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Wu-Woods NJ, Barlow JT, Trigodet F, Shaw DG, Romano AE, Jabri B, Eren AM, Ismagilov RF. Microbial-enrichment method enables high-throughput metagenomic characterization from host-rich samples. Nat Methods 2023; 20:1672-1682. [PMID: 37828152 PMCID: PMC10885704 DOI: 10.1038/s41592-023-02025-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 08/27/2023] [Indexed: 10/14/2023]
Abstract
Host-microbe interactions have been linked to health and disease states through the use of microbial taxonomic profiling, mostly via 16S ribosomal RNA gene sequencing. However, many mechanistic insights remain elusive, in part because studying the genomes of microbes associated with mammalian tissue is difficult due to the high ratio of host to microbial DNA in such samples. Here we describe a microbial-enrichment method (MEM), which we demonstrate on a wide range of sample types, including saliva, stool, intestinal scrapings, and intestinal mucosal biopsies. MEM enabled high-throughput characterization of microbial metagenomes from human intestinal biopsies by reducing host DNA more than 1,000-fold with minimal microbial community changes (roughly 90% of taxa had no significant differences between MEM-treated and untreated control groups). Shotgun sequencing of MEM-treated human intestinal biopsies enabled characterization of both high- and low-abundance microbial taxa, pathways and genes longitudinally along the gastrointestinal tract. We report the construction of metagenome-assembled genomes directly from human intestinal biopsies for bacteria and archaea at relative abundances as low as 1%. Analysis of metagenome-assembled genomes reveals distinct subpopulation structures between the small and large intestine for some taxa. MEM opens a path for the microbiome field to acquire deeper insights into host-microbe interactions by enabling in-depth characterization of host-tissue-associated microbial communities.
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Affiliation(s)
- Natalie J Wu-Woods
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA, USA
| | - Jacob T Barlow
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA, USA
| | - Florian Trigodet
- Department of Medicine, The University of Chicago, Chicago, IL, USA
| | - Dustin G Shaw
- Department of Medicine, The University of Chicago, Chicago, IL, USA
- Committee on Immunology, The University of Chicago, Chicago, IL, USA
- Department of Pathology, The University of Chicago, Chicago, IL, USA
| | - Anna E Romano
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, USA
| | - Bana Jabri
- Department of Medicine, The University of Chicago, Chicago, IL, USA
- Committee on Immunology, The University of Chicago, Chicago, IL, USA
- Department of Pathology, The University of Chicago, Chicago, IL, USA
| | - A Murat Eren
- Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany
- Alfred-Wegener-Institute for Marine and Polar Research, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity, Oldenburg, Germany
| | - Rustem F Ismagilov
- Biology and Bioengineering, California Institute of Technology, Pasadena, CA, USA.
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, USA.
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2
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Ji J, Viloria Winnett A, Shelby N, Reyes JA, Schlenker NW, Davich H, Caldera S, Tognazzini C, Goh YY, Feaster M, Ismagilov RF. Index cases first identified by nasal-swab rapid COVID-19 tests had more transmission to household contacts than cases identified by other test types. PLoS One 2023; 18:e0292389. [PMID: 37796850 PMCID: PMC10553276 DOI: 10.1371/journal.pone.0292389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/19/2023] [Indexed: 10/07/2023] Open
Abstract
At-home rapid COVID-19 tests in the U.S. utilize nasal-swab specimens and require high viral loads to reliably give positive results. Longitudinal studies from the onset of infection have found infectious virus can present in oral specimens days before nasal. Detection and initiation of infection-control practices may therefore be delayed when nasal-swab rapid tests are used, resulting in greater transmission to contacts. We assessed whether index cases first identified by rapid nasal-swab COVID-19 tests had more transmission to household contacts than index cases who used other test types (tests with higher analytical sensitivity and/or non-nasal specimen types). In this observational cohort study, 370 individuals from 85 households with a recent COVID-19 case were screened at least daily by RT-qPCR on one or more self-collected upper-respiratory specimen types. A two-level random intercept model was used to assess the association between the infection outcome of household contacts and each covariable (household size, race/ethnicity, age, vaccination status, viral variant, infection-control practices, and whether a rapid nasal-swab test was used to initially identify the household index case). Transmission was quantified by adjusted secondary attack rates (aSAR) and adjusted odds ratios (aOR). An aSAR of 53.6% (95% CI 38.8-68.3%) was observed among households where the index case first tested positive by a rapid nasal-swab COVID-19 test, which was significantly higher than the aSAR for households where the index case utilized another test type (27.2% 95% CI 19.5-35.0%, P = 0.003 pairwise comparisons of predictive margins). We observed an aOR of 4.90 (95% CI 1.65-14.56) for transmission to household contacts when a nasal-swab rapid test was used to identify the index case, compared to other test types. Use of nasal-swab rapid COVID-19 tests for initial detection of infection and initiation of infection control may be less effective at limiting transmission to household contacts than other test types.
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Affiliation(s)
- Jenny Ji
- California Institute of Technology, Pasadena, California, United States of America
| | - Alexander Viloria Winnett
- California Institute of Technology, Pasadena, California, United States of America
- University of California Los Angeles–California Institute of Technology Medical Scientist Training Program, Los Angeles, California, United States of America
| | - Natasha Shelby
- California Institute of Technology, Pasadena, California, United States of America
| | - Jessica A. Reyes
- California Institute of Technology, Pasadena, California, United States of America
| | - Noah W. Schlenker
- California Institute of Technology, Pasadena, California, United States of America
| | - Hannah Davich
- California Institute of Technology, Pasadena, California, United States of America
| | - Saharai Caldera
- California Institute of Technology, Pasadena, California, United States of America
| | - Colten Tognazzini
- Pasadena Public Health Department, Pasadena, California, United States of America
| | - Ying-Ying Goh
- Pasadena Public Health Department, Pasadena, California, United States of America
| | - Matt Feaster
- Pasadena Public Health Department, Pasadena, California, United States of America
| | - Rustem F. Ismagilov
- California Institute of Technology, Pasadena, California, United States of America
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3
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Poceviciute R, Bogatyrev SR, Romano AE, Dilmore AH, Mondragón-Palomino O, Takko H, Pradhan O, Ismagilov RF. Quantitative whole-tissue 3D imaging reveals bacteria in close association with mouse jejunum mucosa. NPJ Biofilms Microbiomes 2023; 9:64. [PMID: 37679412 PMCID: PMC10485000 DOI: 10.1038/s41522-023-00423-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 07/31/2023] [Indexed: 09/09/2023] Open
Abstract
Because the small intestine (SI) epithelium lacks a thick protective mucus layer, microbes that colonize the thin SI mucosa may exert a substantial effect on the host. For example, bacterial colonization of the human SI may contribute to environmental enteropathy dysfunction (EED) in malnourished children. Thus far, potential bacterial colonization of the mucosal surface of the SI has only been documented in disease states, suggesting mucosal colonization is rare, likely requiring multiple perturbations. Furthermore, conclusive proof of bacterial colonization of the SI mucosal surface is challenging, and the three-dimensional (3D) spatial structure of mucosal colonies remains unknown. Here, we tested whether we could induce dense bacterial association with jejunum mucosa by subjecting mice to a combination of malnutrition and oral co-gavage with a bacterial cocktail (E. coli and Bacteroides spp.) known to induce EED. To visualize these events, we optimized our previously developed whole-tissue 3D imaging tools with third-generation hybridization chain reaction (HCR v3.0) probes. Only in mice that were malnourished and gavaged with the bacterial cocktail did we detect dense bacterial clusters surrounding intestinal villi suggestive of colonization. Furthermore, in these mice we detected villus loss, which may represent one possible consequence that bacterial colonization of the SI mucosa has on the host. Our results suggest that dense bacterial colonization of jejunum mucosa is possible in the presence of multiple perturbations and that whole-tissue 3D imaging tools can enable the study of these rare events.
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Affiliation(s)
- Roberta Poceviciute
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Said R Bogatyrev
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Medically Associated Science and Technology Program, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Anna E Romano
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Amanda H Dilmore
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Biomedical Sciences Program, University of California San Diego, San Diego, CA, USA
| | - Octavio Mondragón-Palomino
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Heli Takko
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Ojas Pradhan
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Rustem F Ismagilov
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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4
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Viloria Winnett A, Akana R, Shelby N, Davich H, Caldera S, Yamada T, Reyna JRB, Romano AE, Carter AM, Kim MK, Thomson M, Tognazzini C, Feaster M, Goh YY, Chew YC, Ismagilov RF. Daily SARS-CoV-2 Nasal Antigen Tests Miss Infected and Presumably Infectious People Due to Viral Load Differences among Specimen Types. Microbiol Spectr 2023; 11:e0129523. [PMID: 37314333 PMCID: PMC10434058 DOI: 10.1128/spectrum.01295-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/21/2023] [Indexed: 06/15/2023] Open
Abstract
In a recent household transmission study of SARS-CoV-2, we found extreme differences in SARS-CoV-2 viral loads among paired saliva, anterior nares swab (ANS), and oropharyngeal swab specimens collected from the same time point. We hypothesized these differences may hinder low-analytical-sensitivity assays (including antigen rapid diagnostic tests [Ag-RDTs]) by using a single specimen type (e.g., ANS) from reliably detecting infected and infectious individuals. We evaluated daily at-home ANS Ag-RDTs (Quidel QuickVue) in a cross-sectional analysis of 228 individuals and a longitudinal analysis (throughout infection) of 17 individuals enrolled early in the course of infection. Ag-RDT results were compared to reverse transcription-quantitative PCR (RT-qPCR) results and high, presumably infectious viral loads (in each, or any, specimen type). The ANS Ag-RDT correctly detected only 44% of time points from infected individuals on cross-sectional analysis, and this population had an inferred limit of detection of 7.6 × 106 copies/mL. From the longitudinal cohort, daily Ag-RDT clinical sensitivity was very low (<3%) during the early, preinfectious period of the infection. Further, the Ag-RDT detected ≤63% of presumably infectious time points. The poor observed clinical sensitivity of the Ag-RDT was similar to what was predicted based on quantitative ANS viral loads and the inferred limit of detection of the ANS Ag-RDT being evaluated, indicating high-quality self-sampling. Nasal Ag-RDTs, even when used daily, can miss individuals infected with the Omicron variant and even those presumably infectious. Evaluations of Ag-RDTs for detection of infected or infectious individuals should be compared with a composite (multispecimen) infection status to correctly assess performance. IMPORTANCE We reveal three findings from a longitudinal study of daily nasal antigen rapid diagnostic test (Ag-RDT) evaluated against SARS-CoV-2 viral load quantification in three specimen types (saliva, nasal swab, and throat swab) in participants enrolled at the incidence of infection. First, the evaluated Ag-RDT showed low (44%) clinical sensitivity for detecting infected persons at all infection stages. Second, the Ag-RDT poorly detected (≤63%) time points that participants had high and presumably infectious viral loads in at least one specimen type. This poor clinical sensitivity to detect infectious individuals is inconsistent with the commonly held view that daily Ag-RDTs have near-perfect detection of infectious individuals. Third, use of a combination nasal-throat specimen type was inferred by viral loads to significantly improve Ag-RDT performance to detect infectious individuals.
