Conrad Quinn - Academia.edu (original) (raw)

Papers by Conrad Quinn

Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Elsevier eBooks, 2002

Publisher Summary Gram-positive spore-forming rods have traditionally been placed in the genus Ba... more Publisher Summary Gram-positive spore-forming rods have traditionally been placed in the genus Bacillus. Even before it became possible to examine relationships at the DNA level, however, it was clear that this group consists of a very diverse range of species. Their classification, based on traditional morphological, physiological, and biochemical tests, is still used but identification is complicated by the need for special media and the problems of strain-to-strain variation. Although only a few species are associated to a greater or lesser extent with primary infections, a substantial number are, however, of clinical or health importance in a variety of other ways. The only obligate pathogen in the genus is B. anthracis, the agent of anthrax. Several Bacillus species are associated with a range of infections, but in the majority of cases there is probably an underlying immunological, metabolic or other disorder, or drug abuse.

Journal of Bacteriology, 2008

Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl ... more Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl compositions. Recent multilocus sequence typing (MLST) refined the relatedness of B. cereus group members by separating them into clades and lineages. Based on MLST, we selected several B. anthracis, B. cereus, and B. thuringiensis strains and compared their cell wall carbohydrates. The cell walls of different B. anthracis strains (clade 1/Anthracis) were composed of glucose (Glc), galactose (Gal), N-acetyl mannosamine (ManNAc), and Nacetylglucosamine (GlcNAc). In contrast, the cell walls from clade 2 strains (B. cereus type strain ATCC 14579 and B. thuringiensis strains) lacked Gal and contained N-acetylgalactosamine (GalNAc). The B. cereus clade 1 strains had cell walls that were similar in composition to B. anthracis in that they all contained Gal. However, the cell walls from some clade 1 strains also contained GalNAc, which was not present in B. anthracis cell walls. Three recently identified clade 1 strains of B. cereus that caused severe pneumonia, i.e., strains 03BB102, 03BB87, and G9241, had cell wall compositions that closely resembled those of the B. anthracis strains. It was also observed that B. anthracis strains cell wall glycosyl compositions differed from one another in a plasmiddependent manner. When plasmid pXO2 was absent, the ManNAc/Gal ratio decreased, while the Glc/Gal ratio increased. Also, deletion of atxA, a global regulatory gene, from a pXO2 ؊ strain resulted in cell walls with an even greater level of Glc.

NATO science for peace and security series, Oct 25, 2010

A range of mass spectrometry-based techniques have been used to identify, characterize and differ... more A range of mass spectrometry-based techniques have been used to identify, characterize and differentiate Bacillus anthracis, both in culture for forensic applications and for diagnosis during infection. This range of techniques could usefully be considered to exist as a continuum, based on the degrees of specificity involved. We show two examples here, a whole-organism fingerprinting method and a high-specificity assay

Medical Microbiology and Immunology, Aug 1, 1988

A forerunning study on the relationship between antibodies to the protective antigen (PA) and let... more A forerunning study on the relationship between antibodies to the protective antigen (PA) and lethal factor (LF) components of anthrax toxin and protective immunity has been expanded and extended to include the third toxin component, the edema factor (EF). It was found that protection against the "vaccine resistant" Ames strain was possible in the absence of detectable anti-LF and anti-EF antibodies. Evidence is given that PA may be the essential anthrax-derived antigen for protection, but that equally essential is that it be presented to the host's immune system in such a manner as to provide stimulation of more than just production of antibody to PA. Titers to the three components in sera of individuals with histories of clinically diagnosed anthrax as well as from human vaccinees are included in the report.

