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Zürcher K, Riou J, Morrow C, Ballif M, Koch A, Bertschinger S, Warner DF, Middelkoop K, Wood R, Egger M, Fenner L. Estimating Tuberculosis Transmission Risks in a Primary Care Clinic in South Africa: Modeling of Environmental and Clinical Data. J Infect Dis 2022; 225:1642-1652. [PMID: 35039860 PMCID: PMC9071349 DOI: 10.1093/infdis/jiab534] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 07/17/2021] [Accepted: 11/09/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Congregate settings, such as healthcare clinics, may play an essential role in Mycobacterium tuberculosis (Mtb) transmission. Using patient and environmental data, we studied transmission at a primary care clinic in South Africa. METHODS We collected patient movements, cough frequency, and clinical data, and measured indoor carbon dioxide (CO2) levels, relative humidity, and Mtb genomes in the air. We used negative binomial regression model to investigate associations. RESULTS We analyzed 978 unique patients who contributed 14 795 data points. The median patient age was 33 (interquartile range [IQR], 26-41) years, and 757 (77.4%) were female. Overall, median CO2 levels were 564 (IQR 495-646) parts per million and were highest in the morning. Median number of coughs per day was 466 (IQR, 368-503), and overall median Mtb DNA copies/μL/day was 4.2 (IQR, 1.2-9.5). We found an increased presence of Mtb DNA in the air of 32% (95% credible interval, 7%-63%) per 100 additional young adults (aged 15-29 years) and 1% (0-2%) more Mtb DNA per 10% increase of relative humidity. Estimated cumulative transmission risks for patients attending the clinic monthly for at least 1 hour range between 9% and 29%. CONCLUSIONS We identified young adults and relative humidity as potentially important factors for transmission risks in healthcare clinics. Our approach should be used to detect transmission and evaluate infection control interventions.
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Affiliation(s)
- Kathrin Zürcher
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Julien Riou
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa,Desmond Tutu HIV Centre, Department of Medicine, University of Cape Town, University of Cape Town, Cape Town, South Africa
| | - Marie Ballif
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Anastasia Koch
- South African Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit and Department of Science and Innovation/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Simon Bertschinger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland,Institute for Medical Informatics, Bern University of Applied Sciences, Bern, Switzerland
| | - Digby F Warner
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa,South African Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit and Department of Science and Innovation/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Keren Middelkoop
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa,Desmond Tutu HIV Centre, Department of Medicine, University of Cape Town, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa,Desmond Tutu HIV Centre, Department of Medicine, University of Cape Town, University of Cape Town, Cape Town, South Africa
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland,Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa,Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland,Correspondence: Lukas Fenner, MD, MSc, Institute of Social and Preventive Medicine, University of Bern (ISPM), Mittelstrasse 43, 3012 Bern, Switzerland ()
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Dinkele R, Gessner S, McKerry A, Leonard B, Seldon R, Koch AS, Morrow C, Gqada M, Kamariza M, Bertozzi CR, Smith B, McLoud C, Kamholz A, Bryden W, Call C, Kaplan G, Mizrahi V, Wood R, Warner DF. Capture and visualization of live Mycobacterium tuberculosis bacilli from tuberculosis patient bioaerosols. PLoS Pathog 2021; 17:e1009262. [PMID: 33524021 PMCID: PMC7877778 DOI: 10.1371/journal.ppat.1009262] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [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: 07/01/2020] [Revised: 02/11/2021] [Accepted: 12/28/2020] [Indexed: 11/19/2022] Open
Abstract
Interrupting transmission is an attractive anti-tuberculosis (TB) strategy but it remains underexplored owing to our poor understanding of the events surrounding transfer of Mycobacterium tuberculosis (Mtb) between hosts. Determining when live, infectious Mtb bacilli are released and by whom has proven especially challenging. Consequently, transmission chains are inferred only retrospectively, when new cases are diagnosed. This process, which relies on molecular analyses of Mtb isolates for epidemiological fingerprinting, is confounded by the prolonged infectious period of TB and the potential for transmission from transient exposures. We developed a Respiratory Aerosol Sampling Chamber (RASC) equipped with high-efficiency filtration and sampling technologies for liquid-capture of all particulate matter (including Mtb) released during respiration and non-induced cough. Combining the mycobacterial cell wall probe, DMN-trehalose, with fluorescence microscopy of RASC-captured bioaerosols, we detected and quantified putative live Mtb bacilli in bioaerosol samples arrayed in nanowell devices. The RASC enabled non-invasive capture and isolation of viable Mtb from bioaerosol within 24 hours of collection. A median 14 live Mtb bacilli (range 0-36) were isolated in single-cell format from 90% of confirmed TB patients following 60 minutes bioaerosol sampling. This represented a significant increase over previous estimates of transmission potential, implying that many more organisms might be released daily than commonly assumed. Moreover, variations in DMN-trehalose incorporation profiles suggested metabolic heterogeneity in aerosolized Mtb. Finally, preliminary analyses indicated the capacity for serial image capture and analysis of nanowell-arrayed bacilli for periods extending into weeks. These observations support the application of this technology to longstanding questions in TB transmission including the propensity for asymptomatic transmission, the impact of TB treatment on Mtb bioaerosol release, and the physiological state of aerosolized bacilli.
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Affiliation(s)
- Ryan Dinkele
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Sophia Gessner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Andrea McKerry
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Bryan Leonard
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Ronnett Seldon
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Anastasia S. Koch
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Melitta Gqada
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Mireille Kamariza
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Carolyn R. Bertozzi
- Department of Chemistry, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Stanford University, Stanford, California, United States of America
| | - Brian Smith
- Edge Embossing, Boston, Massachusetts, United States of America
| | - Courtney McLoud
- Edge Embossing, Boston, Massachusetts, United States of America
| | - Andrew Kamholz
- Edge Embossing, Boston, Massachusetts, United States of America
| | - Wayne Bryden
- Zeteo Tech, Sykesville, Maryland, United States of America
| | - Charles Call
- Zeteo Tech, Sykesville, Maryland, United States of America
| | - Gilla Kaplan
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Digby F. Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa
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3
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Patterson B, Dinkele R, Gessner S, Morrow C, Kamariza M, Bertozzi CR, Kamholz A, Bryden W, Call C, Warner DF, Wood R. Sensitivity optimisation of tuberculosis bioaerosol sampling. PLoS One 2020; 15:e0238193. [PMID: 32881875 PMCID: PMC7470324 DOI: 10.1371/journal.pone.0238193] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 04/19/2020] [Accepted: 08/11/2020] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION Detection of Mycobacterium tuberculosis (Mtb) in patient-derived bioaerosol is a potential tool to measure source case infectiousness. However, current bioaerosol sampling approaches have reported low detection yields in sputum-positive TB cases. To increase the utility of bioaerosol sampling, we present advances in bioaerosol collection and Mtb identification that improve detection yields. METHODS A previously described Respiratory Aerosol Sampling Chamber (RASC) protocol, or "RASC-1", was modified to incorporate liquid collection of bioaerosol using a high-flow wet-walled cyclone (RASC-2). Individuals with GeneXpert-positive pulmonary TB were sampled pre-treatment over 60-minutes. Putative Mtb bacilli were detected in collected fluid by fluorescence microscopy utilising DMN-Trehalose. Exhaled air and bioaerosol volumes were estimated using continuous CO2 monitoring and airborne particle counting, respectively. Mtb capture was calculated per exhaled air volume sampled and bioaerosol volume for RASC-1 (n = 35) and for RASC-2 (n = 21). Empty chamber samples were collected between patients as controls. RESULTS The optimised RASC-2 protocol sampled a median of 258.4L (IQR: 226.9-273.6) of exhaled air per patient compared with 27.5L (IQR: 23.6-30.3) for RASC-1 (p<0.0001). Bioaerosol volume collection was estimated at 2.3nL (IQR: 1.1-3.6) for RASC-2 compared with 0.08nL (IQR: 0.05-0.10) for RASC-1 (p<0.0001). The detection yield of viable Mtb improved from 43% (median 2 CFU, range: 1-14) to 95% (median 20.5 DMN-Trehalose positive bacilli, range: 2-155). These improvements represent a lowering of the limit of detection in the RASC-2 platform to 0.9 Mtb bacilli per 100L of exhaled air from 3.3 Mtb bacilli per 100L (RASC-1). CONCLUSION This study demonstrates that technical improvements in particle collection together with sensitive detection enable rapid quantitation of viable Mtb in bioaerosols of sputum positive TB cases. Increased sampling sensitivity may allow future TB transmission studies to be extended to sputum-negative and subclinical individuals, and suggests the potential utility of bioaerosol measurement for rapid intervention in other airborne infectious diseases.
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Affiliation(s)
- Benjamin Patterson
- Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam, Netherlands
| | - Ryan Dinkele
- Department of Pathology, Faculty of Health Sciences, SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Sophia Gessner
- Department of Pathology, Faculty of Health Sciences, SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Carl Morrow
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Mireille Kamariza
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Carolyn R. Bertozzi
- Department of Chemistry, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Stanford University, Stanford, California, United States of America
| | - Andrew Kamholz
- Edge Embossing, Charlestown, Boston, Massachusetts, United States of America
| | - Wayne Bryden
- Zeteo Tech, Sykesville, Maryland, United States of America
| | - Charles Call
- Zeteo Tech, Sykesville, Maryland, United States of America
| | - Digby F. Warner
- Department of Pathology, Faculty of Health Sciences, SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Disease Research in Africa, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
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Zürcher K, Morrow C, Riou J, Ballif M, Koch AS, Bertschinger S, Liu X, Sharma M, Middelkoop K, Warner D, Wood R, Egger M, Fenner L. Novel approach to estimate tuberculosis transmission in primary care clinics in sub-Saharan Africa: protocol of a prospective study. BMJ Open 2020; 10:e036214. [PMID: 32847906 PMCID: PMC7451471 DOI: 10.1136/bmjopen-2019-036214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
INTRODUCTION Tuberculosis (TB) transmission is difficult to measure, and its drivers are not well understood. The effectiveness of infection control measures at healthcare clinics and the most appropriate intervention strategies to interrupt transmission are unclear. We propose a novel approach using clinical, environmental and position-tracking data to study the risk of TB transmission at primary care clinics in TB and HIV high burden settings in sub-Saharan Africa. METHODS AND ANALYSIS We describe a novel and rapid study design to assess risk factors for airborne TB transmission at primary care clinics in high-burden settings. The study protocol combines a range of different measurements. We will collect anonymous data on the number of patients, waiting times and patient movements using video sensors. Also, we will collect acoustic sound recordings to determine the frequency and intensity of coughing. Environmental data will include indoor carbon dioxide levels (CO2 in parts per million) and relative humidity. We will also extract routinely collected clinical data from the clinic records. The number of Mycobacterium tuberculosis particles in the air will be ascertained from dried filter units using highly sensitive digital droplet PCR. We will calculate rebreathed air volume based on people density and CO2 levels and develop a mathematical model to estimate the risk of TB transmission. The mathematical model can then be used to estimate the effect of possible interventions such as separating patient flows or improving ventilation in reducing transmission. The feasibility of our approach was recently demonstrated in a pilot study in a primary care clinic in Cape Town, South Africa. ETHICS AND DISSEMINATION The study was approved by the University of Cape Town (HREC/REF no. 228/2019), the City of Cape Town (ID-8139) and the Ethics Committee of the Canton Bern (2019-02131), Switzerland. The results will be disseminated in international peer-reviewed journals.