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Affiliation(s)
| | - Reid Akana
- California Institute of Technology, Pasadena, California, USA
| | - Natasha Shelby
- California Institute of Technology, Pasadena, California, USA
| | - Hannah Davich
- California Institute of Technology, Pasadena, California, USA
| | - Saharai Caldera
- California Institute of Technology, Pasadena, California, USA
| | - Taikun Yamada
- Pangea Laboratory LLC, Tustin, California, USA
- Zymo Research Corporation, Irvine, California, USA
| | | | - Anna E. Romano
- California Institute of Technology, Pasadena, California, USA
| | | | - Mi Kyung Kim
- California Institute of Technology, Pasadena, California, USA
| | - Matt Thomson
- California Institute of Technology, Pasadena, California, USA
| | | | - Matthew Feaster
- Pasadena Public Health Department, Pasadena, California, USA
| | - Ying-Ying Goh
- Pasadena Public Health Department, Pasadena, California, USA
| | - Yap Ching Chew
- Pangea Laboratory LLC, Tustin, California, USA
- Zymo Research Corporation, Irvine, California, USA
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5
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Viloria Winnett A, Akana R, Shelby N, Davich H, Caldera S, Yamada T, Reyna JRB, Romano AE, Carter AM, Kim MK, Thomson M, Tognazzini C, Feaster M, Goh YY, Chew YC, Ismagilov RF. Extreme differences in SARS-CoV-2 viral loads among respiratory specimen types during presumed pre-infectious and infectious periods. PNAS Nexus 2023; 2:pgad033. [PMID: 36926220 PMCID: PMC10013338 DOI: 10.1093/pnasnexus/pgad033] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 03/16/2023]
Abstract
SARS-CoV-2 viral-load measurements from a single-specimen type are used to establish diagnostic strategies, interpret clinical-trial results for vaccines and therapeutics, model viral transmission, and understand virus-host interactions. However, measurements from a single-specimen type are implicitly assumed to be representative of other specimen types. We quantified viral-load timecourses from individuals who began daily self-sampling of saliva, anterior-nares (nasal), and oropharyngeal (throat) swabs before or at the incidence of infection with the Omicron variant. Viral loads in different specimen types from the same person at the same timepoint exhibited extreme differences, up to 109 copies/mL. These differences were not due to variation in sample self-collection, which was consistent. For most individuals, longitudinal viral-load timecourses in different specimen types did not correlate. Throat-swab and saliva viral loads began to rise as many as 7 days earlier than nasal-swab viral loads in most individuals, leading to very low clinical sensitivity of nasal swabs during the first days of infection. Individuals frequently exhibited presumably infectious viral loads in one specimen type while viral loads were low or undetectable in other specimen types. Therefore, defining an individual as infectious based on assessment of a single-specimen type underestimates the infectious period, and overestimates the ability of that specimen type to detect infectious individuals. For diagnostic COVID-19 testing, these three single-specimen types have low clinical sensitivity, whereas a combined throat-nasal swab, and assays with high analytical sensitivity, was inferred to have significantly better clinical sensitivity to detect presumed pre-infectious and infectious individuals.
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Affiliation(s)
| | - Reid Akana
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Natasha Shelby
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Hannah Davich
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Saharai Caldera
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Taikun Yamada
- Pangea Laboratory LLC, 14762 Bentley Cir, Tustin, CA 92780, USA.,Zymo Research Corp., 17062 Murphy Ave, Irvine, CA 92614, USA
| | | | - Anna E Romano
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Alyssa M Carter
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Mi Kyung Kim
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Matt Thomson
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Colten Tognazzini
- Pasadena Public Health Department, 1845 N. Fair Oaks Ave, Pasadena, CA 91103, USA
| | - Matthew Feaster
- Pasadena Public Health Department, 1845 N. Fair Oaks Ave, Pasadena, CA 91103, USA
| | - Ying-Ying Goh
- Pasadena Public Health Department, 1845 N. Fair Oaks Ave, Pasadena, CA 91103, USA
| | - Yap Ching Chew
- Pangea Laboratory LLC, 14762 Bentley Cir, Tustin, CA 92780, USA.,Zymo Research Corp., 17062 Murphy Ave, Irvine, CA 92614, USA
| | - Rustem F Ismagilov
- California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
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6
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Earley ZM, Lisicka W, Sifakis JJ, Aguirre-Gamboa R, Kowalczyk A, Barlow JT, Shaw DG, Discepolo V, Tan IL, Gona S, Ernest JD, Matzinger P, Barreiro LB, Morgun A, Bendelac A, Ismagilov RF, Shulzhenko N, Riesenfeld SJ, Jabri B. GATA4 controls regionalization of tissue immunity and commensal-driven immunopathology. Immunity 2023; 56:43-57.e10. [PMID: 36630917 PMCID: PMC10262782 DOI: 10.1016/j.immuni.2022.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/16/2022] [Accepted: 12/12/2022] [Indexed: 01/12/2023]
Abstract
There is growing recognition that regionalization of bacterial colonization and immunity along the intestinal tract has an important role in health and disease. Yet, the mechanisms underlying intestinal regionalization and its dysregulation in disease are not well understood. This study found that regional epithelial expression of the transcription factor GATA4 controls bacterial colonization and inflammatory tissue immunity in the proximal small intestine by regulating retinol metabolism and luminal IgA. Furthermore, in mice without jejunal GATA4 expression, the commensal segmented filamentous bacteria promoted pathogenic inflammatory immune responses that disrupted barrier function and increased mortality upon Citrobacter rodentium infection. In celiac disease patients, low GATA4 expression was associated with metabolic alterations, mucosal Actinobacillus, and increased IL-17 immunity. Taken together, these results reveal broad impacts of GATA4-regulated intestinal regionalization on bacterial colonization and tissue immunity, highlighting an elaborate interdependence of intestinal metabolism, immunity, and microbiota in homeostasis and disease.
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Affiliation(s)
- Zachary M Earley
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Wioletta Lisicka
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Joseph J Sifakis
- Department of Chemistry, University of Chicago, Chicago, IL, USA
| | | | - Anita Kowalczyk
- Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Jacob T Barlow
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Dustin G Shaw
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Valentina Discepolo
- Department of Medical Translational Sciences and European Laboratory for the Investigation of Food Induced Diseases, University of Federico II, Naples, Italy
| | - Ineke L Tan
- Department of Gastroenterology and Hepatology, University of Groningen and University of Medical Center Groningen, Groningen, the Netherlands
| | - Saideep Gona
- Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Jordan D Ernest
- Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Polly Matzinger
- Ghost Lab, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Luis B Barreiro
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA; Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Andrey Morgun
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA; Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Natalia Shulzhenko
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA
| | - Samantha J Riesenfeld
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA; Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA; Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA.
| | - Bana Jabri
- Committee on Immunology, University of Chicago, Chicago, IL, USA; Department of Medicine, University of Chicago, Chicago, IL, USA; Department of Pathology, University of Chicago, Chicago, IL, USA; Department of Pediatrics, University of Chicago, Chicago, IL, USA.
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7
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Carter AM, Viloria Winnett A, Romano AE, Akana R, Shelby N, Ismagilov RF. Laboratory Evaluation Links Some False-Positive COVID-19 Antigen Test Results Observed in a Field Study to a Specific Lot of Test Strips. Open Forum Infect Dis 2023; 10:ofac701. [PMID: 36726541 PMCID: PMC9887260 DOI: 10.1093/ofid/ofac701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
During a household-transmission field study using COVID-19 antigen rapid diagnostic tests (Ag-RDT), a common test strip lot was identified among 3 participants with false-positive results. In blinded laboratory evaluation, this lot exhibited a significantly higher false-positive rate than other lots. Because a positive Ag-RDT result often prompts action, reducing lot-specific false positives can maintain confidence and actionability of true-positive Ag-RDT results.
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Affiliation(s)
- Alyssa M Carter
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | | | - Anna E Romano
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Reid Akana
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Natasha Shelby
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Rustem F Ismagilov
- Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
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8
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Viloria Winnett A, Porter MK, Romano AE, Savela ES, Akana R, Shelby N, Reyes JA, Schlenker NW, Cooper MM, Carter AM, Ji J, Barlow JT, Tognazzini C, Feaster M, Goh YY, Ismagilov RF. Morning SARS-CoV-2 Testing Yields Better Detection of Infection Due to Higher Viral Loads in Saliva and Nasal Swabs upon Waking. Microbiol Spectr 2022; 10:e0387322. [PMID: 36287073 PMCID: PMC9769854 DOI: 10.1128/spectrum.03873-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 01/10/2023] Open
Abstract
Optimizing specimen collection methods to achieve the most reliable SARS-CoV-2 detection for a given diagnostic sensitivity would improve testing and minimize COVID-19 outbreaks. From September 2020 to April 2021, we performed a household-transmission study in which participants self-collected specimens every morning and evening throughout acute SARS-CoV-2 infection. Seventy mildly symptomatic participants collected saliva, and of those, 29 also collected nasal swab specimens. Viral load was quantified in 1,194 saliva and 661 nasal swab specimens using a high-analytical-sensitivity reverse transcription-quantitative PCR (RT-qPCR) assay. Viral loads in both saliva and nasal swab specimens were significantly higher in morning-collected specimens than in evening-collected specimens after symptom onset. This aspect of the biology of SARS-CoV-2 infection has implications for diagnostic testing. We infer that morning collection would have resulted in significantly improved detection and that this advantage would be most pronounced for tests with low to moderate analytical sensitivity. Collecting specimens for COVID-19 testing in the morning offers a simple and low-cost improvement to clinical diagnostic sensitivity of low- to moderate-analytical-sensitivity tests. IMPORTANCE Our findings suggest that collecting saliva and nasal swab specimens in the morning immediately after waking yields higher SARS-CoV-2 viral loads than collection later in the day. The higher viral loads from morning specimen collection are predicted to significantly improve detection of SARS-CoV-2 in symptomatic individuals, particularly when using moderate- to low-analytical-sensitivity COVID-19 diagnostic tests, such as rapid antigen tests.
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Affiliation(s)
| | | | - Anna E. Romano
- California Institute of Technology, Pasadena, California, USA
| | - Emily S. Savela
- California Institute of Technology, Pasadena, California, USA
| | - Reid Akana
- California Institute of Technology, Pasadena, California, USA
| | - Natasha Shelby
- California Institute of Technology, Pasadena, California, USA
| | | | | | | | | | - Jenny Ji
- California Institute of Technology, Pasadena, California, USA
| | - Jacob T. Barlow
- California Institute of Technology, Pasadena, California, USA
| | - Colten Tognazzini
- City of Pasadena Public Health Department, Pasadena, California, USA
| | - Matthew Feaster
- City of Pasadena Public Health Department, Pasadena, California, USA
| | - Ying-Ying Goh
- City of Pasadena Public Health Department, Pasadena, California, USA
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9
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Savela ES, Viloria Winnett A, Romano AE, Porter MK, Shelby N, Akana R, Ji J, Cooper MM, Schlenker NW, Reyes JA, Carter AM, Barlow JT, Tognazzini C, Feaster M, Goh YY, Ismagilov RF. Quantitative SARS-CoV-2 Viral-Load Curves in Paired Saliva Samples and Nasal Swabs Inform Appropriate Respiratory Sampling Site and Analytical Test Sensitivity Required for Earliest Viral Detection. J Clin Microbiol 2022; 60:e0178521. [PMID: 34911366 PMCID: PMC8849374 DOI: 10.1128/jcm.01785-21] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/10/2021] [Indexed: 11/20/2022] Open
Abstract
Early detection of SARS-CoV-2 infection is critical to reduce asymptomatic and presymptomatic transmission, curb the spread of variants, and maximize treatment efficacy. Low-analytical-sensitivity nasal-swab testing is commonly used for surveillance and symptomatic testing, but the ability of these tests to detect the earliest stages of infection has not been established. In this study, conducted between September 2020 and June 2021 in the greater Los Angeles County, California, area, initially SARS-CoV-2-negative household contacts of individuals diagnosed with COVID-19 prospectively self-collected paired anterior-nares nasal-swab and saliva samples twice daily for viral-load quantification by high-sensitivity reverse-transcription quantitative PCR (RT-qPCR) and digital-RT-PCR assays. We captured viral-load profiles from the incidence of infection for seven individuals and compared diagnostic sensitivities between respiratory sites. Among unvaccinated persons, testing saliva with a high-analytical-sensitivity assay detected infection up to 4.5 days before viral loads in nasal swabs reached concentrations detectable by low-analytical-sensitivity nasal-swab tests. For most participants, nasal swabs reached higher peak viral loads than saliva but were undetectable or at lower loads during the first few days of infection. High-analytical-sensitivity saliva testing was most reliable for earliest detection. Our study illustrates the value of acquiring early (within hours after a negative high-sensitivity test) viral-load profiles to guide the appropriate analytical sensitivity and respiratory site for detecting earliest infections. Such data are challenging to acquire but critical to designing optimal testing strategies with emerging variants in the current pandemic and to respond to future viral pandemics.
