scholarly journals Population Genomic Analysis of Mycoplasma bovis Elucidates Geographical Variations and Genes associated with Host-Types

2020 ◽  
Vol 8 (10) ◽  
pp. 1561
Author(s):  
Roshan Kumar ◽  
Karen Register ◽  
Jane Christopher-Hennings ◽  
Paolo Moroni ◽  
Gloria Gioia ◽  
...  

Among more than twenty species belonging to the class Mollecutes, Mycoplasma bovis is the most common cause of bovine mycoplasmosis in North America and Europe. Bovine mycoplasmosis causes significant economic loss in the cattle industry. The number of M. bovis positive herds recently has increased in North America and Europe. Since antibiotic treatment is ineffective and no efficient vaccine is available, M. bovis induced mycoplasmosis is primarily controlled by herd management measures such as the restriction of moving infected animals out of the herds and culling of infected or shedders of M. bovis. To better understand the population structure and genomic factors that may contribute to its transmission, we sequenced 147 M. bovis strains isolated from four different countries viz. USA (n = 121), Canada (n = 22), Israel (n = 3) and Lithuania (n = 1). All except two of the isolates (KRB1 and KRB8) were isolated from two host types i.e., bovine (n = 75) and bison (n = 70). We performed a large-scale comparative analysis of M. bovis genomes by integrating 103 publicly available genomes and our dataset (250 total genomes). Whole genome single nucleotide polymorphism (SNP) based phylogeny using M.agalactiae as an outgroup revealed that M. bovis population structure is composed of five different clades. USA isolates showed a high degree of genomic divergence in comparison to the Australian isolates. Based on host of origin, all the isolates in clade IV was of bovine origin, whereas majority of the isolates in clades III and V was of bison origin. Our comparative genome analysis also revealed that M. bovis has an open pangenome with a large breadth of unexplored diversity of genes. The function based analysis of autogenous vaccine candidates (n = 10) included in this study revealed that their functional diversity does not span the genomic diversity observed in all five clades identified in this study. Our study also found that M. bovis genome harbors a large number of IS elements and their number increases significantly (p = 7.8 × 10−6) as the genome size increases. Collectively, the genome data and the whole genome-based population analysis in this study may help to develop better understanding of M. bovis induced mycoplasmosis in cattle.

2020 ◽  
Author(s):  
Roshan Kumar ◽  
Karen Register ◽  
Jane Christopher-Hennings ◽  
Paolo Moroni ◽  
Gloria Gioa ◽  
...  

AbstractAmong more than twenty species belonging to the class Mollecutes, Mycoplasma bovis is the most common cause of bovine mycoplasmosis in North America and Europe. Bovine mycoplasmosis causes significant economic loss in the cattle industry. The number of M. bovis positive herds has recently increased in North America and Europe. Since antibiotic treatment is ineffective and no efficient vaccine is available, M. bovis-induced mycoplasmosis is primarily controlled by herd management measures such as the restriction of moving infected animals out of the herds and culling of infected animals or shedders. To better understand the population structure and genomic factors that may contribute to its transmission, we sequenced 147 M. bovis strains isolated from four different countries and hosts, primarily cattle. We performed a large-scale comparative analysis of M. bovis genomes by integrating 104 publicly available genomes and our dataset (251 total genomes). A whole genome-single nucleotide polymorphism (SNP)-based phylogeny revealed that M. bovis population structure is composed of five clades with one of the isolates clustering with the outgroup M. agalactiae. These isolates were found to cluster with those from Canada, Israel, Lithuania, and Switzerland, suggesting trans-continental transmission of the strains. We also validated a previous report suggesting minimum divergence in isolates of Australian origin, which grouped within a single clade along with strains from China and Israel. However, no observable pattern of host association in M. bovis genomes was found in this study. Our comparative genome analysis also revealed that M. bovis has an open pangenome with a large breadth of unexplored diversity of genes. Analysis of vsp gene-host association revealed a single vsp significantly associated with bovine isolates that may be targeted for diagnostics or vaccine development. Our study also found that M. bovis genome harbors a large number of IS elements, including a novel 1624 bp IS element, and ISMbov9. Collectively, the genome data and the whole genome-based population analysis in this study may help to develop control measures to reduce the incidence of M. bovis-induced mycoplasmosis in cattle and/or to identify candidate genes for vaccine development.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaoting Xia ◽  
Shunjin Zhang ◽  
Huaju Zhang ◽  
Zijing Zhang ◽  
Ningbo Chen ◽  
...  

