Mary T McBride

Lawrence Livermore National Laboratory, Livermore, California, United States

Are you Mary T McBride?

Claim your profile

Publications (22)59.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Multiplex RT-PCR suspension array assays provide a powerful tool for identifying the causative agent(s) of respiratory infections. These assays are time consuming and laborious on a time-per-sample basis if only a few samples require processing. To address this shortcoming and provide an automated solution for fast detection and identification of viral pathogens, we developed the first automated multiplex RT-PCR suspension array instrument capable of handling unprepared clinical samples. The instrument requires less than 3 minutes of hands-on time for a result generated in approximately 2.5 hours. In analytical studies, the instrument performed as well as manually performed assays. The performance of the instrument and loaded multiplex viral detection assay was then tested using unprepared nasopharyngeal samples. The instrument-performed assay detected 61 of 71 RSV positive samples, for a sensitivity of 85.9%. Adenovirus (n = 5) and influenza B (n = 3) were less prevalent in the sample set, but detected to similar levels, 80% and 75%, respectively. The same sample set was also tested using FDA approved immuno-assay rapid tests, and the instrument was found to be more sensitive than the rapid tests with the sole exception being influenza A (n = 16), which was poorly detected due to significant sequence mismatches between the influenza A primer/probe set included in the multiplex mixture and the circulating influenza A strains. Overall, these data demonstrate the developed prototype platform performs multiplex array assays as well as hand-performed assays, and that the instrument's sensitivity and specificity are dictated by the quality of the loaded multiplex assay.
    The Analyst 09/2010; 135(9):2316-22. · 4.23 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A nucleic acid-based multiplexed assay was developed that combines detection of foot-and-mouth disease virus (FMDV) with rule-out assays for two other foreign animal diseases and four domestic animal diseases that cause vesicular or ulcerative lesions indistinguishable from FMDV infection in cattle, sheep and swine. The FMDV "look-alike" diagnostic assay panel contains 5 PCR and 12 reverse transcriptase PCR (RT-PCR) signatures for a total of 17 simultaneous PCR amplifications for 7 diseases plus incorporating 4 internal assay controls. It was developed and optimized to amplify both DNA and RNA viruses simultaneously in a single tube and employs Luminex liquid array technology. Assay development including selection of appropriate controls, a comparison of signature performance in single and multiplex testing against target nucleic acids, as well of limits of detection for each of the individual signatures is presented. While this assay is a prototype and by no means a comprehensive test for FMDV "look-alike" viruses, an assay of this type is envisioned to have benefit to a laboratory network in routine surveillance and possibly for post-outbreak proof of freedom from foot-and-mouth disease.
    Journal of Virological Methods 10/2008; 153(1):61-9. · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We developed an automated point-of-care diagnostic instrument that is capable of analyzing nasal swab samples for the presence of respiratory diseases. This robust instrument, called FluIDx, performs autonomous multiplexed RT-PCR reactions that are analyzed by microsphere xMAP technology. We evaluated the performance of FluIDx, in comparison rapid tests specific for influenza and respiratory syncytial virus, in a clinical study performed at the UC Davis Medical Center. The clinical study included samples positive for RSV (n = 71), influenza A (n = 16), influenza B (n = 4), adenovirus (n = 5), parainfluenza virus (n = 2), and 44 negative samples, according to a composite reference method. FluIDx and the rapid tests detected 85.9% and 62.0% of the RSV positive samples, respectively. Similar sensitivities were recorded for the influenza B samples; whereas the influenza A samples were poorly detected, likely due to the utilization of an influenza A signature that did not accurately match currently circulating influenza A strains. Data for all pathogens were compiled and indicate that FluIDx is more sensitive than the rapid tests, detecting 74.2% (95% C.I. of 64.7-81.9%) of the positive samples in comparison to 53.6% (95% C.I. of 43.7-63.2%) for the rapid tests. The higher sensitivity of FluIDx was partially offset by a lower specificity, 77.3% versus 100.0%. Overall, these data suggest automated flow-through PCR-based instruments that perform multiplexed assays can successfully screen clinical samples for infectious diseases.
