Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Morse SA[original query] |
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Enterobacterales draft genome sequences: 15 historical (1998-2004) and 30 contemporary (2015-2016) clinical isolates from Pakistan
Crawford MA , Lascols C , Lomonaco S , Timme RE , Fisher DJ , Anderson K , Hodge DR , Morse SA , Pillai SP , Sharma SK , Khan E , Allard MW , Hughes MA . Microbiol Resour Announc 2023 12 (9) e0016323 The continued emergence and spread of antimicrobial resistance among pathogenic bacteria are ever-growing threats to health and economy. Here, we report the draft genomes for 45 Enterobacterales clinical isolates, including historical and contemporary drug-resistant organisms, obtained in Pakistan between 1998 and 2016: 5 Serratia, 3 Salmonella, 3 Enterobacter, and 34 Klebsiella. |
Investigation of multidrug-resistant plasmids from carbapenemase-producing Klebsiella pneumoniae clinical isolates from Pakistan
Lascols C , Cherney B , Conley AB , Rishishwar L , Crawford MA , Morse SA , Fisher DJ , Anderson K , Hodge DR , Pillai SP , Hughes MA , Khan E , Sue D . Front Microbiol 2023 14 1192097 OBJECTIVES: The study aim was to investigate multidrug-resistant (MDR) plasmids from a collection of 10 carbapenemase-producing Klebsiella pneumoniae clinical isolates identified within the same healthcare institution in Pakistan. Full characterization of the MDR plasmids including structure, typing characteristics, and AMR content as well as determination of their plasmid-based antimicrobial susceptibility profiles were carried out. METHODS: Plasmids were isolated from 10 clinical isolates of Klebsiella pneumoniae, and from a corresponding set of Escherichia coli transconjugants, then sequenced using Nanopore/Illumina technology to generate plasmid hybrid assemblies. Full characterization of MDR plasmids, including determination of next generation sequencing (NGS)-based AMR profiles, plasmid incompatibility groups, and types, was carried out. The structure of MDR plasmids was analyzed using the Galileo AMR platform. For E. coli transconjugants, the NGS-based AMR profiles were compared to NGS-predicted AMR phenotypes and conventional broth microdilution (BMD) antimicrobial susceptibility testing (AST) results. RESULTS: All carbapenemase-producing K. pneumoniae isolates (carrying either bla(NDM-1), or/and bla(OXA-48)) carried multiple AMR plasmids encoding 34 antimicrobial resistance genes (ARGs) conferring resistance to antimicrobials from 6 different classes. The plasmid incompatibility groups and types identified were: IncC (types 1 and 3), IncFIA (type 26) IncFIB, IncFII (types K1, K2, K7, and K9), IncHI1B, and IncL. None of the bla(NDM-1) and bla(ESBL)-plasmids identified in this study were previously described. Most bla(NDM-1-)plasmids shared identical AMR regions suggesting potential genetic material/plasmid exchange between K. pneumoniae isolates of this collection. The majority of NGS-based AMR profiles from the E. coli transconjugants correlated well with both NGS-based predicted and conventional AST results. CONCLUSION: This study highlights the complexity and diversity of the plasmid-based genetic background of carbapenemase-producing clinical isolates from Pakistan. This study emphasizes the need for characterization of MDR plasmids to determine their complete molecular background and monitor AMR through plasmid transmission between multi-resistant bacterial pathogens. |
Application of multi-criteria decision analysis techniques and decision support framework for informing select agent designation for agricultural animal pathogens
Pillai SP , West T , Anderson K , Fruetel JA , McNeil C , Hernandez P , Ball C , Beck N , Morse SA . Front Bioeng Biotechnol 2023 11 1185743 The United States Department of Agriculture (USDA), Division of Agricultural Select Agents and Toxins (DASAT) established a list of biological agents and toxins (Select Agent List) that potentially threaten agricultural health and safety, the procedures governing the transfer of those agents, and training requirements for entities working with them. Every 2 years the USDA DASAT reviews the Select Agent List, using subject matter experts (SMEs) to perform an assessment and rank the agents. To assist the USDA DASAT biennial review process, we explored the applicability of multi-criteria decision analysis (MCDA) techniques and a Decision Support Framework (DSF) in a logic tree format to identify pathogens for consideration as select agents, applying the approach broadly to include non-select agents to evaluate its robustness and generality. We conducted a literature review of 41 pathogens against 21 criteria for assessing agricultural threat, economic impact, and bioterrorism risk and documented the findings to support this assessment. The most prominent data gaps were those for aerosol stability and animal infectious dose by inhalation and ingestion routes. Technical review of published data and associated scoring recommendations by pathogen-specific SMEs was found to be critical for accuracy, particularly for pathogens with very few known cases, or where proxy data (e.g., from animal models or similar organisms) were used to address data gaps. The MCDA analysis supported the intuitive sense that select agents should rank high on the relative risk scale when considering agricultural health consequences of a bioterrorism attack. However, comparing select agents with non-select agents indicated that there was not a clean break in scores to suggest thresholds for designating select agents, requiring subject matter expertise collectively to establish which analytical results were in good agreement to support the intended purpose in designating select agents. The DSF utilized a logic tree approach to identify pathogens that are of sufficiently low concern that they can be ruled out from consideration as a select agent. In contrast to the MCDA approach, the DSF rules out a pathogen if it fails to meet even one criteria threshold. Both the MCDA and DSF approaches arrived at similar conclusions, suggesting the value of employing the two analytical approaches to add robustness for decision making. |
