Burt Anderson - Academia.edu (original) (raw)

Papers by Burt Anderson

Advances in Pediatrics, Dec 31, 1995

DNA and Cell Biology, Mar 1, 2000

ABSTRACT A 17-kDa, immunodominant antigen of Bartonella henselae Houston-1 has previously been cl... more ABSTRACT A 17-kDa, immunodominant antigen of Bartonella henselae Houston-1 has previously been cloned, sequenced, and characterized. This clone (H13) contains the 17-kDa antigen gene plus a partial open reading frame, designated ORF1, which is 459 nucleotides long and is directly upstream of the 17-kDa gene. Comparison of the deduced partial amino acid sequence of ORF1 with that of other known genes in GenBank revealed significant identity with several other bacterial virulence genes, including VirB4 of the Agrobacterium tumefaciens virB operon (56/149 amino acids). An overlapping clone, pGB3, was recovered and shown to contain a 3.0-kb region upstream of the 17-kDa gene. Sequence analysis revealed three ORFs upstream of the gene. The deduced amino acid sequence of each ORF was compared with sequences in GenBank, and identity was found with VirB2, VirB3, and VirB4 of A. tumefaciens. In vitro transcription/translation and SDS-PAGE demonstrated that three proteins of 9 kDa, 10 kDa, and 92 kDa, corresponding to the predicted molecular weight of 10.9 kDa, 11.7 kDa, and 89.9 kDa of VirB2, VirB3, and VirB4, respectively, could be expressed from these coding regions. These results indicate that virulence-associated genes and their overall chromosomal arrangement are relatively well conserved between B. henselae and other gram-negative bacteria such as A. tumefaciens.

Journal of Clinical Microbiology, Sep 1, 1995

A library of Bartonella (Rochalimaea) henselae DNA was constructed in the cloning vector lambda Z... more A library of Bartonella (Rochalimaea) henselae DNA was constructed in the cloning vector lambda ZAPII and screened for expression of antigenic proteins by using a pool of sera from patients who had been diagnosed with cat scratch disease (CSD) and had antibodies to Bartonella spp., as determined by indirect fluorescent-antibody (IFA) assay. Ten immunoreactive phages were subcloned as recombinant plasmids by in vivo excision. All 10 recombinants expressed a protein of approximately 17 kDa when they were examined by immunoblot with the pool of human sera. Restriction endonuclease digestion of each recombinant plasmid indicated seven profiles, suggesting that cloning bias was not the reason for repeated isolation of clones expressing the 17-kDa antigen. The gene coding for the 17-kDa antigen was sequenced and shown to code for an open reading frame of 148 amino acids with a predicted molecular mass of 16,893 Da. The amino terminus of the deduced amino acid sequence was hydrophobic in nature and similar in size and composition to signal peptides found in gramnegative bacteria. The remainder of the deduced amino acid sequence was more hydrophilic and may represent surface-exposed epitopes. Further subcloning of the 17-kDa antigen as a biotinylated fusion protein in the expression vector PinPoint Xa-2 resulted in a 30-kDa protein that was highly reactive on immunoblots with individual serum samples from patients with CSD. The agreement between reactivity with the 30-kDa fusion protein on immunoblot analysis and the results obtained by IFA assay was 92% for IFA-positive sera and 88% for IFA-negative sera. The recombinant-expressed 17-kDa protein should be of value as an antigen for serologic diagnosis of CSD and Bartonella infections and warrants further study in attempts to develop a subunit vaccine to prevent long-term Bartonella infection in cats and the potential for further spread of these organisms to humans.