Infection and Immunity, Aug 1, 2009

Systemic anthrax manifests as toxemia, rapidly disseminating septicemia, immune collapse, and dea... more Systemic anthrax manifests as toxemia, rapidly disseminating septicemia, immune collapse, and death. Virulence factors include the anti-phagocytic ␥-linked poly-D-glutamic acid (PGA) capsule and two binary toxins, complexes of protective antigen (PA) with lethal factor (LF) and edema factor. We report the characterization of LF, PA, and PGA levels during the course of inhalation anthrax in five rhesus macaques. We describe bacteremia, blood differentials, and detection of the PA gene (pagA) by PCR analysis of the blood as confirmation of infection. For four of five animals tested, LF exhibited a triphasic kinetic profile. LF levels (mean ؎ standard error [SE] between animals) were low at 24 h postchallenge (0.03 ؎ 1.82 ng/ml), increased at 48 h to 39.53 ؎ 0.12 ng/ml (phase 1), declined at 72 h to 13.31 ؎ 0.24 ng/ml (phase 2), and increased at 96 h (82.78 ؎ 2.01 ng/ml) and 120 h (185.12 ؎ 5.68 ng/ml; phase 3). The fifth animal had an extended phase 2. PGA levels were triphasic; they were nondetectable at 24 h, increased at 48 h (2,037 ؎ 2 ng/ml), declined at 72 h (14 ؎ 0.2 ng/ml), and then increased at 96 h (3,401 ؎ 8 ng/ml) and 120 h (6,004 ؎ 187 ng/ml). Bacteremia was also triphasic: positive at 48 h, negative at 72 h, and positive at euthanasia. Blood neutrophils increased from preexposure (34.4% ؎ 0.13%) to 48 h (75.6% ؎ 0.08%) and declined at 72 h (62.4% ؎ 0.05%). The 72-h declines may establish a "go/no go" turning point in infection, after which systemic bacteremia ensues and the host's condition deteriorates. This study emphasizes the value of LF detection as a tool for early diagnosis of inhalation anthrax before the onset of fulminant systemic infection.

Emerging Infectious Diseases, Oct 1, 2002

, the first inhalational anthrax case in the United States since 1976 was identified in a media c... more , the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

Wiley-VCH Verlag GmbH eBooks, Jan 7, 2005

ChemBioChem, Jul 21, 2008

Bacillus anthracis vaccine candidate: Sera of rabbits exposed to live and irradiated-killed spore... more Bacillus anthracis vaccine candidate: Sera of rabbits exposed to live and irradiated-killed spores of B. anthracis Sterne 34F 2 or immunized with B. anthracis polysaccharide conjugated to KLH elicited antibodies that recognize isolated polysaccharide and two synthetic trisaccharides providing a proof-of-concept step in the development of vegetative and spore-specific reagents for detection and targeting of non-protein structures of B. anthracis.

Emerging Infectious Diseases, 2017

This activity has been planned and implemented through the joint providership of Medscape, LLC an... more This activity has been planned and implemented through the joint providership of Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is accredited by the American Nurses Credentialing Center (ANCC), the Accreditation Council for Pharmacy Education (ACPE), and the Accreditation Council for Continuing Medical Education (ACCME), to provide continuing education for the healthcare team. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 75% minimum passing score and complete the evaluation at http://www.medscape.org/journal/eid; and (4) view/print certificate. For CME questions, see page 175.

Molecules, Mar 14, 2011

Matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry (MS) is a valuable ... more Matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry (MS) is a valuable high-throughput tool for peptide analysis. Liquid chromatography electrospray ionization (LC-ESI) tandem-MS provides sensitive and specific quantification of small molecules and peptides. The high analytic power of MS coupled with high-specificity substrates is ideally suited for detection and quantification of bacterial enzymatic activities. As specific examples of the MS applications in disease diagnosis and select agent detection, we describe recent advances in the analyses of two high profile protein toxin groups, the Bacillus anthracis toxins and the Clostridium botulinum neurotoxins. The two binary toxins produced by B. anthracis consist of protective antigen (PA) which combines with lethal factor (LF) and edema factor (EF), forming lethal toxin and edema toxin respectively. LF is a zinc-dependent endoprotease which hydrolyzes specific proteins involved in inflammation and immunity. EF is an adenylyl cyclase which converts ATP to cyclic-AMP. Toxin-specific enzyme activity for a strategically designed substrate, amplifies reaction products which are detected by MALDI-TOF-MS and LC-ESI-MS/MS. Pre-concentration/purification with toxin specific monoclonal antibodies provides additional specificity. These combined technologies have