Editorial: Biosafety and biosecurity approaches to counter SARS-CoV-2: From detection to best practices and risk assessment Volume 2
Pillai SP , Morse SA . Front Bioeng Biotechnol 2022 10 1118544 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is the causative agent of Coronavirus Disease-19, commonly referred to as COVID-19. SARS-CoV- 2 was discovered in 2019 and is currently responsible for a global pandemic that has resulted in more than 642.7 million cases and 6.625 million deaths worldwide as of 19 November 2022. However, there have been a large number of asymptomatic cases that have gone unreported, which likely results in an overestimation of the case fatality rate of 1.03%. It is also important to note that many deaths due to SARS-CoV-2 have gone unreported. |
The development and use of decision support framework for informing selection of select agent toxins with modelling studies to inform permissible toxin amounts
Pillai SP , West T , Levinson R , Fruetel JA , Anderson K , Edwards D , Morse SA . Front Bioeng Biotechnol 2022 10 1003127 Many countries have worked diligently to establish and implement policies and processes to regulate high consequence pathogens and toxins that could have a significant public health impact if misused. In the United States, the Antiterrorism and Effective Death Penalty Act of 1996 (Public Law 104-132, 1996), as amended by the Bioterrorism Preparedness and Response Act of 2002 (Public Law 107-188, 2002) requires that the Department of Health and Human Services (HHS) [through the Centers for Disease Control and Prevention (CDC)] establish a list of bacteria, viruses, and toxins that have the potential to pose a severe threat to public health and safety. Currently, this list is reviewed and updated on a biennial basis using input from subject matter experts (SMEs). We have developed decision support framework (DSF) approaches to facilitate selection of select toxins and, where toxicity data are known, conducted modelling studies to inform selection of toxin amounts that should be excluded from select agent regulations. Exclusion limits allow laboratories to possess toxins under an established limit to support their research or teaching activities without the requirement to register with the Federal Select Agent Program. Fact sheets capturing data from a previously vetted SME workshop convened by CDC, literature review and SME input were developed to assist in evaluating toxins using the DSF approach. The output of the DSF analysis agrees with the current select toxin designations, and no other toxins evaluated in this study were recommended for inclusion on the select agent and toxin list. To inform the selection of exclusion limits, attack scenarios were developed to estimate the amount of toxin needed to impact public health. Scenarios consisted of simulated aerosol releases of a toxin in high-population-density public facilities and the introduction of a toxin into a daily consumable product supply chain. Using published inhalation and ingestion median toxic dose (TD(50)) and median lethal dose (LD(50)) values, where available, a range of toxin amounts was examined to estimate the number of people exposed to these amounts in these scenarios. Based on data generated by these models, we proposed toxin exclusion values corresponding to levels below those that would trigger a significant public health response (i.e., amounts estimated to expose up to ten people by inhalation or one hundred people by ingestion to LD(50) or TD(50) levels of toxin in the modeled scenarios). |
Comprehensive laboratory evaluation of a specific lateral flow assay for the presumptive identification of Francisella tularensis in suspicious white powders and aerosol samples
Pillai SP , DePalma L , Prentice KW , Ramage JG , Chapman C , Sarwar J , Parameswaran N , Petersen J , Yockey B , Young J , Singh A , Pillai CA , Manickam G , Thirunavkkarasu N , Avila JR , Sharma S , Morse SA , Venkateswaran K , Anderson K , Hodge DR . Health Secur 2020 18 (2) 83-95 We conducted a comprehensive, multi-phase laboratory evaluation of the Tularemia BioThreat Alert(®) (BTA) test, a lateral flow assay (LFA) for the rapid detection of Francisella tularensis. The study, conducted at 2 sites, evaluated the limit of detection (LOD) of this assay using the virulent SchuS4 strain and the avirulent LVS strain of F. tularensis. In 6-phase evaluation (linear dynamic range and reproducibility, inclusivity, near-neighbor, environmental background, white powder, and environmental filter extract), 13 diverse strains of F. tularensis, 8 Francisella near neighbors, 61 environmental background organisms, 26 white powders, and a pooled aerosol extract were tested. In the 937 tests performed, the Tularemia BTA demonstrated an LOD of 10(7) to 10(8) cfu/mL, with a sensitivity of 100.00%, specificity of 98.08%, and accuracy of 98.84%. These performance data are important for accurate interpretation of qualitative results arising from screening suspicious white powders in the field. |
Draft Genome Sequences of Two Extensively Drug-Resistant Strains of Acinetobacter baumannii Isolated from Clinical Samples in Pakistan.
