DIFFERENTIATION OF BARTONELLA-LIKE ISOLATES AT THE SPECIES LEVEL BY PCR-RESTRICTION FRAGMENT LENGTH POLYMORPHISM IN THE CITRATE SYNTHASE GENE

The citrate synthase gene (gltA) of Bartonella henselae was cloned and sequenced to compare genetic divergence among alpha and gamma branche s of the class Proteobacteria and to develop enhanced genotypic reagen ts for B. henselae identification. B, henselae gltA is 1,293 nucleotid es in length and 63 to 66% homologous with corresponding gene sequence s of Rickettsia prowazekii, Escherichia coli, and Coxiella burnetii. T he observed genetic variability suggests that gltA sequences can provi de a useful means for studying moderate divergence among related bacte ria, Oligonucleotides specific for B. henselae gltA were evaluated for the ability to prime PCR amplification within the alpha and gamma bra nches of the proteobacteria, Under the conditions used, only B. hensel ae, Bartonella quintana, and R. prowazekii template DNAs yielded ampli fication products (approximately 380 bp), DNAs from 28 Bartonella-like isolates of feline origin were amplified by B, henselae primers and a nalyzed for restriction fragment length polymorphism. The resulting pa tterns for all 28 isolates were similar or identical to that of the re cognized B, henselae strain, Current studies are aimed at optimization of PCR conditions for specificity and sensitivity of amplification Of Bartonella sequences from clinical isolates.