their manuscript because permission to publish the genome data has not yet been obtained from the owners. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Microsatellite markers, otherwise known as the simple sequence repeats (SSRs), are being used for molecular identification and characterization as well as estimation of evolution pattern of the organism due to their high polymorphic nature. These are tandemly repeated sequences observed almost all organisms and differentially distributed across the genome. Although the primary genome information of Orientia tsutsugamushi (OT) suggested the repeats hold the 40% entire of its genome, but lack of characteristic of this repeats increase our interest to study more about it. Thus we investigated a genome-wide presence of microsatellites within nine complete genomes within OT and analyzed their distribution pattern, composition and complexity. The in-silico study revealed the genome of OT enrich with microsatellites having a total of 126187 SSR and 10374 cSSR throughout the genome from which 70% and 30% represented within the coding and non coding region respectively. The relative density (RD) and relative abundance (RA) of SSRs were 42-44.43/kb and 6.25-6.59/kb while for cSSRs this value ranged from 7.06-8.1/kb and 0.50-0.55/kb respectively. However, RA and RD were weakly correlate with genome size and incidence microsatellites. The mononucleotide repeats (54.55%) were prevalent over di- (33.22%), tri- (11.88%), tetra- (0.27%), penta- (0.02%), hexanucleotide (0.04%) repeats, with poly (A/T) richness over poly (G/C). Motif composition of cSSRs revealed that maximum cSSRs were made up of two microsatellites having unique duplication pattern such as AT-x-AT, CG-x-CG. More numbers microsatellites represented within the coding region provides an insight into the genome plasticity that may interfere for gene regulation to mitigate with host-pathogen interaction and evolution of the species.

Allele-specific expression (ASE) is the imbalanced expression of two alleles of the same locus. It is quite pervasive among mammals and is associated with healthy and economically relevant traits. ASE is often used to support the identification of variants related to gene expression (cis-eQTLs). Thus, profiling ASE represents a significant step in elucidating the mechanism underlying gene expression regulation. In this study, we developed an ASE pipeline using public available RNA-seq data and open-source software. Using this pipeline, we were able to profile pervasive allelic imbalance across 42 tissues and 34 breeds from the Farm-GTEX-pig consortium at both SNP and gene levels without the need for parental genotype or whole genome sequence data. ASE was widely, but not evenly, spread across the genome. We also observed considerable variation in ASE profiles among various tissues, in which the ASE fraction ranged from 1.3% to 54.1%. ASE tends to be highly tissue-specific, and the overlap across tissues is limited. The functional analysis of tissue-specific ASE sites indicates that they are involved in the critical maintenance of these tissues. Our ASE pipeline can be readily applied to other RNA-seq data sets for livestock, thereby significantly expanding its potential utility. The wealth of available ASE resources provides a solid foundation for identifying regulatory elements within the genome that drive complex traits in livestock, making our pipeline and results valuable resources for researchers in this field.

Leishmania donovani causes a neglected tropical disease called visceral leishmaniasis. Additionally, leishmaniasis also manifests opportunistically, under conditions of immune compromise. The continued non-availability of effectively curative interventions (drugs or vaccines) against this disease necessitates a deeper knowledge of Leishmania biology in order to evolve novel strategies against the disease. We have used a meta-analysis approach to analyse Leishmanias composite genetic network rather than investigating individual candidate genes. We performed Weighted Gene Co-expression Network Analysis (WGCNA) on publicly available Leishmania donovani transcriptome data to identify co-regulatory genetic modules. This clustering of Leishmania donovani transcriptomes revealed that genes fall in 30 distinct co-regulated modules with 32 to 3012 genes. In order to analyse the distribution of genes in Leishmania gene modules, we queried the enrichment or depletion of various annotation-qualifiers in the modules. We observed that several modules are specifically and individually enriched or depleted for annotation qualifiers derived from GO-annotation and KEGG-pathways and are differentially associated with life-phases and experimental conditions. Additionally, modules are also enriched or depleted for sequence based genetic features such as chromosomal location, location on co-transcriptional segment, rank of transcript from initiation of transcription, skewed usage of known RNA Binding Protein motifs. Classification of uncharacterized transcripts into co-regulatory modules provides insights in their probable characteristics, aiding future empirical investigation. Strikingly, two of the modules have reciprocal features including individual associations with logarithmic or stationary growth phases of Leishmania, two important life-phases that simulate the vector-dwelling pro-cyclic and the pre-infective meta-cyclic forms. Collectively, our analyses of Leishmania co-regulated gene modules is suggestive of additional regulatory modes over the mere differential mRNA stabilization.