Lomonaco S , Crawford MA , Lascols C , Fisher DJ , Anderson K , Hodge DR , Pillai SP , Morse SA , Khan E , Hughes MA , Allard MW , Sharma SK . Microbiol Resour Announc 2020 9 (20) Infections in immunocompromised patients that are caused by extensively drug-resistant (XDR) Acinetobacter baumannii strains have been increasingly reported worldwide. In particular, carbapenem-resistant A. baumannii strains are a prominent cause of health care-associated infections. Here, we report draft genome assemblies for two clinical XDR A. baumannii isolates obtained from hospitalized patients in Pakistan. |
Comprehensive laboratory evaluation of a lateral flow assay for the detection of Yersinia pestis
Prentice KW , DePalma L , Ramage JG , Sarwar J , Parameswaran N , Petersen J , Yockey B , Young J , Joshi M , Thirunavvukarasu N , Singh A , Chapman C , Avila JR , Pillai CA , Manickam G , Sharma SK , Morse SA , Venkateswaran KV , Anderson K , Hodge DR , Pillai SP . Health Secur 2019 17 (6) 439-453 We conducted a comprehensive, multiphase laboratory evaluation of the Plague BioThreat Alert((R)) (BTA) test, a lateral flow immunoassay (LFA), for the rapid detection of Yersinia pestis. The study was conducted in 7 phases at 2 sites to assess the performance of the LFA. The limit of detection (LOD) was determined using both a virulent and avirulent strain of Y. pestis, CO99-3015 (10(5) CFU/ml) and A1122 (10(4) CFU/ml), respectively. In the other phases, 18 Y. pestis strains, 20 phylogenetic near-neighbor strains, 61 environmental background microorganisms, 26 white powders, and a pooled aerosol sample were also tested. A total of 1,110 LFA test results were obtained, and their analysis indicates that this LFA had a sensitivity of 97.65% and specificity of 96.57%. These performance data are important for accurate interpretation of qualitative results arising from testing suspicious white powders and aerosol samples in the field. Any positive specimen in this assay is considered presumptive positive and should be referred to the Centers for Disease Control and Prevention Laboratory Response Network for additional testing, confirmation, and characterization for an appropriate public health response. |
Rapid presumptive identification of Bacillus anthracis Isolates using the Tetracore RedLine Alert Test
Pillai SP , Prentice KW , Ramage JG , DePalma L , Sarwar J , Parameswaran N , Bell M , Plummer A , Santos A , Singh A , Pillai CA , Thirunavvukarasu N , Manickam G , Avila JR , Sharma SK , Hoffmaster A , Anderson K , Morse SA , Venkateswaran KV , Hodge DR . Health Secur 2019 17 (4) 334-343 A comprehensive laboratory evaluation of the Tetracore RedLine Alert test, a lateral flow immunoassay (LFA) for the rapid presumptive identification of Bacillus anthracis, was conducted at 2 different test sites. The study evaluated the sensitivity of this assay using 16 diverse strains of B. anthracis grown on sheep blood agar (SBA) plates. In addition, 83 clinically relevant microorganisms were tested to assess the specificity of the RedLine Alert test. The results indicated that the RedLine Alert test for the presumptive identification of B. anthracis is highly robust, specific, and sensitive. RedLine Alert is a rapid test that has applicability for use in a clinical setting for ruling-in or ruling-out nonhemolytic colonies of Bacillus spp. grown on SBA medium as presumptive isolates of B. anthracis. |
Draft Genome Sequences of Antimicrobial-Resistant Shigella Clinical Isolates from Pakistan.
