scholarly journals Characterization of Shallow Whole-Metagenome Shotgun Sequencing as a High-Accuracy and Low-Cost Method by Complicated Mock Microbiomes

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenyi Xu ◽  
Tianda Chen ◽  
Yuwei Pei ◽  
Hao Guo ◽  
Zhuanyu Li ◽  
...  

Characterization of the bacterial composition and functional repertoires of microbiome samples is the most common application of metagenomics. Although deep whole-metagenome shotgun sequencing (WMS) provides high taxonomic resolution, it is generally cost-prohibitive for large longitudinal investigations. Until now, 16S rRNA gene amplicon sequencing (16S) has been the most widely used approach and usually cooperates with WMS to achieve cost-efficiency. However, the accuracy of 16S results and its consistency with WMS data have not been fully elaborated, especially by complicated microbiomes with defined compositional information. Here, we constructed two complex artificial microbiomes, which comprised more than 60 human gut bacterial species with even or varied abundance. Utilizing real fecal samples and mock communities, we provided solid evidence demonstrating that 16S results were of poor consistency with WMS data, and its accuracy was not satisfactory. In contrast, shallow whole-metagenome shotgun sequencing (shallow WMS, S-WMS) with a sequencing depth of 1 Gb provided outputs that highly resembled WMS data at both genus and species levels and presented much higher accuracy taxonomic assignments and functional predictions than 16S, thereby representing a better and cost-efficient alternative to 16S for large-scale microbiome studies.

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gongchao Jing ◽  
Yufeng Zhang ◽  
Wenzhi Cui ◽  
Lu Liu ◽  
Jian Xu ◽  
...  

Abstract Background Due to their much lower costs in experiment and computation than metagenomic whole-genome sequencing (WGS), 16S rRNA gene amplicons have been widely used for predicting the functional profiles of microbiome, via software tools such as PICRUSt 2. However, due to the potential PCR bias and gene profile variation among phylogenetically related genomes, functional profiles predicted from 16S amplicons may deviate from WGS-derived ones, resulting in misleading results. Results Here we present Meta-Apo, which greatly reduces or even eliminates such deviation, thus deduces much more consistent diversity patterns between the two approaches. Tests of Meta-Apo on > 5000 16S-rRNA amplicon human microbiome samples from 4 body sites showed the deviation between the two strategies is significantly reduced by using only 15 WGS-amplicon training sample pairs. Moreover, Meta-Apo enables cross-platform functional comparison between WGS and amplicon samples, thus greatly improve 16S-based microbiome diagnosis, e.g. accuracy of gingivitis diagnosis via 16S-derived functional profiles was elevated from 65 to 95% by WGS-based classification. Therefore, with the low cost of 16S-amplicon sequencing, Meta-Apo can produce a reliable, high-resolution view of microbiome function equivalent to that offered by shotgun WGS. Conclusions This suggests that large-scale, function-oriented microbiome sequencing projects can probably benefit from the lower cost of 16S-amplicon strategy, without sacrificing the precision in functional reconstruction that otherwise requires WGS. An optimized C++ implementation of Meta-Apo is available on GitHub (https://github.com/qibebt-bioinfo/meta-apo) under a GNU GPL license. It takes the functional profiles of a few paired WGS:16S-amplicon samples as training, and outputs the calibrated functional profiles for the much larger number of 16S-amplicon samples.


Author(s):  
Anna Lavecchia ◽  
Matteo Chiara ◽  
Caterina De Virgilio ◽  
Caterina Manzari ◽  
Carlo Pazzani ◽  
...  

Abstract Staphylococcus cohnii (SC), a coagulase-negative bacterium, was first isolated in 1975 from human skin. Early phenotypic analyses led to the delineation of two subspecies (subsp.), Staphylococcus cohnii subsp. cohnii (SCC) and Staphylococcus cohnii subsp. urealyticus (SCU). SCC was considered to be specific to humans whereas SCU apparently demonstrated a wider host range, from lower primates to humans. The type strains ATCC 29974 and ATCC 49330 have been designated for SCC and SCU, respectively. Comparative analysis of 66 complete genome sequences—including a novel SC isolate—revealed unexpected patterns within the SC complex, both in terms of genomic sequence identity and gene content, highlighting the presence of 3 phylogenetically distinct groups. Based on our observations, and on the current guidelines for taxonomic classification for bacterial species, we propose a revision of the SC species complex. We suggest that SCC and SCU should be regarded as two distinct species: SC and SU (Staphylococcus urealyticus), and that two distinct subspecies, SCC and SCB (SC subsp. barensis, represented by the novel strain isolated in Bari) should be recognized within SC. Furthermore, since large scale comparative genomics studies recurrently suggest inconsistencies or conflicts in taxonomic assignments of bacterial species, we believe that the approach proposed here might be considered for more general application.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 396
Author(s):  
Ewa Sajnaga ◽  
Marcin Skowronek ◽  
Agnieszka Kalwasińska ◽  
Waldemar Kazimierczak ◽  
Karolina Ferenc ◽  
...  