    02/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have developed a nucleic acid-based assay that is rapid, sensitive, and specific and can be used for the simultaneous detection of five common human respiratory pathogens, including influenza virus A, influenza virus B, parainfluenza virus types 1 and 3, respiratory syncytial virus (RSV), and adenovirus groups B, C, and E. Typically, diagnosis on an unextracted clinical sample can be provided in less than 3 h, including sample collection, preparation, and processing, as well as data analysis. Such a multiplexed panel would enable rapid broad-spectrum pathogen testing on nasal swabs and therefore allow implementation of infection control measures and the timely administration of antiviral therapies. We present here a summary of the assay performance in terms of sensitivity and specificity. The limits of detection are provided for each targeted respiratory pathogen, and result comparisons were performed on clinical samples, our goal being to compare the sensitivity and specificity of the multiplexed assay to the combination of immunofluorescence and shell vial culture currently implemented at the University of California-Davis Medical Center hospital. Overall, the use of the multiplexed reverse transcription-PCR assay reduced the rate of false-negative results by 4% and reduced the rate of false-positive results by up to 10%. The assay correctly identified 99.3% of the clinical negatives and 97% of the adenovirus, 95% of the RSV, 92% of the influenza virus B, and 77% of the influenza virus A samples without any extraction performed on the clinical samples. The data also showed that extraction will be needed for parainfluenza virus, which was only identified correctly 24% of the time on unextracted samples.
    Journal of Clinical Microbiology 12/2007; 45(11):3498-505. · 4.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This article has been withdrawn.
    Journal of Clinical Microbiology 09/2007; · 4.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Initial results demonstrating the feasibility of a multiplexed liquid array immunoassay for foot-and-mouth disease viral antigen detection and simultaneous serotype differentiation are presented. Serotype-specific antibodies from rabbit and guinea pig hyperimmunesera were isolated and prepared for use in a multiplexed, bead-based assay. The performance of all of the available antibodies as both capture and detector reagents was evaluated in the multiplexed system to establish a combination exhibiting the highest homotypic responses and lowest heterotypic reactions. The multiplexed assay was evaluated against inactivated cell culture supernatant samples of the same subtype as the virus used to raise the capture and detector antibodies. Distinct serotype differentiation was observed, except in the case of serotype SAT1. Subsequently, cell culture supernatant samples from a larger pool of viral subtypes were analyzed. Distinct serotype differentiation was obtained when analyzing cell culture supernatant samples from viral serotypes C, Asia, and SAT3, irrespective of the subtype. However, limitations of the current antibody pairs were realized in some inconclusive results obtained when analyzing samples from a broader range of O, A, and SAT2 subtypes. The results obtained in this initial study will be used to further optimize the assay using polyvalent or monoclonal antibodies and move toward the analysis of clinical samples.
    Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 03/2007; 19(2):180-4. · 1.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Liquid array technology was used to develop a multiplexed assay for the detection of antibodies to viral nonstructural proteins (NSPs), raised in cattle in response to infection with foot-and-mouth disease (FMD) virus. Two assays, one based on recombinant NSPs and the other on synthetically produced peptides, were developed and compared side-by-side. Serum samples from serial bleeds of cattle, each experimentally infected with one of the seven serotypes (C, A, O, Asia, SAT1, SAT2, SAT3) of FMD virus were analyzed. A distinct pattern in the detection of NSP antibodies and a close correlation of the recombinant protein and peptide-based assays were observed. The detection of antibodies to NSPs is a method to differentiate FMD-infected and FMD-vaccinated animals, and a high-throughput assay would be an invaluable tool in the case of an outbreak of FMD in North America, when emergency vaccination may be utilized to spare vaccinated, noninfected animals from slaughter and subsequent disposal.
    Analytical Chemistry 09/2006; 78(15):5462-8. · 5.70 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate the feasibility of using Drop-on-Demand microjet printing technology for fabricating imaging sensors by reproducibly printing an array of photo-polymerizable sensing elements, containing a pH sensitive indicator, on the surface of an optical fiber image guide. The reproducibility of the microjet printing process is excellent for microdot (i.e. micrometer-sized polymer) sensor diameter (92.2+/-2.2 microm), height (35.0+/-1.0 microm), and roundness (0.00072+/-0.00023). pH sensors were evaluated in terms of pH sensing ability (< or =2% sensor variation), response time, and hysteresis using a custom fluorescence imaging system. In addition, the microjet technique has distinct advantages over other fabrication methods, which are discussed in detail.
    Biosensors and Bioelectronics 02/2006; 21(7):1359-64. · 5.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system was developed to provide early warning to civilians in the event of a bioterrorism incident and can be used at high profile events for short-term, intensive monitoring or in major public buildings or transportation nodes for long-term monitoring. The APDS is completely automated, offering continuous aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and nucleic acid-based polymerase chain reaction (PCR) amplification and detection. Highly multiplexed antibody-based and duplex nucleic acid-based assays are combined to reduce false positives to a very low level, lower reagent costs, and significantly expand the detection capabilities of this biosensor. This article provides an overview of the current design and operation of the APDS. Certain sub-components of the ADPS are described in detail, including the aerosol collector, the automated sample preparation module that performs multiplexed immunoassays with confirmatory PCR, and the data monitoring and communications system. Data obtained from an APDS that operated continuously for 7 days in a major U.S. transportation hub is reported.