Journal of applied bacteriology, 1992

Gram-positive bacilli isolated during epidemiological investigations which, on the basis of conve... more Gram-positive bacilli isolated during epidemiological investigations which, on the basis of conventional tests, resemble Bacillus anthracis but which fail to produce the capsule or to induce anthrax in test animals have long been dismissed in clinical and veterinary laboratories as B. cereus or simply as unidentified Bacillus spp. and thereupon discarded as inconsequential. In this study, the application of newly available DNA probe, polymerase chain reaction and specific toxin antigen detection technology has revealed that a proportion of such strains are B. anthracis which lack the plasmid carrying the capsule gene (pXO2). While these techniques cannot, of course, be used to confirm the identities of strains resembling B. anthracis but which also lack the plasmid carrying the toxin genes (pXO1), the likelihood that these also are bona fide B. anthracis becomes more acceptable. (As yet no naturally occurring pXO1-/2+ strains have been found.) At this point, the significance of the presence of such avirulent forms of B. anthracis in specimens can only be a subject for speculation, but the possibility that they may be indicators of virulent parents somewhere in the system being examined must be considered.

Emerging Infectious Diseases, Oct 1, 2002

, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility tha... more , four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes' paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility, suggesting multiple aerosolization events. Environmental sampling showed diffuse contamination of the facility. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary. n October 2001, four cases of inhalational anthrax occurred in employees at the Washington, D.C., Postal Processing and Distribution Center (DCPDC) (1,2). These cases were part of a multistate outbreak of inhalational and cutaneous anthrax associated with intentional distribution of envelopes containing Bacillus anthracis spores to media and federal government offices (2-4). Together, these represent the first reported cases of inhalational anthrax in postal workers and the first reported outbreak of inhalational anthrax caused by occupational exposure in the United States since 1957 (5,6). The investigation and public health response to this outbreak of inhalational anthrax are reported here. The urgent public health response was directed at preventing new cases of inhalational anthrax through the use of prophylactic antimicrobial drugs for persons potentially exposed to B. anthracis spores. The public health response also provided useful information about occupational exposure to aerosolized spores in this type of workplace and the performance of potential tools for determining exposure, such as work history, nasal swabs, immune response markers, and environmental sampling. Methods Setting and Background On October 15, 2001, in an office of the Washington, D.C., U. S. Capitol complex, an envelope addressed to Senator Tom Daschle, intentionally contaminated with B. anthracis spores, was opened. This event occurred 2 weeks after a report from Florida of the first-ever inhalational anthrax cases related to envelopes containing B. anthracis spores; those cases occurred in employees of a media company (3). The Washington, D.C., Department of Health (DCDOH), Office of the Attending Physician, U.S. Capitol, and the Centers for Disease Control and Prevention (CDC) immediately initiated a multiagency public health response and epidemiologic investigation (7). Enhanced surveillance activities for inhalational anthrax in the national Capitol area were established through a cooperative effort of the DCDOH,

Journal of the American Chemical Society, Nov 20, 2012

PLOS Pathogens

Inhalation anthrax has three clinical stages: early-prodromal, intermediate-progressive, and late... more Inhalation anthrax has three clinical stages: early-prodromal, intermediate-progressive, and late-fulminant. We report the comprehensive characterization of anthrax toxins, including total protective antigen (PA), total lethal factor (LF), total edema factor (EF), and their toxin complexes, lethal toxin and edema toxin in plasma, during the course of inhalation anthrax in 23 cynomolgus macaques. The toxin kinetics were predominantly triphasic with an early rise (phase-1), a plateau/decline (phase-2), and a final rapid rise (phase-3). Eleven animals had shorter survival times, mean±standard deviation of 58.7±7.6 hours (fast progression), 11 animals had longer survival times, 113±34.4 hours (slow progression), and one animal survived. Median (lower–upper quartile) LF levels at the end-of-phase-1 were significantly higher in animals with fast progression [138 (54.9–326) ng/mL], than in those with slow progression [23.8 (15.6–26.3) ng/mL] (p = 0.0002), and the survivor (11.1 ng/mL). The...

