Sequence analysis of a fragment of rOmpA gene of several isolates of spotted fever group rickettsiae from China.

The nucleotide sequence of rOmpA gene fragment of three Chinese isolates of spotted fever group rickettsiae (SFGR) (BJ-90, Ha-91 and HLJ-054) was determined. The obtained nucleotide and putative amino acid sequences were compared with those of another Chinese SFGR isolate (HL-93) and several prototype SFGR strains. This comparison showed that the isolates BJ-90 and Ha-91 are closely related to each other and R. sibirica but different from the isolates HLJ-054 and HL-93. We assume that with exception of the isolates HLJ-054 and HL-93 that represent new, unique members of SFGR, the isolates BJ-90 and Ha-91 are closely related to R. sibirica, one of the prototype SFGR strains.