    Biosensors and Bioelectronics 05/2005; 20(10):1925-31. · 5.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The autonomous pathogen detection system (APDS) is an automated, podium-sized instrument that continuously monitors the air for biological threat agents (bacteria, viruses, and toxins). The system has been developed to warn of a biological attack in critical or high-traffic facilities and at special events. The APDS performs continuous aerosol collection, sample preparation, and detection using multiplexed immunoassay followed by confirmatory PCR using real-time TaqMan assays. We have integrated completely reusable flow-through devices that perform DNA extraction and PCR amplification. The fully integrated system was challenged with aerosolized Bacillus anthracis, Yersinia pestis, Bacillus globigii, and botulinum toxoid. By coupling highly selective antibody- and DNA-based assays, the probability of an APDS reporting a false positive is extremely low.
    Analytical Chemistry 02/2005; 77(1):284-9. · 5.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An automated sample preparation module, based upon sequential injection analysis (SIA), has been developed for use within an autonomous pathogen detection system. The SIA system interfaced aerosol sampling with multiplexed microsphere immunoassay-flow cytometric detection. Metering and sequestering of microspheres using SIA was found to be reproducible and reliable, over 24-h periods of autonomous operation. Four inbuilt immunoassay controls showed excellent immunoassay and system stability over five days of unattended continuous operation. Titration curves for two biological warfare agents, Bacillus anthracis and Yersinia pestis, obtained using the automated SIA procedure were shown to be similar to those generated using a manual microtiter plate procedure.
    Analytical Chemistry 08/2004; 76(13):3492-7. · 5.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The autonomous pathogen detection system (APDS) is an automated, podium-sized instrument that continuously monitors the air for biological threat agents (bacteria, viruses, and toxins). The system has been developed to warn of a biological attack in critical or high-traffic facilities and at special events. The APDS performs continuous aerosol collection, sample preparation, and detection using multiplexed immunoassay followed by confirmatory PCR using real-time TaqMan assays. We have integrated completely reusable flow-through devices that perform DNA extraction and PCR amplification. The fully integrated system was challenged with aerosolized Bacillus anthracis, Yersinia pestis, Bacillus globigii and botulinum toxoid. By coupling highly selective antibody and DNA based assays, the probability of an APDS reporting a false positive is extremely low.
    Published in: Analytical Chemistry, n/a, n/a, October 12, 2004, In press. 05/2004;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Immobilized antibody microarrays were compared to the Luminex flow cytometry system that utilizes suspensions of polystyrene microbeads covalently coupled with capture antibodies. The two immunoassays were performed for comparison of reproducibility, limits of detection and dynamic range. The Luminex system showed lower limits of detection and increased dynamic range among samples whereas the protein microarrays could be more amenable to miniaturization. Both technologies were capable of sensitive multiplexed detection.
    Journal of Proteome Research 05/2004; 3(4):736-42. · 5.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system is designed to provide early warning to civilians in the event of a terrorist attack. The final APDS will be completely automated, offering aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and orthogonal, multiplexed PCR (nucleic acid) amplification and detection. The system performance (current capabilities include aerosol collection, multiplexed immunoassays, sample archiving, data reporting, and alarming) was evaluated in a field test conducted in a Biosafety Level 3 facility, where the system was challenged with, and detected, a series of aerosolized releases containing two live, virulent biological threat agents (Bacillus anthracis and Yersinia pestis). Results presented here represent the first autonomous, simultaneous measurement of these agents.
    Analytical Chemistry 11/2003; 75(20):5293-9. · 5.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Liquid array-based multiplexed immunoassays designed for rapid, sensitive, specific, and simultaneous detection of multiple simulants of biological warfare agents have been developed. In both blind and standard laboratory trials, we demonstrate the simultaneous detection of four simulant agents from a single sample. The challenge agents comprise broad classes of pathogens (virus, protein toxins, bacterial spores, vegetative cells). Assay performance of each analyte was optimized, and dose-response curves and the limits of detection (LODs) for individual analytes are presented. Assay performance, including dynamic range, sensitivity, and LODs for liquid arrays and enzyme-linked immunosorbant assay were compared and are shown to be similar. Maximum assay sensitivity is obtained in approximately 1 h, and good sensitivity is achieved in as little as 30 min. Although the sample matrixes are very complex, even for highly multiplexed assays the samples do not exhibit evidence of nonspecific binding, demonstrating that the assays also have high specificity.