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Affiliation(s)
- Emily S. Savela
- California Institute of Technology, Pasadena, California, USA
| | | | - Anna E. Romano
- California Institute of Technology, Pasadena, California, USA
| | | | - Natasha Shelby
- California Institute of Technology, Pasadena, California, USA
| | - Reid Akana
- California Institute of Technology, Pasadena, California, USA
| | - Jenny Ji
- California Institute of Technology, Pasadena, California, USA
| | | | | | | | | | - Jacob T. Barlow
- California Institute of Technology, Pasadena, California, USA
| | - Colten Tognazzini
- City of Pasadena Public Health Department, Pasadena, California, USA
| | - Matthew Feaster
- City of Pasadena Public Health Department, Pasadena, California, USA
| | - Ying-Ying Goh
- City of Pasadena Public Health Department, Pasadena, California, USA
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10
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Barlow JT, Leite G, Romano AE, Sedighi R, Chang C, Celly S, Rezaie A, Mathur R, Pimentel M, Ismagilov RF. Quantitative sequencing clarifies the role of disruptor taxa, oral microbiota, and strict anaerobes in the human small-intestine microbiome. Microbiome 2021; 9:214. [PMID: 34724979 PMCID: PMC8561862 DOI: 10.1186/s40168-021-01162-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/14/2021] [Indexed: 05/04/2023]
Abstract
BACKGROUND Upper gastrointestinal (GI) disorders and abdominal pain afflict between 12 and 30% of the worldwide population and research suggests these conditions are linked to the gut microbiome. Although large-intestine microbiota have been linked to several GI diseases, the microbiota of the human small intestine and its relation to human disease has been understudied. The small intestine is the major site for immune surveillance in the gut, and compared with the large intestine, it has greater than 100 times the surface area and a thinner and more permeable mucus layer. RESULTS Using quantitative sequencing, we evaluated total and taxon-specific absolute microbial loads from 250 duodenal-aspirate samples and 21 paired duodenum-saliva samples from participants in the REIMAGINE study. Log-transformed total microbial loads spanned 5 logs and were normally distributed. Paired saliva-duodenum samples suggested potential transmission of oral microbes to the duodenum, including organisms from the HACEK group. Several taxa, including Klebsiella, Escherichia, Enterococcus, and Clostridium, seemed to displace strict anaerobes common in the duodenum, so we refer to these taxa as disruptors. Disruptor taxa were enriched in samples with high total microbial loads and in individuals with small intestinal bacterial overgrowth (SIBO). Absolute loads of disruptors were associated with more severe GI symptoms, highlighting the value of absolute taxon quantification when studying small-intestine health and function. CONCLUSION This study provides the largest dataset of the absolute abundance of microbiota from the human duodenum to date. The results reveal a clear relationship between the oral microbiota and the duodenal microbiota and suggest an association between the absolute abundance of disruptor taxa, SIBO, and the prevalence of severe GI symptoms. Video Abstract.
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Affiliation(s)
- Jacob T. Barlow
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 USA
| | - Gabriela Leite
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Anna E. Romano
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 USA
| | - Rashin Sedighi
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Christine Chang
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Shreya Celly
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Ali Rezaie
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
- Division of Digestive and Liver Diseases, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Ruchi Mathur
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
- Division of Endocrinology, Diabetes, and Metabolism, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Mark Pimentel
- Medically Associated Science and Technology (MAST) Program, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
- Division of Digestive and Liver Diseases, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Rustem F. Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 USA
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11
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Olson CA, Iñiguez AJ, Yang GE, Fang P, Pronovost GN, Jameson KG, Rendon TK, Paramo J, Barlow JT, Ismagilov RF, Hsiao EY. Alterations in the gut microbiota contribute to cognitive impairment induced by the ketogenic diet and hypoxia. Cell Host Microbe 2021; 29:1378-1392.e6. [PMID: 34358434 PMCID: PMC8429275 DOI: 10.1016/j.chom.2021.07.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/17/2021] [Accepted: 07/12/2021] [Indexed: 01/16/2023]
Abstract
Many genetic and environmental factors increase susceptibility to cognitive impairment (CI), and the gut microbiome is increasingly implicated. However, the identity of gut microbes associated with CI risk, their effects on CI, and their mechanisms remain unclear. Here, we show that a carbohydrate-restricted (ketogenic) diet potentiates CI induced by intermittent hypoxia in mice and alters the gut microbiota. Depleting the microbiome reduces CI, whereas transplantation of the risk-associated microbiome or monocolonization with Bilophila wadsworthia confers CI in mice fed a standard diet. B. wadsworthia and the risk-associated microbiome disrupt hippocampal synaptic plasticity, neurogenesis, and gene expression. The CI is associated with microbiome-dependent increases in intestinal interferon-gamma (IFNg)-producing Th1 cells. Inhibiting Th1 cell development abrogates the adverse effects of both B. wadsworthia and environmental risk factors on CI. Together, these findings identify select gut bacteria that contribute to environmental risk for CI in mice by promoting inflammation and hippocampal dysfunction.
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Affiliation(s)
- Christine A. Olson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA,Correspondence to: ,
| | - Alonso J. Iñiguez
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Grace E. Yang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ping Fang
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Geoffrey N. Pronovost
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Kelly G. Jameson
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tomiko K. Rendon
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jorge Paramo
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jacob T. Barlow
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA 91108, USA
| | - Rustem F. Ismagilov
- Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, CA 91108, USA
| | - Elaine Y. Hsiao
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA,Correspondence to: ,
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12
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Savela ES, Winnett A, Romano AE, Porter MK, Shelby N, Akana R, Ji J, Cooper MM, Schlenker NW, Reyes JA, Carter AM, Barlow JT, Tognazzini C, Feaster M, Goh YY, Ismagilov RF. Quantitative SARS-CoV-2 viral-load curves in paired saliva and nasal swabs inform appropriate respiratory sampling site and analytical test sensitivity required for earliest viral detection. medRxiv 2021:2021.04.02.21254771. [PMID: 33851180 PMCID: PMC8043477 DOI: 10.1101/2021.04.02.21254771] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Early detection of SARS-CoV-2 infection is critical to reduce asymptomatic and pre-symptomatic transmission, curb the spread of variants by travelers, and maximize treatment efficacy. Low-sensitivity nasal-swab testing (antigen and some nucleic-acid-amplification tests) is commonly used for surveillance and symptomatic testing, but the ability of low-sensitivity nasal-swab tests to detect the earliest stages of infection has not been established. In this case-ascertained study, initially-SARS-CoV-2-negative household contacts of individuals diagnosed with COVID-19 prospectively self-collected paired anterior-nares nasal-swab and saliva samples twice daily for viral-load quantification by high-sensitivity RT-qPCR and digital-RT-PCR assays. We captured viral-load profiles from the incidence of infection for seven individuals and compared diagnostic sensitivities between respiratory sites. Among unvaccinated persons, high-sensitivity saliva testing detected infection up to 4.5 days before viral loads in nasal swabs reached the limit of detection of low-sensitivity nasal-swab tests. For most participants, nasal swabs reached higher peak viral loads than saliva, but were undetectable or at lower loads during the first few days of infection. High-sensitivity saliva testing was most reliable for earliest detection. Our study illustrates the value of acquiring early (within hours after a negative high-sensitivity test) viral-load profiles to guide the appropriate analytical sensitivity and respiratory site for detecting earliest infections. Such data are challenging to acquire but critical to design optimal testing strategies in the current pandemic and will be required for responding to future viral pandemics. As new variants and viruses emerge, up-to-date data on viral kinetics are necessary to adjust testing strategies for reliable early detection of infections.
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Affiliation(s)
- Emily S. Savela
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Alexander Winnett
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Anna E. Romano
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Michael K. Porter
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Natasha Shelby
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Reid Akana
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jenny Ji
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Matthew M. Cooper
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Noah W. Schlenker
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jessica A. Reyes
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Alyssa M. Carter
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jacob T. Barlow
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Colten Tognazzini
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Matthew Feaster
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Ying-Ying Goh
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Rustem F. Ismagilov
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
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13
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Wu WL, Adame MD, Liou CW, Barlow JT, Lai TT, Sharon G, Schretter CE, Needham BD, Wang MI, Tang W, Ousey J, Lin YY, Yao TH, Abdel-Haq R, Beadle K, Gradinaru V, Ismagilov RF, Mazmanian SK. Microbiota regulate social behaviour via stress response neurons in the brain. Nature 2021; 595:409-414. [PMID: 34194038 DOI: 10.1038/s41586-021-03669-y] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/25/2021] [Indexed: 02/07/2023]
Abstract
Social interactions among animals mediate essential behaviours, including mating, nurturing, and defence1,2. The gut microbiota contribute to social activity in mice3,4, but the gut-brain connections that regulate this complex behaviour and its underlying neural basis are unclear5,6. Here we show that the microbiome modulates neuronal activity in specific brain regions of male mice to regulate canonical stress responses and social behaviours. Social deviation in germ-free and antibiotic-treated mice is associated with elevated levels of the stress hormone corticosterone, which is primarily produced by activation of the hypothalamus-pituitary-adrenal (HPA) axis. Adrenalectomy, antagonism of glucocorticoid receptors, or pharmacological inhibition of corticosterone synthesis effectively corrects social deficits following microbiome depletion. Genetic ablation of glucocorticoid receptors in specific brain regions or chemogenetic inactivation of neurons in the paraventricular nucleus of the hypothalamus that produce corticotrophin-releasing hormone (CRH) reverse social impairments in antibiotic-treated mice. Conversely, specific activation of CRH-expressing neurons in the paraventricular nucleus induces social deficits in mice with a normal microbiome. Via microbiome profiling and in vivo selection, we identify a bacterial species, Enterococcus faecalis, that promotes social activity and reduces corticosterone levels in mice following social stress. These studies suggest that specific gut bacteria can restrain the activation of the HPA axis, and show that the microbiome can affect social behaviours through discrete neuronal circuits that mediate stress responses in the brain.