Journal of Biological Chemistry, 1991

Linker insertion mutagenesis was employed to create structural disruptions of the lethal factor (... more Linker insertion mutagenesis was employed to create structural disruptions of the lethal factor (LF) protein of anthrax toxin to map functional domains. A dodecameric linker was inserted at 17 blunt end restriction enzyme sites throughout the gene. Paired MluI restriction sites within the linker allowed the inserts to be reduced from four to two amino acids. Shuttle vectors containing the mutated genes were transformed into the avirulent Bacillus anthracis UM23C1-1 for expression and secretion of the gene products. Mutations at five sites in the central one-third of the sequence made the protein unstable, and purified protein could not be obtained. Mutated LF proteins with insertions at the other sites were purified and assessed for toxic activity in a macrophage lysis assay and for their ability to bind to the protective antigen (PA) component of anthrax toxin, the receptor binding moiety. Most insertions located in the NH2-terminal one-third of the LF protein eliminated both toxicity and binding to PA, while all four insertions in the COOH-terminal one-third of the protein eliminated toxicity without affecting binding to PA. These data support the hypothesis that the NH2-terminal domain contains the structures required for binding to PA and the COOH-terminal domain contains the putative catalytic domain of LF.

PloS one, 2017

Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and ... more Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and Bc 03BB87 have secondary cell wall polysaccharides (SCWPs) comprising an aminoglycosyl trisaccharide repeat: →4)-β-d-ManpNAc-(1→4)-β-d-GlcpNAc-(1→6)-α-d-GlcpNAc-(1→, substituted at GlcNAc residues with both α- and β-Galp. In Bc G9241 and Bc 03BB87, an additional α-Galp is attached to O-3 of ManNAc. Using NMR spectroscopy, mass spectrometry and immunochemical methods, we compared these structures to SCWPs from Bc biovar anthracis strains isolated from great apes displaying "anthrax-like" symptoms in Cameroon (Bc CA) and Côte d'Ivoire (Bc CI). The SCWPs of Bc CA/CI contained the identical HexNAc trisaccharide backbone and Gal modifications found in Ba, together with the α-Gal-(1→3) substitution observed previously at ManNAc residues only in Bc G9241/03BB87. Interestingly, the great ape derived strains displayed a unique α-Gal-(1→3)-α-Gal-(1→3) disaccharide substitution at som...

Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Elsevier eBooks, 2002

Publisher Summary Gram-positive spore-forming rods have traditionally been placed in the genus Ba... more Publisher Summary Gram-positive spore-forming rods have traditionally been placed in the genus Bacillus. Even before it became possible to examine relationships at the DNA level, however, it was clear that this group consists of a very diverse range of species. Their classification, based on traditional morphological, physiological, and biochemical tests, is still used but identification is complicated by the need for special media and the problems of strain-to-strain variation. Although only a few species are associated to a greater or lesser extent with primary infections, a substantial number are, however, of clinical or health importance in a variety of other ways. The only obligate pathogen in the genus is B. anthracis, the agent of anthrax. Several Bacillus species are associated with a range of infections, but in the majority of cases there is probably an underlying immunological, metabolic or other disorder, or drug abuse.

Journal of Bacteriology, 2008

Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl ... more Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl compositions. Recent multilocus sequence typing (MLST) refined the relatedness of B. cereus group members by separating them into clades and lineages. Based on MLST, we selected several B. anthracis, B. cereus, and B. thuringiensis strains and compared their cell wall carbohydrates. The cell walls of different B. anthracis strains (clade 1/Anthracis) were composed of glucose (Glc), galactose (Gal), N-acetyl mannosamine (ManNAc), and Nacetylglucosamine (GlcNAc). In contrast, the cell walls from clade 2 strains (B. cereus type strain ATCC 14579 and B. thuringiensis strains) lacked Gal and contained N-acetylgalactosamine (GalNAc). The B. cereus clade 1 strains had cell walls that were similar in composition to B. anthracis in that they all contained Gal. However, the cell walls from some clade 1 strains also contained GalNAc, which was not present in B. anthracis cell walls. Three recently identified clade 1 strains of B. cereus that caused severe pneumonia, i.e., strains 03BB102, 03BB87, and G9241, had cell wall compositions that closely resembled those of the B. anthracis strains. It was also observed that B. anthracis strains cell wall glycosyl compositions differed from one another in a plasmiddependent manner. When plasmid pXO2 was absent, the ManNAc/Gal ratio decreased, while the Glc/Gal ratio increased. Also, deletion of atxA, a global regulatory gene, from a pXO2 ؊ strain resulted in cell walls with an even greater level of Glc.