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Affiliation(s)
- Kathrin Zürcher
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Carl Morrow
- Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine and the Department of Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Julien Riou
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Marie Ballif
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Anastasia Sideris Koch
- Institute of Infectious Disease and Molecular Medicine and the Department of Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
- Molecular Mycobacteriology Research Unit, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Simon Bertschinger
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
- Medical Informatics, Berne University of Applied Sciences, Bern, Switzerland
| | - Xin Liu
- Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, Washington, USA
| | - Manuja Sharma
- Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, Washington, USA
| | - Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine and the Department of Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Digby Warner
- Institute of Infectious Disease and Molecular Medicine and the Department of Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
- Molecular Mycobacteriology Research Unit, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Robin Wood
- Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine and the Department of Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
| | - Matthias Egger
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
- Centre for Infectious Disease Epidemiology & Research, School of Public Health & Family Medicine, University of Cape Town, Rondebosch, Western Cape, South Africa
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Lukas Fenner
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
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Penn-Nicholson A, Mbandi SK, Thompson E, Mendelsohn SC, Suliman S, Chegou NN, Malherbe ST, Darboe F, Erasmus M, Hanekom WA, Bilek N, Fisher M, Kaufmann SHE, Winter J, Murphy M, Wood R, Morrow C, Van Rhijn I, Moody B, Murray M, Andrade BB, Sterling TR, Sutherland J, Naidoo K, Padayatchi N, Walzl G, Hatherill M, Zak D, Scriba TJ. RISK6, a 6-gene transcriptomic signature of TB disease risk, diagnosis and treatment response. Sci Rep 2020; 10:8629. [PMID: 32451443 PMCID: PMC7248089 DOI: 10.1038/s41598-020-65043-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [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: 09/08/2019] [Accepted: 04/27/2020] [Indexed: 11/17/2022] Open
Abstract
Improved tuberculosis diagnostics and tools for monitoring treatment response are urgently needed. We developed a robust and simple, PCR-based host-blood transcriptomic signature, RISK6, for multiple applications: identifying individuals at risk of incident disease, as a screening test for subclinical or clinical tuberculosis, and for monitoring tuberculosis treatment. RISK6 utility was validated by blind prediction using quantitative real-time (qRT) PCR in seven independent cohorts. Prognostic performance significantly exceeded that of previous signatures discovered in the same cohort. Performance for diagnosing subclinical and clinical disease in HIV-uninfected and HIV-infected persons, assessed by area under the receiver-operating characteristic curve, exceeded 85%. As a screening test for tuberculosis, the sensitivity at 90% specificity met or approached the benchmarks set out in World Health Organization target product profiles for non-sputum-based tests. RISK6 scores correlated with lung immunopathology activity, measured by positron emission tomography, and tracked treatment response, demonstrating utility as treatment response biomarker, while predicting treatment failure prior to treatment initiation. Performance of the test in capillary blood samples collected by finger-prick was noninferior to venous blood collected in PAXgene tubes. These results support incorporation of RISK6 into rapid, capillary blood-based point-of-care PCR devices for prospective assessment in field studies.
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Affiliation(s)
- Adam Penn-Nicholson
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Stanley Kimbung Mbandi
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Ethan Thompson
- Center for Infectious Disease Research, Seattle, WA, USA
| | - Simon C Mendelsohn
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Sara Suliman
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa.,Brigham and Women's Hospital, Division of Rheumatology, Immunity and Inflammation, Harvard Medical School, Boston, USA
| | - Novel N Chegou
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Stephanus T Malherbe
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Fatoumatta Darboe
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Mzwandile Erasmus
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Willem A Hanekom
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Nicole Bilek
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Michelle Fisher
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Stefan H E Kaufmann
- Max Planck Institute for Infection Biology, Berlin, Germany.,Hagler Institute for Advanced Study at Texas A&M University, College Station, TX, USA
| | - Jill Winter
- Catalysis Foundation for Health, San Ramon, CA, USA
| | - Melissa Murphy
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Desmond Tutu HIV Centre, and Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Carl Morrow
- Desmond Tutu HIV Centre, and Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Ildiko Van Rhijn
- Brigham and Women's Hospital, Division of Rheumatology, Immunity and Inflammation, Harvard Medical School, Boston, USA
| | - Branch Moody
- Brigham and Women's Hospital, Division of Rheumatology, Immunity and Inflammation, Harvard Medical School, Boston, USA
| | - Megan Murray
- Department of Global Health and Social Medicine, and Division of Global Health Equity, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Bruno B Andrade
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Timothy R Sterling
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, USA
| | - Jayne Sutherland
- Vaccines and Immunity, Medical Research Council Unit, Fajara, The Gambia
| | - Kogieleum Naidoo
- Centre for the AIDS Programme of Research in Africa, Durban, South Africa.,South African Medical Research Council-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Durban, South Africa
| | - Nesri Padayatchi
- Centre for the AIDS Programme of Research in Africa, Durban, South Africa.,South African Medical Research Council-CAPRISA HIV-TB Pathogenesis and Treatment Research Unit, Durban, South Africa
| | - Gerhard Walzl
- DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Mark Hatherill
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Daniel Zak
- Center for Infectious Disease Research, Seattle, WA, USA
| | - Thomas J Scriba
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa.
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Abstract
Streptococcus mutans resides in the oral polymicrobial biofilm and is a major contributor to the development of dental caries. Interestingly, high salivary nitrite concentrations have been associated with a decreased prevalence of dental caries. Moreover, the combination of hydrogen peroxide-producing oral commensal streptococci and nitrite has been shown to mediate the generation of reactive nitrogen species, which have antimicrobial activity. The goal of this study was to examine whether nitrite affects S. mutans virulence during polymicrobial infections with the commensal Streptococcus parasanguinis. Here, we report that the combination of S. parasanguinis and nitrite inhibited S. mutans growth and biofilm formation in vitro. Glucan production, which is critical for S. mutans biofilm formation, was also inhibited in 2-species biofilms with S. parasanguinis containing nitrite as compared with biofilms that contained no nitrite. In the in vivo caries model, enamel and dentin carious lesions were significantly reduced in rats that were colonized with S. parasanguinis prior to infection with S. mutans and received nitrite in the drinking water, as compared with animals that had a single S. mutans infection or were co-colonized with both bacteria and received no nitrite. Last, we report that S. mutans LiaS, a sensor kinase of the LiaFSR 3-component system, mediates resistance to nitrosative stress. In summary, our data demonstrate that commensal streptococci and nitrite provide protection against S. mutans pathogenesis. Modulating nitrite concentrations in the oral cavity could be a useful strategy to combat the prevalence of dental caries.
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Affiliation(s)
- J Scoffield
- 1 Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.,2 Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - S Michalek
- 1 Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - G Harber
- 1 Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - P Eipers
- 3 Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - C Morrow
- 3 Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - H Wu
- 2 Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
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7
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Patterson B, Morrow C, Singh V, Moosa A, Gqada M, Woodward J, Mizrahi V, Bryden W, Call C, Patel S, Warner D, Wood R. Detection of Mycobacterium tuberculosis bacilli in bio-aerosols from untreated TB patients. Gates Open Res 2018; 1:11. [PMID: 29355225 PMCID: PMC5757796 DOI: 10.12688/gatesopenres.12758.2] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2018] [Indexed: 12/02/2022] Open
Abstract
Background: Tuberculosis (TB) is predominantly an airborne disease. However, quantitative and qualitative analysis of bio-aerosols containing the aetiological agent,
Mycobacterium tuberculosis (Mtb), has proven very challenging. Our objective is to sample bio-aerosols from newly diagnosed TB patients for detection and enumeration of
Mtb bacilli. Methods: We monitored each of 35 newly diagnosed, GeneXpert sputum-positive, TB patients during 1 hour confinement in a custom-built Respiratory Aerosol Sampling Chamber (RASC). The RASC (a small clean-room of 1.4m
) incorporates aerodynamic particle size detection, viable and non-viable sampling devices, real-time CO
2 monitoring, and cough sound-recording. Microbiological culture and droplet digital polymerase chain reaction (ddPCR) were used to detect
Mtb in each of the bio-aerosol collection devices. Results:
Mtb was detected in 27/35 (77.1%) of aerosol samples; 15/35 (42.8%) samples were positive by mycobacterial culture and 25/27 (92.96%) were positive by ddPCR. Culturability of collected bacilli was not predicted by radiographic evidence of pulmonary cavitation, sputum smear positivity. A correlation was found between cough rate and culturable bioaerosol.
Mtb was detected on all viable cascade impactor stages with a peak at aerosol sizes 2.0-3.5μm. This suggests a median of 0.09 CFU/litre of exhaled air (IQR: 0.07 to 0.3 CFU/l) for the aerosol culture positives and an estimated median concentration of 4.5x10
CFU/ml (IQR: 2.9x10
-5.6x10
) of exhaled particulate bio-aerosol. Conclusions:
Mtb was identified in bio-aerosols exhaled by the majority of untreated TB patients using the RASC. Molecular detection was more sensitive than mycobacterial culture on solid media, suggesting that further studies are required to determine whether this reflects a significant proportion of differentially detectable bacilli in these samples.
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Affiliation(s)
- Benjamin Patterson
- Division of Infectious Diseases, Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Vinayak Singh
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Atica Moosa
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Melitta Gqada
- Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Jeremy Woodward
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | | | - Shwetak Patel
- Computer Science and Engineering, Electrical Engineering DUB group, University of Washington, Seattle, USA
| | - Digby Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
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8
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Patterson B, Morrow C, Singh V, Moosa A, Gqada M, Woodward J, Mizrahi V, Bryden W, Call C, Patel S, Warner D, Wood R. Detection of Mycobacterium tuberculosis bacilli in bio-aerosols from untreated TB patients. Gates Open Res 2018; 1:11. [PMID: 29355225 DOI: 10.12688/gatesopenres.12758.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2017] [Indexed: 11/20/2022] Open
Abstract
Background: Tuberculosis (TB) is predominantly an airborne disease. However, quantitative and qualitative analysis of bio-aerosols containing the aetiological agent, Mycobacterium tuberculosis (Mtb), has proven very challenging. Our objective is to sample bio-aerosols from newly diagnosed TB patients for detection and enumeration of Mtb bacilli. Methods: We monitored each of 35 newly diagnosed, GeneXpert sputum-positive, TB patients during 1 hour confinement in a custom-built Respiratory Aerosol Sampling Chamber (RASC). The RASC (a small clean-room of 1.4m ) incorporates aerodynamic particle size detection, viable and non-viable sampling devices, real-time CO 2 monitoring, and cough sound-recording. Microbiological culture and droplet digital polymerase chain reaction (ddPCR) were used to detect Mtb in each of the bio-aerosol collection devices. Results: Mtb was detected in 27/35 (77.1%) of aerosol samples; 15/35 (42.8%) samples were positive by mycobacterial culture and 25/27 (92.96%) were positive by ddPCR. Culturability of collected bacilli was not predicted by radiographic evidence of pulmonary cavitation, sputum smear positivity. A correlation was found between cough rate and culturable bioaerosol. Mtb was detected on all viable cascade impactor stages with a peak at aerosol sizes 2.0-3.5μm. This suggests a median of 0.09 CFU/litre of exhaled air (IQR: 0.07 to 0.3 CFU/l) for the aerosol culture positives and an estimated median concentration of 4.5x10 CFU/ml (IQR: 2.9x10 -5.6x10 ) of exhaled particulate bio-aerosol. Conclusions: Mtb was identified in bio-aerosols exhaled by the majority of untreated TB patients using the RASC. Molecular detection was more sensitive than mycobacterial culture on solid media, suggesting that further studies are required to determine whether this reflects a significant proportion of differentially detectable bacilli in these samples.