Isoniazid (INH) is an important first-line medication for the treatment of tuberculosis. The impact that tuberculosis drug resistance has on treatment outcomes is a topic that is receiving a lot of attention these days because of the rising incidence of INH-resistant cases. Study involves a single group of patients who have been diagnosed with Isoniazid monoresistant tuberculosis. Treatment history and demographic data of the patients were obtained after informed consent. The mutation patterns of isoniazid were observed after multiplex PCR and Line Probe Assay (LPA). A total of 101 patient (M,F) records at the IRL, Puducherry were analyzed. The predominant gene responsible for TB was KATG (67.3%). The KATG Mut1 was a prime mutation observed in the present study population (58.41%). Study showed positive association with males (74%), occupation as coolie (88%), diabetes as comorbidity (33%), pulmonary tuberculosis as the TB site (98.01%), history of previous ATT intake in 43 patients (42.6%), katG mutation (67.3%), katG Mut 1 was the prime mutation (58.4%).The cure rate was high in INH high concentration resistance patients which was statistically significant (p=0.0167). INH monoresistance mutations seen in 64.3% of the patients with katG, compared to inhA (34.65%). Similar to katG mutations, inhA mutations also have MUT1 as their most frequent gene pattern. There is a significant association between males, diabetes, smoking and alcohol addictions were associated with high risk of developing high dose INH monoresistance (katG). High prevalence of recurrent tuberculosis was seen in high dose INH monoresistance tuberculosis. Patients who are microbiologically confirmed pulmonary tuberculosis and diabetes with rifampicin sensitive status needs to be checked for LPA for isoniazid sensitivity status to prevent treatment failure and relapse. It is crucial to understand the gene pattern in each of these patients since these mutations are closely associated to high or low-degree resistance to INH

The limited knowledge of genomic non-coding and regulatory regions has limited our ability to decipher the genetic mechanisms underlying complex traits in pigs. In this study, we characterize the spatiotemporal landscape of putative enhancers and promoters and their target genes by combining H3K27ac targeted ChIP-Seq and RNA-Seq in fetal (day 74-75 pc) and adult (day 132-150 pn) tissues (brain, liver, heart, muscle and small intestine) sampled from Asian aboriginal Bamaxiang and European highly selected Large White pigs of both sexes. We identify 101,290 H3K27ac peaks marking 18,521 promoters and 82,769 enhancers, including peaks that are active across all tissues and developmental stages could indicate safe harbors for exogenous gene insertion, and tissue and developmental-stage specific peaks that regulate genes pathways matching tissue and developmental stage specific physiological functions. We found H3K27ac and DNA methylation in the promoter region of the XIST gene may involve in X chromosome inactivation, and demonstrate utility of the present resource to reveal regulatory patterns of known causal genes and to prioritize candidate causal variants for complex traits in pigs. We have developed a web browser to improve the accessibility of the results (http://39.108.231.116/browser/?genome=susScr11).

ObjectiveTo evaluate the diagnostic efficiency of different methods in detecting COVID-19 to provide preliminary evidence on choosing favourable method for COVID-19 detection. MethodsPubMed, Web of Science and Embase databases were searched for identifing eligible articles. All data were calculated utilizing Meta Disc 1.4, Revman 5.3.2 and Stata 12. The diagnostic efficiency was assessed via these indicators including summary sensitivity and specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic odds ratio (DOR), summary receiver operating characteristic curve (sROC) and calculate the AUC. Results18 articles (3648 cases) were included. The results showed no significant threshold exist. EPlex: pooled sensitivity was 0.94; specificity was 1.0; PLR was 90.91; NLR was 0.07; DOR was 1409.49; AUC=0.9979, Q*=0.9840. Panther Fusion: pooled sensitivity was 0.99; specificity was 0.98; PLR was 42.46; NLR was 0.02; DOR was 2300.38; AUC=0.9970, Q*=0.9799. Simplexa: pooled sensitivity was 1.0; specificity was 0.97; PLR was 26.67; NLR was 0.01; DOR was 3100.93; AUC=0.9970, Q*=0.9800. Cobas(R): pooled sensitivity was 0.99; specificity was 0.96; PLR was 37.82; NLR was 0.02; DOR was 3754.05; AUC=0.9973, Q*=0.9810. RT-LAMP: pooled sensitivity was 0.98; specificity was 0.99; PLR was 36.22; NLR was 0.04; DOR was 751.24; AUC=0.9905, Q*=0.9596. Xpert Xpress: pooled sensitivity was 0.99; specificity was 0.97; PLR was 27.44; NLR was 0.01; DOR was 3488.15; AUC=0.9977, Q*=0.9829. ConclusionsThese methods (ePlex, Panther Fusion, Simplexa, Cobas(R), RT-LAMP and Xpert Xpress) bear higher sensitivity and specificity, and might be efficient methods complement to the gold standard.