    Analytical Chemistry 05/2003; 75(8):1924-30. · 5.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Summary form only given. We have developed a prototype system for reducing Luminex based immunoassay technology to a portable, customizable platform that can perform multiplexed assays on location - independent of clinical laboratory support. In principle, this device can be used to test for any biomolecular interaction in which strong binding occurs, including receptor-ligand coupling, enzyme-substrate binding, antibody-antigen interactions, and nucleic acid (DNA) hybridization reactions. Since an overwhelming majority of clinical laboratory tests are based on antibody-antigen interactions, however, we have focusing our initial efforts on multiplexed immunoassay detection.
    01/2002; 1.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Microdot Array Sensor (MiDAS) platform for making optical fiber-based sensors using inkjet printing technology is a paradigm shifting technology for delivering low cost, rapid, in-vivo, reproducible, multianalyte biosensors. A fast-response, reproducible, pH sensor is demonstrated. The MiDAS platform is very adaptable to new and existing indicator chemistries and can be used for detecting blood/gas and enzyme biomarkers.
    01/2002; 1.
  • [Show abstract] [Hide abstract]
    ABSTRACT: An Autonomous Pathogen Detection System (APDS) is being designed and evaluated for use in domestic counter-terrorism. The goal is a fully automated system that utilizes both flow cytometry and polymerase chain reaction (PCR) to continuously monitor the air for BW pathogens in major buildings or high profile events. A version 1 APDS system consisting of an aerosol collector, a sample preparation subsystem, and a flow cytometer for detecting the antibody-labeled target organisms has been completed and evaluated. Improved modules are under development for a version 2 APDS including a Lawrence Livermore National Laboratory-designed aerosol preconcentrator, a multiplex flow cytometer, and a flow-through PCR detector.
    10/2000
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Autonomous Pathogen Detection System (APDS) 1 is a stand-alone pathogen detection system capable of rapid, continuous, low cost environmental monitoring of multiple airborne biological threat agents. Its basic design comprises aerosol sampling, in-line sample preparation, multiplex detection and identification immunoassays, and orthogonal, multiplexed PCR (nucleic acid) amplification and detection. Its primary application is to warn civilians and emergency preparedness personnel of a terrorist attack, the same system could also have a role in protecting military personnel from biological warfare attacks. APDS instruments can be used at high profile events such as the Olympics for short-term, intensive monitoring or more permanent installation in major public buildings or transportation nodes. All of these units can be networked to a single command center so that a small group of technical experts could maintain and respond to alarms at any of the sensors. The APDS has several key advantages over competing technologies: (1) the ability to measure up to 100 different agents and controls in a single sample, (2) the flexibility and ease with which new bead-based assays can be developed and integrated into the system, (3) the presence of an orthogonal, real-time detection module for highly sensitive and selective nucleic acid amplification and detection, (4) the ability to use the same basic system components for multiple deployment architectures, and (5) the relatively low cost per assay (<2 per 10-plex or2 per 10-plex or 0.20 per assay) and minimal consumables.
    01/1970: pages 67-75;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this project is to design, fabricate and field demonstrate a biological agent detection and identification capability, the Autonomous Pathogen Detector System (APDS). Integrating a flow cytometer and real-time polymerase chain reaction (PCR) detector with sample collection, sample preparation and fluidics will provide a compact, autonomously operating instrument capable of simultaneously detecting multiple pathogens and/or toxins. The APDS will operate in fixed locations, continuously monitoring air samples and automatically reporting the presence of specific biological agents. The APDS will utilize both multiplex immunoassays and nucleic acid assays to provide ''quasi-orthogonal'' multiple agent detection approaches to minimize false positives and increase the reliability of identification. Technical advances across several fronts must occur, however, to realize the full extent of the APDS. The end goal of a commercially available system for civilian biological weapon defense will be accomplished through three progressive generations of APDS instruments. The APDS is targeted for civilian applications in which the public is at high risk of exposure to covert releases of bioagent, such as major subway systems and other transportation terminals, large office complexes and convention centers. APDS is also designed to be part of a monitoring network of sensors integrated with command and control systems for wide-area monitoring of urban areas and major public gatherings. In this latter application there is potential that a fully developed APDS could add value to DoD monitoring architectures.