Journal of Clinical Microbiology, Aug 1, 1992

We report a case of ehrlichiosis in a 72-year-old man who developed extreme lethargy, acute renal... more We report a case of ehrlichiosis in a 72-year-old man who developed extreme lethargy, acute renal failure requiring hemodialysis, and respiratory insufficiency requiring intubation. Lumbar puncture performed on the second day of hospitalization revealed significant cellular pleocytosis. Ehrlichia morulae were tentatively identified in mononuclear cells in routinely processed Wright-stained cytospin preparations of cerebrospinal fluid (CSF). Identification was confirmed by a specific immunocytochemical staining procedure. Subsequent identification specifically as Ehrlichia chaffeensis morulae was established by polymerase chain reaction analysis, which revealed E. chaffeensis-specific DNA in CSF, bone marrow, and blood samples; by indirect fluorescent-antibody analysis, the patient developed an antibody titer of 32,768 against E. chaffeensis antigen. The patient responded to intravenous therapy with doxycycline and dexamethasone. Subsequently, neurologic, hematologic, renal, and pulmonary status had returned to baseline at follow-up 12 weeks after admission. To our knowledge, this is the first identification of E. chaffeensis morulae in CSF cells in an infected patient.

The three families of bacteria described in this chapter share several common characteristics des... more The three families of bacteria described in this chapter share several common characteristics despite the phylogenetic distance between the group that includes Bartonella and Brucella, from the Alphaproteobacteria, and the more distantly related Francisella in the Gammaproteobacteria class. All three genera are zoonotic bacteria with species capable of infecting both animals and humans and are fastidious with special growth requirements; many species among these three genera cause emerging infections in humans. The diversity of natural animal reservoirs for members of the genera Bartonella and Brucella are just now becoming fully defined and appreciated and are likely all around us. Brucella spp. and Francisella spp. are well-established as agents that warrant special attention and focus because of their potential for misuse and intentional release in acts of bioterrorism or biowarfare. This chapter briefly summarizes our knowledge of the taxonomy, epidemiology, and pathobiology of these zoonotic bacteria and describes the immunologic and molecular tools for the laboratory diagnosis of infections caused by these microbes.

Kluwer Academic Publishers eBooks, Nov 21, 2005

PubMed, Dec 1, 1994

Detection and identification of fastidious pathogenic bacteria have traditionally presented an ob... more Detection and identification of fastidious pathogenic bacteria have traditionally presented an obstacle to the clinical and laboratory microbiologist. The diagnosis of disease caused by these bacteria is often empiric relying on clinical observations or indirect laboratory tests. Recently, a technique called broad-range polymerase chain reaction (PCR) has been integrated into studies designed to detect and identify previously uncharacterized bacterial pathogens. By using regions of the bacterial 16S ribosomal RNA (rRNA) gene that are highly conserved to prime synthesis of the remainder of this gene, PCR amplification can be performed directly from clinical samples which may contain small numbers of bacteria. The resulting PCR-amplified DNA can be sequenced to identify variable regions of the 16S rRNA gene that are bacteria-specific. This technique has proven valuable in identifying new fastidious bacterial pathogens that have resisted detection and identification by traditional microbiological methods.

Annals of the New York Academy of Sciences, Jun 1, 1990

Gene, 1996

ABSTRACT A cloned fragment of Bartonella (Rochalimaea) henselae (Bh) DNA was found to direct synt... more ABSTRACT A cloned fragment of Bartonella (Rochalimaea) henselae (Bh) DNA was found to direct synthesis of an immunoreactive protein in Escherichia coli (Ec). Sequence analysis revealed an open reading frame of 1509 nucleotides encoding a protein of 503 amino acids that exhibited extensive identity (over the entire protein) with the HtrA stress-response proteins of Brucella abortus (59%), Ec (37%) and Salmonella typhimurium (36%). When the putative htrA gene was amplified by polymerase chain reaction and used as template for in vitro transcription and translation, a protein with an apparent molecular mass of 62 kDa was synthesized from the plasmid template. These results suggest that the immunoreactive Bh protein is homologous to the HtrA class of stress-response proteins.

