scholarly journals Quantitative PCR provides a simple and accessible method for quantitative microbiome profiling

2018 ◽  
Author(s):  
Ching Jian ◽  
Panu Luukkonen ◽  
Hannele Yki-Järvinen ◽  
Anne Salonen ◽  
Katri Korpela

AbstractThe use of relative next generation sequencing (NGS) abundance data can lead to misinterpretations of microbial community structures as the increase of one taxon leads to concurrent decrease of the other(s). To overcome compositionality, we provide a quantitative NGS solution, which is achieved by adjusting the relative 16S rRNA gene amplicon NGS data with quantitative PCR (qPCR-based) total bacterial counts. By comparing the enumeration of dominant bacterial groups on different taxonomic levels in human fecal samples using taxon-specific 16S rRNA gene-targeted qPCR we show that quantitative NGS is able to estimate absolute bacterial abundances accurately. We also observed a higher degree of correspondence in the estimated microbe-metabolite relationship when quantitative NGS was applied. Being conceptually and methodologically analogous to amplicon-based NGS, our qPCR-based method can be readily incorporated into the standard, high-throughput NGS sample processing pipeline for more accurate description of interactions within and between the microbes and host.

2020 ◽  
Author(s):  
Po-Yu Liu ◽  
Wei-Kai Wu ◽  
Chieh-Chang Chen ◽  
Suraphan Panyod ◽  
Lee-Yan Sheen ◽  
...  

ABSTRACTSequencing of the 16S rRNA gene by Illumina next-generation sequencing is broadly used in microbiome studies. Different hypervariable regions of the 16S rRNA gene, V3V4 (amplified with primers 341F–805R) or V4 (V4O; primers 515F–806R), are selected, depending on the targeted resolution. However, in population-based clinical studies, combining V3V4 and V4 data from different studies for a meta-analysis is challenging. Reads generated by short-read (150-bp) high-throughput sequencing platforms do not fully recover the V4 region read-length. Here, we evaluated the compatibility of 16S rRNA V3V4 and V4 amplicons for microbiome profiling. We compared taxonomic compositions obtained by the analysis of V3V4 and V4 amplicons, and V4 fragments trimmed from V3V4 amplicons. We also evaluated an alternative V4 region (V4N; primers 519F–798R) designed for efficient stitching with 150-bp paired-end sequencing. First, we simulated a global investigation of environmental prokaryotes in silico. This revealed that V4O primers recovered the highest proportion of fragments (81.7%) and most phyla, including archaea. Empirical sequencing of standard (mock) and human fecal samples revealed biased patterns of each primer that were similar to the ones determined by in silico simulation. Further, for human fecal microbiome profiling, the between-sample variance was greater than the systematic bias of each primer. The use of trimmed V4 fragments and single-end amplicons resulted in the same systematic bias. In conclusion, paired-end V4O sequencing yielded the most accurate data for both, simulation and mock community sequencing; the V4O amplicons were compatible with trimmed V4 sequences for microbiome profiling.IMPORTANCENext-generation sequencing of the 16S rRNA gene is a commonly used approach for clinical microbiome studies. Different amplicons of the 16S rRNA hypervariable regions are used in different studies, which creates incompatible sequence features when comparing and integrating data among studies by using 16S denoising pipelines. Here we compared the type of data and coverage obtained when different 16S rRNA amplicons were analyzed. In silico and empirical analyses of the human fecal microbiome revealed that the V3V4 amplicons are compatible with V4 amplicons after trimming up to the same region. These observations demonstrate that reconciling the compatibility of clinical microbiome data from different studies improve not only the sample size but also the confidence of the hypothesis tested.


2004 ◽  
Vol 70 (8) ◽  
pp. 4911-4920 ◽  
Author(s):  
Nadia N. North ◽  
Sherry L. Dollhopf ◽  
Lainie Petrie ◽  
Jonathan D. Istok ◽  
David L. Balkwill ◽  
...  

