Influence of MKP medium stored for prolonged periods on growth and morphology of B orrelia afzelii, B orrelia garinii, and B orrelia burgdorferi sensu stricto

Modified Kelly‐Pettenkofer ( MKP ) medium is one of the several media used for isolation and cultivation of B orrelia . The aim of the study was to assess whether particular B orrelia species ( B . afzelii , B . garinii , and B . burgdorferi sensu stricto) have the ability to grow in MKP medium stored at +4 °C for periods for 1 month up to 1 year, and how prolonged storage may influences B orrelia growth and morphology. The growth of B orrelia was evaluated after 5 days of incubation at 33 °C: cell count per mL, morphology, and motility were assessed. The results of this study showed that the duration of storage of MKP medium had statistically significant influence on growth of B . afzelii (p = 0.021) and B . garinii (p = 0.004), but not on growth of B . burgdorferi sensu stricto (p = 0.204), whereas duration of storage of the medium had no impact on B orrelia morphology and motility. The results of the study indicate that medium stored for more than 1 and up to 12 months supports Borrelia growth.