Abstract Background Native cattle breeds are an important source of genetic variation because they might carry alleles that enable them to adapt to local environment and tough feeding conditions. Jiaxian Red, a Chinese native cattle breed, is reported to have originated from crossbreeding between taurine and indicine cattle; their history as a draft and meat animal dates back at least 30 years. Using whole-genome sequencing (WGS) data of 30 animals from the core breeding farm, we investigated the genetic diversity, population structure and genomic regions under selection of Jiaxian Red cattle. Furthermore, we used 131 published genomes of world-wide cattle to characterize the genomic variation of Jiaxian Red cattle. Results The population structure analysis revealed that Jiaxian Red cattle harboured the ancestry with East Asian taurine (0.493), Chinese indicine (0.379), European taurine (0.095) and Indian indicine (0.033). Three methods (nucleotide diversity, linkage disequilibrium decay and runs of homozygosity) implied the relatively high genomic diversity in Jiaxian Red cattle. We used θπ, CLR, FST and XP-EHH methods to look for the candidate signatures of positive selection in Jiaxian Red cattle. A total number of 171 (θπ and CLR) and 17 (FST and XP-EHH) shared genes were identified using different detection strategies. Functional annotation analysis revealed that these genes are potentially responsible for growth and feed efficiency (CCSER1), meat quality traits (ROCK2, PPP1R12A, CYB5R4, EYA3, PHACTR1), fertility (RFX4, SRD5A2) and immune system response (SLAMF1, CD84 and SLAMF6). Conclusion We provide a comprehensive overview of sequence variations in Jiaxian Red cattle genomes. Selection signatures were detected in genomic regions that are possibly related to economically important traits in Jiaxian Red cattle. We observed a high level of genomic diversity and low inbreeding in Jiaxian Red cattle. These results provide a basis for further resource protection and breeding improvement of this breed.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S54-S54
Author(s):  
Ron Dagan ◽  
Shalom Ben-Shimol ◽  
Rachel Benisty ◽  
Gili Regev-Yochay ◽  
Merav Ron ◽  
...  

Abstract Background IPD caused by Sp2 (non-PCV13 serotype) is relatively rare. However, Sp2 has a high potential for causing IPD including meningitis. Large-scale outbreaks of Sp2 IPD are rare and were not reported post-PCV implementation. We describe Sp2 IPD outbreak in Israel, in the PCV13 era, caused by a novel clone. Additionally, we analyzed the population structure and evolutionary dynamics of Sp2 during 2006–2018. Methods An ongoing, population-based, nationwide active surveillance, conducted since July 2009. PCV7/PCV13 were implemented in Israel in July 2009 and November 2010, respectively. All isolates were tested for antimicrobial susceptibility, PFGE, MLST and whole-genome sequencing (WGS). Results. Overall, 173 Sp2 IPD cases were identified; all isolates were analyzed by MLST (Figure 1). During 2016–2017, Sp2 caused 7.6% of all-IPD, a 7-fold increase compared with 2006–2015, and ranked second (after serotype 12F causing 12%) among IPD isolates. During 2006–2015, 98% (40/41) Sp2 IPD were caused by the previously reported global ST-1504 clone. The outbreak was caused by a novel clone ST-13578, not previously reported (Figure 2). WGS analysis confirmed that ST-13578 was related, but genetically distinct from ST-1504, observed exclusively before the outbreak. A single strain of clone ST-74 previously globally reported was identified in 2017–2018. An additional case was identified in an adult in the UK, following a family visit from Israel. The ST-13578 clone was identified only in the Jewish population and was mainly distributed in 3 of the 7 Israeli districts. All tested strains were penicillin-susceptible (MIC < 0.06 μg/mL). Conclusion To the best of our knowledge, this is the first widespread Sp2 outbreak since PCV13 introduction worldwide, caused by a novel clone ST-13578. The outbreak is still ongoing, although a declining trend was noted since 2017. Disclosures All Authors: No reported Disclosures.


2018 ◽  
Author(s):  
Peng Xu ◽  
Zechen Chong ◽  

AbstractMeiotic recombination (MR), which transmits exchanged genetic materials between homologous chromosomes to offspring, plays a crucial role in shaping genomic diversity in eukaryotic organisms. In humans, thousands of meiotic recombination hotspots have been mapped by population genetics approaches. However, direct identification of MR events for individuals is still challenging due to the difficulty in resolving the haplotypes of homologous chromosomes and reconstructing the gamete genome. Whole genome linked-read sequencing (lrWGS) can generate haplotype sequences of mega-base pairs (N50 ~2.5Mb) after computational phasing. However, the haplotype information is still isolated in a large number of fragmented genomic regions and limited by switch errors, impeding its further application in the chromosome-scale analysis. In this study, we developed a tool MRLR (Meiotic Recombination identification by Linked-Read sequencing) for the analysis of individual MR events. By leveraging trio pedigree information with lrWGS haplotypes, our pipeline is sufficient to reconstruct the whole human gamete genome with 99.8% haplotyping accuracy. By analyzing the haplotype exchange between homologous chromosomes, MRLR identified 462 high-resolution MR events in 6 human trio samples from the Genome In A Bottle (GIAB) and the Human Genome Structural Variation Consortium (HGSVC). In three datasets of the HGSVC, our results recapitulated 149 (92%) previously identified high-confident MR events and discovered 85 novel events. About half (40) of the new events are supported by single-cell template strand sequencing (Strand-seq) results. We found that 332 (71.9%) MR events co-localize with recombination hotspots (>10 cM/Mb) in human populations, and MR breakpoint regions are enriched in PRDM9 and DMC1 binding sites. In addition, 48% (221) breakpoint regions were detected inside a gene, indicating these MRs can directly affect the haplotype diversity of genic regions. Taken together, our approach provides new opportunities in the haplotype-based genomic analysis of individual meiotic recombination. The MRLR software is implemented in Perl and is freely available at https://github.com/ChongLab/MRLR.


