Diagnostic problems observed in patients infected with Borrelia burgdorferi are a significant impediment to therapeutic decision making. It appears that the pathogen is characterized by morphological and immunological variation in particular stages of development. The bacterium has the ability to morphologically transform into a cell wall deficient form of spheroplast, L-form, bleb-like spirochetes and round body/form cysts. It also has the ability to create biofilm, which is a major barrier to antibiotics. Bacteria are characterized by significant heterogeneity and antigen polymorphism, which greatly hampers the detailed definition of the pathogen, since the antibodies produced may differ significantly from the accepted patterns and also lead to cross reactions. The above conditions affect the reliability of diagnostic tests, especially screening, which may lead to wrong therapeutic decisions.
Keywords: antigens; biofilm; borreliosis; diagnostics.