Vaccines, Blood & Biologics

Bacterial Vaccine Safety: Biomarkers of Virulence and Attenuation in Bordetella Pertussis (Whooping Cough) and Anthrax Bacteria

Principal Investigator: E. Scott Stibitz, PhD
Office / Division / Lab: OVRR / DBPAP / LESTD

General Overview

Our laboratory is studying disease-causing bacteria for which new vaccines and novel therapeutic approaches are being developed.

We are developing new ways to study respiratory infections caused by the bacterium Bordetella pertussis (whooping cough) and the mechanisms by which it causes severe disease. Although a vaccine for this organism exists, the number of whooping cough cases in the US continues to rise, making this research vital to ultimate control.

We also support the development and evaluation of vaccines against Staphylococcus aureus, which causes many infections in the US each year, some of which are extremely serious (e.g., "flesh-eating" bacteria that can cause death in a matter of hours). S. aureus also causes infections of implanted devices such as pacemakers and joint replacements that can be very difficult to treat without removing the device. Currently no vaccine for this disease exists and development of new vaccines against this organism is especially critical due to problems with antibiotic resistance typified by MRSA (methicillin-resistant Staphylococcus aureus), and the new strains of community-acquired MRSA (CA-MRSA).

We also study live biotherapeutic products (i.e., probiotics--live microorganisms that provide health benefits to an individual when consumed in appropriate quantities) to help treat and prevent bacterial infections and other conditions. The investigation of the full potential of these promising products is currently being hindered by difficulties in evaluation of the manufacturing process, purity, safety and quality of these products. We seek to solve this problem by developing better tests for the purity and safety of probiotics, thereby allowing their further testing and development in the clinic.

Diarrheal diseases are also targetted. We are investigating the use of the live attenuated Salmonella strain Ty21a as a platform for eliciting protective immune responses against other serious diseases such as Shigellosis. We are also examining ways to more fully understand some of the as yet uncharacterized genetic bases of attenuation in Ty21a as well as to confer advantageous traits such as acid resistance. We are also seeking to understand why some bacterial pathogens, such as Shigella can cause arthritis and are testing novel approaches to killed Shigella vaccines in order to control this deadly disease.

Another major worldwide health challenge and emerging problem in the US - tuberculosis - is in a class by itself in terms of its difficulty to study, its overall importance, its resistance to date to vaccine interventions, and the threat from antibiotic resistance. Our lab is working to develop and execute new ways to assess the usefullness of vaccine candidates, including the development of animal models and of in vitro tests to measure host responses.

Malaria, while not a bacterial disease, in one which also has a huge worldwide burden. Recent exciting research has brought us much closer to having a useful anti-malaria vaccine. Our lab is studying biomarkers for severe malaria in an effort to both better understand the variables that can lead to tragic outcomes as well as to better assess how current vaccine candidates control disease and infection.

Scientific Overview

Our laboratory takes a genetic approach to studies of bacterial pathogenesis and vaccine development.

In our studies of Bordetella pertussis we introduce specific mutations that affect the expression and regulation of virulence factors, such as toxins and adhesins. We then test the effects of these mutations in a mouse model of respiratory infection that uses bioluminescent B. pertussis to track infection without harming the test animal. This approach has several advantages over older methods that involve sacrificing a group of test animals at each time point, and reduces dramatically the number of animals that must be used.

Our approach to studying Bacillus anthracis pathogenesis has also been largely genetic. We developed and have recently improved, new genetic tools to introduce specific mutations into this organism. These tools, which are now used widely around the world, are significantly easier and more powerful than previous such techniques. They also allow the consecutive deletion or mutation of a unlimited number of genes. This approach has been critical to our studies of anthrax vaccine stability. For example, it has enabled us to create improved strains of the organism used to produce protective antigen (part of the anthrax toxin). These strains lack a number of secreted proteases (currently up to 16 separate deletions). This characteristic increases the production of protective antigen and leads to a purified product that has increased stability.

Our new program in Staphylococcus aureus will follow a similar path, synergizing our genetic capabilities with other OVRR researchers to evaluate new vaccine candidates and identify new candidates for virulence factors and vaccine antigens. We are also examining the utility of a novel approach - bacteriophage therapy - to deal with antibiotic resistant S. aureus.

We are using bacteriophages to develop improved tests for detecting pathogens in probiotic products. We plan to exploit the exquisite specificity of these bacterial viruses to specifically kill product organisms, thereby increasing the sensitivity of detection of extraneous and potentially harmful bacterial pathogens, such as Salmonella and Shigella. Such tests are necessary to ensure the safety of these preparations, a factor that is especially important when tested in clinical trials in very sick or otherwise compromised patients.

Another application of bacteriophages is to actually treat bacterial diseases. Our lab is initiating a project to set up an animal model to examine the usefullness of phage in host decolonization of Staphylococcus aureus. If successful, this could have a major impact on carriage in hospitals and significantly improve the situation there where dangerous, highly antibiotic strains, MRSA, have a high toll.