ABSTRACT Previous studies have demonstrated that metal-reducing microorganisms can effectively promote the precipitation and removal of uranium from contaminated groundwater. Microbial communities were stimulated in the acidic subsurface by pH neutralization and addition of an electron donor to wells. In single-well push-pull tests at a number of treated sites, nitrate, Fe(III), and uranium were extensively reduced and electron donors (glucose, ethanol) were consumed. Examination of sediment chemistry in cores sampled immediately adjacent to treated wells 3.5 months after treatment revealed that sediment pH increased substantially (by 1 to 2 pH units) while nitrate was largely depleted. A large diversity of 16S rRNA gene sequences were retrieved from subsurface sediments, including species from the α, β, δ, and γ subdivisions of the class Proteobacteria, as well as low- and high-G+C gram-positive species. Following in situ biostimulation of microbial communities within contaminated sediments, sequences related to previously cultured metal-reducing δ-Proteobacteria increased from 5% to nearly 40% of the clone libraries. Quantitative PCR revealed that Geobacter-type 16S rRNA gene sequences increased in biostimulated sediments by 1 to 2 orders of magnitude at two of the four sites tested. Evidence from the quantitative PCR analysis corroborated information obtained from 16S rRNA gene clone libraries, indicating that members of the δ-Proteobacteria subdivision, including Anaeromyxobacter dehalogenans-related and Geobacter-related sequences, are important metal-reducing organisms in acidic subsurface sediments. This study provides the first cultivation-independent analysis of the change in metal-reducing microbial communities in subsurface sediments during an in situ bioremediation experiment.


2009 ◽  
Vol 75 (9) ◽  
pp. 2677-2683 ◽  
Author(s):  
Sergio E. Morales ◽  
William E. Holben

ABSTRACT Phylogenetic and “fingerprinting” analyses of the 16S rRNA genes of prokaryotes have been a mainstay of microbial ecology during the last two decades. However, many methods and results from studies that rely on the 16S rRNA gene for detection and quantification of specific microbial taxa have seemingly received only cursory or even no validation. To directly examine the efficacy and specificity of 16S rRNA gene-based primers for phylum-, class-, and operational taxonomic unit-specific target amplification in quantitative PCR, we created a collection of primers based solely on an extensive soil bacterial 16S rRNA gene clone library containing ∼5,000 sequences from a single soil sample (i.e., a closed site-specific library was used to create PCR primers for use at this site). These primers were initially tested in silico prior to empirical testing by PCR amplification of known target sequences and of controls based on disparate phylogenetic groups. Although all primers were highly specific according to the in silico analysis, the empirical analyses clearly exhibited a high degree of nonspecificity for many of the phyla or classes, while other primers proved to be highly specific. These findings suggest that significant care must be taken when interpreting studies whose results were obtained with target specific primers that were not adequately validated, especially where population densities or dynamics have been inferred from the data. Further, we suggest that the reliability of quantification of specific target abundance using 16S rRNA-based quantitative PCR is case specific and must be determined through rigorous empirical testing rather than solely in silico.


2021 ◽  
Vol 12 ◽  
Author(s):  
Iines S. Salonen ◽  
Panagiota-Myrsini Chronopoulou ◽  
Hidetaka Nomaki ◽  
Dewi Langlet ◽  
Masashi Tsuchiya ◽  
...  

Foraminifera are unicellular eukaryotes that are an integral part of benthic fauna in many marine ecosystems, including the deep sea, with direct impacts on benthic biogeochemical cycles. In these systems, different foraminiferal species are known to have a distinct vertical distribution, i.e., microhabitat preference, which is tightly linked to the physico-chemical zonation of the sediment. Hence, foraminifera are well-adapted to thrive in various conditions, even under anoxia. However, despite the ecological and biogeochemical significance of foraminifera, their ecology remains poorly understood. This is especially true in terms of the composition and diversity of their microbiome, although foraminifera are known to harbor diverse endobionts, which may have a significant meaning to each species’ survival strategy. In this study, we used 16S rRNA gene metabarcoding to investigate the microbiomes of five different deep-sea benthic foraminiferal species representing differing microhabitat preferences. The microbiomes of these species were compared intra- and inter-specifically, as well as with the surrounding sediment bacterial community. Our analysis indicated that each species was characterized with a distinct, statistically different microbiome that also differed from the surrounding sediment community in terms of diversity and dominant bacterial groups. We were also able to distinguish specific bacterial groups that seemed to be strongly associated with particular foraminiferal species, such as the family Marinilabiliaceae for Chilostomella ovoidea and the family Hyphomicrobiaceae for Bulimina subornata and Bulimina striata. The presence of bacterial groups that are tightly associated to a certain foraminiferal species implies that there may exist unique, potentially symbiotic relationships between foraminifera and bacteria that have been previously overlooked. Furthermore, the foraminifera contained chloroplast reads originating from different sources, likely reflecting trophic preferences and ecological characteristics of the different species. This study demonstrates the potential of 16S rRNA gene metabarcoding in resolving the microbiome composition and diversity of eukaryotic unicellular organisms, providing unique in situ insights into enigmatic deep-sea ecosystems.


