A5033478784- Bacterial Infections and Vaccines
- Reproductive tract infections research
- Pneumonia and Respiratory Infections
- Bacterial Genetics and Biotechnology
- Antibiotic Resistance in Bacteria
- Amoebic Infections and Treatments
- RNA and protein synthesis mechanisms
- CRISPR and Genetic Engineering
- Bacteriophages and microbial interactions
- Immune Response and Inflammation
- Antimicrobial Resistance in Staphylococcus
- Streptococcal Infections and Treatments
- Vaccine Coverage and Hesitancy
- Nanocluster Synthesis and Applications
- Bacterial Identification and Susceptibility Testing
- Advanced biosensing and bioanalysis techniques
- Infective Endocarditis Diagnosis and Management
- Escherichia coli research studies
- Near-Field Optical Microscopy
- Legume Nitrogen Fixing Symbiosis
- Genomics and Phylogenetic Studies
- Polymer Surface Interaction Studies
- Infant Nutrition and Health
- Syphilis Diagnosis and Treatment
- Bacillus and Francisella bacterial research
Emory University
2015-2025
Office of Infectious Diseases
2003-2019
Veterans Health Administration
2000-2013
Georgia Institute of Technology
2008
United States Department of Veterans Affairs
2001
Scripps Research Institute
1996-1999
Wadsworth Center
1998
New York State Department of Health
1998
Single-stranded oligonucleotides stabilize highly fluorescent Ag nanoclusters, with emission colors tunable via DNA sequence. We utilized microarrays to optimize these scaffold sequences for creating nearly spectrally pure nanocluster fluorophores that are photostable and exhibit great buffer stability. Five different emitters have been created from the blue near-IR excellent photophysical properties. Ensemble single molecule fluorescence studies show oligonucleotide encapsulated...
Individual fluorescent molecules and individual singly labeled proteins were observed in the water-filled pores of poly(acrylamide) gels by far-field microscopy. Brownian motion was markedly reduced gel framework, thus enabling extended study single fluorophores aqueous environments. A highly axially dependent laser field used both to excite image three dimensions. Single followed as they moved within through porous structure. In contrast dry polymeric hosts, these water-based may form a...
Cationic antimicrobial peptides (CAMPs) are important components of the innate host defense system against microbial infections and products. However, human pathogen Neisseria meningitidis is intrinsically highly resistant to CAMPs, such as polymyxin B (PxB) (MIC > or = 512 microg/ml). To ascertain mechanisms by which meningococci resist PxB, mutants that displayed increased sensitivity (> =4-fold) PxB were identified from a library mariner transposon generated in meningococcal strain, NMB....
Meningococcal lipopoly(oligo)saccharide (LOS) is a major inflammatory mediator of fulminant meningococcal sepsis and meningitis. Highly purified wild-type LOS from genetically defined mutants Neisseria meningitidis that contained specific mutations in biosynthesis pathways were used to confirm activation macrophages was CD14/Toll-like receptor 4 (TLR4)-MD-2 dependent elucidate the structural requirement for TLR4 activation. Expression but not TLR2 required, antibodies both CD14 blocked...
Neisseria meningitidis (Nm) clonal complex 11 (cc11) lineage is a hypervirulent pathogen responsible for outbreaks of invasive meningococcal disease, including among men who have sex with men, and increasingly associated urogenital infections. Recently, clusters Nm urethritis emerged primarily heterosexual males in the United States. We determined that nonencapsulated isolates from an ongoing outbreak epidemiologically unrelated Columbus, Ohio, are linked to increased cases multiple US...
Increased reports of Neisseria meningitidis urethritis in multiple U.S. cities during 2015 have been attributed to the emergence a novel clade nongroupable N. within ST-11 clonal complex, "U.S. NmNG clade". Genetic recombination with gonorrhoeae has proposed enable efficient sexual transmission by this clade. To understand evolutionary origin and diversification clade, whole-genome phylogenetic analysis was performed identify its members among strain collection from Centers for Disease...
We compared exemplar strains from two hypervirulent clonal complexes, strain NMB-CDC ST-8/11 cc and MC58 ST-32/269 cc, in host cell attachment invasion. Strain attached to invaded cells at a significantly greater frequency than MC58. Type IV pili retained the primary role for initial both isolates regardless of pilin class glycosylation pattern. In MC58, serogroup B capsule was major inhibitory determinant affecting bacterial invasion cells. Removal terminal sialylation lipooligosaccharide...
Neisseria meningitidis (Nm) is a Gram-negative diplococcus that normally colonizes the nasopharynx and rarely infects urogenital tract. On Gram stain of urethral exudates, Nm can be misidentified as more common sexually transmitted pathogen gonorrhoeae.