Embryogenesis is the crucial first step of ontogeny, where an organism with a complex body plan arises from a single undifferentiated totipotent cell. This process is orchestrated by dynamic changes in transcriptional regulation, influenced by chromatin accessibility and nucleotide and histone modifications constituting epigenetic signals enabling access to transcription factors. The epigenomic regulation of embryogenesis has been studied in model fishes, but little attention has been paid to farmed fish - where traits of importance to aquaculture rely on early developmental processes. This study, framed within the AQUA-FAANG consortium, reports a comprehensive regulatory atlas of embryogenesis for turbot (Scophthalmus maximus), a farmed flatfish representing order Pleuronectiformes. 14,560 genes were expressed in the embryonic transcriptome with > 90% showing differential expression across consecutive stages. By integrating multi-histone ChIP-Seq marks with ATAC-Seq, we built a genome-wide chromatin state model, defining promoter and enhancer activity across stages. Transcription factor binding motif (TFBM) analysis of differentially active promoters and enhancers revealed dynamism in regulated gene functions, with more than half the TFBM enriched in a single developmental transition. Significant shifts in chromatin accessibility occurred across stages, most notably during the transition from shield to early segmentation, suggesting a profound chromatin reorganization underpins somitogenesis and early organ development. Most changes in chromatin accessibility across stages did not involve promoter regions of differentially expressed genes, suggesting a trend of promoter accessibility preceding gene transcriptional activity. Comparative analyses with zebrafish revealed a global transcriptomic correlation of single copy orthologs at matched stages of embryogenesis across species. While conserved expression dynamics were revealed for many orthologous Hox genes, notable cross-species differences were identified from before zygotic genome activation leading up to hatching. This multi-omics investigation provides a novel atlas of non-coding regulatory elements controlling turbot development, with key applications for flatfish biology and enhancing sustainable aquaculture.

AbstractLactiplantibacillus plantarum is a beneficial bacterium commonly found in fermented foods, including fermented milk products. In the present study, we reported the whole genome sequence of L. plantarum LPJBC5. The complete genome sequence of LPJBC5 was 3.23Mb, and the average GC% was found to be 44.55% encoding a total of 3016 genes. A comprehensive analysis of the LPJBC5 genome detected major carbohydrate-active enzymes, exopolysaccharide synthesis genes (eps), and the presence of genes related to stress response and antioxidant activity. Longevity regulating genes including katE, CAT (chloramphenicol acetyltransferase), catB and their regulating pathways (MAPK signaling pathway) were detected in the LPJBC5 genome. The genome was found to contain plantaracin (pln) operon for the production of antimicrobial bacteriocin and various regions of secondary metabolite biosynthetic gene clusters, including the type III polyketide synthases (T3PKS), Ribosomally synthesized and post- translationally modified peptide product (Ripp-Like), which exhibit specific antimicrobial activity. A comparative pangenome analysis was performed to further evaluate the metabolic framework of L. plantarum JBC5, including the complete L. plantarum genome (N=30) retrieved from publicly available repositories. The core/soft-core genome was found to harbor probiotic associated marker genes. Functional analysis revealed the presence of genes majorly enriched in cell wall/membrane/envelop biogenesis, carbohydrate metabolism and transport, amino acid metabolism and transport, translational mechanism, and transcription processes. Identification of probiotic and longevity associated genes suggests that LPJBC5 holds potential as a probiotic candidate with multifaceted applications in the food industries. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/584937v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1a0299dorg.highwire.dtl.DTLVardef@c347dorg.highwire.dtl.DTLVardef@14a28baorg.highwire.dtl.DTLVardef@1b7f81b_HPS_FORMAT_FIGEXP M_FIG C_FIG

DNA methylation is one of the most important epigenetic processes that regulates gene expression. While the human genome is predominately methylated, CpG-rich regions known as CpG islands (CGIs) are unmethylated and are sites of transcriptional control. While the importance of CGI and DNA methylation at gene promoters is well understood, the significance of CGIs at 3 untranslated regions (3UTRs) remains largely unexplored. In this study, we characterised CGIs located within 3UTRs and investigated their role in gene regulation. Here, we show that around 3% of CGIs (909 CGIs) are exclusively located at 3UTR and are not associated with any nearby promoters. Importantly, 3UTR CGIs are highly conserved, with a conservation score even higher than promoter CGI implying their importance. In contrast to promoter CGIs which are predominantly unmethylated, 3UTR CGIs are often methylated. Genes with 3UTR CGIs are associated with several different cancers and cancer-related signalling pathways. Moreover, 3UTR CGIs are differentially methylated in cancers, with changes in methylation associated with changes in gene expression. Together this data suggests the importance of 3UTR CGIs and their methylation in gene expression regulation in cancer.

