title: First detection of the Anaplasma phagocytophilum groEL-A genotype in man.
abstract: OBJECTIVE
  Human Granulocytic Anaplasmosis (HGA) is an emerging disease caused by the gram-negative bacterium Anaplasma phagocytophilum which is transmitted by ticks of the genus Ixodes ricinus. For molecular detection of the pathogen by PCR, a conserved portion of the groEL gene within the groESL operon is frequently used as a target. A single G/A polymorphism in this region allows to discriminate between two genotypes, groEL-G and groEL-A.
  
  
  METHODS
  Total DNA from peripheral blood samples of two HGA patients was analysed by RealTime PCR, employing a protocol designed for genotyping groEL-G- and groEL-A variants of A. phagocytophilum.
  
  
  RESULTS
  We confirmed two clinical cases of HGA by PCR; in one patient, and for the first time in a human host, the groEL-A variant was detected, in the other case the pathogen was recognised as the groEL-G variant, up to now representing the only genotype reported in man.
  
  
  CONCLUSIONS
  It is documented that HGA infections can be caused by two A. phagocytophilum groEL genotypes. At present, the preference of the A. phagocytophilum groEL-G genotype in humans remains unclear, as we describe the first patient with HGA caused by the groEL-A variant. For a conclusive interpretation, more data from HGA patients will be required.
authors.affiliation: Central Laboratory, University Hospital of Neurology, Paracelsus Medical University of Salzburg (PMU), Ignaz-Harrer-Strasse 79, A-5020 Salzburg, Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Haschke-Becher
authors.forename: Rainer
authors.initials: R
authors.lastname: Bernauer
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Walleczek
authors.forename: Petra
authors.initials: P
authors.lastname: Apfalter
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Afazel-Saeedi
authors.forename: Joerg
authors.initials: J
authors.lastname: Kraus
authors.forename: Gunther
authors.initials: G
authors.lastname: Ladurner
authors.forename: Peter
authors.initials: P
authors.lastname: Strasser
mesh_terms: D000368:Aged; D041081:Anaplasma phagocytophilum / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D000712:Anaplasmosis / Q000175:diagnosis* / Q000382:microbiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D001769:Blood / Q000382:microbiology; D018834:Chaperonin 60 / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D004269:DNA, Bacterial