The New England Journal of Medicine, May 23, 1991

After reading the report by Relman et al. on the identification of the agent of bacillary angioma... more After reading the report by Relman et al. on the identification of the agent of bacillary angiomatosis (Dec. 6 issue), I wondered whether Kaposi&amp;#x27;s sarcoma, another disorder of the immunosuppressed, characterized by a&amp;quot; proliferation of small blood vessels in the skin ...

Kluwer Academic Publishers eBooks, Dec 6, 2005

ABSTRACT Bartonella spp. have been recently identified as emerging infectious agents. A variety o... more ABSTRACT Bartonella spp. have been recently identified as emerging infectious agents. A variety of clinical manifestations have been associated with B. haselae and B. quintana, with the spectrum of illnesses still expanding. In light of this, especially in the immunocompromised host, it is possible that Bartonella spp. thought to be nonpathogenic for humans will be shown to cause human disease and that new species within the genus Bartonella will be identified. In general,patients who are immunocompromised by having AIDS, chronic alcoholism, immunosuppression, or other compromising health problems tend to have systemic disease. As our knowledge of Bartonella as infectious agents in immunocompromised, as well as immunocompetent, individuals increases, better diagnosis treatment, and prevention of diseases caused by these organisms will be developed.

Microbial Pathogenesis, Apr 1, 2001

The cloning and sequencing of a gene from Rickettsia rickettsii which confers haemolytic activity... more The cloning and sequencing of a gene from Rickettsia rickettsii which confers haemolytic activity on Escherichia coli strain TB1 is described. The open reading frame of the haemolysis-promoting gene, cjsT, is 1041 bp and encodes a putative protein with a molecular mass of 33 825 Da. CjsT has high sequence similarity to several bacterial proteases, particularly type IV signal peptidases. Cell lysates from an E. coli clone containing cjsT in pUC19 (pJON1) exhibited greater protease activity in functional assays than found in E. coli containing pUC19 alone. Disruption of the cjsT gene by insertional inactivation with a kanamycin cassette reduced both the protease and haemolytic activities conferred by cjsT. The protease inhibitors antipain and diisopropylfluorophosphate (DFP) both reduced the proteolytic activity of pJON1. The mechanism by which the R. rickettsii cjsT promotes haemolysis in E. coli remains unclear.

Infection and Immunity, May 1, 1983

Three strains of Neisseria gonorrhoeae carried novel plasmids of 7.8 megadaltons (mdal) molecular... more Three strains of Neisseria gonorrhoeae carried novel plasmids of 7.8 megadaltons (mdal) molecular mass in addition to plasmids previously observed in this organism. The presence of the 7.8-mdal plasmids was not accompanied by any distinguishable phenotype in the strain possessing them. Analysis of plasmid DNA with restriction endonucleases showed that these plasmids were composed of three directly repeated copies of a 2.6-mdal cryptic plasmid frequently found in N. gonorrhoeae. In addition, the 7.8-mdal plasmids exhibited characteristics common to the 2.6-mdal plasmid, structural lability and sites resistant to cleavage with HpaII. The concatemeric forms of the cryptic plasmid appear to be stable in these strains and do not undergo internal recombination to produce the 2.6-mdal monomer, nor were higher concatemers detected.

npj biofilms and microbiomes, Mar 14, 2019

Bartonella henselae (Bh) is a Gram-negative rod transmitted to humans by a scratch from the commo... more Bartonella henselae (Bh) is a Gram-negative rod transmitted to humans by a scratch from the common house cat. Infection of humans with Bh can result in a range of clinical diseases including lymphadenopathy observed in cat-scratch disease and more serious disease from persistent bacteremia. It is a common cause of blood-culture negative endocarditis as the bacterium is capable of growing as aggregates, and forming biofilms on infected native and prosthetic heart valves. The aggregative growth requires a trimeric autotransporter adhesin (TAA) called Bartonella adhesin A (BadA). TAAs are found in all Bartonella species and many other Gram-negative bacteria. Using Bh Houston-1, Bh Houston-1 ΔbadA and Bh Houston-1 ΔbadA/pNS2P Trc badA (a partial complement of badA coding for a truncated protein of 741 amino acid residues), we analyze the role of BadA in adhesion and biofilm formation. We also investigate the role of environmental factors such as temperature on badA expression and biofilm formation. Real-time cell adhesion monitoring and electron microscopy show that Bh Houston-1 adheres and forms biofilm more efficiently than the Bh Houston-1 ΔbadA. Deletion of the badA gene significantly decreases adhesion, the first step in biofilm formation in vitro, which is partially restored in Bh Houston-1 ΔbadA/pNS2P Trc badA. The biofilm formed by Bh Houston-1 includes polysaccharides, proteins, and DNA components and is susceptible to enzymatic degradation of these components. Furthermore, both pH and temperature influence both badA expression and biofilm formation. We conclude that BadA is required for optimal adhesion, agglutination and biofilm formation.