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Affiliation(s)
- Benjamin Patterson
- Division of Infectious Diseases, Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Vinayak Singh
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Atica Moosa
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Melitta Gqada
- Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Jeremy Woodward
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | | | - Shwetak Patel
- Computer Science and Engineering, Electrical Engineering DUB group, University of Washington, Seattle, USA
| | - Digby Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
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9
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Umeakunne KE, Morrow C. Gut Microbial Profile, Body Composition and Nutrient Intake in Obese African American Females adhering to Vegetarian and Vegan Dietary Patterns. J Acad Nutr Diet 2017. [DOI: 10.1016/j.jand.2017.08.108] [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: 11/28/2022]
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10
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Jablonski-Jaudon R, Winstead V, Jones-Townsend C, Azuero A, Geisinger M, Morrow C, Ptacek T. ONCE-DAILY MOUTH CARE REDUCES PLAQUE AND CHANGES ORAL MICROBIOME COMPOSITION IN NURSING HOME ELDERS. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.2076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - V. Winstead
- The University of Alabama at Birmingham, Birmingham, Alabama
| | | | - A. Azuero
- The University of Alabama at Birmingham, Birmingham, Alabama
| | - M. Geisinger
- The University of Alabama at Birmingham, Birmingham, Alabama
| | - C. Morrow
- The University of Alabama at Birmingham, Birmingham, Alabama
| | - T. Ptacek
- The University of Alabama at Birmingham, Birmingham, Alabama
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11
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Ahmed H, Morrow C, Yusuf N, Lim H, Hamzavi I, Burns E, Shaheen A, Muzaffar A, Abdelgawwad M, Al-Sadek C, Foy T, Kumar R, Ptacek T, Huda S, Isedeh P, Kohli I. 591 Ultraviolet radiation alters the skin microbiome composition. J Invest Dermatol 2017. [DOI: 10.1016/j.jid.2017.02.613] [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: 10/19/2022]
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12
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Olson C, Rochau G, Slutz S, Morrow C, Olson R, Cuneo M, Hanson D, Bennett G, Sanford T, Bailey J, Stygar W, Vesey R, Mehlhorn T, Struve K, Mazarakis M, Savage M, Pointon T, Kiefer M, Rosenthal S, Cochrane K, Schneider L, Glover S, Reed K, Schroen D, Farnum C, Modesto M, Oscar D, Chhabildas L, Boyes J, Vigil V, Keith R, Turgeon M, Cipiti M, Lindgren E, Dandini V, Tran H, Smith D, McDaniel D, Quintenz J, Matzen MK, VanDevender JP, Gauster W, Shephard L, Walck M, Renk T, Tanaka T, Ulrickson M, Meier W, Latkowski J, Moir R, Schmitt R, Reyes S, Abbott R, Peterson R, Pollock G, Ottinger P, Schumer J, Peterson P, Kammer D, Kulcinski G, El-Guebaly L, Moses G, Sviatoslavsky I, Sawan M, Anderson M, Bonazza R, Oakley J, Meekunasombat P, De Groot J, Jensen N, Abdou M, Ying A, Calderoni P, Morley N, Abdel-Khalik S, Dillon C, Lascar C, Sadowski D, Curry R, McDonald K, Barkey M, Szaroletta W, Gallix R, Alexander N, Rickman W, Charman C, Shatoff H, Welch D, Rose D, Panchuk P, Louie D, Dean S, Kim A, Nedoseev S, Grabovsky E, Kingsep A, Smirnov V. Development Path for Z-Pinch IFE. Fusion Science and Technology 2017. [DOI: 10.13182/fst05-a757] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- C. Olson
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - G. Rochau
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - S. Slutz
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - C. Morrow
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - R. Olson
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Cuneo
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - D. Hanson
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - G. Bennett
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - T. Sanford
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - J. Bailey
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - W. Stygar
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - R. Vesey
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - T. Mehlhorn
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - K. Struve
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Mazarakis
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Savage
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - T. Pointon
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Kiefer
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - S. Rosenthal
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - K. Cochrane
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - L. Schneider
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - S. Glover
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - K. Reed
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - D. Schroen
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - C. Farnum
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Modesto
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - D. Oscar
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - L. Chhabildas
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - J. Boyes
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - V. Vigil
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - R. Keith
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Turgeon
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Cipiti
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - E. Lindgren
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - V. Dandini
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - H. Tran
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - D. Smith
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - D. McDaniel
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - J. Quintenz
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. K. Matzen
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | | | - W. Gauster
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - L. Shephard
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Walck
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - T. Renk
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - T. Tanaka
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - M. Ulrickson
- Sandia National Laboratories, Albuquerque, NM 87107 USA
| | - W. Meier
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - J. Latkowski
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - R. Moir
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - R. Schmitt
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - S. Reyes
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - R. Abbott
- Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
| | - R. Peterson
- Los Alamos National Laboratories, Los Alamos, NM 87545, USA
| | - G. Pollock
- Los Alamos National Laboratories, Los Alamos, NM 87545, USA
| | - P. Ottinger
- Naval Research Laboratory, Washington, DC 20375, USA
| | - J. Schumer
- Naval Research Laboratory, Washington, DC 20375, USA
| | - P. Peterson
- University of California, Berkeley, CA 94720, USA
| | - D. Kammer
- University of Wisconsin, Madison, WI 53706, USA
| | | | | | - G. Moses
- University of Wisconsin, Madison, WI 53706, USA
| | | | - M. Sawan
- University of Wisconsin, Madison, WI 53706, USA
| | - M. Anderson
- University of Wisconsin, Madison, WI 53706, USA
| | - R. Bonazza
- University of Wisconsin, Madison, WI 53706, USA
| | - J. Oakley
- University of Wisconsin, Madison, WI 53706, USA
| | | | - J. De Groot
- University of California, Davis, Davis, CA 95616, USA
| | - N. Jensen
- University of California, Davis, Davis, CA 95616, USA
| | - M. Abdou
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - A. Ying
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - P. Calderoni
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - N. Morley
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - S. Abdel-Khalik
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - C. Dillon
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - C. Lascar
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - D. Sadowski
- Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - R. Curry
- University of Missouri-Columbia, Columbia, MO 65211, USA
| | - K. McDonald
- University of Missouri-Columbia, Columbia, MO 65211, USA
| | - M. Barkey
- University of Alabama, Tuscaloosa, AL 35487, USA
| | - W. Szaroletta
- University of New Mexico, Albuquerque, NM 87106, USA
| | - R. Gallix
- General Atomics, San Diego, CA 92121, USA
| | | | - W. Rickman
- General Atomics, San Diego, CA 92121, USA
| | - C. Charman
- General Atomics, San Diego, CA 92121, USA
| | - H. Shatoff
- General Atomics, San Diego, CA 92121, USA
| | - D. Welch
- ATK Mission Research, Albuquerque, NM 87110, USA
| | - D. Rose
- ATK Mission Research, Albuquerque, NM 87110, USA
| | | | - D. Louie
- Omicron, Albuquerque, NM 87110, USA
| | - S. Dean
- Fusion Power Associates, Gaithersburg, MD 20879, USA
| | - A. Kim
- Institute of High Current Electronics, Tomsk, Russia
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13
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Garcia SS, Blackledge MS, Michalek S, Su L, Ptacek T, Eipers P, Morrow C, Lefkowitz EJ, Melander C, Wu H. Targeting of Streptococcus mutans Biofilms by a Novel Small Molecule Prevents Dental Caries and Preserves the Oral Microbiome. J Dent Res 2017; 96:807-814. [PMID: 28571487 DOI: 10.1177/0022034517698096] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dental caries is a costly and prevalent disease characterized by the demineralization of the tooth's enamel. Disease outcome is influenced by host factors, dietary intake, cariogenic bacteria, and other microbes. The cariogenic bacterial species Streptococcus mutans metabolizes sucrose to initiate biofilm formation on the tooth surface and consequently produces lactic acid to degrade the tooth's enamel. Persistence of S. mutans biofilms in the oral cavity can lead to tooth decay. To date, no anticaries therapies that specifically target S. mutans biofilms but do not disturb the overall oral microbiome are available. We screened a library of 2-aminoimidazole antibiofilm compounds with a biofilm dispersion assay and identified a small molecule that specifically targets S. mutans biofilms. At 5 µM, the small molecule annotated 3F1 dispersed 50% of the established S. mutans biofilm but did not disperse biofilms formed by the commensal species Streptococcus sanguinis or Streptococcus gordonii. 3F1 dispersed S. mutans biofilms independently of biofilm-related factors such as antigen I/II and glucosyltransferases. 3F1 treatment effectively prevented dental caries by controlling S. mutans in a rat caries model without perturbing the oral microbiota. Our study demonstrates that selective targeting of S. mutans biofilms by 3F1 was able to effectively reduce dental caries in vivo without affecting the overall oral microbiota shaped by the intake of dietary sugars, suggesting that the pathogenic biofilm-specific treatment is a viable strategy for disease prevention.
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Affiliation(s)
- S S Garcia
- 1 Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA.,2 Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - M S Blackledge
- 3 Department of Chemistry, North Carolina State University, Raleigh, NC, USA
| | - S Michalek
- 2 Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - L Su
- 1 Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - T Ptacek
- 2 Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.,4 Schools of Dentistry and Medicine, Center for Clinical and Translational Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - P Eipers
- 5 Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - C Morrow
- 5 Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - E J Lefkowitz
- 5 Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - C Melander
- 3 Department of Chemistry, North Carolina State University, Raleigh, NC, USA
| | - H Wu
- 1 Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA
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14
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Revell AD, Wang D, Wood R, Morrow C, Tempelman H, Hamers RL, Reiss P, van Sighem AI, Nelson M, Montaner JSG, Lane HC, Larder BA. An update to the HIV-TRePS system: the development and evaluation of new global and local computational models to predict HIV treatment outcomes, with or without a genotype. J Antimicrob Chemother 2016; 71:2928-37. [PMID: 27330070 PMCID: PMC5031919 DOI: 10.1093/jac/dkw217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 01/28/2016] [Revised: 05/06/2016] [Accepted: 05/09/2016] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES Optimizing antiretroviral drug combination on an individual basis in resource-limited settings is challenging because of the limited availability of drugs and genotypic resistance testing. Here, we describe our latest computational models to predict treatment responses, with or without a genotype, and compare the potential utility of global and local models as a treatment tool for South Africa. METHODS Global random forest models were trained to predict the probability of virological response to therapy following virological failure using 29 574 treatment change episodes (TCEs) without a genotype, 3179 of which were from South Africa and were used to develop local models. In addition, 15 130 TCEs including genotypes were used to develop another set of models. The 'no-genotype' models were tested with an independent global test set (n = 1700) plus a subset from South Africa (n = 222). The genotype models were tested with 750 independent cases. RESULTS The global no-genotype models achieved area under the receiver-operating characteristic curve (AUC) values of 0.82 and 0.79 with the global and South African tests sets, respectively, and the South African models achieved AUCs of 0.70 and 0.79. The genotype models achieved an AUC of 0.84. The global no-genotype models identified more alternative, locally available regimens that were predicted to be effective for cases that failed their new regimen in the South African clinics than the local models. Both sets of models were significantly more accurate predictors of outcomes than genotyping with rules-based interpretation. CONCLUSIONS These latest global models predict treatment responses accurately even without a genotype, out-performed the local South African models and have the potential to help optimize therapy, particularly in resource-limited settings.
