CandidatusNeoehrlichia mikurensis is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of Neoehrlichia has been studied only by comparing 16S rRNA gene and groEL operon sequences. We describe the development and use of a multi-locus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinicalNeoehrlichiastrains in Europe and their relatedness to other species within the Anaplasmataceae family.Six genes were selected:ftsZ, clpB, gatB,lipA,groEL and 16SrRNA. Each MLSA locus was amplified by real-time PCR, and the PCR-products sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed Neoehrlichia infection from Sweden (n = 9), the Czech Republic (n = 2) and Germany (n = 1) were analyzed with the MLSA protocol.Threeof the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other.One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16SrRNA,ftsZ, gatB, and groEL.According to the MLSA, Neoehrlichia is most closely related to E. ruminantium, less so to A. phagocytophilum and least to Wolbachiaendosymbiont, among the Anaplasmataceae.To conclude, three sequence types of infectious Neoehrlichia wereidentified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.
- Mikrobiologi inom det medicinska området