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.


Author(s):  
Ajay S. Arya ◽  
Minh T. H. Hang ◽  
Mark A. Eiteman

Bacteria were isolated from wastewater and soil containing charred wood remnants based on their ability to use levoglucosan as a sole carbon source and on their levoglucosan dehydrogenase (LGDH) activity. On the basis of their 16S rRNA gene sequences, these bacteria represented diverse genera of Microbacterium, Paenibacillus , Shinella , and Klebsiella . Genomic sequencing of the isolates verified that two isolates represented novel species, Paenibacillus athensensis MEC069 T and Shinella sumterensis MEC087 T , while the remaining isolates were closely related to either Microbacterium lacusdiani or Klebsiella pneumoniae . The genetic sequence of LGDH, lgdA , was found in the genomes of these four isolates as well as Pseudarthrobacter phenanthrenivorans Sphe3. The identity of the P. phenanthrenivorans LGDH was experimentally verified following recombinant expression in E. coli . Comparison of the putative genes surrounding lgdA in the isolate genomes indicated that several other gene products facilitate the bacterial catabolism of levoglucosan, including a putative sugar isomerase and several transport proteins. Importance Levoglucosan is the most prevalent soluble carbohydrate remaining after high temperature pyrolysis of lignocellulosic biomass, but it is not fermented by typical production microbes such as Escherichia coli and Saccharomyces cerevisiae . A few fungi metabolize levoglucosan via the enzyme levoglucosan kinase, while several bacteria metabolize levoglucosan via levoglucosan dehydrogenase. This study describes the isolation and characterization of four bacterial species which degrade levoglucosan. Each isolate is shown to contain several genes within an operon involved in levoglucosan degradation, furthering our understanding of bacteria which metabolize levoglucosan.


Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 748 ◽  
Author(s):  
Jin-Young Lee ◽  
Mohamed Mannaa ◽  
Yunkyung Kim ◽  
Jehun Kim ◽  
Geun-Tae Kim ◽  
...  

The aim of this study was to investigate differences between the gut microbiota composition in patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA). Stool samples from nine RA patients and nine OA patients were collected, and DNA was extracted. The gut microbiome was assessed using 16S rRNA gene amplicon sequencing. The structures and differences in the gut microbiome between RA and OA were analyzed. The analysis of diversity revealed no differences in the complexity of samples. The RA group had a lower Bacteroidetes: Firmicutes ratio than did the OA group. Lactobacilli and Prevotella, particularly Prevotella copri, were more abundant in the RA than in the OA group, although these differences were not statistically significant. The relative abundance of Bacteroides and Bifidobacterium was lower in the RA group. At the species level, the abundance of certain bacterial species was significantly lower in the RA group, such as Fusicatenibacter saccharivorans, Dialister invisus, Clostridium leptum, Ruthenibacterium lactatiformans, Anaerotruncus colihominis, Bacteroides faecichinchillae, Harryflintia acetispora, Bacteroides acidifaciens, and Christensenella minuta. The microbial properties of the gut differed between RA and OA patients, and the RA dysbiosis revealed results similar to those of other autoimmune diseases, suggesting that a specific gut microbiota pattern is related to autoimmunity.


2012 ◽  
Vol 13 (1) ◽  
pp. 78-88 ◽  
Author(s):  
Seema Hooda ◽  
Yasushi Minamoto ◽  
Jan S. Suchodolski ◽  
Kelly S. Swanson

AbstractGastrointestinal (GI) microbes have important roles in the nutritional, immunological, and physiologic processes of the host. Traditional cultivation techniques have revealed bacterial density ranges from 104to 105colony forming units (CFU)/g in the stomach, from 105to 107CFU/g in the small intestine, and from 109to 1011CFU/g in the colon of healthy dogs. As a small number of bacterial species can be grown and studied in culture, however, progress was limited until the recent emergence of DNA-based techniques. In recent years, DNA sequencing technology and bioinformatics have allowed for better phylogenetic and functional/metabolic characterization of the canine gut microbiome. Predominant phyla include Firmicutes, Bacteroidetes, Fusobacteria, Proteobacteria, and Actinobacteria. Studies using 16S ribosomal RNA (rRNA) gene pyrosequencing have demonstrated spatial differences along the GI tract and among microbes adhered to the GI mucosa compared to those in intestinal contents or feces. Similar to humans, GI microbiome dysbiosis is common in canine GI diseases such as chronic diarrhea and inflammatory bowel diseases. DNA-based assays have also identified key pathogens contributing to such conditions, including variousClostridium,Campylobacter,Salmonella, andEscherichiaspp. Moreover, nutritionists have applied DNA-based techniques to study the effects of dietary interventions such as dietary fiber, prebiotics, and probiotics on the canine GI microbiome and associated health indices. Despite recent advances in the field, the canine GI microbiome is far from being fully characterized and a deeper characterization of the phylogenetic and functional/metabolic capacity of the GI microbiome in health and disease is needed. This paper provides an overview of recent studies performed to characterize the canine GI microbiome.