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Affiliation(s)
- Andrew D Revell
- The HIV Resistance Response Database Initiative (RDI), London, UK
| | - Dechao Wang
- The HIV Resistance Response Database Initiative (RDI), London, UK
| | - Robin Wood
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | - Carl Morrow
- Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa
| | | | - Raph L Hamers
- Departments of Internal Medicine and Global Health, Academic Medical Centre of the University of Amsterdam, Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands
| | - Peter Reiss
- Departments of Internal Medicine and Global Health, Academic Medical Centre of the University of Amsterdam, Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands Stichting HIV Monitoring, Amsterdam, The Netherlands
| | | | - Mark Nelson
- Chelsea and Westminster Hospital, London, UK
| | | | - H Clifford Lane
- National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Brendan A Larder
- The HIV Resistance Response Database Initiative (RDI), London, UK
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15
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Revell A, Khabo P, Ledwaba L, Emery S, Wang D, Wood R, Morrow C, Tempelman H, Hamers RL, Reiss P, van Sighem A, Pozniak A, Montaner J, Lane HC, Larder B. Computational models as predictors of HIV treatment outcomes for the Phidisa cohort in South Africa. South Afr J HIV Med 2016; 17:450. [PMID: 29568609 PMCID: PMC5843195 DOI: 10.4102/sajhivmed.v17i1.450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [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] [Received: 11/12/2015] [Accepted: 04/22/2016] [Indexed: 11/16/2022] Open
Abstract
Background Selecting the optimal combination of HIV drugs for an individual in resource-limited settings is challenging because of the limited availability of drugs and genotyping. Objective The evaluation as a potential treatment support tool of computational models that predict response to therapy without a genotype, using cases from the Phidisa cohort in South Africa. Methods Cases from Phidisa of treatment change following failure were identified that had the following data available: baseline CD4 count and viral load, details of failing and previous antiretroviral drugs, drugs in new regimen and time to follow-up. The HIV Resistance Response Database Initiative’s (RDI’s) models used these data to predict the probability of a viral load < 50 copies/mL at follow-up. The models were also used to identify effective alternative combinations of three locally available drugs. Results The models achieved accuracy (area under the receiver–operator characteristic curve) of 0.72 when predicting response to therapy, which is less accurate than for an independent global test set (0.80) but at least comparable to that of genotyping with rules-based interpretation. The models were able to identify alternative locally available three-drug regimens that were predicted to be effective in 69% of all cases and 62% of those whose new treatment failed in the clinic. Conclusion The predictive accuracy of the models for these South African patients together with the results of previous studies suggest that the RDI’s models have the potential to optimise treatment selection and reduce virological failure in different patient populations, without the use of a genotype.
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Affiliation(s)
- Andrew Revell
- The HIV Resistance Response Database Initiative (RDI), London, United Kingdom
| | - Paul Khabo
- Project PHIDISA, South African Military Health Service (SAMHS), Lyttelton, South Africa
| | - Lotty Ledwaba
- Project PHIDISA, South African National Defence Force (SANDF), Lyttelton, South Africa
| | - Sean Emery
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Dechao Wang
- The HIV Resistance Response Database Initiative (RDI), London, United Kingdom
| | - Robin Wood
- The Desmond Tutu HIV Centre, University of Cape Town, South Africa
| | - Carl Morrow
- The Desmond Tutu HIV Centre, University of Cape Town, South Africa
| | | | - Raph L Hamers
- Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands
| | - Peter Reiss
- Academic Medical Center of the University of Amsterdam, Amsterdam, the Netherlands.,Stichting HIV Monitoring, Amsterdam, the Netherlands
| | | | - Anton Pozniak
- Chelsea and Westminster Hospital, London, United Kingdom
| | | | - H Clifford Lane
- National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Brendan Larder
- The HIV Resistance Response Database Initiative (RDI), London, United Kingdom
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Blaser N, Zahnd C, Hermans S, Salazar-Vizcaya L, Estill J, Morrow C, Egger M, Keiser O, Wood R. Tuberculosis in Cape Town: An age-structured transmission model. Epidemics 2016; 14:54-61. [PMID: 26972514 PMCID: PMC4791535 DOI: 10.1016/j.epidem.2015.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 12/23/2014] [Revised: 10/05/2015] [Accepted: 10/11/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is the leading cause of death in South Africa. The burden of disease varies by age, with peaks in TB notification rates in the HIV-negative population at ages 0-5, 20-24, and 45-49 years. There is little variation between age groups in the rates in the HIV-positive population. The drivers of this age pattern remain unknown. METHODS We developed an age-structured simulation model of Mycobacterium tuberculosis (Mtb) transmission in Cape Town, South Africa. We considered five states of TB progression: susceptible, infected (latent TB), active TB, treated TB, and treatment default. Latently infected individuals could be re-infected; a previous Mtb infection slowed progression to active disease. We further considered three states of HIV progression: HIV negative, HIV positive, on antiretroviral therapy. To parameterize the model, we analysed treatment outcomes from the Cape Town electronic TB register, social mixing patterns from a Cape Town community and used literature estimates for other parameters. To investigate the main drivers behind the age patterns, we conducted sensitivity analyses on all parameters related to the age structure. RESULTS The model replicated the age patterns in HIV-negative TB notification rates of Cape Town in 2009. Simulated TB notification rate in HIV-negative patients was 1000/100,000 person-years (pyrs) in children aged <5 years and decreased to 51/100,000 in children 5-15 years. The peak in early adulthood occurred at 25-29 years (463/100,000 pyrs). After a subsequent decline, simulated TB notification rates gradually increased from the age of 30 years. Sensitivity analyses showed that the dip after the early adult peak was due to the protective effect of latent TB and that retreatment TB was mainly responsible for the rise in TB notification rates from the age of 30 years. CONCLUSION The protective effect of a first latent infection on subsequent infections and the faster progression in previously treated patients are the key determinants of the age-structure of TB notification rates in Cape Town.
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Affiliation(s)
- Nello Blaser
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Cindy Zahnd
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Sabine Hermans
- Desmond Tutu HIV Centre, Institute for Infectious Disease & Molecular Medicine, University of Cape Town, South Africa; Department of Global Health, Academic Medical Center, University of Amsterdam, Amsterdam Institute for Global Health and Development,The Netherlands; Department of Internal Medicine, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Luisa Salazar-Vizcaya
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Janne Estill
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Carl Morrow
- Desmond Tutu HIV Centre, Institute for Infectious Disease & Molecular Medicine, University of Cape Town, South Africa
| | - Matthias Egger
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland; School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
| | - Olivia Keiser
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
| | - Robin Wood
- Desmond Tutu HIV Centre, Institute for Infectious Disease & Molecular Medicine, University of Cape Town, South Africa; Department of Medicine, University of Cape Town,, South Africa; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, UK
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Wood R, Morrow C, Barry CE, Bryden WA, Call CJ, Hickey AJ, Rodes CE, Scriba TJ, Blackburn J, Issarow C, Mulder N, Woodward J, Moosa A, Singh V, Mizrahi V, Warner DF. Real-Time Investigation of Tuberculosis Transmission: Developing the Respiratory Aerosol Sampling Chamber (RASC). PLoS One 2016; 11:e0146658. [PMID: 26807816 PMCID: PMC4726558 DOI: 10.1371/journal.pone.0146658] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [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: 09/02/2015] [Accepted: 12/21/2015] [Indexed: 11/18/2022] Open
Abstract
Knowledge of the airborne nature of respiratory disease transmission owes much to the pioneering experiments of Wells and Riley over half a century ago. However, the mechanical, physiological, and immunopathological processes which drive the production of infectious aerosols by a diseased host remain poorly understood. Similarly, very little is known about the specific physiological, metabolic and morphological adaptations which enable pathogens such as Mycobacterium tuberculosis (Mtb) to exit the infected host, survive exposure to the external environment during airborne carriage, and adopt a form that is able to enter the respiratory tract of a new host, avoiding innate immune and physical defenses to establish a nascent infection. As a first step towards addressing these fundamental knowledge gaps which are central to any efforts to interrupt disease transmission, we developed and characterized a small personal clean room comprising an array of sampling devices which enable isolation and representative sampling of airborne particles and organic matter from tuberculosis (TB) patients. The complete unit, termed the Respiratory Aerosol Sampling Chamber (RASC), is instrumented to provide real-time information about the particulate output of a single patient, and to capture samples via a suite of particulate impingers, impactors and filters. Applying the RASC in a clinical setting, we demonstrate that a combination of molecular and microbiological assays, as well as imaging by fluorescence and scanning electron microscopy, can be applied to investigate the identity, viability, and morphology of isolated aerosolized particles. Importantly, from a preliminary panel of active TB patients, we observed the real-time production of large numbers of airborne particles including Mtb, as confirmed by microbiological culture and polymerase chain reaction (PCR) genotyping. Moreover, direct imaging of captured samples revealed the presence of multiple rod-like Mtb organisms whose physical dimensions suggested the capacity for travel deep into the alveolar spaces of the human lung.
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Affiliation(s)
- Robin Wood
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Desmond Tutu HIV Centre, IDM, University of Cape Town, Cape Town, South Africa
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Desmond Tutu HIV Centre, IDM, University of Cape Town, Cape Town, South Africa
- * E-mail:
| | - Clifton E. Barry
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, United States of America
| | - Wayne A. Bryden
- Zeteo Tech LLC, Ellicott City, Maryland, United States of America
| | - Charles J. Call
- Zeteo Tech LLC, Ellicott City, Maryland, United States of America
| | - Anthony J. Hickey
- RTI International, Research Triangle Park, North Carolina, United States of America
| | - Charles E. Rodes
- Aerosol Exposure Dimensions, Cary, North Carolina, United States of America
| | - Thomas J. Scriba
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- South African Tuberculosis Vaccine Initiative, Department of Paediatrics and Child Health, University of Cape Town, Cape Town, South Africa
| | - Jonathan Blackburn
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Chacha Issarow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Nicola Mulder
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Jeremy Woodward
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Atica Moosa
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Vinayak Singh
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Digby F. Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Erickson B, Subramaniam A, Kumar R, Huh W, Morrow C. Microbial diversity in the fimbriae, fallopian tube and peritoneum in women with benign disease and advanced pelvic malignancies. Gynecol Oncol 2015. [DOI: 10.1016/j.ygyno.2015.01.140] [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: 11/25/2022]
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Erickson B, Subramaniam A, Kumar R, Huh W, Morrow C. Different microbial communities of malignant and benign endometrium. Gynecol Oncol 2015. [DOI: 10.1016/j.ygyno.2015.01.339] [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: 11/25/2022]
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Sloane R, Bola B, Lancashire M, Hodgkinson C, Morrow C, Simpson K, Dive C. 437 PIM kinase inhibitor AZD1208 sensitises SCLC to BH3 mimetic AZD4320. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70563-5] [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: 11/29/2022]
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Wood R, Morrow C, Ginsberg S, Piccoli E, Kalil D, Sassi A, Walensky RP, Andrews JR. Quantification of shared air: a social and environmental determinant of airborne disease transmission. PLoS One 2014; 9:e106622. [PMID: 25181526 PMCID: PMC4152288 DOI: 10.1371/journal.pone.0106622] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [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: 05/02/2014] [Accepted: 07/30/2014] [Indexed: 12/03/2022] Open
Abstract
Background Tuberculosis is endemic in Cape Town, South Africa where a majority of the population become tuberculosis infected before adulthood. While social contact patterns impacting tuberculosis and other respiratory disease spread have been studied, the environmental determinants driving airborne transmission have not been quantified. Methods Indoor carbon dioxide levels above outdoor levels reflect the balance of exhaled breath by room occupants and ventilation. We developed a portable monitor to continuously sample carbon dioxide levels, which were combined with social contact diary records to estimate daily rebreathed litres. A pilot study established the practicality of monitor use up to 48-hours. We then estimated the daily volumes of air rebreathed by adolescents living in a crowded township. Results One hundred eight daily records were obtained from 63 adolescents aged between 12- and 20-years. Forty-five lived in wooden shacks and 18 in brick-built homes with a median household of 4 members (range 2–9). Mean daily volume of rebreathed air was 120.6 (standard error: 8.0) litres/day, with location contributions from household (48%), school (44%), visited households (4%), transport (0.5%) and other locations (3.4%). Independent predictors of daily rebreathed volumes included household type (p = 0.002), number of household occupants (p = 0.021), number of sleeping space occupants (p = 0.022) and winter season (p<0.001). Conclusions We demonstrated the practical measurement of carbon dioxide levels to which individuals are exposed in a sequence of non-steady state indoor environments. A novel metric of rebreathed air volume reflects social and environmental factors associated with airborne infection and can identify locations with high transmission potential.