NATO science for peace and security series, Oct 25, 2010

A range of mass spectrometry-based techniques have been used to identify, characterize and differ... more A range of mass spectrometry-based techniques have been used to identify, characterize and differentiate Bacillus anthracis, both in culture for forensic applications and for diagnosis during infection. This range of techniques could usefully be considered to exist as a continuum, based on the degrees of specificity involved. We show two examples here, a whole-organism fingerprinting method and a high-specificity assay

Medical Microbiology and Immunology, Aug 1, 1988

A forerunning study on the relationship between antibodies to the protective antigen (PA) and let... more A forerunning study on the relationship between antibodies to the protective antigen (PA) and lethal factor (LF) components of anthrax toxin and protective immunity has been expanded and extended to include the third toxin component, the edema factor (EF). It was found that protection against the "vaccine resistant" Ames strain was possible in the absence of detectable anti-LF and anti-EF antibodies. Evidence is given that PA may be the essential anthrax-derived antigen for protection, but that equally essential is that it be presented to the host's immune system in such a manner as to provide stimulation of more than just production of antibody to PA. Titers to the three components in sera of individuals with histories of clinically diagnosed anthrax as well as from human vaccinees are included in the report.

Infection and Immunity, Aug 1, 2009

Systemic anthrax manifests as toxemia, rapidly disseminating septicemia, immune collapse, and dea... more Systemic anthrax manifests as toxemia, rapidly disseminating septicemia, immune collapse, and death. Virulence factors include the anti-phagocytic ␥-linked poly-D-glutamic acid (PGA) capsule and two binary toxins, complexes of protective antigen (PA) with lethal factor (LF) and edema factor. We report the characterization of LF, PA, and PGA levels during the course of inhalation anthrax in five rhesus macaques. We describe bacteremia, blood differentials, and detection of the PA gene (pagA) by PCR analysis of the blood as confirmation of infection. For four of five animals tested, LF exhibited a triphasic kinetic profile. LF levels (mean ؎ standard error [SE] between animals) were low at 24 h postchallenge (0.03 ؎ 1.82 ng/ml), increased at 48 h to 39.53 ؎ 0.12 ng/ml (phase 1), declined at 72 h to 13.31 ؎ 0.24 ng/ml (phase 2), and increased at 96 h (82.78 ؎ 2.01 ng/ml) and 120 h (185.12 ؎ 5.68 ng/ml; phase 3). The fifth animal had an extended phase 2. PGA levels were triphasic; they were nondetectable at 24 h, increased at 48 h (2,037 ؎ 2 ng/ml), declined at 72 h (14 ؎ 0.2 ng/ml), and then increased at 96 h (3,401 ؎ 8 ng/ml) and 120 h (6,004 ؎ 187 ng/ml). Bacteremia was also triphasic: positive at 48 h, negative at 72 h, and positive at euthanasia. Blood neutrophils increased from preexposure (34.4% ؎ 0.13%) to 48 h (75.6% ؎ 0.08%) and declined at 72 h (62.4% ؎ 0.05%). The 72-h declines may establish a "go/no go" turning point in infection, after which systemic bacteremia ensues and the host's condition deteriorates. This study emphasizes the value of LF detection as a tool for early diagnosis of inhalation anthrax before the onset of fulminant systemic infection.

Emerging Infectious Diseases, Oct 1, 2002

, the first inhalational anthrax case in the United States since 1976 was identified in a media c... more , the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

Wiley-VCH Verlag GmbH eBooks, Jan 7, 2005

ChemBioChem, Jul 21, 2008

Bacillus anthracis vaccine candidate: Sera of rabbits exposed to live and irradiated-killed spore... more Bacillus anthracis vaccine candidate: Sera of rabbits exposed to live and irradiated-killed spores of B. anthracis Sterne 34F 2 or immunized with B. anthracis polysaccharide conjugated to KLH elicited antibodies that recognize isolated polysaccharide and two synthetic trisaccharides providing a proof-of-concept step in the development of vegetative and spore-specific reagents for detection and targeting of non-protein structures of B. anthracis.