Neisseria meningitidis (Nm) urogenital infections, although less common than infections caused by gonorrhoeae (Ng), have been associated with urethritis, cervicitis, proctitis, and pelvic inflammatory disease. Nm can appear similar to Ng on Gram stain analysis (gram-negative intracellular diplococci) (1-5). Because colonizes the nasopharynx, men who receive oral sex (fellatio) acquire urethral (1,3,5). This report describes an increase in Nm-associated urethritis attending sexual health...
ABSTRACT Lipopolysaccharide, lipooligosaccharide (LOS), or endotoxin is important in bacterial survival and the pathogenesis of gram-negative bacteria. A necessary step biosynthesis 3-deoxy- d -manno-octulosonic acid (Kdo) glycosylation lipid A, catalyzed by Kdo transferase KdtA (WaaA). In enteric bacteria, this essential for survival. nonpolar kdtA :: aphA-3 mutation was created Neisseria meningitidis via allelic exchange, mutant viable. Detailed structural analysis demonstrated that...
ABSTRACT Over the last decade, a Neisseria meningitidis ( Nm ) urethritis-causing clade UC) has emerged to cause clusters of meningococcal urethritis in United States and globally. One genomic signature UC is integration gonorrhoeae Ng DNA an operon, NEIS1446-NEIS1438 , which partially replaced ispD gene. IspD 2-C-methyl-d-erythritol 4-phosphate cytidylyltransferase terpenoid precursor synthesis pathway, required for production ubiquinones electron transfer chain. essential several...
The capsule of N. meningitidis serogroup B, (alpha2-->8)-linked polysialic acid and the capsules other meningococcal serogroups gram-negative bacterial pathogens are anchored in outer membrane through a 1,2-diacylglycerol moiety. Previous work on cps complex Escherichia coli K-12 indicated that deletion genes designated lipA lipB caused intracellular accumulation hyperelongated polymers lacking phospholipid substitution. To better understand role lip expression background, location,...
Flow cytometry holds promise to accelerate antibiotic susceptibility determinations; however, without robust multidimensional statistical analysis, general discrimination criteria have remained elusive. In this study, a new method, probability binning signature quadratic form (PB-sQF), was developed and applied analyze flow cytometric data of bacterial responses exposure. Both sensitive lab strains (Escherichia coli Pseudomonas aeruginosa) multidrug resistant, clinically isolated strain (E....
Abstract Sepsis, a life‐threatening immune response to blood infections (bacteremia), has ∼30% mortality rate and is the 10th leading cause of US hospital deaths. The typical bacterial loads in adult septic patients are ≤100 cells (colony forming units, CFU) per ml blood, while pediatric exhibit only ∼1000 CFU/ml. Due low numbers, bacteria must be propagated through ∼24‐hours cultures generate sufficient CFUs for diagnosis further analyses. Herein, we demonstrate that, unlike other rapid...
Introduction Outer membrane vesicles (OMVs) of Neisseria meningitidis in the group B-directed vaccine MenB-4C (Bexsero R ) protect against infections with gonorrhoeae . The immunological basis for protection remains unclear. N. OMV vaccines generate human antibodies to and lipooligosaccharide (LOS/endotoxin), but structural specificity these LOS is not defined. Methods Ten paired sera obtained pre- post-MenB-4C immunization were used Western blots probe LOS. Post-MenB-4C (7v5, 19v5, 17v5),...
We have identified and defined the function of<i>kpsF</i> of <i>Neisseria meningitidis</i> homologues <i>kpsF</i> in encapsulated K1 K5<i>Escherichia coli</i>. KpsF was shown to be arabinose-5-phosphate isomerase, an enzyme not previously prokaryotes, that mediates interconversion ribulose 5-phosphate arabinose 5-phosphate. is required for 3-deoxy-d-manno-octulosonic acid (Kdo) biosynthesis in<i>N. meningitidis</i>. Mutation or gene encoding CMP-Kdo synthetase (<i>kpsU</i>/<i>kdsB</i>)...
ABSTRACT We have located a locus, pgl , in Neisseria meningitidis strain NMB required for the glycosylation of class II pili. Between five and eight open reading frames (ORFs) ( pglF, pglB, pglC, pglB2, orf2, orf3, orf8 avtA ) were present clusters different meningococcal isolates. The Class I pilus-expressing strains gonorrhoeae MS11 N. MC58 each contain cluster which orf2 orf3 been deleted. Strain other isolates express type IV pili contained pglB had replaced by pglB2 an additional novel...
Lipooligosaccharide (LOS) of Neisseria meningitidis is the major inflammatory mediator that contributes to meningococcal pathogenesis. Variable attachments HepII residue LOS inner core together with alpha-chain heterogeneity result in immunologically distinct structures, which may be selected for during human infection. Lpt-3, a phosphoethanolamine (PEA) transferase, and LgtG, glucosyltransferase, mediate substitution PEA or glucose at O-3 position L3 L2 immunotypes, respectively....