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Affiliation(s)
- Robin Wood
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, and Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
- * E-mail:
| | - Carl Morrow
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, and Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Samuel Ginsberg
- Department of Electrical Engineering, Faculty of Engineering & the Built Environment, University of Cape Town, Cape Town, South Africa
| | - Elizabeth Piccoli
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, and Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Darryl Kalil
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, and Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Angelina Sassi
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, and Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Rochelle P. Walensky
- Center for AIDS Research, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jason R. Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, United States of America
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Middelkoop K, Bekker LG, Morrow C, Lee N, Wood R. Decreasing household contribution to TB transmission with age: a retrospective geographic analysis of young people in a South African township. BMC Infect Dis 2014; 14:221. [PMID: 24758715 PMCID: PMC4012060 DOI: 10.1186/1471-2334-14-221] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [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: 10/22/2013] [Accepted: 04/10/2014] [Indexed: 12/02/2022] Open
Abstract
Background Tuberculosis (TB) transmission rates are exceptionally high in endemic TB settings. Adolescence represents a period of increasing TB infection and disease but little is known as to where adolescents acquire TB infection. We explored the relationship between residential exposure to adult TB cases and infection in children and adolescents in a South African community with high burdens of TB and HIV. Methods TB infection data were obtained from community, school-based tuberculin skin test (TST) surveys performed in 2006, 2007 and 2009. A subset of 2007 participants received a repeat TST in 2009, among which incident TB infections were identified. Using residential address, all adult TB cases notified by the community clinic between 1996 and 2009 were cross-referenced with childhood and adolescent TST results. Demographic and clinic data including HIV status were abstracted for TB cases. Multivariate logistic regression models examined the association of adult TB exposure with childhood and adolescent prevalent and incident TB infection. Results Of 1,100 children and adolescents included in the prevalent TB infection analysis, 480 (44%) were TST positive and 651 (59%) were exposed to an adult TB case on their residential plot. Prevalent TB infection in children aged 5–9 and 10–14 years was positively associated with residential exposure to an adult TB case (odds ratio [OR]:2.0; 95% confidence interval [CI]: 1.1-3.6 and OR:1.5; 95% CI: 1.0-2.3 respectively), but no association was found in adolescents ≥15 years (OR:1.4; 95% CI: 0.9-2.0). HIV status of adult TB cases was not associated with TB infection (p = 0.62). Of 67 previously TST negative children, 16 (24%) converted to a positive TST in 2009. These incident infections were not associated with residential exposure to an adult TB case (OR: 1.9; 95% CI: 0.5-7.3). Conclusions TB infection among young children was strongly associated with residential exposure to an adult TB case, but prevalent and incident TB infection in adolescents was not associated with residential exposure. The HIV-status of adult TB cases was not a risk factor for transmission. The high rates of TB infection and disease among adolescents underscore the importance of identifying where infection occurs in this age group.
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Affiliation(s)
- Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Disease & Molecular Medicine, University of Cape Town, Cape Town, South Africa.
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Andrews JR, Morrow C, Walensky RP, Wood R. Integrating social contact and environmental data in evaluating tuberculosis transmission in a South African township. J Infect Dis 2014; 210:597-603. [PMID: 24610874 DOI: 10.1093/infdis/jiu138] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Population models of tuberculosis transmission have not accounted for social contact structure and the role of the environment in which tuberculosis is transmitted. METHODS We utilized extensions to the Wells-Riley model of tuberculosis transmission, using exhaled carbon dioxide as a tracer gas, to describe transmission patterns in an endemic community. Drawing upon social interaction data and carbon dioxide measurements from a South African township, we created an age-structured model of tuberculosis transmission in households, public transit, schools, and workplaces. We fit the model to local data on latent tuberculosis prevalence by age. RESULTS Most tuberculosis infections (84%) were estimated to occur outside of one's own household. Fifty percent of infections among young adults (ages 15-19) occurred in schools, due to high contact rates and poor ventilation. Despite lower numbers of contacts in workplaces, assortative mixing among adults with high rates of smear-positive tuberculosis contributed to transmission in this environment. Households and public transit were important sites of transmission between age groups. CONCLUSIONS Consistent with molecular epidemiologic estimates, a minority of tuberculosis transmission was estimated to occur within households, which may limit the impact of contact investigations. Further work is needed to investigate the role of schools in tuberculosis transmission.
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Affiliation(s)
- Jason R Andrews
- Division of Infectious Diseases, Massachusetts General Hospital, Boston
| | - Carl Morrow
- Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | | | - Robin Wood
- Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
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Revell AD, Wang D, Wood R, Morrow C, Tempelman H, Hamers R, Alvarez-Uria G, Streinu-Cercel A, Ene L, Wensing A, Reiss P, van Sighem AI, Nelson M, Emery S, Montaner JSG, Lane HC, Larder BA. An update to the HIV-TRePS system: the development of new computational models that do not require a genotype to predict HIV treatment outcomes. J Antimicrob Chemother 2013; 69:1104-10. [PMID: 24275116 DOI: 10.1093/jac/dkt447] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The optimal individualized selection of antiretroviral drugs in resource-limited settings is challenging because of the limited availability of drugs and genotyping. Here we describe the development of the latest computational models to predict the response to combination antiretroviral therapy without a genotype, for potential use in such settings. METHODS Random forest models were trained to predict the probability of a virological response to therapy (<50 copies HIV RNA/mL) following virological failure using the following data from 22,567 treatment-change episodes including 1090 from southern Africa: baseline viral load and CD4 cell count, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. The models were assessed during cross-validation and with an independent global test set of 1000 cases including 100 from southern Africa. The models' accuracy [area under the receiver-operating characteristic curve (AUC)] was evaluated and compared with genotyping using rules-based interpretation systems for those cases with genotypes available. RESULTS The models achieved AUCs of 0.79-0.84 (mean 0.82) during cross-validation, 0.80 with the global test set and 0.78 with the southern African subset. The AUCs were significantly lower (0.56-0.57) for genotyping. CONCLUSIONS The models predicted virological response to HIV therapy without a genotype as accurately as previous models that included a genotype. They were accurate for cases from southern Africa and significantly more accurate than genotyping. These models will be accessible via the online treatment support tool HIV-TRePS and have the potential to help optimize antiretroviral therapy in resource-limited settings where genotyping is not generally available.
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Affiliation(s)
- Andrew D Revell
- HIV Resistance Response Database Initiative (RDI), London, UK
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Abstract
Current tuberculosis notification rates in South Africa are among the highest ever recorded. Although the human immunodeficiency virus epidemic has been a critical factor, the density of respiratory contacts in high-risk environments may be an important and underappreciated driver. Using a modified Wells-Riley model for airborne disease transmission, we estimated the risk of tuberculosis transmission on 3 modes of public transit (minibus taxis, buses, and trains) in Cape Town, South Africa, using exhaled carbon dioxide as a natural tracer gas to evaluate air exchange. Carbon dioxide measurements were performed between October and December of 2011. Environmental risk, reflected in the rebreathed fraction of air, was highest in minibus taxis and lowest in trains; however, the average number of passengers sharing an indoor space was highest in trains and lowest in minibus taxis. Among daily commuters, the annual risk of tuberculosis infection was projected to be 3.5%-5.0% and was highest among minibus taxi commuters. Assuming a duration of infectiousness of 1 year, the basic reproductive number attributable to transportation was more than 1 in all 3 modes of transportation. Given its poor ventilation and high respiratory contact rates, public transportation may play a critical role in sustaining tuberculosis transmission in South African cities.
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Affiliation(s)
- Jason R Andrews
- Division of Infectious Diseases, Massachusetts General Hospital, 50 Staniford Street, 9th Floor, Boston, MA 02114, USA.
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Revell AD, Wang D, Wood R, Morrow C, Tempelman H, Hamers RL, Alvarez-Uria G, Streinu-Cercel A, Ene L, Wensing AMJ, DeWolf F, Nelson M, Montaner JS, Lane HC, Larder BA. Computational models can predict response to HIV therapy without a genotype and may reduce treatment failure in different resource-limited settings. J Antimicrob Chemother 2013; 68:1406-14. [PMID: 23485767 DOI: 10.1093/jac/dkt041] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVES Genotypic HIV drug-resistance testing is typically 60%-65% predictive of response to combination antiretroviral therapy (ART) and is valuable for guiding treatment changes. Genotyping is unavailable in many resource-limited settings (RLSs). We aimed to develop models that can predict response to ART without a genotype and evaluated their potential as a treatment support tool in RLSs. METHODS Random forest models were trained to predict the probability of response to ART (≤400 copies HIV RNA/mL) using the following data from 14 891 treatment change episodes (TCEs) after virological failure, from well-resourced countries: viral load and CD4 count prior to treatment change, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. Models were assessed by cross-validation during development, with an independent set of 800 cases from well-resourced countries, plus 231 cases from Southern Africa, 206 from India and 375 from Romania. The area under the receiver operating characteristic curve (AUC) was the main outcome measure. RESULTS The models achieved an AUC of 0.74-0.81 during cross-validation and 0.76-0.77 with the 800 test TCEs. They achieved AUCs of 0.58-0.65 (Southern Africa), 0.63 (India) and 0.70 (Romania). Models were more accurate for data from the well-resourced countries than for cases from Southern Africa and India (P < 0.001), but not Romania. The models identified alternative, available drug regimens predicted to result in virological response for 94% of virological failures in Southern Africa, 99% of those in India and 93% of those in Romania. CONCLUSIONS We developed computational models that predict virological response to ART without a genotype with comparable accuracy to genotyping with rule-based interpretation. These models have the potential to help optimize antiretroviral therapy for patients in RLSs where genotyping is not generally available.