2017 ◽  
Author(s):  
Matthew Parks ◽  
Teofil Nakov ◽  
Elizabeth Ruck ◽  
Norman J. Wickett ◽  
Andrew J. Alverson

ABSTRACTPremise of the studyDiatoms are one of the most species-rich lineages of microbial eukaryotes. Similarities in clade age, species richness, and contributions to primary production motivate comparisons to flowering plants, whose genomes have been inordinately shaped by whole genome duplication (WGD). These events that have been linked to speciation and increased rates of lineage diversification, identifying WGDs as a principal driver of angiosperm evolution. We synthesized a relatively large but scattered body of evidence that, taken together, suggests that polyploidy may be common in diatoms.MethodsWe used data from gene counts, gene trees, and patterns of synonymous divergence to carry out the first large-scale phylogenomic analysis of genome-scale duplication histories for a phylogenetically diverse set of 37 diatom taxa.Key resultsSeveral methods identified WGD events of varying age across diatoms, though determining the exact number and placement of events and, more broadly, inferences of WGD at all, were greatly impacted by gene-tree uncertainty. Gene-tree reconciliations supported allopolyploidy as the predominant mode of polyploid formation, with particularly strong evidence for ancient allopolyploid events in the thalassiosiroid and pennate diatom clades.ConclusionsWhole genome duplication appears to have been an important driver of genome evolution in diatoms. Denser taxon sampling will better pinpoint the timing of WGDs and likely reveal many more of them. We outline potential challenges in reconstructing paleopolyploid events in diatoms that, together with these results, offer a framework for understanding the evolutionary roles of genome duplication in a group that likely harbors substantial genomic diversity.


2019 ◽  
Author(s):  
Hemanoel Passarelli-Araujo ◽  
Jussara K. Palmeiro ◽  
Kanhu C. Moharana ◽  
Francisnei Pedrosa-Silva ◽  
Libera M. Dalla-Costa ◽  
...  

ABSTRACTKlebsiella aerogenesis an important pathogen in healthcare-associated infections. Nevertheless, in comparison to other clinically important pathogens,K. aerogenespopulation structure, genetic diversity, and pathogenicity remain poorly understood. Here, we elucidateK. aerogenesclonal complexes (CCs) and genomic features associated with resistance and virulence. We present a detailed description of the population structure ofK. aerogenesbased on 97 publicly available genomes by using both, multilocus sequence typing and single nucleotide polymorphisms extracted from core genome. We also assessed virulence and resistance profiles using VFDB and CARD, respectively. We show thatK. aerogeneshas an open pangenome and a large effective population size, which account for its high genomic diversity and support that negative selection prevents fixation of most deleterious alleles. The population is structured in at least ten CCs, including two novel ones identified here, CC9 and CC10. The repertoires of resistance genes comprise a high number of antibiotic efflux proteins as well as narrow and extended spectrum β-lactamases. Regarding the population structure, we identified two clusters based on virulence profile due to the presence of the toxin-encodingclboperon and the siderophore production genes,irpandybt.Notably, CC3 comprises the majority ofK. aerogenesisolates associated with hospital outbreaks, emphasizing the importance of its constant monitoring. Collectively, our results can be useful in the development of new therapeutic and surveillance strategies worldwide.


2020 ◽  
Vol 10 (7) ◽  
pp. 2241-2255 ◽  
Author(s):  
Abraham Morales-Cruz ◽  
Shahin S. Ali ◽  
Andrea Minio ◽  
Rosa Figueroa-Balderas ◽  
Jadran F. García ◽  
...  

