A5087731284- Bacillus and Francisella bacterial research
- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Yersinia bacterium, plague, ectoparasites research
- Vibrio bacteria research studies
- Reproductive tract infections research
- SARS-CoV-2 and COVID-19 Research
- Antibiotic Resistance in Bacteria
- Viral gastroenteritis research and epidemiology
- Microbial Community Ecology and Physiology
- Enzyme Structure and Function
- Microbial Metabolic Engineering and Bioproduction
- Photosynthetic Processes and Mechanisms
- Mycobacterium research and diagnosis
- Microbial Inactivation Methods
- Salmonella and Campylobacter epidemiology
- RNA and protein synthesis mechanisms
- Hepatitis B Virus Studies
- Legionella and Acanthamoeba research
- Enzyme Production and Characterization
- Tuberculosis Research and Epidemiology
- Gut microbiota and health
- Escherichia coli research studies
- Probiotics and Fermented Foods
- Urinary Tract Infections Management
University of Victoria
2011-2023
Victor (Japan)
2021
University of Cincinnati
2004
The University of Texas Health Science Center at San Antonio
2004
Merck & Co., Inc., Rahway, NJ, USA (United States)
1992
National Institutes of Health
1985-1991
National Institute of Allergy and Infectious Diseases
1985-1989
University of Illinois Urbana-Champaign
1983-1985
Francisella tularensis is a gram-negative, facultative intracellular pathogen that causes the highly infectious zoonotic disease tularemia. We have discovered ca. 30-kb pathogenicity island of F. (FPI) includes four large open reading frames (ORFs) 2.5 to 3.9 kb and 13 ORFs 1.5 or smaller. Previously, two small genes located near center FPI were shown be needed for intramacrophage growth. In this work we show ORFs, toward ends FPI, are virulence. Although most in encode proteins with amino...
Francisella tularensis is a gram negative, facultative intracellular bacterium that the etiological agent of tularemia. F. novicida closely related to but has low virulence for humans while being highly virulent in mice. IglA 21 kDa protein encoded by gene part an iglABCD operon located on pathogenicity island (FPI).Bioinformatics analysis FPI suggests and IglB are components newly described type VI secretion system. In this study, we showed regulation controlled global regulators MglA MglB....
Chlamydia trachomatis is an obligate prokaryotic intracellular pathogen of humans that infects mucosal epithelial cells. Exposed domains its major outer membrane protein (MOMP) are both serotyping and protective antigenic determinants. To identify these domains, we have cloned epitope-mapped the genes serovars A, C (C serogroup) L2, B (B with a panel monoclonal antibodies (mAbs). Predominantly conserved regions serogroups interspersed four short variable (I-IV). Recombinant phage clones...
Francisella tularensis is able to survive and grow within macrophages, a trait that contributes pathogenesis. Several genes have been identified are important for intramacrophage survival, including mglA iglC. F. also amoebae. It shown here iglC mutant strains not only defective survival replication the macrophage-like cell line J774, but Acanthamoebae castellanii . Moreover, these highly attenuated virulence in mice, suggesting common mechanism underlies intraamoebae virulence. A 2D gel...
We examined the nature of interactions between facultative intracellular pathogens Francisella tularensis and F. novicida rodent macrophages. Growth LVS was observed in macrophage monolayers from mice, guinea pigs, or rats. In contrast, grew macrophages mice pigs but not Transmission electron microscopy studies indicated that both species survive within phagosomes are unfused with lysosomes.
Francisella novicida is a facultative intracellular pathogen capable of growing in macrophages. A spontaneous mutant F. defective for growth macrophages was isolated on LB media containing the chromogenic phosphatase substrate 5‐bromo‐4‐chloro‐3‐indolyl phosphate (X‐p) and designated GB2. Using an cis complementation strategy, four strains were that are restored locus from one these complements GB2 both defect colony morphology media. The consists apparent operon two genes, mglAB ,...
Five transposon mutants of Francisella novicida were isolated that are compromised in their ability to grow mouse macrophages vitro. Sequence analysis the DNA flanking insertions identified genes interrupted these mutants. One inactivated loci corresponds tularensis gene encodes a 23-kDa protein is most prominently induced following macrophage infection. Another insertion was localised approximately 2 kb upstream encoding protein. By incomplete genome sequence it surmised two disrupt...
ABSTRACT Francisella tularensis is a facultative intracellular pathogen that infects wide variety of mammals and causes tularemia in humans. It recognized as potential agent bioterrorism due to its low infectious dose multiple routes transmission. To date, genetic manipulation spp. has been limited the inefficiency DNA transformation, relative lack useful selective markers, stably replicating plasmids. Therefore, goal this study was develop an enhanced shuttle plasmid could be utilized for...
Acid phosphatases (Acp) of intracellular pathogens have recently been implicated as virulence factors that enhance survival through suppression the respiratory burst. We describe here identification, purification, characterization, and sequencing a novel burst-inhibiting acid phosphatase from facultative bacterium, Francisella tularensis. Similar to other Acps, F. tularensis Acp (AcpA) is tartrate-resistant has broad substrate specificity. The AcpA enzyme unique, however, in it easily...
Members of the bacterial genus Chlamydia are responsible for widespread disease among humans and animals, including endemic trachoma in developing countries, venereal developed a variety other diseases such as infantile pneumonia lymphogranuloma venereum. Although there is little genetic relatedness between large antigenic diversity two chlamydial species, one determinant has been preserved all serovars: genus-specific lipopolysaccharide epitope. In this report, tools molecular genetics,...
Tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. It caused by infection gram-negative bacterium, Francisella tularensis. In order to better understand its potency as an etiological agent well potential biological weapon, we have completed draft assemblies report the first complete genomic characterization of five strains belonging following different subspecies (subsp.): F. tularensis subsp. FSC033, holarctica FSC257 FSC022, novicida...
Francisella tularensis is a highly infectious, facultative intracellular bacterial pathogen that the causative agent of tularemia. Nearly century ago, researchers observed tularemia was often fatal in North America but almost never Europe and Asia. The chromosomes F. strains carry two identical copies pathogenicity island (FPI), FPIs America-specific biotypes contain genes, anmK pdpD, are not found distributed over entire Northern Hemisphere. In this work, we studied contribution pdpD to...
The Francisella pathogenicity island (FPI) encodes proteins thought to compose a type VI secretion system (T6SS) that is required for the intracellular growth of novicida. In this work we used deletion mutagenesis and genetic complementation determine F. novicida was dependent on 14 18 genes in FPI. products iglABCD operon were localized by biochemical fractionation novicida, tularensis LVS. Sucrose gradient separation water-insoluble material showed FPI-encoded IglA, IglB IglC found...
Summary Many microbial pathogens, such as Mycobacterium spp. and Salmonella spp., use macrophage intracellular growth or antigenic variation mechanisms for avoiding the host immune system. In this work we present evidence to show that pathogen Francisella tularensis uses phase alter antigenicity nitric oxide response simultaneously, thereby modulating its growth. The lipopolysaccharide (LPS) lipid A of F. fails stimulate production significant levels (NO) by rat macrophages. However,...
We have examined the abilities of recombinant murine lymphokines IFN-gamma, granulocyte-macrophage (GM)-CSF, and IL-4 to stimulate in vitro antimicrobial activity macrophages against live vaccine strain (LVS) Francisella tularensis. Resident peritoneal from C57BL/6 mice were cultured overnight with GM-CSF, or IL-4, then infected LVS. In treated growth LVS was suppressed by a factor 100- 1000-fold comparison untreated cells. This effect dose-dependent enhanced addition LPS. contrast, either...
We describe here a technique for allelic exchange in Francisella tularensis subsp. novicida utilizing polymerase chain reaction (PCR) products. Linear PCR fragments containing gene deletions with an erythromycin resistance cassette insertion were transformed into F. tularensis. The subsequent ErmR progeny found to have undergone at the correct location genome; minimum flanking homology necessary was 500 bp. This used create mglA, iglC, bla, and tul4 mutants strains. mglA iglC defective...
DNA cloned from Chlamydia trachomatis is able to direct the formation of genus-specific lipopolysaccharide epitope chlamydiae in enteric Gram-negative bacteria. We now demonstrate that a single C. gene (gseA) sufficient impart this trait Escherichia coli. The deduced amino acid sequence gseA shows 23% identity (66% similarity) kdtA, an E. coli codes for bifunctional enzyme catalyzing addition two 3-deoxy-D-manno-octulosonic (Kdo) residues lipid A precursors (Clementz, T., and Raetz, R. H....
The obligate intracellular prokaryote Chlamydia trachomatis is the etiological agent of trachoma and a primary causative pathogen sexually transmitted genital tract disease; both diseases affect millions people each year. cloning genes encoding enzyme or enzymes producing genus-specific lipopolysaccharide antigen into Escherichia coli reported here. cloned chlamydial appears to be hybrid molecule composed components. expressed on surfaces viable recombinants. These findings may have...
The Mycobacterium tuberculosis H37Rv efpA gene encodes a putative efflux protein, EfpA, of 55,670 Da. deduced EfpA protein was similar in secondary structure to Pur8, MmrA, TcmA, LfrA, EmrB, and other members the QacA transporter family (QacA TF) which mediate antibiotic chemical resistance bacteria yeast. predicted sequence possessed all motifs characteristic TF, including those associated with proton-antiport function motif considered be specific exporters. 1,590-bp open reading frame G+C...
We describe methods for transposon mutagenesis and allelic replacement in the facultative intracellular pathogen Francisella. Recombinant clones were constructed by insertion of partially cut F. tularensis or novicida DNA into pUC19 then mutagenized with a mini-Tn10-Km transposon. could be transformed these plasmids either chemical transformation method electroporation, whereas only electroporation. Transformation electroporation was enhanced absence capsule. Southern blot analysis showed...
Several genes contained in the Francisella pathogenicity island (FPI) encode proteins needed for intracellular growth and virulence of tularensis. The pdpA gene is first cistron larger two operons found FPI. In this work we studied phenotype a novicida mutant gene. DeltapdpA strain was capable small amount replication but, unlike wild-type F. novicida, remained associated with lysosomal marker LAMP-1, suggesting that PdpA necessary progression from early phagosome phase infection. Strains...
All bacteria share a set of evolutionarily conserved essential genes that encode products are required for viability. The great diversity environments inhabit, including at extreme temperatures, place adaptive pressure on genes. We sought to use this evolutionary engineer bacterial pathogens be stably temperature-sensitive, and thus useful as live vaccines. isolated from found in the Arctic substituted them their counterparts into mammals. substitution nine different psychrophilic...