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Affiliation(s)
- Wei-Li Wu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. .,Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
| | - Mark D Adame
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chia-Wei Liou
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jacob T Barlow
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tzu-Ting Lai
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Gil Sharon
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Catherine E Schretter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Brittany D Needham
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Madelyn I Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Weiyi Tang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - James Ousey
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yuan-Yuan Lin
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tzu-Hsuan Yao
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Reem Abdel-Haq
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Keith Beadle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sarkis K Mazmanian
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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14
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Winnett A, Cooper MM, Shelby N, Romano AE, Reyes JA, Ji J, Porter MK, Savela ES, Barlow JT, Akana R, Tognazzini C, Feaster M, Goh YY, Ismagilov RF. SARS-CoV-2 Viral Load in Saliva Rises Gradually and to Moderate Levels in Some Humans. medRxiv 2020:2020.12.09.20239467. [PMID: 33330885 PMCID: PMC7743094 DOI: 10.1101/2020.12.09.20239467] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Transmission of SARS-CoV-2 in community settings often occurs before symptom onset, therefore testing strategies that can reliably detect people in the early phase of infection are urgently needed. Early detection of SARS-CoV-2 infection is especially critical to protect vulnerable populations who require frequent interactions with caretakers. Rapid COVID-19 tests have been proposed as an attractive strategy for surveillance, however a limitation of most rapid tests is their low sensitivity. Low-sensitivity tests are comparable to high sensitivity tests in detecting early infections when two assumptions are met: (1) viral load rises quickly (within hours) after infection and (2) viral load reaches and sustains high levels (>105-106 RNA copies/mL). However, there are no human data testing these assumptions. In this study, we document a case of presymptomatic household transmission from a healthy young adult to a sibling and a parent. Participants prospectively provided twice-daily saliva samples. Samples were analyzed by RT-qPCR and RT-ddPCR and we measured the complete viral load profiles throughout the course of infection of the sibling and parent. This study provides evidence that in at least some human cases of SARS-CoV-2, viral load rises slowly (over days, not hours) and not to such high levels to be detectable reliably by any low-sensitivity test. Additional viral load profiles from different samples types across a broad demographic must be obtained to describe the early phase of infection and determine which testing strategies will be most effective for identifying SARS-CoV-2 infection before transmission can occur.
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Affiliation(s)
- Alexander Winnett
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Matthew M. Cooper
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Natasha Shelby
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Anna E. Romano
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jessica A. Reyes
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jenny Ji
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Michael K. Porter
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Emily S. Savela
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Jacob T. Barlow
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Reid Akana
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
| | - Colten Tognazzini
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Matthew Feaster
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Ying-Ying Goh
- City of Pasadena Public Health Department, 1845 N. Fair Oaks Ave., Pasadena, CA, USA 91103
| | - Rustem F. Ismagilov
- California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA 91125
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15
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Khazaei T, Williams RL, Bogatyrev SR, Doyle JC, Henry CS, Ismagilov RF. Metabolic multistability and hysteresis in a model aerobe-anaerobe microbiome community. Sci Adv 2020; 6:eaba0353. [PMID: 32851161 PMCID: PMC7423363 DOI: 10.1126/sciadv.aba0353] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 06/26/2020] [Indexed: 05/20/2023]
Abstract
Major changes in the microbiome are associated with health and disease. Some microbiome states persist despite seemingly unfavorable conditions, such as the proliferation of aerobe-anaerobe communities in oxygen-exposed environments in wound infections or small intestinal bacterial overgrowth. Mechanisms underlying transitions into and persistence of these states remain unclear. Using two microbial taxa relevant to the human microbiome, we combine genome-scale mathematical modeling, bioreactor experiments, transcriptomics, and dynamical systems theory to show that multistability and hysteresis (MSH) is a mechanism describing the shift from an aerobe-dominated state to a resilient, paradoxically persistent aerobe-anaerobe state. We examine the impact of changing oxygen and nutrient regimes and identify changes in metabolism and gene expression that lead to MSH and associated multi-stable states. In such systems, conceptual causation-correlation connections break and MSH must be used for analysis. Using MSH to analyze microbiome dynamics will improve our conceptual understanding of stability of microbiome states and transitions between states.
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Affiliation(s)
- Tahmineh Khazaei
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Rory L. Williams
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Said R. Bogatyrev
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - John C. Doyle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA
| | - Christopher S. Henry
- Data Science and Learning Division, Argonne National Laboratory, Lemont, IL, USA
| | - Rustem F. Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
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16
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Yu Z, Lyu W, Yu M, Wang Q, Qu H, Ismagilov RF, Han X, Lai D, Shen F. Self-partitioning SlipChip for slip-induced droplet formation and human papillomavirus viral load quantification with digital LAMP. Biosens Bioelectron 2020; 155:112107. [DOI: 10.1016/j.bios.2020.112107] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/05/2020] [Accepted: 02/17/2020] [Indexed: 01/20/2023]
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17
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Rolando JC, Jue E, Barlow JT, Ismagilov RF. Real-time kinetics and high-resolution melt curves in single-molecule digital LAMP to differentiate and study specific and non-specific amplification. Nucleic Acids Res 2020; 48:e42. [PMID: 32103255 PMCID: PMC7144905 DOI: 10.1093/nar/gkaa099] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/08/2020] [Accepted: 02/06/2020] [Indexed: 12/15/2022] Open
Abstract
Isothermal amplification assays, such as loop-mediated isothermal amplification (LAMP), show great utility for the development of rapid diagnostics for infectious diseases because they have high sensitivity, pathogen-specificity and potential for implementation at the point of care. However, elimination of non-specific amplification remains a key challenge for the optimization of LAMP assays. Here, using chlamydia DNA as a clinically relevant target and high-throughput sequencing as an analytical tool, we investigate a potential mechanism of non-specific amplification. We then develop a real-time digital LAMP (dLAMP) with high-resolution melting temperature (HRM) analysis and use this single-molecule approach to analyze approximately 1.2 million amplification events. We show that single-molecule HRM provides insight into specific and non-specific amplification in LAMP that are difficult to deduce from bulk measurements. We use real-time dLAMP with HRM to evaluate differences between polymerase enzymes, the impact of assay parameters (e.g. time, rate or florescence intensity), and the effect background human DNA. By differentiating true and false positives, HRM enables determination of the optimal assay and analysis parameters that leads to the lowest limit of detection (LOD) in a digital isothermal amplification assay.
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Affiliation(s)
- Justin C Rolando
- Division of Chemistry and Chemical Engineering, California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Erik Jue
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Jacob T Barlow
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Boulevard, Pasadena, CA 91125, USA
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18
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Schoepp NG, Liaw EJ, Winnett A, Savela ES, Garner OB, Ismagilov RF. Differential DNA accessibility to polymerase enables 30-minute phenotypic β-lactam antibiotic susceptibility testing of carbapenem-resistant Enterobacteriaceae. PLoS Biol 2020; 18:e3000652. [PMID: 32191697 PMCID: PMC7081982 DOI: 10.1371/journal.pbio.3000652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 02/14/2020] [Indexed: 12/22/2022] Open
Abstract
The rise in carbapenem-resistant Enterobacteriaceae (CRE) infections has created a global health emergency, underlining the critical need to develop faster diagnostics to treat swiftly and correctly. Although rapid pathogen-identification (ID) tests are being developed, gold-standard antibiotic susceptibility testing (AST) remains unacceptably slow (1-2 d), and innovative approaches for rapid phenotypic ASTs for CREs are urgently needed. Motivated by this need, in this manuscript we tested the hypothesis that upon treatment with β-lactam antibiotics, susceptible Enterobacteriaceae isolates would become sufficiently permeabilized, making some of their DNA accessible to added polymerase and primers. Further, we hypothesized that this accessible DNA would be detectable directly by isothermal amplification methods that do not fully lyse bacterial cells. We build on these results to develop the polymerase-accessibility AST (pol-aAST), a new phenotypic approach for β-lactams, the major antibiotic class for gram-negative infections. We test isolates of the 3 causative pathogens of CRE infections using ceftriaxone (CRO), ertapenem (ETP), and meropenem (MEM) and demonstrate agreement with gold-standard AST. Importantly, pol-aAST correctly categorized resistant isolates that are undetectable by current genotypic methods (negative for β-lactamase genes or lacking predictive genotypes). We also test contrived and clinical urine samples. We show that the pol-aAST can be performed in 30 min sample-to-answer using contrived urine samples and has the potential to be performed directly on clinical urine specimens.
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Affiliation(s)
- Nathan G. Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Eric J. Liaw
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Alexander Winnett
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Emily S. Savela
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Omai B. Garner
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, United States of America
| | - Rustem F. Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
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19
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Savela ES, Schoepp NG, Cooper MM, Rolando JC, Klausner JD, Soge OO, Ismagilov RF. Surfactant-enhanced DNA accessibility to nuclease accelerates phenotypic β-lactam antibiotic susceptibility testing of Neisseria gonorrhoeae. PLoS Biol 2020; 18:e3000651. [PMID: 32191696 PMCID: PMC7081974 DOI: 10.1371/journal.pbio.3000651] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 02/14/2020] [Indexed: 11/19/2022] Open
Abstract
Rapid antibiotic susceptibility testing (AST) for Neisseria gonorrhoeae (Ng) is critically needed to counter widespread antibiotic resistance. Detection of nucleic acids in genotypic AST can be rapid, but it has not been successful for β-lactams (the largest antibiotic class used to treat Ng). Rapid phenotypic AST for Ng is challenged by the pathogen's slow doubling time and the lack of methods to quickly quantify the pathogen's response to β-lactams. Here, we asked two questions: (1) Is it possible to use nucleic acid quantification to measure the β-lactam susceptibility phenotype of Ng very rapidly, using antibiotic-exposure times much shorter than the 1- to 2-h doubling time of Ng? (2) Would such short-term antibiotic exposures predict the antibiotic resistance profile of Ng measured by plate growth assays over multiple days? To answer these questions, we devised an innovative approach for performing a rapid phenotypic AST that measures DNA accessibility to exogenous nucleases after exposure to β-lactams (termed nuclease-accessibility AST [nuc-aAST]). We showed that DNA in antibiotic-susceptible cells has increased accessibility upon exposure to β-lactams and that a judiciously chosen surfactant permeabilized the outer membrane and enhanced this effect. We tested penicillin, cefixime, and ceftriaxone and found good agreement between the results of the nuc-aAST after 15-30 min of antibiotic exposure and the results of the gold-standard culture-based AST measured over days. These results provide a new pathway toward developing a critically needed phenotypic AST for Ng and additional global-health threats.
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Affiliation(s)
- Emily S. Savela
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Nathan G. Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Matthew M. Cooper
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Justin C. Rolando
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Jeffrey D. Klausner
- David Geffen School of Medicine, Division of Infectious Disease, University of California Los Angeles, Los Angeles, California, United States of America
| | - Olusegun O. Soge
- Neisseria Reference Laboratory, Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Rustem F. Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
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20
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Bogatyrev SR, Rolando JC, Ismagilov RF. Self-reinoculation with fecal flora changes microbiota density and composition leading to an altered bile-acid profile in the mouse small intestine. Microbiome 2020; 8:19. [PMID: 32051033 PMCID: PMC7017497 DOI: 10.1186/s40168-020-0785-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/05/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND The upper gastrointestinal tract plays a prominent role in human physiology as the primary site for enzymatic digestion and nutrient absorption, immune sampling, and drug uptake. Alterations to the small intestine microbiome have been implicated in various human diseases, such as non-alcoholic steatohepatitis and inflammatory bowel conditions. Yet, the physiological and functional roles of the small intestine microbiota in humans remain poorly characterized because of the complexities associated with its sampling. Rodent models are used extensively in microbiome research and enable the spatial, temporal, compositional, and functional interrogation of the gastrointestinal microbiota and its effects on the host physiology and disease phenotype. Classical, culture-based studies have documented that fecal microbial self-reinoculation (via coprophagy) affects the composition and abundance of microbes in the murine proximal gastrointestinal tract. This pervasive self-reinoculation behavior could be a particularly relevant study factor when investigating small intestine microbiota. Modern microbiome studies either do not take self-reinoculation into account, or assume that approaches such as single housing mice or housing on wire mesh floors eliminate it. These assumptions have not been rigorously tested with modern tools. Here, we used quantitative 16S rRNA gene amplicon sequencing, quantitative microbial functional gene content inference, and metabolomic analyses of bile acids to evaluate the effects of self-reinoculation on microbial loads, composition, and function in the murine upper gastrointestinal tract. RESULTS In coprophagic mice, continuous self-exposure to the fecal flora had substantial quantitative and qualitative effects on the upper gastrointestinal microbiome. These differences in microbial abundance and community composition were associated with an altered profile of the small intestine bile acid pool, and, importantly, could not be inferred from analyzing large intestine or stool samples. Overall, the patterns observed in the small intestine of non-coprophagic mice (reduced total microbial load, low abundance of anaerobic microbiota, and bile acids predominantly in the conjugated form) resemble those typically seen in the human small intestine. CONCLUSIONS Future studies need to take self-reinoculation into account when using mouse models to evaluate gastrointestinal microbial colonization and function in relation to xenobiotic transformation and pharmacokinetics or in the context of physiological states and diseases linked to small intestine microbiome and to small intestine dysbiosis. Video abstract.