Emerging Infectious Diseases, 2017

This activity has been planned and implemented through the joint providership of Medscape, LLC an... more This activity has been planned and implemented through the joint providership of Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is accredited by the American Nurses Credentialing Center (ANCC), the Accreditation Council for Pharmacy Education (ACPE), and the Accreditation Council for Continuing Medical Education (ACCME), to provide continuing education for the healthcare team. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 75% minimum passing score and complete the evaluation at http://www.medscape.org/journal/eid; and (4) view/print certificate. For CME questions, see page 175.

Molecules, Mar 14, 2011

Matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry (MS) is a valuable ... more Matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry (MS) is a valuable high-throughput tool for peptide analysis. Liquid chromatography electrospray ionization (LC-ESI) tandem-MS provides sensitive and specific quantification of small molecules and peptides. The high analytic power of MS coupled with high-specificity substrates is ideally suited for detection and quantification of bacterial enzymatic activities. As specific examples of the MS applications in disease diagnosis and select agent detection, we describe recent advances in the analyses of two high profile protein toxin groups, the Bacillus anthracis toxins and the Clostridium botulinum neurotoxins. The two binary toxins produced by B. anthracis consist of protective antigen (PA) which combines with lethal factor (LF) and edema factor (EF), forming lethal toxin and edema toxin respectively. LF is a zinc-dependent endoprotease which hydrolyzes specific proteins involved in inflammation and immunity. EF is an adenylyl cyclase which converts ATP to cyclic-AMP. Toxin-specific enzyme activity for a strategically designed substrate, amplifies reaction products which are detected by MALDI-TOF-MS and LC-ESI-MS/MS. Pre-concentration/purification with toxin specific monoclonal antibodies provides additional specificity. These combined technologies have

Journal of applied bacteriology, 1992

Gram-positive bacilli isolated during epidemiological investigations which, on the basis of conve... more Gram-positive bacilli isolated during epidemiological investigations which, on the basis of conventional tests, resemble Bacillus anthracis but which fail to produce the capsule or to induce anthrax in test animals have long been dismissed in clinical and veterinary laboratories as B. cereus or simply as unidentified Bacillus spp. and thereupon discarded as inconsequential. In this study, the application of newly available DNA probe, polymerase chain reaction and specific toxin antigen detection technology has revealed that a proportion of such strains are B. anthracis which lack the plasmid carrying the capsule gene (pXO2). While these techniques cannot, of course, be used to confirm the identities of strains resembling B. anthracis but which also lack the plasmid carrying the toxin genes (pXO1), the likelihood that these also are bona fide B. anthracis becomes more acceptable. (As yet no naturally occurring pXO1-/2+ strains have been found.) At this point, the significance of the presence of such avirulent forms of B. anthracis in specimens can only be a subject for speculation, but the possibility that they may be indicators of virulent parents somewhere in the system being examined must be considered.

Emerging Infectious Diseases, Oct 1, 2002

, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility tha... more , four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes' paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility, suggesting multiple aerosolization events. Environmental sampling showed diffuse contamination of the facility. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary. n October 2001, four cases of inhalational anthrax occurred in employees at the Washington, D.C., Postal Processing and Distribution Center (DCPDC) (1,2). These cases were part of a multistate outbreak of inhalational and cutaneous anthrax associated with intentional distribution of envelopes containing Bacillus anthracis spores to media and federal government offices (2-4). Together, these represent the first reported cases of inhalational anthrax in postal workers and the first reported outbreak of inhalational anthrax caused by occupational exposure in the United States since 1957 (5,6). The investigation and public health response to this outbreak of inhalational anthrax are reported here. The urgent public health response was directed at preventing new cases of inhalational anthrax through the use of prophylactic antimicrobial drugs for persons potentially exposed to B. anthracis spores. The public health response also provided useful information about occupational exposure to aerosolized spores in this type of workplace and the performance of potential tools for determining exposure, such as work history, nasal swabs, immune response markers, and environmental sampling. Methods Setting and Background On October 15, 2001, in an office of the Washington, D.C., U. S. Capitol complex, an envelope addressed to Senator Tom Daschle, intentionally contaminated with B. anthracis spores, was opened. This event occurred 2 weeks after a report from Florida of the first-ever inhalational anthrax cases related to envelopes containing B. anthracis spores; those cases occurred in employees of a media company (3). The Washington, D.C., Department of Health (DCDOH), Office of the Attending Physician, U.S. Capitol, and the Centers for Disease Control and Prevention (CDC) immediately initiated a multiagency public health response and epidemiologic investigation (7). Enhanced surveillance activities for inhalational anthrax in the national Capitol area were established through a cooperative effort of the DCDOH,

