title: Cloning, characterization, and expression of Bartonella henselae p26.
abstract: In order to identify immunoreactive Bartonella henselae proteins, B. henselae antiserum from an experimentally infected cat was used to screen a B. henselae genomic DNA expression library. One immunoreactive phage clone contained a gene (p26) with significant nucleotide identity with orthologs in brucellae, bartonellae, and several plant-associated bacteria. p26 gene sequences from four B. henselae strains, one B. koehlerae strain, and one B. clarridgeiae strain were cloned. Comparative nucleotide sequence analysis showed that p26 is a potential marker for molecular diagnosis of infection, as well as for identification to species level and genotyping of Bartonella sp. isolates. Alignment of the predicted amino acid sequences illustrated conserved putative protein features including a hydrophobic transmembrane region, a peptide cleavage site, and four dominant antigenic sites. Expression of p26 in Escherichia coli produced two proteins (26 and 27.5 kDa), both of which were reactive with feline anti-B. henselae antisera. Furthermore, murine hyperimmune serum raised against either recombinant protein reacted with both proteins. No reactivity to either recombinant protein was detected in nonimmune serum, and reactivity persisted as long as 20 weeks for one cat. The p26 protein product is an immunodominant antigen that is expressed during infection in cats as a preprotein and is subsequently cleaved to form mature P26.
authors.affiliation: Center for Comparative Medicine, Schools of Medicine and Veterinary Medicine, University of California at Davis, California 95616, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Werner
authors.forename: Sunlian
authors.initials: S
authors.lastname: Feng
authors.forename: Rickie W
authors.initials: RW
authors.lastname: Kasten
authors.forename: Emir
authors.initials: E
authors.lastname: Hodzic
authors.forename: Bruno B
authors.initials: BB
authors.lastname: Chomel
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Barthold
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D018416:Bartonella henselae / Q000235:genetics* / Q000276:immunology; D015153:Blotting, Western; D002415:Cats; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015723:Gene Library; D016680:Genome, Bacterial; D007114:Immunization; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D000942:Antigens, Bacterial; D011994:Recombinant Proteins