Lomonaco S , Lascols C , Crawford MA , Anderson K , Hodge DR , Fisher DJ , Pillai SP , Morse SA , Khan E , Hughes MA , Allard MW , Sharma SK . Microbiol Resour Announc 2019 8 (30) Shigella spp. are the most common cause of dysentery in developing countries and the second leading cause of diarrheal deaths worldwide. Multidrug-resistant (MDR) Shigella spp. are a serious threat to global health. Herein, we report draft genome sequences for three MDR Shigella isolates from Pakistan, two Shigella flexneri isolates and one Shigella sonnei isolate. |
Perspective on improving environmental monitoring of biothreats
Dunbar J , Pillai S , Wunschel D , Dickens M , Morse SA , Franz D , Bartko A , Challacombe J , Persons T , Hughes MA , Blanke SR , Holland R , Hutchison J , Merkley ED , Campbell K , Branda CS , Sharma S , Lindler L , Anderson K , Hodge D . Front Bioeng Biotechnol 2018 6 147 For more than a decade, the United States has performed environmental monitoring by collecting and analyzing air samples for a handful of biological threat agents (BTAs) in order to detect a possible biological attack. This effort has faced numerous technical challenges including timeliness, sampling efficiency, sensitivity, specificity, and robustness. The cost of city-wide environmental monitoring using conventional technology has also been a challenge. A large group of scientists with expertise in bioterrorism defense met to assess the objectives and current efficacy of environmental monitoring and to identify operational and technological changes that could enhance its efficacy and cost-effectiveness, thus enhancing its value. The highest priority operational change that was identified was to abandon the current concept of city-wide environmental monitoring because the operational costs were too high and its value was compromised by low detection sensitivity and other environmental factors. Instead, it was suggested that the focus should primarily be on indoor monitoring and secondarily on special-event monitoring because objectives are tractable and these operational settings are aligned with likelihood and risk assessments. The highest priority technological change identified was the development of a reagent-less, real-time sensor that can identify a potential airborne release and trigger secondary tests of greater sensitivity and specificity for occasional samples of interest. This technological change could be transformative with the potential to greatly reduce operational costs and thereby create the opportunity to expand the scope and effectiveness of environmental monitoring. |
Resistome of carbapenem- and colistin-resistant Klebsiella pneumoniae clinical isolates.
Lomonaco S , Crawford MA , Lascols C , Timme RE , Anderson K , Hodge DR , Fisher DJ , Pillai SP , Morse SA , Khan E , Hughes MA , Allard MW , Sharma SK . PLoS One 2018 13 (6) e0198526 The emergence and dissemination of carbapenemases, bacterial enzymes able to inactivate most beta-lactam antibiotics, in Enterobacteriaceae is of increasing concern. The concurrent spread of resistance against colistin, an antibiotic of last resort, further compounds this challenge further. Whole-genome sequencing (WGS) can play a significant role in the rapid and accurate detection/characterization of existing and emergent resistance determinants, an essential aspect of public health surveillance and response activities to combat the spread of antimicrobial resistant bacteria. In the current study, WGS data was used to characterize the genomic content of antimicrobial resistance genes, including those encoding carbapenemases, in 10 multidrug-resistant Klebsiella pneumoniae isolates from Pakistan. These clinical isolates represented five sequence types: ST11 (n = 3 isolates), ST14 (n = 3), ST15 (n = 1), ST101 (n = 2), and ST307 (n = 1). Resistance profiles against 25 clinically-relevant antimicrobials were determined by broth microdilution; resistant phenotypes were observed for at least 15 of the 25 antibiotics tested in all isolates except one. Specifically, 8/10 isolates were carbapenem-resistant and 7/10 isolates were colistin-resistant. The blaNDM-1 and blaOXA-48 carbapenemase genes were present in 7/10 and 5/10 isolates, respectively; including 2 isolates carrying both genes. No plasmid-mediated determinants for colistin resistance (e.g. mcr) were detected, but disruptions and mutations in chromosomal loci (i.e. mgrB and pmrB) previously reported to confer colistin resistance were observed. A blaOXA-48-carrying IncL/M-type plasmid was found in all blaOXA-48-positive isolates. The application of WGS to molecular epidemiology and surveillance studies, as exemplified here, will provide both a more complete understanding of the global distribution of MDR isolates and a robust surveillance tool useful for detecting emerging threats to public health. |
AOAC SMPR 2016.010: Standard Method Performance Requirements (SMPRs) for DNA-based methods of detecting Burkholderia pseudomallei in field-deployable, Department of Defense aerosol collection devices