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Affiliation(s)
- A D Revell
- The HIV Resistance Response Database Initiative (RDI), London, UK
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Wood R, Racow K, Bekker LG, Morrow C, Middelkoop K, Mark D, Lawn SD. Indoor social networks in a South African township: potential contribution of location to tuberculosis transmission. PLoS One 2012; 7:e39246. [PMID: 22768066 PMCID: PMC3387133 DOI: 10.1371/journal.pone.0039246] [Citation(s) in RCA: 42] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 05/17/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We hypothesized that in South Africa, with a generalized tuberculosis (TB) epidemic, TB infection is predominantly acquired indoors and transmission potential is determined by the number and duration of social contacts made in locations that are conducive to TB transmission. We therefore quantified time spent and contacts met in indoor locations and public transport by residents of a South African township with a very high TB burden. METHODS A diary-based community social mixing survey was performed in 2010. Randomly selected participants (n = 571) prospectively recorded numbers of contacts and time spent in specified locations over 24-hour periods. To better characterize age-related social networks, participants were stratified into ten 5-year age strata and locations were classified into 11 types. RESULTS Five location types (own-household, other-households, transport, crèche/school, and work) contributed 97.2% of total indoor time and 80.4% of total indoor contacts. Median time spent indoors was 19.1 hours/day (IQR:14.3-22.7), which was consistent across age strata. Median daily contacts increased from 16 (IQR:9-40) in 0-4 year-olds to 40 (IQR:18-60) in 15-19 year-olds and declined to 18 (IQR:10-41) in ≥45 year-olds. Mean daily own-household contacts was 8.8 (95%CI:8.2-9.4), which decreased with increasing age. Mean crèche/school contacts increased from 6.2/day (95%CI:2.7-9.7) in 0-4 year-olds to 28.1/day (95%CI:8.1-48.1) in 15-19 year-olds. Mean transport contacts increased from 4.9/day (95%CI:1.6-8.2) in 0-4 year-olds to 25.5/day (95%CI:12.1-38.9) in 25-29 year-olds. CONCLUSIONS A limited number of location types contributed the majority of indoor social contacts in this community. Increasing numbers of social contacts occurred throughout childhood, adolescence, and young adulthood, predominantly in school and public transport. This rapid increase in non-home socialization parallels the increasing TB infection rates during childhood and young adulthood reported in this community. Further studies of the environmental conditions in schools and public transport, as potentially important locations for ongoing TB infection, are indicated.
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Affiliation(s)
- Robin Wood
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
- Department of Science and Technology/National Research Foundation, Centre of Excellence in Epidemiological Modeling and Analysis, University of Stellenbosch, Cape Town, South Africa
| | - Kimberly Racow
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Linda-Gail Bekker
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Carl Morrow
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
| | - Daniella Mark
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Stephen D. Lawn
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Medicine, University of Cape Town Faculty of Health Sciences, Cape Town, South Africa
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Morrow C, Smentkowski K, Schwartz S, Gruber-Baldini A, Anderson K, Weiner W, Reich S, Shulman L. Does Spouse Participation Influence Quality of Life Reporting in Patients with Parkinson's Disease? (P06.063). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p06.063] [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: 11/15/2022] Open
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Johnstone-Robertson SP, Mark D, Morrow C, Middelkoop K, Chiswell M, Aquino LDH, Bekker LG, Wood R. Social mixing patterns within a South African township community: implications for respiratory disease transmission and control. Am J Epidemiol 2011; 174:1246-55. [PMID: 22071585 DOI: 10.1093/aje/kwr251] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [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: 01/08/2023] Open
Abstract
A prospective survey of social mixing patterns relevant to respiratory disease transmission by large droplets (e.g., influenza) or small droplet nuclei (e.g., tuberculosis) was performed in a South African township in 2010. A total of 571 randomly selected participants recorded the numbers, times, and locations of close contacts (physical/nonphysical) and indoor casual contacts met daily. The median number of physical contacts was 12 (interquartile range (IQR), 7-18), the median number of close contacts was 20 (IQR, 13-29), and the total number of indoor contacts was 30 (IQR, 12-54). Physical and close contacts were most frequent and age-associative in youths aged 5-19 years. Numbers of close contacts were 40% higher than in corresponding populations in industrialized countries (P < 0.001). This may put township communities at higher risk for epidemics of acute respiratory illnesses. Simulations of an acute influenza epidemic predominantly involved adolescents and young adults, indicating that control strategies should be directed toward these age groups. Of all contacts, 86.2% occurred indoors with potential exposure to respiratory droplet nuclei, of which 27.2%, 20.1%, 20.0%, and 8.0% were in transport, own household, crèche/school, and work locations, respectively. Indoor contact time was long in households and short during transport. High numbers of indoor contacts and intergenerational mixing in households and transport may contribute to exceptionally high rates of tuberculosis transmission reported in the community.
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Affiliation(s)
- Simon P Johnstone-Robertson
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Western Cape, South Africa.
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Lawn SD, Campbell L, Kaplan R, Little F, Morrow C, Wood R. Delays in starting antiretroviral therapy in patients with HIV-associated tuberculosis accessing non-integrated clinical services in a South African township. BMC Infect Dis 2011; 11:258. [PMID: 21957868 PMCID: PMC3203070 DOI: 10.1186/1471-2334-11-258] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [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: 06/17/2011] [Accepted: 09/30/2011] [Indexed: 11/21/2022] Open
Abstract
Background Delays in the initiation of antiretroviral therapy (ART) in patients with HIV-associated tuberculosis (TB) are associated with increased mortality risk. We examined the timing of ART among patients receiving care provided by non-integrated TB and ART services in Cape Town, South Africa. Methods In an observational cohort study, we determined the overall time delay between starting treatment for TB and starting ART in patients treated in Gugulethu township between 2002 and 2008. For patients referred from TB clinics to the separate ART clinic, we quantified and identified risk factors associated with the two component delays between starting TB treatment, enrolment in the ART clinic and subsequent initiation of ART. Results Among 893 TB patients studied (median CD4 count, 81 cells/μL), the delay between starting TB treatment and starting ART was prolonged (median, 95 days; IQR = 49-155). Delays were shorter in more recent calendar periods and among those with lower CD4 cell counts. However, the median delay was almost three-fold longer for patients referred from separate TB clinics compared to patients whose TB was diagnosed in the ART clinic (116 days versus 41 days, respectively; P < 0.001). In the most recent calendar period, the proportions of patients with CD4 cell counts < 50 cells/μL who started ART within 4 weeks of TB diagnosis were 11.1% for patients referred from TB clinics compared to 54.6% of patients with TB diagnosed in the ART service (P < 0.001). Conclusions Delays in starting ART were prolonged, especially for patients referred from separate TB clinics. Non-integration of TB and ART services is likely to be a substantial obstacle to timely initiation of ART.
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Affiliation(s)
- Stephen D Lawn
- The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
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Middelkoop K, Bekker LG, Myer L, Johnson LF, Kloos M, Morrow C, Wood R. Antiretroviral therapy and TB notification rates in a high HIV prevalence South African community. J Acquir Immune Defic Syndr 2011; 56:263-9. [PMID: 21317585 PMCID: PMC3801097 DOI: 10.1097/qai.0b013e31820413b3] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [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: 11/26/2022]
Abstract
BACKGROUND Antiretroviral therapy (ART) has been proposed as an intervention for reducing tuberculosis (TB) burdens in areas with high HIV prevalence. However, little data is available on the impact of ART on population-level TB. METHODS Trends in adult TB case fatality and notifications were assessed before and during increasing ART coverage in a well-defined periurban community, from 1997 to 2008. Mean changes in TB rates were measured using linear autoregression models. ART coverage increased from 1% in 2003 to 5%, 13%, and 21% of HIV-infected population in 2004, 2005, and 2008, respectively. RESULTS From 1997 to end of 2004 TB notification rates increased by an average of 187 cases/100,000/year (P < 0.001), reaching a peak of 2536/100,000 in 2005. From 2005 to 2008, TB notification rates declined by approximately 202 cases/100,000/year (P < 0.001). TB rates were initially stable in HIV-uninfected individuals, but declined moderately from 2005. TB rates declined in HIV-infected adults from 6513/100,000 in 2005 to 4741/100,000 in 2008. The predominant decline in TB notifications occurred among HIV-infected patients receiving ART (1156 cases/100,000/year) and was less marked in those not receiving ART (416 cases/100,000/year). Similarly, TB case fatality was constant for HIV-uninfected individuals, but declined in HIV-infected individuals from 23% in 2002 to 8% in 2008 (P = 0.01). CONCLUSIONS In this community heavily affected by both HIV and TB epidemics, rapid and high ART coverage was associated with significant reductions in TB notifications and TB-associated case fatality.
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Affiliation(s)
- Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
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Middelkoop K, Bekker LG, Mathema B, Shashkina E, Kurepina N, Whitelaw A, Fallows D, Morrow C, Kreiswirth B, Kaplan G, Wood R. Molecular epidemiology of Mycobacterium tuberculosis in a South African community with high HIV prevalence. J Infect Dis 2009; 200:1207-11. [PMID: 19764885 DOI: 10.1086/605930] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
To explore the relationship between human immunodeficiency virus (HIV) and Mycobacterium tuberculosis genotypes, we performed IS6110-based restriction fragment-length polymorphism analysis on M. tuberculosis culture specimens from patients with smear-positive tuberculosis in a periurban community in South Africa from 2001 through 2005. Among 151 isolates, 95 strains were identified within 26 families, with 54% clustering. HIV status was associated with W-Beijing strains (P = .009) but not with clustering per se. The high frequency of clustering suggests ongoing transmission in both HIV-negative and HIV-positive individuals in this community. The strong association between W-Beijing and HIV infection may have important implications for tuberculosis control.
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Affiliation(s)
- Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, Cape Town, South Africa.
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Middelkoop K, Bekker LG, Morrow C, Zwane E, Wood R. Childhood tuberculosis infection and disease: a spatial and temporal transmission analysis in a South African township. S Afr Med J 2009; 99:738-743. [PMID: 20128273 PMCID: PMC2932468] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Tuberculosis (TB) remains a leading cause of mortality and morbidity in South Africa. While adult TB results from both recent and past infection, childhood TB results from recent infection and reflects ongoing transmission despite current TB control strategies. SETTING A South African community with high rates of TB and HIV disease. OUTCOMES A Geographic Information System was used to spatially and temporally define the relationships between TB exposure, infection and disease in children < 15 years of age with exposure to adult HIV-positive and HIV-negative TB disease on residential plots between 1997 and 2007. RESULTS During the study period the annual adult TB notification rate increased from 629 to 2 106/100 000 and the rate in children aged < 15 years ranged between 664/100 000 and 1 044/100 000. The mean number of exposures to adult TB for TB-uninfected children, latently TB-infected children and TB cases were 5.1%, 5.4% and 33% per annum and the mean number of adult smear-positive cases per exposed child was 1.0, 1.6 and 1.9, respectively. Acquisition of TB infection was not associated with HIV status of the adult TB case to which the child was exposed, and 36% of child TB cases were diagnosed before the temporally closest adult case on their plot. CONCLUSIONS Childhood infection and disease were quantitatively linked to infectious adult TB prevalence in an immediate social network. Childhood infection should be monitored in high-burden settings as a marker of ongoing TB transmission. Improved knowledge of township childhood and adult social networks could also facilitate targeted active case finding, which may provide an adjunct to currently failing TB control strategies.
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Affiliation(s)
- Keren Middelkoop
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, Department of Medicine, University of Cape Town.