Proc Natl Acad Sci U S A 2017 Feb 21;114(8):E1519-27
Bordetella PlrSR regulatory system controls BvgAS activity and virulence in the lower respiratory tract.
Bone MA, Wilk AJ, Perault AI, Marlatt SA, Scheller EV, Anthouard R, Chen Q, Stibitz S, Cotter PA, Julio SM

Clin Vaccine Immunol 2017 Jan 5;24(1):e00509-16
Trained immunity and susceptibility to HIV.
Derrick SC

Pathog Dis 2016 Nov;74(8):ftw098
Stable expression of Shigella dysenteriae serotype 1 O-antigen genes integrated into the chromosome of live Salmonella oral vaccine vector Ty21a.
Dharmasena MN, Osorio M, Filipova S, Marsh C, Stibitz S, Kopecko DJ

PLoS One 2016 Sep 27;11(9):e0163511
Development of an Acid-Resistant Salmonella Typhi Ty21a Attenuated Vector For Improved Oral Vaccine Delivery.
Dharmasena MN, Feuille CM, Starke CE, Bhagwat AA, Stibitz S, Kopecko DJ

J Microbiol Methods 2016 Dec;131:7-9
A simplified mycobacterial growth inhibition assay (MGIA) using direct infection of mouse splenocytes and the MGIT system.
Yang AL, Schmidt TE, Stibitz S, Derrick SC, Morris SL, Parra M

Sci Rep 2016 Sep 13;6:32774
The multifaceted RisA regulon of Bordetella pertussis.
Coutte L, Huot L, Antoine R, Slupek S, Merkel TJ, Chen Q, Stibitz S, Hot D, Locht C

Viruses 2015 Dec 16;7(12):6675-88
Development of phage lysin LysA2 for use in improved purity assays for live biotherapeutic products.
Dreher-Lesnick SM, Schreier JE, Stibitz S

PLoS One 2015 Dec 1;10(12):e0142758
Improvements to a markerless allelic exchange system for Bacillus anthracis.
Plaut RD, Stibitz S

Proc Natl Acad Sci U S A 2015 Feb 10;112(6):E526-35
Bordetella pertussis fim3 gene regulation by BvgA: Phosphorylation controls the formation of inactive vs. active transcription complexes.
Boulanger A, Moon K, Decker KB, Chen Q, Knipling L, Stibitz S, Hinton DM

Mol Microbiol 2014 Aug;93(4):748-58
Strong inhibition of fimbrial 3 subunit gene transcription by a novel downstream repressive element in Bordetella pertussis.
Chen Q, Boulanger A, Hinton DM, Stibitz S

J Infect Dis 2014 Apr;209(7):982-5
Pertussis pathogenesis--what we know and what we don't know.
Hewlett EL, Burns DL, Cotter PA, Harvill ET, Merkel TJ, Quinn CP, Stibitz ES

J Bacteriol 2014 Mar;196(6):1143-54
Genetic evidence for the involvement of the S-layer protein gene sap and the sporulation genes spo0A, spo0B, and spo0F in phage AP50c infection of Bacillus anthracis.
Plaut RD, Beaber JW, Zemansky J, Kaur AP, George M, Biswas B, Henry M, Bishop-Lilly KA, Mokashi V, Hannah RM, Pope RK, Read TD, Stibitz S, Calendar R, Sozhamannan S

Bio-Protocol 2013 Nov 20:970
Separation and Detection of Phosphorylated and Nonphosphorylated BvgA, a Bordetella pertussis Response Regulator, in vivo and in vitro
Chen Q, Boulanger A, Hinton DM, Stibitz S

Infect Immun 2013 Apr;81(4):1306-15
Epicutaneous model of community-acquired Staphylococcus aureus skin infections.
Prabhakara R, Foreman O, De Pascalis R, Lee GM, Plaut RD, Kim SY, Stibitz S, Elkins KL, Merkel TJ

Mol Microbiol 2013 Apr;88(1):156-72
In vivo phosphorylation dynamics of the Bordetella pertussis virulence-controlling response regulator BvgA.
Boulanger A, Chen Q, Hinton DM, Stibitz S

PLoS One 2013;8(3):e59232
Stably luminescent Staphylococcus aureus clinical strains for use in bioluminescent imaging.
Plaut RD, Mocca CP, Prabhakara R, Merkel TJ, Stibitz S

Infect Immun 2013 Jan;81(1):278-84
Use of site-directed mutagenesis to model the effects of spontaneous deamidation on the immunogenicity of Bacillus anthracis protective antigen.
Verma A, McNichol B, Domínguez-Castillo RI, Amador-Molina JC, Arciniega JL, Reiter K, Meade BD, Ngundi MM, Stibitz S, Burns DL

Virol J 2012 Oct 26;9:246
Whole genome sequencing of phage resistant Bacillus anthracis mutants reveals an essential role for cell surface anchoring protein CsaB in phage AP50c adsorption.
Bishop-Lilly KA, Plaut RD, Chen PE, Akmal A, Willner KM, Butani A, Dorsey S, Mokashi V, Mateczun AJ, Chapman C, George M, Luu T, Read TD, Calendar R, Stibitz S, Sozhamannan S