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Affiliation(s)
- Said R Bogatyrev
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Justin C Rolando
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, USA
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, USA.
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21
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Jue E, Witters D, Ismagilov RF. Two-phase wash to solve the ubiquitous contaminant-carryover problem in commercial nucleic-acid extraction kits. Sci Rep 2020; 10:1940. [PMID: 32029846 PMCID: PMC7004994 DOI: 10.1038/s41598-020-58586-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/02/2020] [Indexed: 11/09/2022] Open
Abstract
The success of fundamental and applied nucleic acid (NA) research depends on NA purity, but obtaining pure NAs from raw, unprocessed samples is challenging. Purification using solid-phase NA extractions utilizes sequential additions of lysis and wash buffers followed by elution. The resulting eluent contains NAs and carryover of extraction buffers. Typically, these inhibitory buffers are heavily diluted by the reaction mix (e.g., 10x dilution is 1 µL eluent in 9 µL reaction mix), but in applications requiring high sensitivity (e.g., single-cell sequencing, pathogen diagnostics) it is desirable to use low dilutions (e.g., 2x) to maximize NA concentration. Here, we demonstrate pervasive carryover of inhibitory buffers into eluent when several commercial sample-preparation kits are used following manufacturer protocols. At low eluent dilution (2-2.5x) we observed significant reaction inhibition of polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and reverse transcription (RT). We developed a two-phase wash (TPW) method by adding a wash buffer with low water solubility prior to the elution step. The TPW reduces carryover of extraction buffers, phase-separates from the eluent, and does not reduce NA yield (measured by digital PCR). We validated the TPW for silica columns and magnetic beads by demonstrating significant improvements in performance and reproducibility of qPCR, LAMP, and RT reactions.
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Affiliation(s)
- Erik Jue
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Blvd., Pasadena, CA, 91125, United States
| | - Daan Witters
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd., Pasadena, CA, 91125, United States
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Blvd., Pasadena, CA, 91125, United States.
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd., Pasadena, CA, 91125, United States.
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22
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Zhukov DV, Khorosheva EM, Khazaei T, Du W, Selck DA, Shishkin AA, Ismagilov RF. Microfluidic SlipChip device for multistep multiplexed biochemistry on a nanoliter scale. Lab Chip 2019; 19:3200-3211. [PMID: 31441477 DOI: 10.1039/c9lc00541b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have developed a multistep microfluidic device that expands the current SlipChip capabilities by enabling multiple steps of droplet merging and multiplexing. Harnessing the interfacial energy between carrier and sample phases, this manually operated device accurately meters nanoliter volumes of reagents and transfers them into on-device reaction wells. Judiciously shaped microfeatures and surface-energy traps merge droplets in a parallel fashion. Wells can be tuned for different volumetric capacities and reagent types, including for pre-spotted reagents that allow for unique identification of original well contents even after their contents are pooled. We demonstrate the functionality of the multistep SlipChip by performing RNA transcript barcoding on-device for synthetic spiked-in standards and for biologically derived samples. This technology is a good candidate for a wide range of biological applications that require multiplexing of multistep reactions in nanoliter volumes, including single-cell analyses.
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Affiliation(s)
- Dmitriy V Zhukov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA.
| | - Eugenia M Khorosheva
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA.
| | - Tahmineh Khazaei
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Wenbin Du
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - David A Selck
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA.
| | - Alexander A Shishkin
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA. and Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
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23
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Porter MK, Preska Steinberg A, Ismagilov RF. Interplay of motility and polymer-driven depletion forces in the initial stages of bacterial aggregation. Soft Matter 2019; 15:7071-7079. [PMID: 31441486 DOI: 10.1039/c9sm00791a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Motile bacteria are often found in complex, polymer-rich environments in which microbes can aggregate via polymer-induced depletion forces. Bacterial aggregation has many biological implications; it can promote biofilm formation, upregulate virulence factors, and lead to quorum sensing. The steady state aggregation behavior of motile bacteria in polymer solutions has been well studied and shows that stronger depletion forces are required to aggregate motile bacteria as compared with their nonmotile analogs. However, no one has studied whether these same trends hold at the initial stages of aggregation. We use experiments and numerical calculations to investigate the polymer-induced depletion aggregation of motile Escherichia coli in polyethylene glycol solutions on short experimental timescales (∼10 min). Our work reveals that in the semi-dilute polymer concentration regime and at short timescales, in contrast to what is found at steady state, bacterial motility actually enhances aggregate formation by increasing the collision rate in viscous environments. These unexpected findings have implications for developing models of active matter, and for understanding bacterial aggregation in dynamic, biological environments, where the system may never reach steady state.
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Affiliation(s)
- Michael K Porter
- Division of Chemistry & Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA.
| | - Asher Preska Steinberg
- Division of Chemistry & Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA.
| | - Rustem F Ismagilov
- Division of Chemistry & Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA. and Division of Biology & Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
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24
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Preska Steinberg A, Wang ZG, Ismagilov RF. Food Polyelectrolytes Compress the Colonic Mucus Hydrogel by a Donnan Mechanism. Biomacromolecules 2019; 20:2675-2683. [PMID: 31244018 DOI: 10.1021/acs.biomac.9b00442] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Systems consisting of a polyelectrolyte solution in contact with a cross-linked polyelectrolyte network are ubiquitous (e.g., biofilms, drug-delivering hydrogels, and mammalian extracellular matrices), yet the underlying physics governing these interactions is not well understood. Here, we find that carboxymethyl cellulose, a polyelectrolyte commonly found in processed foods and associated with inflammation and obesity, compresses the colonic mucus hydrogel (a key regulator of host-microbe interactions and a protective barrier) in mice. The extent of this polyelectrolyte-induced compression is enhanced by the degree of polymer negative charge. Through animal experiments and numerical calculations, we find that this phenomenon can be described by a Donnan mechanism. Further, the observed behavior can be quantitatively described by a simple, one-parameter model. This work suggests that polymer charge should be considered when developing food products because of its potential role in modulating the protective properties of colonic mucus.
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25
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26
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Yu M, Chen X, Qu H, Ma L, Xu L, Lv W, Wang H, Ismagilov RF, Li M, Shen F. Multistep SlipChip for the Generation of Serial Dilution Nanoliter Arrays and Hepatitis B Viral Load Quantification by Digital Loop Mediated Isothermal Amplification. Anal Chem 2019; 91:8751-8755. [PMID: 31117407 DOI: 10.1021/acs.analchem.9b01270] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Serial dilution is a commonly used technique that generates a low-concentration working sample from a high-concentration stock solution and is used to set up screening conditions over a large dynamic range for biological study, optimization of reaction conditions, drug screening, etc. Creating an array of serial dilutions usually requires cumbersome manual pipetting steps or a robotic liquid handling system. Moreover, it is very challenging to set up an array of serial dilutions in nanoliter volumes in miniaturized assays. Here, a multistep SlipChip microfluidic device is presented for generating serial dilution nanoliter arrays in high throughput with a series of simple sliding motions. The dilution ratio can be precisely predetermined by the volumes of mother microwells and daughter microwells, and this paper demonstrates devices designed to have dilution ratios of 1:1, 1:2, and 1:4. Furthermore, an eight-step serial dilution SlipChip with a dilution ratio of 1:4 is applied for digital loop-mediated isothermal amplification (LAMP) across a large dynamic range and tested for hepatitis B viral load quantification with clinical samples. With 64 wells of each dilution and fewer than 600 wells in total, the serial dilution SlipChip can achieve a theoretical quantification dynamic range of 7 orders of magnitude.
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Affiliation(s)
- Mengchao Yu
- School of Biomedical Engineering , Shanghai Jiao Tong University , 1954 Hua Shan Road , Shanghai 200030 , China
| | - Xiaoying Chen
- Department of Laboratory Medicine, Renji Hospital, School of Medicine , Shanghai Jiao Tong University , Shanghai 200127 , China
| | - Haijun Qu
- School of Biomedical Engineering , Shanghai Jiao Tong University , 1954 Hua Shan Road , Shanghai 200030 , China
| | - Liang Ma
- Department of Chemistry and Institute for Biophysical Dynamics , The University of Chicago , 929 East 57th Street , Chicago , Illinois 60637 , United States
| | - Lei Xu
- School of Biomedical Engineering , Shanghai Jiao Tong University , 1954 Hua Shan Road , Shanghai 200030 , China
| | - Weiyuan Lv
- School of Biomedical Engineering , Shanghai Jiao Tong University , 1954 Hua Shan Road , Shanghai 200030 , China
| | - Hua Wang
- Department of Laboratory Medicine, Renji Hospital, School of Medicine , Shanghai Jiao Tong University , Shanghai 200127 , China
| | - Rustem F Ismagilov
- Division of Chemistry & Chemical Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California 91125 , United States.,Division of Biology & Biological Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California 91125 , United States
| | - Min Li
- Department of Laboratory Medicine, Renji Hospital, School of Medicine , Shanghai Jiao Tong University , Shanghai 200127 , China.,China State Key Laboratory of Microbial Resources, Institute of Microbiology , Chinese Academy of Sciences , Beijing 100080 , China
| | - Feng Shen
- School of Biomedical Engineering , Shanghai Jiao Tong University , 1954 Hua Shan Road , Shanghai 200030 , China
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27
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Preska Steinberg A, Datta SS, Naragon T, Rolando JC, Bogatyrev SR, Ismagilov RF. High-molecular-weight polymers from dietary fiber drive aggregation of particulates in the murine small intestine. eLife 2019; 8:40387. [PMID: 30666958 PMCID: PMC6342521 DOI: 10.7554/elife.40387] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 12/28/2018] [Indexed: 12/28/2022] Open
Abstract
The lumen of the small intestine (SI) is filled with particulates: microbes, therapeutic particles, and food granules. The structure of this particulate suspension could impact uptake of drugs and nutrients and the function of microorganisms; however, little is understood about how this suspension is re-structured as it transits the gut. Here, we demonstrate that particles spontaneously aggregate in SI luminal fluid ex vivo. We find that mucins and immunoglobulins are not required for aggregation. Instead, aggregation can be controlled using polymers from dietary fiber in a manner that is qualitatively consistent with polymer-induced depletion interactions, which do not require specific chemical interactions. Furthermore, we find that aggregation is tunable; by feeding mice dietary fibers of different molecular weights, we can control aggregation in SI luminal fluid. This work suggests that the molecular weight and concentration of dietary polymers play an underappreciated role in shaping the physicochemical environment of the gut. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Asher Preska Steinberg
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Sujit S Datta
- Department of Chemical and Biological Engineering, Princeton University, Princeton, United States
| | - Thomas Naragon
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Justin C Rolando
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Said R Bogatyrev
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
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28
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Rolando JC, Jue E, Schoepp NG, Ismagilov RF. Real-Time, Digital LAMP with Commercial Microfluidic Chips Reveals the Interplay of Efficiency, Speed, and Background Amplification as a Function of Reaction Temperature and Time. Anal Chem 2018; 91:1034-1042. [PMID: 30565936 PMCID: PMC6322147 DOI: 10.1021/acs.analchem.8b04324] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Real-time,
isothermal, digital nucleic acid amplification is emerging
as an attractive approach for a multitude of applications including
diagnostics, mechanistic studies, and assay optimization. Unfortunately,
there is no commercially available and affordable real-time, digital
instrument validated for isothermal amplification; thus, most researchers
have not been able to apply digital, real-time approaches to isothermal
amplification. Here, we generate an approach to real-time digital
loop-mediated isothermal amplification (LAMP) using commercially available
microfluidic chips and reagents and open-source components. We demonstrate
this approach by testing variables that influence LAMP reaction speed
and the probability of detection. By analyzing the interplay of amplification
efficiency, background, and speed of amplification, this real-time
digital method enabled us to test enzymatic performance over a range
of temperatures, generating high-precision kinetic and end-point measurements.