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Morrow C, Kudeweh S, Goold M, Standley S. 162 REPRODUCTIVE CYCLES, PREGNANCY AND REVERSAL OF LONG TERM ACYCLICITY IN CAPTIVE SOUTHERN WHITE RHINOCEROS AT HAMILTON ZOO. Reprod Fertil Dev 2009. [DOI: 10.1071/rdv21n1ab162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In 1999, the New Zealand captive population of Southern white rhinoceros (Ceratotherium simum simum) was increased with the addition of six wild-caught founders. We report on the breeding success of two females (est. 5 to 6 years at import) and a female born in 2000 (conceived in the wild). Fecal samples were collected 1 to 3 times per week from females (n = 3) for several periods (5 to 24 months) between 2000 and 2008. Reproductive cycles and pregnancy were characterized using fecal progestogen concentrations, observations of courtship behaviour and parturition dates. The average length of the reproductive cycle was 31.6 ± 0.6 days (range 26–38 days, n = 34 cycles). Four pregnancies were confirmed in one female with a sex ratio of 1 female to 3 males (including 1 male loss at an estimated 5 months of gestation), known gestation lengths were 514 and 507 days. In the non-reproducing adult female, long cycles (67.2 ± 1.3 days, n = 5) were detected in addition to regular cycles (31.9 ± 0.9 days, n = 13) during the first 3 years in captivity, consistent with previous reports (Schwarzenberger F et al. 1998 An. Repro. Sci. 53, 173–190; Brown JL et al. 2001 Zoo Biol. 20, 463–486). The absence of breeding behavior and low progestogen concentrations for an extended 4-year period was cause for concern for the Australasian Species Management Programme managers (Hermes R et al. 2004 An. Repro. Sci. 82–83, 49–60; Hermes R et al. 2006 Theriogenology 65, 1492–1515). In 2007, the social structure of the Hamilton Zoo rhinoceros group was altered by exchanging the breeding male and two male offspring for a wild-caught male from Auckland Zoo. Within two months of arrival the long-term acyclic female had resumed cycling and had conceived six months after introduction of the new male. The young captive-born female continued to have regular length cycles and mating was observed with the new male. Recently, early embryonic loss was determined by ultrasound in the young female having a long 70 day cycle determined by fecal analysis. Fecal progestogen concentrations were useful for diagnosing pregnancy after 3 months gestation with concentrations four times higher than luteal phase concentrations by 9 to 12 weeks after mating (n = 3). Two females exhibited seasonal acyclic periods characterized by low progestogen concentrations corresponding to decreasing daylength (autumn and winter months). Fecal progestogen monitoring of reproductive status and pregnancy combined with behaviour observations has provided valuable information for breeding management decisions and planning for parturition in this population. The reversal of long-term acyclicity and a resulting pregnancy that represents two original founders is particularly significant for the genetic diversity of the Australasian population of white rhinoceros.
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Abstract
*Assessing plant nutrient limitation is a fundamental part of understanding grassland dynamics. The ratio of concentrations of nitrogen (N) and phosphorus (P) in vegetation has been proposed as an index of the relative limitation of biomass production by N and P, but its utility has not been tested well in grasslands. *At five sites in Kruger National Park, South Africa, across soil and precipitation contrasts, N and P were added in a factorial design to grass-dominated plots. *Although the N:P ratio of unfertilized vegetation across all sites (5.8) would have indicated that production was N-limited, aboveground production was consistently co-limited by N and P. Aboveground production was still greater in plots fertilized with N and P than in those fertilized with just N, but the N:P ratio did not exceed standard thresholds for P limitation in N-fertilized vegetation. Comparisons among sites showed little pattern between site N:P ratio and relative responses to N and P. *When combined with results from other grassland fertilization studies, these data suggest that the N:P ratio of grasses has little ability to predict limitation in upland grasslands. Co-limitation between N and P appears to be much more widespread than would be predicted from simple assumptions of vegetative N:P ratios.
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Affiliation(s)
- Joseph M Craine
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
- Environmental Studies Program, Dartmouth College, Hanover, NH 03755, USA
- (present address) Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carl Morrow
- Department of Botany, University of Cape Town, Cape Town, South Africa
| | - William D Stock
- Centre for Ecosystem Management, Edith Cowan University, Perth, Western Australia, Australia
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Abstract
With anthropogenic nutrient inputs to ecosystems increasing globally, there are long-standing, fundamental questions about the role of nutrients in the decomposition of organic matter. We tested the effects of exogenous nitrogen and phosphorus inputs on litter decomposition across a broad suite of litter and soil types. In one experiment, C mineralization was compared across a wide array of plants individually added to a single soil, while in the second, C mineralization from a single substrate was compared across 50 soils. Counter to basic stoichiometric decomposition theory, low N availability can increase litter decomposition as microbes use labile substrates to acquire N from recalcitrant organic matter. This "microbial nitrogen mining" is consistently suppressed by high soil N supply or substrate N concentrations. There is no evidence for phosphorus mining as P fertilization increases short- and long-term mineralization. These results suggest that basic stoichiometric decomposition theory needs to be revised and ecosystem models restructured accordingly in order to predict ecosystem carbon storage responses to anthropogenic changes in nutrient availability.
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Affiliation(s)
- Joseph M Craine
- Department of Ecology, Evolution, and Behavior, 100 Ecology, 1987 Upper Buford Circle, Saint Paul, Minnesota 55108, USA.
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Abstract
With anthropogenic nutrient inputs to ecosystems increasing globally, there are long-standing, fundamental questions about the role of nutrients in the decomposition of organic matter. We tested the effects of exogenous nitrogen and phosphorus inputs on litter decomposition across a broad suite of litter and soil types. In one experiment, C mineralization was compared across a wide array of plants individually added to a single soil, while in the second, C mineralization from a single substrate was compared across 50 soils. Counter to basic stoichiometric decomposition theory, low N availability can increase litter decomposition as microbes use labile substrates to acquire N from recalcitrant organic matter. This "microbial nitrogen mining" is consistently suppressed by high soil N supply or substrate N concentrations. There is no evidence for phosphorus mining as P fertilization increases short- and long-term mineralization. These results suggest that basic stoichiometric decomposition theory needs to be revised and ecosystem models restructured accordingly in order to predict ecosystem carbon storage responses to anthropogenic changes in nutrient availability.
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Affiliation(s)
- Joseph M Craine
- Department of Ecology, Evolution, and Behavior, 100 Ecology, 1987 Upper Buford Circle, Saint Paul, Minnesota 55108, USA.
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Abstract
BACKGROUND AND AIMS A test was made of the hypothesis that the prostrate growth habit of the leaves of the geophyte Brunsvigia orientalis enables utilization of soil-derived CO(2) and is related to the presence of lysigenous air-filled channels characteristic of B. orientalis leaves. METHODS Brunsvigia orientalis was sampled at a field site. Leaf anatomy, stomatal density, leaf/soil gas exchange characteristics and soil atmosphere and leaf delta(13)C isotope abundances were examined. KEY RESULTS The leaves of B. orientalis have large lysigenous air-filled channels separating the upper and lower surfaces of the leaves. The upper surface comprised approx. 70 % of the leaf mass and 75 % of the leaf N (mmol g(-1)). Between 20 % and 30 % of the stomatal conductance and CO(2) assimilation was through the lower surface of the leaf. CO(2) efflux rates from the soil surface were up to 5.4 micromol m(-2) s(-1) while photosynthetic fluxes through the lower surface of the leaves were approx. 7 micromol m(-2) s(-1). However, the utilization of soil-derived CO(2) only altered the leaf delta(13)C isotope abundance of the prostrate leaves by a small amount. Using delta(13)C values it was estimated that 7 % of the leaf tissue C was derived from soil-derived CO(2). CONCLUSIONS A small proportion of photosynthetically fixed CO(2) was derived from the soil, with minimal associated transpirational H(2)O loss into the space between the leaf and soil. The soil-derived CO(2), taken up through the lower surface was probably assimilated by the palisade tissue in the upper surface of the leaf which was exposed to sunlight and where most of the leaf N was located. The occurrence of lysigenous air channels in the leaves may provide longitudinal strength without impaired transfer of CO(2) taken up through the lower surface to the upper surface.
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Affiliation(s)
- M D Cramer
- Department of Botany, University of Cape Town, Private Bag X1, Rondebosch 7701, South Africa.
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Morrow C, Berg M, McDonald R, Wells D, Peterson A, Lee R. 54 COMPOSITION OF ALLANTOIC FLUID IN CATTLE PREGNANT WITH AI-, IVP-, OR NUCLEAR TRANSFER-GENERATED EMBRYOS. Reprod Fertil Dev 2005. [DOI: 10.1071/rdv17n2ab54] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Abnormal placentation, pregnancy failure, and hydroallantois are associated with somatic cell nuclear transfer (SCNT) in cattle. Identification of diagnostic markers for abnormal placentation in early gestation would permit therapeutic intervention. Ultrasonography and transvaginal sampling of amniotic and/or allantoic (fetal) fluid enables regular monitoring of fetal health. We report on the composition of serial samples of fetal fluid from individual cows between Days 70–130 of gestation and the potential of steroid and electrolyte composition as an early diagnostic marker for the subsequent occurrence of hydroallantois in SCNT pregnancies in cattle. On Day 70, pregnancy rates were 50% and 60% for cows or heifers implanted with single in vitro-fertilized (IVP, 20/40) or SCNT (25/42) embryos, respectively, and 67% for pregnancies generated by artificial insemination (AI, 12/18). Resulting fetuses were either clones (SCNT) or offspring (IVP/AI) of a donor Holstein bull. Fetal fluids, sampled using ultrasound-guided transvaginal puncture, were collected on Days 70, 100, and 130 of gestation (n = 12 and 139 for amniotic and allantoic samples, respectively). Placental and fetal morphological data were collected following slaughter between Days 135–163 of gestation (n = 14, 20, and 10 for SCNT, IVP, and AI groups, respectively). Fetal fluids were analyzed for progesterone, estrone sulphate, sodium, chloride, potassium, creatinine, urea, calcium, magnesium and phosphate. Pregnancy outcomes for the SCNT group were retrospectively classified as: Fail 100 (pregnancies failing between Days 70–99; n = 6); Fail 130 (failing between Days 100–129; n = 5); Hydrops (greater than 10 L combined amniotic and allantoic fluid at postmortem between Days 135–163; n = 8) and SCNT Pregnant 150 (pregnant between Days 135–163; n = 6). IVP and AI pregnancies were classified as IVP or AI Pregnant 150. Fluid composition was analyzed by ANOVA on log-transformed data. On Day 70, allantoic progesterone and estrone sulphate concentrations were significantly higher (P < 0.05) for the SCNT cows compared to the IVP/AI Pregnant 150 cows. On Day 70, allantoic potassium, chloride, creatinine, and urea concentrations were significantly higher (P < 0.05) for the SCNT Hydrops cows compared to the IVP/AI Pregnant 150 cows. In addition, Day 70 allantoic creatinine and urea concentrations were significantly higher (P < 0.05) for the SCNT Hydrops cows compared to other SCNT groups. By Day 100, allantoic chloride, creatinine, and urea concentrations in SCNT Hydrops cows were significantly lower (P < 0.05) than in IVP/AI Pregnant 150 groups. We conclude that elevated Day 70 allantoic urea and creatinine concentrations are potential early diagnostic markers predicting hydroallantois in recipient cattle carrying SCNT fetuses. Further investigation of these markers in other somatic donor cell lines used for nuclear transfer is warranted to determine their general utility.