Gee J , Arce J , Beck LC , Blank TR , Blyn L , Cahall R , Clark AJ , Currie B , Damer K , Davenport M , DeShazer D , Johns M , Keim PS , Kiss K , Lesho M , Lin N , Morse SA , Naraghi-Arani P , Ozanich R , Roberto F , Rozak D , Sahl J , Schaefer F , Schutzer S , Schweizer HP , Sozhamannan S , Tuanyok A , Coates S . J AOAC Int 2017 100 (1) 261-265 Intended Use: Field-deployed use for analysis of | aerosol collection filters and/or liquids | 1 Applicability | Detection of Burkholderia pseudomallei in collection buffers | from aerosol collection devices. Field-deployable assays are | preferred. | 2 Analytical Technique | Molecular detection of nucleic acid. | 3 Definitions | Acceptable minimum detection level (AMDL).— | Predetermined minimum level of an analyte, as specified by | an expert committee which must be detected by the candidate | method at a specified probability of detection (POD). | Exclusivity.—Study involving pure nontarget strains, which | are potentially cross-reactive, that shall not be detected or | enumerated by the candidate method. | Inclusivity.—Study involving pure target strains that shall be | detected or enumerated by the candidate method. | Maximum time-to-result.—Maximum time to complete an | analysis starting from the collection buffer to assay result. | Probability of detection (POD).—Proportion of positive | analytical outcomes for a qualitative method for a given matrix | at a specified analyte level or concentration with a ≥0.95 | confidence interval. | System false-negative rate.—Proportion of test results that | are negative contained within a population of known positives. | System false-positive rate.—Proportion of test results that are | positive contained within a population of known negatives. | 4 Method Performance Requirements | See Table 1. | 5 System Suitability Tests and/or Analytical Quality Control | The controls listed in Table 2 shall be embedded in assays as | appropriate. Manufacturer must provide written justification if | controls are not embedded in the assay. |
Genome Sequences of Multidrug-Resistant, Colistin-Susceptible and -Resistant Klebsiella pneumoniae Clinical Isolates from Pakistan.
Crawford MA , Timme R , Lomonaco S , Lascols C , Fisher DJ , Sharma SK , Strain E , Allard MW , Brown EW , McFarland MA , Croley T , Hammack TS , Weigel LM , Anderson K , Hodge DR , Pillai SP , Morse SA , Khan E , Hughes MA . Genome Announc 2016 4 (6) The emergence and spread of colistin resistance among multidrug-resistant (MDR) Klebsiella pneumoniae represent a critical threat to global health. Here, we report the complete genome sequences of 10 MDR, colistin-susceptible and -resistant K. pneumoniae clinical isolates obtained in Pakistan between 2010 and 2013. |
Pathogen security-help or hindrance?
Morse SA . Front Bioeng Biotechnol 2014 2 83 Events over the past 15 years have resulted in the promulgation of regulations in the United States to enhance biosecurity by restricting the access to pathogens and toxins (i.e., biological select agents and toxins [BSATs]), which pose a severe threat to human being, animal, or plant health or to animal or plant products, to qualified institutions, laboratories, and scientists. These regulations also reduce biosafety concerns by imposing specific requirements on laboratories working with BSATs. Furthermore, they provide a legal framework for prosecuting someone who possesses a BSAT illegally. With the implementation of these regulations has come discussion in the scientific community about the potential of these regulations to affect the cost of doing BSAT research, hamper research and international collaborations, or whether it would stop someone with a microbiological background from isolating many of the select agents from nature. |
Quantification of ricin, RCA and comparison of enzymatic activity in 18 Ricinus communis cultivars by isotope dilution mass spectrometry
Schieltz DM , McWilliams LG , Kuklenyik Z , Prezioso SM , Carter AJ , Williamson YM , McGrath SC , Morse SA , Barr JR . Toxicon 2015 95 72-83 The seeds of the Ricinus communis (Castor bean) plant are the source of the economically important commodity castor oil. Castor seeds also contain the proteins ricin and R. communis agglutinin (RCA), two toxic lectins that are hazardous to human health. Radial immunodiffusion (RID) and the enzyme linked immunosorbent assay (ELISA) are two antibody-based methods commonly used to quantify ricin and RCA; however, antibodies currently used in these methods cannot distinguish between ricin and RCA due to the high sequence homology of the respective proteins. In this study, a technique combining antibody-based affinity capture with liquid chromatography and multiple reaction monitoring (MRM) mass spectrometry (MS) was used to quantify the amounts of ricin and RCA independently in extracts prepared from the seeds of eighteen representative cultivars of R. communis which were propagated under identical conditions. Additionally, liquid chromatography and MRM-MS was used to determine rRNA N-glycosidase activity for each cultivar and the overall activity in these cultivars was compared to a purified ricin standard. Of the cultivars studied, the average ricin content was 9.3 mg/g, the average RCA content was 9.9 mg/g, and the enzymatic activity agreed with the activity of a purified ricin reference within 35% relative activity. |
Validation of high throughput sequencing and microbial forensics applications.