2018 ◽  
Author(s):  
Zongfu Hu ◽  
Xi CHEN ◽  
Jie CHANG ◽  
Jianhua YU ◽  
Qing TONG ◽  
...  

Widely distributed across the world, the freshwater snail Radix auricularia plays an important role in freshwater systems. In this study, gut bacterial communities of R. auricularia were characterized using 16S rRNA amplicon sequencing, then intestinal bacteria were compared at different growth stages: adult snails (AS) (with complete gonadal development) and juvenile snails (JS) (with incomplete gonadal development). We obtained 251,072 high quality sequences which were clustered into 1,196 operational taxonomic units (OTUs) with 97% sequence identity. The predominant phyla were Proteobacteria and Cyanobacteria, followed by Chloroflexi, Firmicutes, and Actinobacteria. Other bacterial species such as Tenericutes, Bacteroidetes, Fusobacteria and Verrucomicrobia were present to a lesser extent. 52 bacterial families and 55 genera were found in > 1% of each sample. A large number of species could not be successfully identified. 469 core OTUs were found to make up 39.38% of all OTUs and 88.38% of all sequences. Samples obtained from juvenile organisms possessed higher ratios of Ruminococcaceae, Subdoligranulum, and Faecalibacterium than adult species. Furthermore, 16S rRNA gene data was used to predict function, showing that genes related to metabolism and environmental information processing were rich in snail samples.


2018 ◽  
Vol 17 (2) ◽  
pp. 105
Author(s):  
Agus Eko Prasetyo ◽  
Kikin Hamzah Mutaqin ◽  
Giyanto .

Characterization of phytoplasmas associated with coconut wilt disease in Derawan Island using in silico RFLP. Coconutwilt disease has been reported in Derawan Island that resulted in eradication up to 10% of the total cultivated palms. Theobjective of this study was to detect and characterize phytoplasmas associated with coconut wilt disease in Derawan islandusing nested PCR technique and in silico RFLP based on 16S rRNA gene sequences. Detection of phytoplasmas was performedusing nested PCR method, cloning of nPCR products, sequencing, and analysis of sequencing results using in silico RFLP.The results revealed that phytoplasmas could not be detected by PCR using P1/P7 primer pairs however it could be amplifiedby nested PCR using R16F2n/R16R2 primer pairs resulting amplicon at about 1.25 kb. In silico RFLP analysis indicated thatphytoplasmas associated with coconut wilt disease in Derawan Island belong to 16SrII (witches broom phytoplasma). PCRproduct of the nPCR need to be sequenced because the R16F2n/R16R2 primer will also amplify the other bacterial species, mainly from Gram positive bacteria.


Author(s):  
Nicholas A Bokulich ◽  
Jai Ram Rideout ◽  
Evguenia Kopylova ◽  
Evan Bolyen ◽  
Jessica Patnode ◽  
...  

Background: Taxonomic classification of marker-gene (i.e., amplicon) sequences represents an important step for molecular identification of microorganisms. Results: We present three advances in our ability to assign and interpret taxonomic classifications of short marker gene sequences: two new methods for taxonomy assignment, which reduce runtime up to two-fold and achieve high precision genus-level assignments; an evaluation of classification methods that highlights differences in performance with different marker genes and at different levels of taxonomic resolution; and an extensible framework for evaluating and optimizing new classification methods, which we hope will serve as a model for standardized and reproducible bioinformatics methods evaluations. Conclusions: Our new methods are accessible in QIIME 1.9.0, and our evaluation framework will support ongoing optimization of classification methods to complement rapidly evolving short-amplicon sequencing and bioinformatics technologies. Static versions of all of the analysis notebooks generated with this framework, which contain all code and analysis results, can be viewed at http://bit.ly/srta-010.


2021 ◽  
Author(s):  
Yuta Kinoshita ◽  
Hidekazu NIWA ◽  
Eri UCHIDA-FUJII ◽  
Toshio NUKADA

Abstract Microbial communities are commonly studied by using amplicon sequencing of part of the 16S rRNA gene. Sequencing of the full-length 16S rRNA gene can provide higher taxonomic resolution and accuracy. To obtain even higher taxonomic resolution, with as few false-positives as possible, we assessed a method using long amplicon sequencing targeting the rRNA operon combined with a CCMetagen pipeline. Taxonomic assignment had >90% accuracy at the species level in a mock sample and at the family level in equine fecal samples, generating similar taxonomic composition as shotgun sequencing. The rRNA operon amplicon sequencing of equine fecal samples underestimated compositional percentages of bacterial strains containing unlinked rRNA genes by a third to almost a half, but unlinked rRNA genes had a limited effect on the overall results. The rRNA operon amplicon sequencing with the A519F + U2428R primer set was able to reflect archaeal genomes, whereas full-length 16S rRNA with 27F + 1492R could not. Therefore, we conclude that amplicon sequencing targeting the rRNA operon captures more detailed variations of bacterial and archaeal microbiota.


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