GROWTH TEMPERATURE RANGES OF BORRELIA-BURGDORFERI SENSU-LATO STRAINS

Three strains of Borrelia burgdorferi sensu lato, representing three h uman pathogenic genomospecies (B31, B. burgdorferi sensu stricto; BR14 , B. garinii; BR75, B. afzelii) were grown in BSK-H medium at differen t temperatures and the spirochaetal cells were counted by dark-field m icroscopy after 0, 4, 8, 16 and 48 days. Approximate optimum (minimum- maximum) temperatures for the in-vitro growth were found to be 33 degr ees C (22-39 degrees C) in strain B31, 35 degrees C (20-40 degrees C) in strain BR75 and 37 degrees C (20-41 degrees C) in strain BR14, Maxi mum, optimum and minimum growth temperatures seem to be important char acteristics of B. burgdorferi s.l. strains, with relevance for the sym ptomatology, epidemiology and epizoology of Lyme borreliosis.