Budowle B , Connell ND , Bielecka-Oder A , Colwell RR , Corbett CR , Fletcher J , Forsman M , Kadavy DR , Markotic A , Morse SA , Murch RS , Sajantila A , Schmedes SE , Ternus KL , Turner SD , Minot S . Investig Genet 2014 5 9 High throughput sequencing (HTS) generates large amounts of high quality sequence data for microbial genomics. The value of HTS for microbial forensics is the speed at which evidence can be collected and the power to characterize microbial-related evidence to solve biocrimes and bioterrorist events. As HTS technologies continue to improve, they provide increasingly powerful sets of tools to support the entire field of microbial forensics. Accurate, credible results allow analysis and interpretation, significantly influencing the course and/or focus of an investigation, and can impact the response of the government to an attack having individual, political, economic or military consequences. Interpretation of the results of microbial forensic analyses relies on understanding the performance and limitations of HTS methods, including analytical processes, assays and data interpretation. The utility of HTS must be defined carefully within established operating conditions and tolerances. Validation is essential in the development and implementation of microbial forensics methods used for formulating investigative leads attribution. HTS strategies vary, requiring guiding principles for HTS system validation. Three initial aspects of HTS, irrespective of chemistry, instrumentation or software are: 1) sample preparation, 2) sequencing, and 3) data analysis. Criteria that should be considered for HTS validation for microbial forensics are presented here. Validation should be defined in terms of specific application and the criteria described here comprise a foundation for investigators to establish, validate and implement HTS as a tool in microbial forensics, enhancing public safety and national security. |
Comprehensive laboratory evaluation of a highly specific lateral flow assay for the presumptive identification of ricin in suspicious white powders and environmental samples
Hodge DR , Prentice KW , Ramage JG , Prezioso S , Gauthier C , Swanson T , Hastings R , Basavanna U , Datta S , Sharma SK , Garber EA , Staab A , Pettit D , Drumgoole R , Swaney E , Estacio PL , Elder IA , Kovacs G , Morse BS , Kellogg RB , Stanker L , Morse SA , Pillai SP . Biosecur Bioterror 2013 11 (4) 237-50 Ricin, a heterodimeric toxin that is present in the seeds of the Ricinus communis plant, is the biothreat agent most frequently encountered by law enforcement agencies in the United States. Even in untrained hands, the easily obtainable seeds can yield a highly toxic product that has been used in various types of threats, including "white-powder" letters. Although the vast majority of these threats are hoaxes, an impediment to accurate hazard assessments by first responders is the unreliability of rapid detection assays for ricin, such as lateral flow assays (LFAs). One of the complicating factors associated with LFAs is the incorporation of antibodies of poor specificity that cross-react with near-neighbors or with plant lectins that are capable of nonspecifically cross-linking the capture and detector antibodies. Because of the compelling and critical need to promote the interests of public safety and public health, the Department of Homeland Security conducted a comprehensive laboratory evaluation study of a commercial LFA for the rapid detection of ricin. This study was conducted using comprehensive inclusivity and exclusivity panels of ricin and near-neighbor plant materials, along with panels of lectins and "white-powders," to determine the specificity, sensitivity, limits of detection, dynamic range, and repeatability of the assay for the specific intended use of evaluating suspicious white powders and environmental samples in the field. |
The case for developing consensus standards for research in microbial pathogenesis: bacillus anthracis toxins as an example
Hughes MA , Burns DL , Juris SJ , Tang WJ , Clement KH , Eaton LJ , Kelly-Cirino CD , McKee ML , Powell BS , Bishop BL , Rudge TL , Shine N , Verma A , Willis MS , Morse SA . Infect Immun 2009 77 (10) 4182-6 Communication between research laboratories within a given field is often an important key to rapid successes within that field. ... |
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