Publications by authors named "Maribel Gallegos Candela"

Article Synopsis
  • Inhalation anthrax has three stages: early, intermediate, and late, and scientists studied it using 23 monkeys.
  • They found that the toxins in the blood changed in a specific way, like rising, leveling off, and then rising fast again during the illness.
  • Animals that got really sick quickly had higher toxin levels earlier than those who got sick slowly, showing that the way anthrax gets worse depends more on toxin levels than on the time that's passed.
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Bacillus anthracis has traditionally been considered the etiologic agent of anthrax. However, anthrax-like illness has been documented in welders and other metal workers infected with Bacillus cereus group spp. harboring pXO1 virulence genes that produce anthrax toxins.

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Inhalation of Bacillus anthracis spores can cause a rapidly progressing fatal infection. B. anthracis secretes three protein toxins: lethal factor (LF), edema factor (EF), and protective antigen (PA).

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Anthrax protective antigen (83 kDa, PA83) is an essential component of two major binary toxins produced by Bacillus anthracis, lethal toxin (LTx) and edema toxin (ETx). During infection, LTx and ETx contribute to immune collapse, endothelial dysfunction, hemorrhage and high mortality. Following protease cleavage on cell receptors or in circulation, the 20 kDa (PA20) N-terminus is released, activating the 63 kDa (PA63) form which binds lethal factor (LF) and edema factor (EF), facilitating their entry into their cellular targets.

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Anthrax lethal factor (LF) is a zinc-dependent endoprotease and a critical virulence factor for Bacillus anthracis, the causative agent of anthrax. The mass spectrometry (MS) method for total-LF quantification includes three steps; 1) LF specific antibody capture/concentration, 2) LF-specific hydrolysis of a peptide substrate, and 3) detection and quantification of LF-cleaved peptides by isotope-dilution MALDI-TOF/MS. Recombinant LF spiked plasma was used for calibration and quality control (QC) materials.

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Article Synopsis
  • Bacillus cereus isolates, like B. cereus G9241, can carry Bacillus anthracis toxin genes and cause serious infections, including pneumonia.
  • The new isolate BcFL2013 has been linked to a skin lesion similar to anthrax and shares significant genetic similarities with G.9241, including specific toxin genes and multi-locus sequence types.
  • This study is the first to report on blood tests from patients infected with this B. cereus strain, revealing the presence of anthrax toxins and an immune response against them.
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Article Synopsis
  • * A new method was developed to specifically quantify LTx in plasma, demonstrating high sensitivity and accuracy, allowing for detection even post-antibiotic treatment.
  • * The method achieved 100% diagnostic sensitivity and specificity, indicating its potential for use in diagnosing and evaluating therapies targeting anthrax toxins.
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Article Synopsis
  • PMNs play a crucial protective role against Bacillus anthracis infection, but the bacteria can effectively undermine this response, leading to high mortality rates.
  • Lethal toxin (LT), a key virulence factor of B. anthracis, is essential for the bacteria's spread in mouse models, but its effects on PMN function remain unclear due to their short lifespan.
  • Research shows that LT not only hampers PMN recruitment to inflamed areas but also diminishes their ability to kill B. anthracis, indicating a dual role in weakening the immune response.
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Anthrax is caused by infection with Bacillus anthracis, a spore-forming gram-positive bacterium. A major virulence factor for B. anthracis is an immunomodulatory tripartite exotoxin that has been reported to alter immune cell chemotaxis and activation.

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Cutaneous anthrax outbreaks occurred in Bangladesh from August to October 2009. As part of the epidemiological response and to confirm anthrax diagnoses, serum samples were collected from suspected case patients with observed cutaneous lesions. Anthrax lethal factor (LF), anti-protective antigen (anti-PA) immunoglobulin G (IgG), and anthrax lethal toxin neutralization activity (TNA) levels were determined in acute and convalescent serum of 26 case patients with suspected cutaneous anthrax from the first and largest of these outbreaks.

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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.

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The Bacillus anthracis exosporium protein BclA contains an O-linked antigenic tetrasaccharide whose terminal sugar is known as anthrose (J. M. Daubenspeck et al.

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Article Synopsis
  • Early diagnosis and treatment of anthrax are essential, and a new method has been developed to detect anthrax lethal factor (LF) in plasma or serum at extremely low levels (attomol/mL).
  • This method utilizes isotope dilution matrix-assisted laser-desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and has been adapted for electrospray ionization (ESI) tandem MS to make it accessible for more public health labs.
  • The study confirmed that both MALDI-TOF-MS and ESI-MS/MS provide comparable LF quantification, demonstrating the reliability and precision of MALDI-TOF-MS as an effective diagnostic tool for anthrax.
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Botulinum neurotoxins (BoNTs) are very potent toxins and category A biological threat agents. BoNT serotypes /C1 and /D affect birds and mammals and can be potentially lethal to humans. We have previously described the usefulness of the Endopep-MS method to detect the activity of BoNT A through G.

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