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Faraj A, El Alaoui AM, Gosselin G, Imbach JL, Morrow C, Sommadossi JP. Effects of beta-L-3'-azido-3'-deoxythymidine 5'-triphosphate on host and viral DNA polymerases. Antiviral Res 2000; 47:97-102. [PMID: 10996397 DOI: 10.1016/s0166-3542(00)00095-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have previously reported that several beta-L-thymidine analogues including beta-L-3'-azido-3'-deoxythymidine (beta-L-AZT), beta-L-3'-fluoro-2',3'-dideoxythymidine (beta-L-FLT) and beta-L-2', 3'-didehydro-2',3'-dideoxythymidine (beta-L-D4T) did not inhibit HIV replication in human peripheral blood mononuclear (PBM) cells whereas their corresponding beta-D-counterparts are known as potent and selective anti-HIV agents [Faraj et al., 1997. Nucleosides and Nucleotides 16, 1287-1290]. In order to gain insight on the lack of antiviral activities of these beta-L-derivatives, in vitro enzymatic steady state studies were conducted in the present study with beta-L-AZT. beta-L-AZT 5'-triphosphate (L-AZTTP) was chemically synthesized and found to moderately inhibit wild-type HIV reverse transcriptase (HIV-1 RT) with a K(i) value of 2 microM; while lacking any inhibitory effect towards human DNA polymerase alpha, beta or gamma. However, the inhibitory effect of L-AZTTP towards HIV-1 RT was very modest (266-fold less potent) when compared to its isomer beta-D-AZT 5'-triphosphate (D-AZTTP) which exhibits a K(i) value of 0.0075 microM and this finding was further confirmed by DNA chain termination assay. These data suggest that the absence of antiviral activity of the parent beta-L-AZT may in part be explained by the poor inhibition of the targeted viral enzyme by L-AZTTP, the active metabolite. Finally, L-AZTTP was found to lack affinity for the mutant RT at position 184 (M184V) demonstrating that this mutation confers resistance not only to beta-L-2',3'-dideoxycytidine analogs as previously reported by our group [Faraj et al., 1994. Antimicrob. Agents Chemother. 38, 2300-2305] but as well as to beta-L-2',3'-dideoxythymidine analogs.
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Affiliation(s)
- A Faraj
- Department of Pharmacology, Center for AIDS Research, The Comprehensive Cancer Center, and Division of Clinical Pharmacology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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Fishkin PE, Armstrong FD, Routh DK, Harris L, Thompson W, Miloslavich K, Levy JD, Johnson A, Morrow C, Bandstra ES, Mason CA, Scott G. Brief report: relationship between HIV infection and WPPSI-R performance in preschool-age children. J Pediatr Psychol 2000; 25:347-51. [PMID: 10880065 DOI: 10.1093/jpepsy/25.5.347] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [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: 11/13/2022] Open
Abstract
OBJECTIVE To determine the neurodevelopmental effects of perinatally acquired HIV infection on children of preschool age. METHODS Participants included 40 children infected with HIV between the ages of three and five and an equal number of noninfected controls individually matched according to ethnicity, age, sex, and prenatal drug exposure. Participants were administered the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), upon which an analysis of subtest distribution was conducted. RESULTS Whereas both groups evidenced mean IQ and subtest scores significantly below published norms, an effect for HIV group status was not found when a factor combining Performance IQ (PIQ) and Verbal IQ (VIQ) was analyzed. However, the group infected with HIV scored significantly lower than controls on the Block Design subtest. CONCLUSIONS Gross cognitive deficits are not evident among preschool children infected with HIV relative to matched controls. However, this study does provides some evidence for more focal deficits. Further investigation with older children should be conducted.
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Morrow C, Cowan KH. Drug resistance markers: are they bad or good? Ann Oncol 1997; 8:314-5. [PMID: 9209659 DOI: 10.1023/a:1008211227476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Myers PR, Katwa LC, Tanner M, Morrow C, Guarda E, Parker JL. Effects of angiotensin II on canine and porcine coronary epicardial and resistance arteries. J Vasc Res 1994; 31:338-46. [PMID: 7986958 DOI: 10.1159/000159062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Coronary resistance arteriolar diameter importantly regulates myocardial blood flow, and is influenced by circulating neurohumoral agents. Angiotensin II (A-II) is a circulating polypeptide that is chronically elevated in heart failure and serves as a potent peripheral vasoconstrictor agent. However, its effects on isolated coronary resistance arterioles is relatively unknown. We compared the vasomotor effects of A-II on coronary epicardial and resistance arterioles in vitro from both the canine and porcine heart in order to determine the effects of A-II in different vascular beds and species. Epicardial rings were studied under isometric recording conditions, while resistance arterioles (50-150 microns) were studied in vitro using a video imaging system to record diameter. A-II, whether applied to passively distended or preconstricted porcine resistance arterioles, did not cause vasoconstriction when applied as a bolus or as cumulative doses. In preconstricted canine resistance arterioles, A-II elicited dose-dependent vasodilation (EC50 = 0.2 nM). In passively distended canine arterioles, high concentrations of A-II (0.1 microM) applied as a bolus elicited transient vasoconstriction in 28% of the vessels studied. In large epicardial rings, A-II was a weak vasoconstrictor, with greater potency in canine arteries compared to porcine arteries. In canine arteries, vasoconstriction to A-II was augmented after incubation with indomethacin. In contrast to the findings in canine arteries, the A-II vasoconstrictor response in porcine coronary arteries was decreased after incubation with indomethacin or removal of the endothelium. Thus, A-II elicits the release of a vasodilator prostanoid in epicardial canine coronary arteries and a vasoconstrictor prostanoid in porcine vessels which modulate the vasomotor action of A-II.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P R Myers
- Department of Medicine College of Medicine, Columbia, MO
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Abstract
The addition of exogenous phosphatidic acid (PA) to cultured cortical astrocytes prelabelled with [3H]inositol resulted in the accumulation of intracellular [3H]inositol phosphates (IP) in a concentration-dependent (EC50 = 20 microM) manner. Analysis of the individual IPs formed following a PA challenge revealed a rapid but transient generation of [3H]inositol trisphosphate (IP3) indicating the involvement of phosphatidylinositol 4,5-bisphosphate (PIP2) breakdown in this response a fact which was confirmed when the recovery of radiolabel in membrane phosphoinositides was assessed. PA's ability to stimulate IP3 accumulation was found to be dependent upon its acyl-chain length. Dioleoyl-PA (C18:1) was equally as effective as PA from egg yolk lecithin in this respect whilst dipalmitoyl-PA (C16:0) was less so and dimyristoyl-PA (C14:0) and dilauroyl-PA (C12:0) were without effect. In subconfluent, serum-deprived cultures, PA was found to increase DNA synthesis following a 48 h exposure period. This effect was observed over the same concentration range used to measure phosphoinositide breakdown and was found to be mediated by the activation of protein kinase C. As with its effect on phosphoinositide metabolism, PA's ability to promote DNA synthesis was correlated with its acyl-chain length. These data show that PA is capable of stimulating both phosphoinositide metabolism and DNA synthesis in cultured astrocytes possibly via the activation of specific membrane receptors. However, the precise relationship between these events remains to be elucidated.
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Affiliation(s)
- B Pearce
- Pharmacology Department, School of Pharmacy, London, U.K
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Morrow C, Lockner D, Hickman S, Rusanov M, Röckel T. Effects of lithology and depth on the permeability of core samples from the Kola and KTB drill holes. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93jb03458] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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LaClave L, Kronenberger WG, Baker EL, Morrow C. Use of hypnosis following training in a psychiatry residency and psychology internship program: a brief communication. Int J Clin Exp Hypn 1993; 41:265-71. [PMID: 8407016 DOI: 10.1080/00207149308414557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Despite growing numbers of internships and residencies offering training in hypnotherapy, no systematic attempt has been made to assess hypnotherapy beliefs and use among former trainees in these settings. This study investigated posttraining hypnotherapy use and effectiveness beliefs in a sample of 77 former psychiatry residents and psychology interns. Over 50% of the study sample had sought additional hypnotherapy training beyond the standard lectures and seminars, and almost 30% had attended external hypnotherapy workshops or presentations. Beliefs in hypnotherapy effectiveness were high, but use of hypnotherapy in clinical practice was very low. Former residents and interns who had received supervised training with patients, who had attended hypnosis workshops, and who had a colleague using hypnotherapy were more likely to use hypnotherapy following training.
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Affiliation(s)
- L LaClave
- Indiana University School of Medicine
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Nakagawa M, Schneider E, Dixon KH, Horton J, Kelley K, Morrow C, Cowan KH. Reduced intracellular drug accumulation in the absence of P-glycoprotein (mdr1) overexpression in mitoxantrone-resistant human MCF-7 breast cancer cells. Cancer Res 1992; 52:6175-81. [PMID: 1358431] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
A mitoxantrone-resistant human MCF-7 breast cancer subline (MCF/MX) which is approximately 4000-fold resistant to mitoxantrone was isolated by serial passage of the parental wild-type MCF-7 cells (MCF/WT) in stepwise increasing concentrations of drug. MCF/MX cells were also approximately 10-fold cross-resistant to doxorubicin and etoposide but were not cross-resistant to vinblastine. Intracellular accumulation of radiolabeled mitoxantrone was markedly reduced in MCF/MX cells relative to that in the drug-sensitive MCF/WT cells. This decrease in intracellular drug accumulation into MCF/MX cells was associated with enhanced drug efflux, which was reversed when cells were incubated in the presence of sodium azide and 2, 4-dinitrophenol, suggesting an energy-dependent process. Incubation of MCF/MX cells with verapamil did not affect either the accumulation of mitoxantrone or the level of resistance in these cells. Furthermore, RNase protection and Western blot analyses failed to detect the expression of the mdr1 RNA or P-glycoprotein, a drug efflux pump known to be associated with the development of multidrug resistance in vitro. However, a polyclonal antibody directed against a synthetic peptide corresponding to the putative ATP binding domain of P-glycoprotein reacted with two (M(r) 42,000 and 85,000) membrane proteins from MCF/MX cells which were not found in MCF/WT. Functional assays and Western blot analysis for topoisomerase II revealed no differences in topoisomerase II activity or protein levels in MCF/MX cells. Thus, resistance in this cell line is apparently associated with enhanced drug efflux involving a pathway distinct from the mdr1-encoded multidrug transporter P-glycoprotein.
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Affiliation(s)
- M Nakagawa
- Medicine Branch, National Cancer Institute, Bethesda, Maryland 20892
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McPherson DT, Morrow C, Minehan DS, Wu J, Hunter E, Urry DW. Production and purification of a recombinant elastomeric polypeptide, G-(VPGVG)19-VPGV, from Escherichia coli. Biotechnol Prog 1992; 8:347-52. [PMID: 1368456 DOI: 10.1021/bp00016a012] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.2] [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: 11/28/2022]
Abstract
An elastomeric polypeptide was produced, with the sequence G-(VPGVG)19-VPGV, as a fusion to glutathione S-transferase using the vector pGEX-3X. The fusion protein was expressed to high levels in Escherichia coli as indicated by SDS-PAGE analysis of induced cells. The fusion protein was affinity purified and cleaved with protease factor Xa, and the elastomeric polypeptide was recovered to a high degree of purity as indicated by SDS-PAGE followed by staining with CuCl2. The physical characterizations of carbon-13 and proton nuclear magnetic resonance and of the temperature profile for turbidity formation for the inverse temperature transition of hydrophobic folding and assembly attest to the successful microbial synthesis of the polypentapeptide of elastin. The results of these studies provide the initial progress toward achieving a more economical and practical means of producing material for elastic protein-based polymer research and applications.
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Affiliation(s)
- D T McPherson
- Department of Microbiology, School of Medicine, University of Alabama, Birmingham 35294-0019
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