Analytical Biochemistry, Jun 1, 1993

Applied and Environmental Microbiology, Aug 15, 2009

Six broad-host-range plasmid vectors were developed to study gene expression in Bartonella hensel... more Six broad-host-range plasmid vectors were developed to study gene expression in Bartonella henselae. The vectors were used to express a ␤-galactosidase reporter gene in B. henselae and to generate antisense RNA for gene knockdown. When applied to ompR, a putative transcription response regulator of B. henselae, this antisense RNA gene knockdown strategy reduced bacterial invasion of human endothelial cells by over 60%.

Gene, Aug 1, 2003

Molecular genetics are difficult to perform in Bartonella henselae, the causative agent of cat sc... more Molecular genetics are difficult to perform in Bartonella henselae, the causative agent of cat scratch disease and the vasculoproliferative disorders bacillary angiomatosis and bacillary peliosis. To elucidate the underlying bacterial pathogenic mechanisms, genetic manipulation of B. henselae is the method of choice. We describe how to perform transposon mutagenesis in B. henselae using transposome technology. B. henselae mutants revealed by this technique showed random transpositional insertion into the chromosome. In contrast to transposon mutagenesis by conjugational transfer, transposome technology allows transposon mutagenesis of early passaged Bartonella spp. with approximately 100-fold higher efficiency. The results show that transposome technique is a rapid, efficient and simple method to generate transposon mutants of B. henselae.

American Journal of Ophthalmology, Aug 1, 1994

Microbial Pathogenesis, Sep 1, 1998

Members of the genus Bartonella are unique in that they are bacteria which cause proliferation of... more Members of the genus Bartonella are unique in that they are bacteria which cause proliferation of microvascular endothelial cells and neovascularization (angiogenesis). The mechanisms by which Bartonella henselae causes these processes are unknown. Given the importance of surface-exposed determinants in the pathogenesis of many organisms, outer membrane proteins (OMPs) of B. henselae were identified. Enrichment of the outer membrane fraction of B. henselae by sarkosyl treatment of total membranes, together with radioiodination and biotinylation of intact organisms, suggest that at least nine proteins, with molecular weights of 28, 30, 35, 43, 58, 61, 79, 92 and 171 kDa, are located in the outer membrane. Triton X-100-extracted biotinylated human umbilical vein endothelial cell (HUVEC) surface proteins bound to the 43 kDa B. henselae OMP after B. henselae whole-cell lysates and sarkosyl-fractionated OMPs were separated by SDS-PAGE and transferred onto nylon. Biotinylated B. henselae surface proteins of 28, 32, 43, 52 and 58 kDa were shown to bind intact HUVEC, with the 43 kDa protein being the major adhesin. Preincubation of HUVEC with an increasing concentration (20 microg/ml to 4 mg/ml) of sarkosyl-fractionated unlabelled B. henselae outer membrane proteins inhibited the attachment of all identified HUVEC binding proteins. The identification of B. henselae OMPs, as well as adhesins, should provide a basis for further investigation of the role of adherence in the pathogenesis of B. henselae.

Journal of Clinical Microbiology, Dec 1, 1989