Epidemiology, Zoonotic Aspect and Current Epidemiological Situation of Q Fever in Poland

Pleomorphic bacteria are classified in three groups: large cell variants (LCV), small-cell variants (SVC) and small dense cells (SDC). The SCVs and the SDCs are the most frequent forms in the host and certainly (the most) resistant forms in the environment. The LCV form of Coxiella burnetii, which shares features common with gram-negative bacteria, diffuse chromatin and process clearly distinguishable outside and cytoplasmic membranes with LPS exposed on the surface. The LCVs are larger, more pleomorphic and metabolically active than the SCVs and the SDCs. The SDCs have been visualised in LCV as endospores, and they may be liberated upon the lysis of LCV or binary transverse fission with unequal cell division. The SDCs alone have never been isolated, free-living amoeba can provide an intra-cellular niche for SDC formation and survival of Coxiella burnetii in the environment. Binary transverse fission was observed both in the SCVs and the LCVs in cells cultured. The form changes within lifecycle of Coxiella burnetii are strategy to survive (Arricau-Bouvery & Rodolakis, 2005).