Phytophthora megakarya and P. palmivora are oomycete pathogens that cause black pod rot of cacao (Theobroma cacao), the most economically important disease on cacao globally. While P. palmivora is a cosmopolitan pathogen, P. megakarya, which is more aggressive on cacao than P. palmivora, has been reported only in West and Central Africa where it has been spreading and devastating cacao farms since the 1950s. In this study, we reconstructed the complete diploid genomes of multiple isolates of both species using single-molecule real-time sequencing. Thirty-one additional genotypes were sequenced to analyze inter- and intra-species genomic diversity. The P. megakarya genome is exceptionally large (222 Mbp) and nearly twice the size of P. palmivora (135 Mbp) and most known Phytophthora species (∼100 Mbp on average). Previous reports pointed toward a whole-genome duplication (WGD) in P. palmivora. In this study, we demonstrate that both species underwent independent and relatively recent WGD events. In P. megakarya we identified a unique combination of WGD and large-scale transposable element driven genome expansion, which places this genome in the upper range of Phytophthora genome sizes, as well as effector pools with 1,382 predicted RxLR effectors. Finally, this study provides evidence of adaptive evolution of effectors like RxLRs and Crinklers, and discusses the implications of effector expansion and diversification.


2008 ◽  
Vol 190 (20) ◽  
pp. 6881-6893 ◽  
Author(s):  
David A. Rasko ◽  
M. J. Rosovitz ◽  
Garry S. A. Myers ◽  
Emmanuel F. Mongodin ◽  
W. Florian Fricke ◽  
...  

ABSTRACT Whole-genome sequencing has been skewed toward bacterial pathogens as a consequence of the prioritization of medical and veterinary diseases. However, it is becoming clear that in order to accurately measure genetic variation within and between pathogenic groups, multiple isolates, as well as commensal species, must be sequenced. This study examined the pangenomic content of Escherichia coli. Six distinct E. coli pathovars can be distinguished using molecular or phenotypic markers, but only two of the six pathovars have been subjected to any genome sequencing previously. Thus, this report provides a seminal description of the genomic contents and unique features of three unsequenced pathovars, enterotoxigenic E. coli, enteropathogenic E. coli, and enteroaggregative E. coli. We also determined the first genome sequence of a human commensal E. coli isolate, E. coli HS, which will undoubtedly provide a new baseline from which workers can examine the evolution of pathogenic E. coli. Comparison of 17 E. coli genomes, 8 of which are new, resulted in identification of ∼2,200 genes conserved in all isolates. We were also able to identify genes that were isolate and pathovar specific. Fewer pathovar-specific genes were identified than anticipated, suggesting that each isolate may have independently developed virulence capabilities. Pangenome calculations indicate that E. coli genomic diversity represents an open pangenome model containing a reservoir of more than 13,000 genes, many of which may be uncharacterized but important virulence factors. This comparative study of the species E. coli, while descriptive, should provide the basis for future functional work on this important group of pathogens.


2018 ◽  
Author(s):  
Christine Tranchant-Dubreuil ◽  
Sébastien Ravel ◽  
Cécile Monat ◽  
Gautier Sarah ◽  
Abdoulaye Diallo ◽  
...  

ABSTRACTThe advent of NGS has intensified the need for robust pipelines to perform high-performance automated analyses. The required softwares depend on the sequencing method used to produce raw data (e.g. Whole genome sequencing, Genotyping By Sequencing, RNASeq) as well as the kind of analyses to carry on (GWAS, population structure, differential expression). These tools have to be generic and scalable, and should meet the biologists needs.Here, we present the new version of TOGGLe (Toolbox for Generic NGS Analyses), a simple and highly flexible framework to easily and quickly generate pipelines for large-scale second- and third-generation sequencing analyses, including multi-sample and multi-threading support. TOGGLe is a workflow manager designed to be as effortless as possible to use for biologists, so the focus can remain on the analyses. Pipelines are easily customizable and supported analyses are reproducible and shareable. TOGGLe is designed as a generic, adaptable and fast evolutive solution, and has been tested and used in large-scale projects on various organisms. It is freely available at http://toggle.southgreen.fr/, under the GNU GPLv3/CeCill-C licenses) and can be deployed onto HPC clusters as well as on local machines.


Author(s):  
Allison Black ◽  
Duncan R. MacCannell ◽  
Thomas R. Sibley ◽  
Trevor Bedford

Public health agencies are increasingly using pathogen whole genome sequencing (WGS) to support surveillance and epidemiologic investigations. As access to WGS has grown, greater amounts of molecular data have helped improve our ability to detect outbreaks, investigate transmission chains, and explore large-scale population dynamics, such as the spread of antibiotic resistance. However, the wide adoption of WGS also poses challenges due to the amount of data generated and the need to transform raw data prior to analysis. This complexity means that public health agencies may need more advanced computational infrastructure, a broader technical workforce, and new approaches to data management and stewardship. As both a guide for how this development could occur, and a place to initiate discussion, we describe ten proposals for developing and supporting an informatics infrastructure for public health.


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