Diarrhea typically indicates an intestinal disorder, which can occur from viruses, parasites or bacterial infection. Along with the common diarrhea-causing pathogens, opportunistic bacteria may also play a role in the etiology of diarrheal disease. One of the opportunists bacteria that can cause diarrhea in both children and adults is Providencia stuartii. Therefore, the goal of this study is to explore the genetic mechanism of the opportunistic P. stuartii in microbial interactions with common diarrheal pathogens. Hence, P. stuartii was identified by utilizing the morphological observation and molecular techniques. Afterwards, the entire genome of P. stuartii was sequenced, assembled and annotated to explore the genomic insights. In addition, the virulence genes of 100 whole genome sequences from ten prevalent diarrhea-causing bacteria were identified and prioritized. Finally, the system biology approach was used to predict the protein-protein interaction network between P. stuartii and the virulence genes. The results of the present study suggests that complete genome sequencing of this bacteria contains 4011 proteins, which are crucial for this bacterium to survive. Additionally, 16 gene clusters provide 207 interacting genes that could interact with biological and molecular function, subcellular localization and pathway. The microbial interaction accompanying the virulence gene was found in all 10 diarrhea-causing bacteria except Clostridium difficile. These findings of this study could aid in the exploration of Providencia stuartii as the major causative agent of diarrhea. Additionally, the pathophysiology of diarrhea can be investigated using the microbial interactions between P. stuartii and the typical diarrheal bacteria. The results of this study may therefore be used to determine the most effective therapeutic targets for the development of medications to treat diarrhea.

Pseudomonas aeruginosa has been considered one of the major nosocomial pathogens associated with elevated morbidity and mortality worldwide. Outbreaks have been associated with few high-risk pandemic P. aeruginosa lineages, presenting a remarkable antimicrobial resistance. However, the biological features involved with the persistence and spread of such lineages among clinical settings remain to be unravel. This study reports the emergence of the ST309 P. aeruginosa lineage in South America/Brazil, more precisely, in the Amazon region. Global genomic analyses were performed with the Brazilian strain (PA834) and more 41 complete and draft ST309 genomes publicly available, giving insights about ST309 epidemiology and its resistome and mobilome. Antimicrobial susceptibility tests revealed that the Brazilian PA834 strain presented the XDR phenotype, which was mainly due to intrinsic resistance mechanisms. Genomic analyses revealed a heterogeneous distribution of acquired antimicrobial resistance genes among ST309 genomes, which included blaVIM-2, blaIMP-15 and qnrVC1, all of them associated with class 1 integrons. The mobilome mining showed the presence of Integrative and Conjugative Elements, transposons and genomic islands harbouring a huge arsenal of hevy metal resistance genes. Moreover, these elements also carried genes involved with virulence and adaptive traits. Therefore, the presence of such genes in ST309 lineage possibly accounted for the global spread and persistence of this emerging clone, and for its establishment as a pandemic lineage of clinical importance.

BackgroundRecent studies showed promising results on application of iodine-containing nanomicelles, FS-1, against antibiotic resistant pathogens. The effect was studied on Escherichia coli ATCC BAA-196. Materials & methodsRNA sequencing for transcriptomics and the complete genome sequencing by SMRT PacBio RS II technology followed by genome assembly and methylomics study were performed. Results & conclusionsFS-1 treated E. coli showed an increased susceptibility to antibiotics ampicillin and gentamicin. The analysis of differential gene regulation showed that possible targets of iodine-containing particles are cell membrane fatty acids and proteins, particularly cytochromes, that leads to oxidative, osmotic and acidic stresses. Cultivation with FS-1 caused gene expression alterations towards anaerobic respiration, increased anabolism and inhibition of many nutrient uptake systems. Identification of methylated nucleotides showed an altered pattern in the FS-1 treated culture. Possible role of transcriptional and epigenetic modifications in the observed increase in susceptibility to gentamicin and ampicillin were discussed. Lay abstractNew approaches of combatting drug resistance infections are in demand as the development of new antibiotics is in a deep crisis. This study was set out to investigate molecular mechanisms of action of new iodine-containing nano-micelle drug FS-1, which potentially may improve the antibiotic therapy of drug resistant infections. Iodine is one of the oldest antimicrobials and until now there were no reports on development of resistance to iodine. Recent studies showed promising results on application of iodine-containing nano-micelles against antibiotic resistant pathogens as a supplement to antibiotic therapy. The mechanisms of action, however, remain unclear. The collection strain Escherichia coli ATCC BAA-196 showing an extended spectrum of resistance to beta-lactam and aminoglycoside antibiotics was used in this study as a model organism. Antibiotic resistance patterns, whole genomes and total RNA sequences of the FS-1 treated (FS) and negative control (NC) variants of E. coli BAA-196 were obtained and analyzed. FS culture showed an increased susceptibility to antibiotics associated with profound gene expression alterations switching the bacterial metabolism to anaerobic respiration, increased anabolism, osmotic stress response and inhibition of many nutrient uptake systems. Nucleotide methylation pattern were identified in FS and NC cultures. While the numbers of methylated sites in both genomes remained similar, some peculiar alterations were observed in their distribution along chromosomal and plasmid sequences.