We were able to identify the unique optimal temperature for two polymerase
enzymes while accounting for amplification efficiency, nonspecific
background, and time to threshold. We validated this digital LAMP
assay and pipeline by performing a phenotypic antibiotic susceptibility
test on 17 archived clinical urine samples from patients diagnosed
with urinary tract infections. We provide all the necessary workflows
to perform digital LAMP using standard laboratory equipment and commercially
available materials. This real-time digital approach will be useful
to others in the future to understand the fundamentals of isothermal
chemistries, including which components determine amplification fate,
reaction speed, and enzymatic performance. Researchers can also adapt
this pipeline, which uses only standard equipment and commercial components,
to quickly study and optimize assays using precise, real-time digital
quantification, accelerating development of critically needed diagnostics.
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Affiliation(s)
- Justin C Rolando
- Division of Chemistry & Chemical Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California , 91125 , United States
| | - Erik Jue
- Division of Biology & Biological Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California 91125 United States
| | - Nathan G Schoepp
- Division of Chemistry & Chemical Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California , 91125 , United States
| | - Rustem F Ismagilov
- Division of Chemistry & Chemical Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California , 91125 , United States.,Division of Biology & Biological Engineering , California Institute of Technology , 1200 East California Boulevard , Mail Code 210-41, Pasadena , California 91125 United States
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29
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Khazaei T, Barlow JT, Schoepp NG, Ismagilov RF. RNA markers enable phenotypic test of antibiotic susceptibility in Neisseria gonorrhoeae after 10 minutes of ciprofloxacin exposure. Sci Rep 2018; 8:11606. [PMID: 30072794 PMCID: PMC6072703 DOI: 10.1038/s41598-018-29707-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/11/2018] [Indexed: 11/29/2022] Open
Abstract
Antimicrobial-resistant Neisseria gonorrhoeae is an urgent public-health threat, with continued worldwide incidents of infection and rising resistance to antimicrobials. Traditional culture-based methods for antibiotic susceptibility testing are unacceptably slow (1-2 days), resulting in the use of broad-spectrum antibiotics and the further development and spread of resistance. Critically needed is a rapid antibiotic susceptibility test (AST) that can guide treatment at the point-of-care. Rapid phenotypic approaches using quantification of DNA have been demonstrated for fast-growing organisms (e.g. E. coli) but are challenging for slower-growing pathogens such as N. gonorrhoeae. Here, we investigate the potential of RNA signatures to provide phenotypic responses to antibiotics in N. gonorrhoeae that are faster and greater in magnitude compared with DNA. Using RNA sequencing, we identified antibiotic-responsive transcripts. Significant shifts (>4-fold change) in transcript levels occurred within 5 min of antibiotic exposure. We designed assays for responsive transcripts with the highest abundances and fold changes, and validated gene expression using digital PCR. Using the top two markers (porB and rpmB) we correctly determined the antibiotic susceptibility and resistance of 49 clinical isolates after 10 min exposure to ciprofloxacin. RNA signatures are therefore promising as an approach on which to build rapid AST devices for N. gonorrhoeae at the point-of-care, which is critical for disease management, surveillance, and antibiotic stewardship efforts.
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Affiliation(s)
- Tahmineh Khazaei
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, United States of America
| | - Jacob T Barlow
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, United States of America
| | - Nathan G Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, United States of America
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, United States of America.
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA, United States of America.
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Schoepp NG, Schlappi TS, Curtis MS, Butkovich SS, Miller S, Humphries RM, Ismagilov RF. Rapid pathogen-specific phenotypic antibiotic susceptibility testing using digital LAMP quantification in clinical samples. Sci Transl Med 2018; 9:9/410/eaal3693. [PMID: 28978750 DOI: 10.1126/scitranslmed.aal3693] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 06/30/2017] [Accepted: 09/05/2017] [Indexed: 12/30/2022]
Abstract
Rapid antimicrobial susceptibility testing (AST) is urgently needed for informing treatment decisions and preventing the spread of antimicrobial resistance resulting from the misuse and overuse of antibiotics. To date, no phenotypic AST exists that can be performed within a single patient visit (30 min) directly from clinical samples. We show that AST results can be obtained by using digital nucleic acid quantification to measure the phenotypic response of Escherichia coli present within clinical urine samples exposed to an antibiotic for 15 min. We performed this rapid AST using our ultrafast (~7 min) digital real-time loop-mediated isothermal amplification (dLAMP) assay [area under the curve (AUC), 0.96] and compared the results to a commercial (~2 hours) digital polymerase chain reaction assay (AUC, 0.98). The rapid dLAMP assay can be used with SlipChip microfluidic devices to determine the phenotypic antibiotic susceptibility of E. coli directly from clinical urine samples in less than 30 min. With further development for additional pathogens, antibiotics, and sample types, rapid digital AST (dAST) could enable rapid clinical decision-making, improve management of infectious diseases, and facilitate antimicrobial stewardship.
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Affiliation(s)
- Nathan G Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Travis S Schlappi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Matthew S Curtis
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Slava S Butkovich
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Shelley Miller
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, 10888 Le Conte Avenue, Brentwood Annex, Los Angeles, CA 90095, USA
| | - Romney M Humphries
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, 10888 Le Conte Avenue, Brentwood Annex, Los Angeles, CA 90095, USA
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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Schoepp NG, Khorosheva EM, Schlappi TS, Curtis MS, Humphries RM, Hindler JA, Ismagilov RF. Corrigendum: Digital Quantification of DNA Replication and Chromosome Segregation Enables Determination of Antimicrobial Susceptibility after only 15 Minutes of Antibiotic Exposure. Angew Chem Int Ed Engl 2017; 56:11675. [DOI: 10.1002/anie.201707742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Schoepp NG, Khorosheva EM, Schlappi TS, Curtis MS, Humphries RM, Hindler JA, Ismagilov RF. Berichtigung: Digital Quantification of DNA Replication and Chromosome Segregation Enables Determination of Antimicrobial Susceptibility after only 15 Minutes of Antibiotic Exposure. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201707742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pompano RR, Chiang AH, Kastrup CJ, Ismagilov RF. Conceptual and Experimental Tools to Understand Spatial Effects and Transport Phenomena in Nonlinear Biochemical Networks Illustrated with Patchy Switching. Annu Rev Biochem 2017; 86:333-356. [PMID: 28654324 PMCID: PMC10852032 DOI: 10.1146/annurev-biochem-060815-014207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many biochemical systems are spatially heterogeneous and exhibit nonlinear behaviors, such as state switching in response to small changes in the local concentration of diffusible molecules. Systems as varied as blood clotting, intracellular calcium signaling, and tissue inflammation are all heavily influenced by the balance of rates of reaction and mass transport phenomena including flow and diffusion. Transport of signaling molecules is also affected by geometry and chemoselective confinement via matrix binding. In this review, we use a phenomenon referred to as patchy switching to illustrate the interplay of nonlinearities, transport phenomena, and spatial effects. Patchy switching describes a change in the state of a network when the local concentration of a diffusible molecule surpasses a critical threshold. Using patchy switching as an example, we describe conceptual tools from nonlinear dynamics and chemical engineering that make testable predictions and provide a unifying description of the myriad possible experimental observations. We describe experimental microfluidic and biochemical tools emerging to test conceptual predictions by controlling transport phenomena and spatial distribution of diffusible signals, and we highlight the unmet need for in vivo tools.
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Affiliation(s)
- Rebecca R Pompano
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904;
| | - Andrew H Chiang
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637;
| | - Christian J Kastrup
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada;
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125;
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Schoepp NG, Khorosheva EM, Schlappi TS, Curtis MS, Humphries RM, Hindler JA, Ismagilov RF. Digital Quantification of DNA Replication and Chromosome Segregation Enables Determination of Antimicrobial Susceptibility after only 15 Minutes of Antibiotic Exposure. Angew Chem Int Ed Engl 2016; 55:9557-61. [PMID: 27357747 PMCID: PMC5215780 DOI: 10.1002/anie.201602763] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/05/2016] [Indexed: 01/11/2023]
Abstract
Rapid antimicrobial susceptibility testing (AST) would decrease misuse and overuse of antibiotics. The "holy grail" of AST is a phenotype-based test that can be performed within a doctor visit. Such a test requires the ability to determine a pathogen's susceptibility after only a short antibiotic exposure. Herein, digital PCR (dPCR) was employed to test whether measuring DNA replication of the target pathogen through digital single-molecule counting would shorten the required time of antibiotic exposure. Partitioning bacterial chromosomal DNA into many small volumes during dPCR enabled AST results after short exposure times by 1) precise quantification and 2) a measurement of how antibiotics affect the states of macromolecular assembly of bacterial chromosomes. This digital AST (dAST) determined susceptibility of clinical isolates from urinary tract infections (UTIs) after 15 min of exposure for all four antibiotic classes relevant to UTIs. This work lays the foundation to develop a rapid, point-of-care AST and strengthen global antibiotic stewardship.
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Affiliation(s)
- Nathan G Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125, USA
| | - Eugenia M Khorosheva
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125, USA
| | - Travis S Schlappi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125, USA
| | - Matthew S Curtis
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125, USA
| | - Romney M Humphries
- Pathology and Laboratory Medicine, University of California, Los Angeles, 10888 Le Conte Avenue, Brentwood Annex, Los Angeles, CA, 90095, USA
| | - Janet A Hindler
- Pathology and Laboratory Medicine, University of California, Los Angeles, 10888 Le Conte Avenue, Brentwood Annex, Los Angeles, CA, 90095, USA
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125, USA.