Infect Immun 2012 Sep;80(9):3189-93
A dissemination bottleneck in murine inhalational anthrax.
Plaut RD, Kelly VK, Lee GM, Stibitz S, Merkel TJ

Cell Microbiol 2012 Aug;14(8):1219-1230
Bacillus anthracis protease InhA regulates BslA-mediated adhesion in human endothelial cells.
Tonry JH, McNichol BA, Ramarao N, Chertow DS, Kim KS, Stibitz S, Schneewind O, Kashanchi F, Bailey CL, Popov S, Chung MC

Microbiology 2012 Jul;158(Pt 7):1665-76
The Bordetella pertussis model of exquisite gene control by the global transcription factor BvgA.
Decker KB,James TD, Stibitz S, Hinton DM

Infect Immun 2012 Mar;80(3):1025-36
Phenotypic Modulation of the Virulent Bvg Phase Is Not Required for Pathogenesis and Transmission of Bordetella bronchiseptica in Swine.
Nicholson TL, Brockmeier SL, Loving CL, Register KB, Kehrli ME Jr, Stibitz SE, Shore SM

Proc Natl Acad Sci U S A 2011 Oct 11;108(41):17159-64
Identification of the bacterial protein FtsX as a unique target of chemokine-mediated antimicrobial activity against Bacillus anthracis.
Crawford MA, Lowe DE, Fisher DJ, Stibitz S, Plaut RD, Beaber JW, Zemansky J, Mehrad B, Glomski IJ, Strieter RM, Hughes MA

J Mol Biol 2011 Jun 24;409(5):692-709
Different Requirements for sigma Region 4 in BvgA Activation of the Bordetella pertussis Promoters P(fim3) and P(fhaB).
Decker KB, Chen Q, Hsieh ML, Boucher P, Stibitz S, Hinton DM

Mol Microbiol 2010 Sep;77(5):1326-40
Novel architectural features of Bordetella pertussis fimbrial subunit promoters and their activation by the global virulence regulator BvgA.
Chen Q, Decker KB, Boucher PE, Hinton D, Stibitz S

Infect Immun 2010 Jul;78(7):2901-9
Pertactin is required for Bordetella to resist neutrophil-mediated clearance.
Inatsuka CS, Xu Q, Vujkovic-Cvijin I, Wong S, Stibitz S, Miller JF, Cotter PA

Infect Immun 2009 Jan;77(1):255-65
Role of anthrax toxins in dissemination, disease progression, and induction of protective adaptive immunity in the mouse aerosol challenge model.
Loving CL, Khurana T, Osorio M, Lee GM, Kelly VK, Stibitz S, Merkel TJ

Infect Immun 2009 Jan;77(1):274-85
Four superoxide dismutases contribute to Bacillus anthracis virulence and provide spores with redundant protection from oxidative stress.
Cybulski RJ Jr, Sanz P, Alem F, Stibitz S, Bull RL, O'Brien AD

Clin Vaccine Immunol 2008 Nov;15(11):1737-41
Role of the N-terminal amino acid of Bacillus anthracis lethal factor in lethal toxin cytotoxicity and its effect on the lethal toxin neutralization assay.
Verma A, Wagner L, Stibitz S, Nguyen N, Guerengomba F, Burns DL

Infect Immun 2008 Apr;76(4):1774-80
O antigen Protects Bordetella parapertussis from Complement.
Goebel EM, Wolfe DN, Elder K, Stibitz S, Harvill ET

Infect Immun 2007 Nov;75(11):5233-9
Bacillus anthracis Exosporium Protein BclA Affects Spore Germination, Interaction with Extracellular Matrix Proteins, and Hydrophobicity.
Brahmbhatt TN, Janes BK, Stibitz ES, Darnell SC, Sanz P, Rasmussen SB, O'brien AD

Curr Opin Microbiol 2007 Feb;10(1):17-23
c-di-GMP-mediated regulation of virulence and biofilm formation.
Cotter PA, Stibitz S

Infect Immun 2006 Mar;74(3):1949-53
Routine markerless gene replacement in Bacillus anthracis.
Janes BK, Stibitz S

Mol Microbiol 2005 Nov;58(3):700-13
Role of BvgA phosphorylation and DNA binding affinity in control of Bvg-mediated phenotypic phase transition in Bordetella pertussis.
Jones AM, Boucher PE, Williams CL, Stibitz S, Cotter PA

Mol Microbiol 2005 Apr;56(1):175-88
BvgA functions as both an activator and a repressor to control Bvg phase expression of bipA in Bordetella pertussis.
Williams CL, Boucher PE, Stibitz S, Cotter PA

Mol Microbiol 2005 Feb;55(3):788-98
Demonstration of differential virulence gene promoter activation in vivo in Bordetella pertussis using RIVET.
Veal-Carr WL, Stibitz S


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