2019 ◽  
Author(s):  
Jessica L. O’Callaghan ◽  
Dana Willner ◽  
Melissa Buttini ◽  
Flavia Huygens ◽  
Elise S. Pelzer

ABSTRACTBackgroundThe endometrial cavity is an upper genital tract site largely heralded as sterile, however, advances in culture-independent, next generation sequencing technology have revealed that this site harbours a rich microbial community which includes multiple Lactobacillus species. These bacteria are considered to be the most common non-pathogenic genital tract commensals. Next-generation sequencing of the female lower genital tract has revealed significant variation amongst microbial community composition with respect to Lactobacillus sp. in samples collected from healthy and diseased women. The aim of this study was to evaluate the ability of the 16S rRNA gene to characterize genital tract lactobacilli to species-level taxonomy.MethodsSamples were interrogated for the presence of microbial DNA using two-step next generation sequencing technology to exploit the V5–V8 regions of the 16S rRNA gene and compared to standard speciation using qPCR.ResultsThe V5-V8 region of the 16S rRNA gene has sufficient sequence variation within frequently encountered genital tract lactobacilli to allow accurate determination of relative abundance within the community, and speciation for several key community members without completing additional experimentation.ConclusionsNext-generation sequencing of clinical genital tract isolates is an effective method for high throughput identification to species-level of key Lactobacillus sp.IMPORTANCEHuman microbiome experiments, including the low biomass organs such as the upper genital tract, require the development of consensus protocols to ensure accurate comparison between such studies and our data forms an important foundation for future protocols.This paper provides evidence to support the selection of the V5-V8 regions of the 16S rRNA gene improved Lactobacillus speciation using next generation sequencing technology. The choice of variable region for broad-range amplification in microbiome studies is important due to preferential primer binding associated with some genera based on nucleotide sequence patterns. By utilising the V5-V8 region, multiple species of Lactobacillus can be characterised with relative confidence.


Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Paula Santibáñez ◽  
Concepción García-García ◽  
Aránzazu Portillo ◽  
Sonia Santibáñez ◽  
Lara García-Álvarez ◽  
...  

Infective endocarditis (IE) is a severe and life-threatening disease. Identification of infectious etiology is essential for establishing the appropriate antimicrobial treatment and decreasing mortality. The aim of this study was to explore the potential utility of metataxonomics for improving microbiological diagnosis of IE. Here, next-generation sequencing (NGS) of the V3–V4 region of the 16S rRNA gene was performed in 27 heart valve tissues (18 natives, 5 intravascular devices, and 4 prosthetics) from 27 patients diagnosed with IE (4 of them with negative blood cultures). Metataxonomics matched with conventional diagnostic techniques in 24/27 cases (88.9%). The same bacterial family was assigned to 24 cases; the same genus, to 23 cases; and the same species, to 13 cases. In 22 of them, the etiological agent was represented by percentages > 99% of the reads and in two cases, by ~70%. Staphylococcus aureus was detected in a previously microbiological undiagnosed patient. Thus, microbiological diagnosis with 16S rRNA gene targeted-NGS was possible in one more sample than using traditional techniques. The remaining two patients showed no coincidence between traditional and 16S rRNA gene-targeted NGS microbiological diagnoses. In addition, 16S rRNA gene-targeted NGS allowed us to suggest coinfections that were supported by clinical data in one patient, and minority records also verified mixed infections in three cases. In our series, metataxonomics was valid for the identification of the causative agents, although more studies are needed before implementation of 16S rRNA gene-targeted NGS for the diagnosis of IE.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 175 ◽  
Author(s):  
Ghaju Shrestha ◽  
Sherchan ◽  
Kitajima ◽  
Tanaka ◽  
Gerba ◽  
...  

This study aimed to identify the bacterial community in two wastewater treatment plants (WWTPs) and to determine the occurrence and reduction of Arcobacter, along with virulence genes (ciaB and pldA). A total of 48 samples (24 influent and 24 effluent) were collected at two WWTPs in southern Arizona in the United States, monthly from August 2011 to July 2012. Bacterial DNA extract was utilized for 16S rRNA metagenomic sequencing. Quantification of Arcobacter 16S rRNA gene was conducted using a recently developed SYBR Green-based quantitative PCR assay. Among 847 genera identified, 113 (13%) were identified as potentially pathogenic bacteria. Arcobacter 16S rRNA gene was detected in all influent samples and ten (83%) and nine (75%) effluent samples at each plant, respectively. Log reduction ratios of Arcobacter 16S rRNA gene in Plant A and Plant B were 1.7 ± 0.9 (n = 10) and 2.3 ± 1.5 (n = 9), respectively. The ciaB gene was detected by quantitative PCR in eleven (92%) and twelve (100%) of 12 influent samples from Plant A and Plant B, respectively, while the pldA gene was detected in eight (67%) and six (50%) influent samples from Plant A and Plant B, respectively. The prevalence of potentially pathogenic bacteria in WWTP effluent indicated the need for disinfection before discharge into the environment.


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