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Schlappi TS, McCalla SE, Schoepp NG, Ismagilov RF. Flow-through Capture and in Situ Amplification Can Enable Rapid Detection of a Few Single Molecules of Nucleic Acids from Several Milliliters of Solution. Anal Chem 2016; 88:7647-53. [PMID: 27429181 DOI: 10.1021/acs.analchem.6b01485] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Detecting nucleic acids (NAs) at zeptomolar concentrations (few molecules per milliliter) currently requires expensive equipment and lengthy processing times to isolate and concentrate the NAs into a volume that is amenable to amplification processes, such as PCR or LAMP. Shortening the time required to concentrate NAs and integrating this procedure with amplification on-device would be invaluable to a number of analytical fields, including environmental monitoring and clinical diagnostics. Microfluidic point-of-care (POC) devices have been designed to address these needs, but they are not able to detect NAs present in zeptomolar concentrations in short time frames because they require slow flow rates and/or they are unable to handle milliliter-scale volumes. In this paper, we theoretically and experimentally investigate a flow-through capture membrane that solves this problem by capturing NAs with high sensitivity in a short time period, followed by direct detection via amplification. Theoretical predictions guided the choice of physical parameters for a chitosan-coated nylon membrane; these predictions can also be applied generally to other capture situations with different requirements. The membrane is also compatible with in situ amplification, which, by eliminating an elution step enables high sensitivity and will facilitate integration of this method into sample-to-answer detection devices. We tested a wide range of combinations of sample volumes and concentrations of DNA molecules using a capture membrane with a 2 mm radius. We show that for nucleic acid detection, this approach can concentrate and detect as few as ∼10 molecules of DNA with flow rates as high as 1 mL/min, handling samples as large as 50 mL. In a specific example, this method reliably concentrated and detected ∼25 molecules of DNA from 50 mL of sample.
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Affiliation(s)
- Travis S Schlappi
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Stephanie E McCalla
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Nathan G Schoepp
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States
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Schoepp NG, Khorosheva EM, Schlappi TS, Curtis MS, Humphries RM, Hindler JA, Ismagilov RF. Digital Quantification of DNA Replication and Chromosome Segregation Enables Determination of Antimicrobial Susceptibility after only 15 Minutes of Antibiotic Exposure. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602763] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Nathan G. Schoepp
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd. Pasadena CA 91125 USA
| | - Eugenia M. Khorosheva
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd. Pasadena CA 91125 USA
| | - Travis S. Schlappi
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd. Pasadena CA 91125 USA
| | - Matthew S. Curtis
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd. Pasadena CA 91125 USA
| | - Romney M. Humphries
- Pathology and Laboratory Medicine; University of California, Los Angeles; 10888 Le Conte Avenue, Brentwood Annex Los Angeles CA 90095 USA
| | - Janet A. Hindler
- Pathology and Laboratory Medicine; University of California, Los Angeles; 10888 Le Conte Avenue, Brentwood Annex Los Angeles CA 90095 USA
| | - Rustem F. Ismagilov
- Division of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd. Pasadena CA 91125 USA
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Jue E, Schoepp NG, Witters D, Ismagilov RF. Evaluating 3D printing to solve the sample-to-device interface for LRS and POC diagnostics: example of an interlock meter-mix device for metering and lysing clinical urine samples. Lab Chip 2016; 16:1852-60. [PMID: 27122199 DOI: 10.1039/c6lc00292g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This paper evaluates the potential of 3D printing, a semi-automated additive prototyping technology, as a means to design and prototype a sample-to-device interface, amenable to diagnostics in limited-resource settings, where speed, accuracy and user-friendly design are critical components. As a test case, we built and validated an interlock meter-mix device for accurately metering and lysing human urine samples for use in downstream nucleic acid amplification. Two plungers and a multivalve generated and controlled fluid flow through the device and demonstrate the utility of 3D printing to create leak-free seals. Device operation consists of three simple steps that must be performed sequentially, eliminating manual pipetting and vortexing to provide rapid (5 to 10 s) and accurate metering and mixing. Bretherton's prediction was applied, using the bond number to guide a design that prevents potentially biohazardous samples from leaking from the device. We employed multi-material 3D printing technology, which allows composites with rigid and elastomeric properties to be printed as a single part. To validate the meter-mix device with a clinically relevant sample, we used urine spiked with inactivated Chlamydia trachomatis and Neisseria gonorrhoeae. A downstream nucleic acid amplification by quantitative PCR (qPCR) confirmed there was no statistically significant difference between samples metered and mixed using the standard protocol and those prepared with the meter-mix device, showing the 3D-printed device could accurately meter, mix and dispense a human urine sample without loss of nucleic acids. Although there are some limitations to 3D printing capabilities (e.g. dimension limitations related to support material used in the printing process), the advantages of customizability, modularity and rapid prototyping illustrate the utility of 3D printing for developing sample-to-device interfaces for diagnostics.
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Affiliation(s)
- Erik Jue
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, USA.
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Rodriguez-Manzano J, Karymov MA, Begolo S, Selck DA, Zhukov D, Jue E, Ismagilov RF. Reading Out Single-Molecule Digital RNA and DNA Isothermal Amplification in Nanoliter Volumes with Unmodified Camera Phones. ACS Nano 2016; 10:3102-13. [PMID: 26900709 PMCID: PMC4819493 DOI: 10.1021/acsnano.5b07338] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Digital single-molecule technologies are expanding diagnostic capabilities, enabling the ultrasensitive quantification of targets, such as viral load in HIV and hepatitis C infections, by directly counting single molecules. Replacing fluorescent readout with a robust visual readout that can be captured by any unmodified cell phone camera will facilitate the global distribution of diagnostic tests, including in limited-resource settings where the need is greatest. This paper describes a methodology for developing a visual readout system for digital single-molecule amplification of RNA and DNA by (i) selecting colorimetric amplification-indicator dyes that are compatible with the spectral sensitivity of standard mobile phones, and (ii) identifying an optimal ratiometric image-process for a selected dye to achieve a readout that is robust to lighting conditions and camera hardware and provides unambiguous quantitative results, even for colorblind users. We also include an analysis of the limitations of this methodology, and provide a microfluidic approach that can be applied to expand dynamic range and improve reaction performance, allowing ultrasensitive, quantitative measurements at volumes as low as 5 nL. We validate this methodology using SlipChip-based digital single-molecule isothermal amplification with λDNA as a model and hepatitis C viral RNA as a clinically relevant target. The innovative combination of isothermal amplification chemistry in the presence of a judiciously chosen indicator dye and ratiometric image processing with SlipChip technology allowed the sequence-specific visual readout of single nucleic acid molecules in nanoliter volumes with an unmodified cell phone camera. When paired with devices that integrate sample preparation and nucleic acid amplification, this hardware-agnostic approach will increase the affordability and the distribution of quantitative diagnostic and environmental tests.
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Khorosheva EM, Karymov MA, Selck DA, Ismagilov RF. Lack of correlation between reaction speed and analytical sensitivity in isothermal amplification reveals the value of digital methods for optimization: validation using digital real-time RT-LAMP. Nucleic Acids Res 2016; 44:e10. [PMID: 26358811 PMCID: PMC4737171 DOI: 10.1093/nar/gkv877] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 08/14/2015] [Accepted: 08/20/2015] [Indexed: 12/27/2022] Open
Abstract
In this paper, we asked if it is possible to identify the best primers and reaction conditions based on improvements in reaction speed when optimizing isothermal reactions. We used digital single-molecule, real-time analyses of both speed and efficiency of isothermal amplification reactions, which revealed that improvements in the speed of isothermal amplification reactions did not always correlate with improvements in digital efficiency (the fraction of molecules that amplify) or with analytical sensitivity. However, we observed that the speeds of amplification for single-molecule (in a digital device) and multi-molecule (e.g. in a PCR well plate) formats always correlated for the same conditions. Also, digital efficiency correlated with the analytical sensitivity of the same reaction performed in a multi-molecule format. Our finding was supported experimentally with examples of primer design, the use or exclusion of loop primers in different combinations, and the use of different enzyme mixtures in one-step reverse-transcription loop-mediated amplification (RT-LAMP). Our results show that measuring the digital efficiency of amplification of single-template molecules allows quick, reliable comparisons of the analytical sensitivity of reactions under any two tested conditions, independent of the speeds of the isothermal amplification reactions.
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Affiliation(s)
- Eugenia M Khorosheva
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Mikhail A Karymov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - David A Selck
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Blvd., Pasadena, CA 91125, USA
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40
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Hun Yeon J, Chan KYT, Wong TC, Chan K, Sutherland MR, Ismagilov RF, Pryzdial ELG, Kastrup CJ. A biochemical network can control formation of a synthetic material by sensing numerous specific stimuli. Sci Rep 2015; 5:10274. [PMID: 25975772 PMCID: PMC4432564 DOI: 10.1038/srep10274] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/10/2015] [Indexed: 11/29/2022] Open
Abstract
Developing bio-compatible smart materials that assemble in response to environmental cues requires strategies that can discriminate multiple specific stimuli in a complex milieu. Synthetic materials have yet to achieve this level of sensitivity, which would emulate the highly evolved and tailored reaction networks of complex biological systems. Here we show that the output of a naturally occurring network can be replaced with a synthetic material. Exploiting the blood coagulation system as an exquisite biological sensor, the fibrin clot end-product was replaced with a synthetic material under the biological control of a precisely regulated cross-linking enzyme. The functions of the coagulation network remained intact when the material was incorporated. Clot-like polymerization was induced in indirect response to distinct small molecules, phospholipids, enzymes, cells, viruses, an inorganic solid, a polyphenol, a polysaccharide, and a membrane protein. This strategy demonstrates for the first time that an existing stimulus-responsive biological network can be used to control the formation of a synthetic material by diverse classes of physiological triggers.
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Affiliation(s)
- Ju Hun Yeon
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Karen Y T Chan
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Ting-Chia Wong
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Kelvin Chan
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Sutherland
- 1] Centre for Innovation, Canadian Blood Services, Vancouver, BC, Canada [2] Centre for Blood Research and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Edward L G Pryzdial
- 1] Centre for Innovation, Canadian Blood Services, Vancouver, BC, Canada [2] Centre for Blood Research and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Christian J Kastrup
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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41
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Yano JM, Yu K, Donaldson GP, Shastri GG, Ann P, Ma L, Nagler CR, Ismagilov RF, Mazmanian SK, Hsiao EY. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell 2015; 161:264-76. [PMID: 25860609 PMCID: PMC4393509 DOI: 10.1016/j.cell.2015.02.047] [Citation(s) in RCA: 1972] [Impact Index Per Article: 219.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/16/2014] [Accepted: 02/18/2015] [Indexed: 01/16/2023]
Abstract
The gastrointestinal (GI) tract contains much of the body's serotonin (5-hydroxytryptamine, 5-HT), but mechanisms controlling the metabolism of gut-derived 5-HT remain unclear. Here, we demonstrate that the microbiota plays a critical role in regulating host 5-HT. Indigenous spore-forming bacteria (Sp) from the mouse and human microbiota promote 5-HT biosynthesis from colonic enterochromaffin cells (ECs), which supply 5-HT to the mucosa, lumen, and circulating platelets. Importantly, microbiota-dependent effects on gut 5-HT significantly impact host physiology, modulating GI motility and platelet function. We identify select fecal metabolites that are increased by Sp and that elevate 5-HT in chromaffin cell cultures, suggesting direct metabolic signaling of gut microbes to ECs. Furthermore, elevating luminal concentrations of particular microbial metabolites increases colonic and blood 5-HT in germ-free mice. Altogether, these findings demonstrate that Sp are important modulators of host 5-HT and further highlight a key role for host-microbiota interactions in regulating fundamental 5-HT-related biological processes.