Codon usage bias is a ubiquitous phenomenon occurring at both, interspecies and intraspecies level in different organisms. P. knowlesi, whose natural host is long-tailed Macaque monkeys, has recently started infecting humans as well. The genome as well as coding sequence data of P. knowlesi is used to understand their codon usage pattern in the light of other human infecting Plasmodium species: P. vivax and P. falciparum. The different codon usage indicators: GC content, relative synonymous codon usage, effective number of codon and codon adaptation index are studied to analyze codon usage in the Plasmodium species. The codon usage pattern is found to be less conserved in studied Plasmodium species, and changes species to species at the genus level. The codon usage pattern of P. knowlesi shows similarity to P. vivax as compared to P. falciparum. The ENC vs. GC3 study indicates that compositional constraints and translation selection is the decisive forces responsible for shaping their codon usage. The studies Plasmodium species shows a higher usage of A/T ending optimal codons. This favors the codon bias in P. knowlesi and P. vivax is due to high selection pressure and in P. falciparum, the compositional mutational pressure is a dominant force. In a nutshell, our finding suggests that the more or less similar codon usage pattern of P. knowlesi and P. vivax may suggest the similar host invasion and immune evasion strategies for disease establishment.

Mutations in tumour suppressor p53 confer enhanced metastasis and chemoresistance in colorectal cancer (CRC). Though the genetic events regulating CRC with p53 loss/mutation have been documented, the epigenetic events accompanying the loss of p53 have not been well understood. Epigenome based classification of CRC tumours has identified the active enhancer mark as a distinct marker for progression, however the role of the distal regulatory regions upon p53 loss in CRC remains to be established. This work investigates the influence of p53 loss on enhancer regulation in colorectal cancer cells. Genome wide profiling of active enhancer mark, H3K27ac in p53wt and p53-/- CRC cells reveal an overall gain of this mark around the promoters and intronic regions. These active enhancers show strong association with oncogenes and hallmark MYC and E2F targets suggesting an enhancer mediated regulation of MYC/E2F pathway governed by E2Fs, MAZ and PATZ1. Interestingly, we also observed a gain in oncogenic super enhancers mediated by E2Fs/KLFs accompanying loss of p53. The promoters of histone methyl transferases EZH2 and SuV39H1 (E2F targets) show elevated levels of H3K27ac suggesting a novel epigenetic regulation of CRC around the promoters and distal regulatory regions. Our validation of these findings in p53 deficient colon cancer cohorts shows that the super enhancer associated genes align more to the CMS4 subtype and exhibit lower survivability. The observed cancer stemness and gain of oncogenic super enhancers with p53 loss presents a hitherto unexplored paradigm of enhancer mediated oncogenic progression which may be exploited for devising epigenetic therapy in p53-/- CRC patients. SignificanceColorectal cancers (CRC) lose tumour-suppressor function and gain neomorphic functions with mutation/loss of p53. This work explores the epigenomic modulation of p53 null CRC cells by distal regulatory elements which has not been not clearly understood yet. We report a global increase in the active enhancer mark H3K27ac at active promoter and enhancer regions. We find that the gained enhancers/promoters are regulated by E2Fs/MAZ/PATZ1 which drive cancer stemness while the lost enhancers/promoters are regulated by tumour-suppressive IRFs. The activation of E2Fs correlates with elevated H3K27ac implying positive feedback driving E2F targets such as EZH2 and SuV39H1. The indirect activation of histone methyltransferases by p53 and the gain of oncogenic super-enhancers present a novel epigenetic regulatory paradigm which we also validated in p53 null CRC cohorts. These findings aid the design of epigenetic therapy for p53 deficient colorectal tumours.