The essential protein lysyl-tRNA synthetase (LysRS) exists in two unrelated forms, a class I and a class II-type aminoacyl-tRNA synthetase. Comparative genome sequence analysis revealed that Borrelia burgdorferi sensu lato, the etiological agent of
Lyme disease, contains a class I-type LysRS, whereas its tick and mammalian hosts would be expected to contain a class II-type protein. To investigate the utility of the class I LysRS as a diagnostic target for
Lyme disease, the corresponding gene ( lysK) was cloned and sequenced from B. afzelii, B. garinii, and B. hermsii. These lysK sequences were then used to design a primer set that could detect and genotype B. burgdorferisensu strictu, B. afzelii, and B. garinii in one single polymerase chain reaction, while showing no cross reactivity with examples of other Borrelia or spirochetes.