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Affiliation(s)
- Jessica M. Yano
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kristie Yu
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Gregory P. Donaldson
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Gauri G. Shastri
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Phoebe Ann
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Liang Ma
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Cathryn R. Nagler
- Department of Pathology and Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Rustem F. Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sarkis K. Mazmanian
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Elaine Y. Hsiao
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA,Correspondence to:
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Begolo S, Zhukov DV, Selck DA, Li L, Ismagilov RF. The pumping lid: investigating multi-material 3D printing for equipment-free, programmable generation of positive and negative pressures for microfluidic applications. Lab Chip 2014; 14:4616-28. [PMID: 25231706 PMCID: PMC10773560 DOI: 10.1039/c4lc00910j] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Equipment-free pumping is a challenging problem and an active area of research in microfluidics, with applications for both laboratory and limited-resource settings. This paper describes the pumping lid method, a strategy to achieve equipment-free pumping by controlled generation of pressure. Pressure was generated using portable, lightweight, and disposable parts that can be integrated with existing microfluidic devices to simplify workflow and eliminate the need for pumping equipment. The development of this method was enabled by multi-material 3D printing, which allows fast prototyping, including composite parts that combine materials with different mechanical properties (e.g. both rigid and elastic materials in the same part). The first type of pumping lid we describe was used to produce predictable positive or negative pressures via controlled compression or expansion of gases. A model was developed to describe the pressures and flow rates generated with this approach and it was validated experimentally. Pressures were pre-programmed by the geometry of the parts and could be tuned further even while the experiment was in progress. Using multiple lids or a composite lid with different inlets enabled several solutions to be pumped independently in a single device. The second type of pumping lid, which relied on vapor-liquid equilibrium to generate pressure, was designed, modeled, and experimentally characterized. The pumping lid method was validated by controlling flow in different types of microfluidic applications, including the production of droplets, control of laminar flow profiles, and loading of SlipChip devices. We believe that applying the pumping lid methodology to existing microfluidic devices will enhance their use as portable diagnostic tools in limited resource settings as well as accelerate adoption of microfluidics in laboratories.
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Affiliation(s)
- Stefano Begolo
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA.
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43
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Kelley SO, Mirkin CA, Walt DR, Ismagilov RF, Toner M, Sargent EH. Advancing the speed, sensitivity and accuracy of biomolecular detection using multi-length-scale engineering. Nat Nanotechnol 2014; 9:969-80. [PMID: 25466541 PMCID: PMC4472305 DOI: 10.1038/nnano.2014.261] [Citation(s) in RCA: 266] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 10/13/2014] [Indexed: 05/05/2023]
Abstract
Rapid progress in identifying disease biomarkers has increased the importance of creating high-performance detection technologies. Over the last decade, the design of many detection platforms has focused on either the nano or micro length scale. Here, we review recent strategies that combine nano- and microscale materials and devices to produce large improvements in detection sensitivity, speed and accuracy, allowing previously undetectable biomarkers to be identified in clinical samples. Microsensors that incorporate nanoscale features can now rapidly detect disease-related nucleic acids expressed in patient samples. New microdevices that separate large clinical samples into nanocompartments allow precise quantitation of analytes, and microfluidic systems that utilize nanoscale binding events can detect rare cancer cells in the bloodstream more accurately than before. These advances will lead to faster and more reliable clinical diagnostic devices.
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Affiliation(s)
- Shana O. Kelley
- Department of Pharmaceutical Sciences and Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Correspondence should be addressed to S.O.K.,
| | - Chad A. Mirkin
- Department of Chemistry, International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, USA
| | - David R. Walt
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Rustem F. Ismagilov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Mehmet Toner
- Center for Bioengineering in Medicine, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Edward H. Sargent
- Department of Computer and Electrical Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada
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Pickard JM, Maurice CF, Kinnebrew MA, Abt MC, Schenten D, Golovkina TV, Bogatyrev SR, Ismagilov RF, Pamer EG, Turnbaugh PJ, Chervonsky AV. Rapid fucosylation of intestinal epithelium sustains host-commensal symbiosis in sickness. Nature 2014; 514:638-41. [PMID: 25274297 PMCID: PMC4214913 DOI: 10.1038/nature13823] [Citation(s) in RCA: 373] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 09/03/2014] [Indexed: 02/06/2023]
Abstract
Systemic infection induces conserved physiological responses that include both resistance and 'tolerance of infection' mechanisms. Temporary anorexia associated with an infection is often beneficial, reallocating energy from food foraging towards resistance to infection or depriving pathogens of nutrients. However, it imposes a stress on intestinal commensals, as they also experience reduced substrate availability; this affects host fitness owing to the loss of caloric intake and colonization resistance (protection from additional infections). We hypothesized that the host might utilize internal resources to support the gut microbiota during the acute phase of the disease. Here we show that systemic exposure to Toll-like receptor (TLR) ligands causes rapid α(1,2)-fucosylation of small intestine epithelial cells (IECs) in mice, which requires the sensing of TLR agonists, as well as the production of interleukin (IL)-23 by dendritic cells, activation of innate lymphoid cells and expression of fucosyltransferase 2 (Fut2) by IL-22-stimulated IECs. Fucosylated proteins are shed into the lumen and fucose is liberated and metabolized by the gut microbiota, as shown by reporter bacteria and community-wide analysis of microbial gene expression. Fucose affects the expression of microbial metabolic pathways and reduces the expression of bacterial virulence genes. It also improves host tolerance of the mild pathogen Citrobacter rodentium. Thus, rapid IEC fucosylation appears to be a protective mechanism that utilizes the host's resources to maintain host-microbial interactions during pathogen-induced stress.
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Affiliation(s)
- Joseph M Pickard
- Department of Pathology and Committee on Immunology, The University of Chicago, Chicago, Illinois 60637, USA
| | - Corinne F Maurice
- FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | - Michael C Abt
- Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | | | - Tatyana V Golovkina
- Department of Microbiology, The University of Chicago, Chicago, Illinois 60637, USA
| | - Said R Bogatyrev
- California Institute of Technology, Pasadena, California 91125, USA
| | | | - Eric G Pamer
- Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
| | - Peter J Turnbaugh
- FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Alexander V Chervonsky
- Department of Pathology and Committee on Immunology, The University of Chicago, Chicago, Illinois 60637, USA
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Ge S, Liu W, Schlappi T, Ismagilov RF. Digital, Ultrasensitive, End-Point Protein Measurements with Large Dynamic Range via Brownian Trapping with Drift. J Am Chem Soc 2014; 136:14662-5. [DOI: 10.1021/ja507849b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Shencheng Ge
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Weishan Liu
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Travis Schlappi
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
| | - Rustem F. Ismagilov
- Division of Chemistry and
Chemical Engineering, California Institute of Technology, 1200 East
California Boulevard, Pasadena, California 91125, United States
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Abstract
This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and cellular analysis. Microfluidics will impact digital biology and chemistry and will also benefit from them if it becomes massively distributed.
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Affiliation(s)
- Daan Witters
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA.
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Ma L, Datta SS, Karymov MA, Pan Q, Begolo S, Ismagilov RF. Individually addressable arrays of replica microbial cultures enabled by splitting SlipChips. Integr Biol (Camb) 2014; 6:796-805. [PMID: 24953827 PMCID: PMC4131746 DOI: 10.1039/c4ib00109e] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Isolating microbes carrying genes of interest from environmental samples is important for applications in biology and medicine. However, this involves the use of genetic assays that often require lysis of microbial cells, which is not compatible with the goal of obtaining live cells for isolation and culture. This paper describes the design, fabrication, biological validation, and underlying physics of a microfluidic SlipChip device that addresses this challenge. The device is composed of two conjoined plates containing 1000 microcompartments, each comprising two juxtaposed wells, one on each opposing plate. Single microbial cells are stochastically confined and subsequently cultured within the microcompartments. Then, we split each microcompartment into two replica droplets, both containing microbial culture, and then controllably separate the two plates while retaining each droplet within each well. We experimentally describe the droplet retention as a function of capillary pressure, viscous pressure, and viscosity of the aqueous phase. Within each pair of replicas, one can be used for genetic analysis, and the other preserves live cells for growth. This microfluidic approach provides a facile way to cultivate anaerobes from complex communities. We validate this method by targeting, isolating, and culturing Bacteroides vulgatus, a core gut anaerobe, from a clinical sample. To date, this methodology has enabled isolation of a novel microbial taxon, representing a new genus. This approach could also be extended to the study of other microorganisms and even mammalian systems, and may enable targeted retrieval of solutions in applications including digital PCR, sequencing, single cell analysis, and protein crystallization.
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Affiliation(s)
- Liang Ma
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, USA.
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Sun B, Rodriguez-Manzano J, Selck DA, Khorosheva E, Karymov MA, Ismagilov RF. Measuring Fate and Rate of Single-Molecule Competition of Amplification and Restriction Digestion, and Its Use for Rapid Genotyping Tested with Hepatitis C Viral RNA. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Sun B, Rodriguez-Manzano J, Selck DA, Khorosheva E, Karymov MA, Ismagilov RF. Measuring fate and rate of single-molecule competition of amplification and restriction digestion, and its use for rapid genotyping tested with hepatitis C viral RNA. Angew Chem Int Ed Engl 2014; 53:8088-8092. [PMID: 24889060 DOI: 10.1002/anie.201403035] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Indexed: 01/16/2023]
Abstract
We experimentally monitored, at the single-molecule level, the competition among reverse transcription, exponential amplification (RT-LAMP), and linear degradation (restriction enzymes) starting with hepatitis C viral RNA molecules. We found significant heterogeneity in the rate of single-molecule amplification; introduction of the restriction enzymes affected both the rate and the "fate" (the binary outcome) of single-molecule amplification. While end-point digital measurements were primarily sensitive to changes in fate, the bulk real-time kinetic measurements were dominated by the rate of amplification of the earliest molecules, and were not sensitive to fate of the rest of the molecules. We show how this competition of reactions can be used for rapid HCV genotyping with either digital or bulk readout. This work advances our understanding of single-molecule dynamics in reaction networks and may help bring genotyping capabilities out of clinical labs and into limited-resource settings.
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Affiliation(s)
- Bing Sun
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
| | - Jesus Rodriguez-Manzano
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
| | - David A Selck
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
| | - Eugenia Khorosheva
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
| | - Mikhail A Karymov
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
| | - Rustem F Ismagilov
- Division of Chemistry and Chemical Engineering California Institute of Technology 1200 E. California Blvd. Pasadena, CA 91125 (USA)
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Abstract
This paper describes a microfluidic device for dry preservation of biological specimens at room temperature that incorporates chemical stabilization matrices. Long-term stabilization of samples is crucial for remote medical analysis, biosurveillance, and archiving, but the current paradigm for transporting remotely obtained samples relies on the costly "cold chain" to preserve analytes within biospecimens. We propose an alternative approach that involves the use of microfluidics to preserve samples in the dry state with stabilization matrices, developed by others, that are based on self-preservation chemistries found in nature. We describe a SlipChip-based device that allows minimally trained users to preserve samples with the three simple steps of placing a sample at an inlet, closing a lid, and slipping one layer of the device. The device fills automatically, and a pre-loaded desiccant dries the samples. Later, specimens can be rehydrated and recovered for analysis in a laboratory. This device is portable, compact, and self-contained, so it can be transported and operated by untrained users even in limited-resource settings. Features such as dead-end and sequential filling, combined with a "pumping lid" mechanism, enable precise quantification of the original sample's volume while avoiding overfilling. In addition, we demonstrated that the device can be integrated with a plasma filtration module, and we validated device operations and capabilities by testing the stability of purified RNA solutions. These features and the modularity of this platform (which facilitates integration and simplifies operation) would be applicable to other microfluidic devices beyond this application. We envision that as the field of stabilization matrices develops, microfluidic devices will be useful for cost-effectively facilitating remote analysis and biosurveillance while also opening new opportunities for diagnostics, drug development, and other medical fields.
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Affiliation(s)
- Stefano Begolo
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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