Journal of the American Chemical Society, Nov 20, 2012

PLOS Pathogens

Inhalation anthrax has three clinical stages: early-prodromal, intermediate-progressive, and late... more Inhalation anthrax has three clinical stages: early-prodromal, intermediate-progressive, and late-fulminant. We report the comprehensive characterization of anthrax toxins, including total protective antigen (PA), total lethal factor (LF), total edema factor (EF), and their toxin complexes, lethal toxin and edema toxin in plasma, during the course of inhalation anthrax in 23 cynomolgus macaques. The toxin kinetics were predominantly triphasic with an early rise (phase-1), a plateau/decline (phase-2), and a final rapid rise (phase-3). Eleven animals had shorter survival times, mean±standard deviation of 58.7±7.6 hours (fast progression), 11 animals had longer survival times, 113±34.4 hours (slow progression), and one animal survived. Median (lower–upper quartile) LF levels at the end-of-phase-1 were significantly higher in animals with fast progression [138 (54.9–326) ng/mL], than in those with slow progression [23.8 (15.6–26.3) ng/mL] (p = 0.0002), and the survivor (11.1 ng/mL). The...

Journal of Biological Chemistry, 1991

Linker insertion mutagenesis was employed to create structural disruptions of the lethal factor (... more Linker insertion mutagenesis was employed to create structural disruptions of the lethal factor (LF) protein of anthrax toxin to map functional domains. A dodecameric linker was inserted at 17 blunt end restriction enzyme sites throughout the gene. Paired MluI restriction sites within the linker allowed the inserts to be reduced from four to two amino acids. Shuttle vectors containing the mutated genes were transformed into the avirulent Bacillus anthracis UM23C1-1 for expression and secretion of the gene products. Mutations at five sites in the central one-third of the sequence made the protein unstable, and purified protein could not be obtained. Mutated LF proteins with insertions at the other sites were purified and assessed for toxic activity in a macrophage lysis assay and for their ability to bind to the protective antigen (PA) component of anthrax toxin, the receptor binding moiety. Most insertions located in the NH2-terminal one-third of the LF protein eliminated both toxicity and binding to PA, while all four insertions in the COOH-terminal one-third of the protein eliminated toxicity without affecting binding to PA. These data support the hypothesis that the NH2-terminal domain contains the structures required for binding to PA and the COOH-terminal domain contains the putative catalytic domain of LF.

PloS one, 2017

Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and ... more Bacillus anthracis (Ba) and human infection-associated Bacillus cereus (Bc) strains Bc G9241 and Bc 03BB87 have secondary cell wall polysaccharides (SCWPs) comprising an aminoglycosyl trisaccharide repeat: →4)-β-d-ManpNAc-(1→4)-β-d-GlcpNAc-(1→6)-α-d-GlcpNAc-(1→, substituted at GlcNAc residues with both α- and β-Galp. In Bc G9241 and Bc 03BB87, an additional α-Galp is attached to O-3 of ManNAc. Using NMR spectroscopy, mass spectrometry and immunochemical methods, we compared these structures to SCWPs from Bc biovar anthracis strains isolated from great apes displaying "anthrax-like" symptoms in Cameroon (Bc CA) and Côte d'Ivoire (Bc CI). The SCWPs of Bc CA/CI contained the identical HexNAc trisaccharide backbone and Gal modifications found in Ba, together with the α-Gal-(1→3) substitution observed previously at ManNAc residues only in Bc G9241/03BB87. Interestingly, the great ape derived strains displayed a unique α-Gal-(1→3)-α-Gal-(1→3) disaccharide substitution at som...