Establishment of a research model for the osmotic dehydration tolerance of Coxiella burnetii
The aim of this study was to establish a laboratory research model for the desiccation tolerance of Coxiella bur-netii(C.burnetii),based on an axenic culture system.The conditions for osmotic pressure in the axenic culture system of C.burnetii were set via a gradient.Quantitative PCR was used to determine the C.burnetii genome equivalents during the culture cycle under different osmotic pressures,and the growth curves were recorded.In addition,the bacterial manifestations of C.burnetii obtained from eukaryotic cell cultures or cell-free cultures were analyzed with phase contrast microscopy and transmis-sion electron microscopy(TEM).The bacterial infection levels and vacuole forming units(VFU)were measured by infection of BGMK cells.C.burnetii showed as many as 7 days of adaptive survival in osmotic axenic medium under high osmotic condi-tions.The bacteria shrank by dehydration under extremely high osmotic pressure and appeared primarily as hypo-hydrated small cell variants(SCVs).The VFUs were significantly diminished 24 hours after infection,as compared with the parallel contrasts.The method for researching desiccation tolerance was thus successfully established.This method provides a basis for further investigation of the genetic mechanisms of the anti-desiccation properties of C.burnetii in the natural environment,through proteomics and other methods.
万方数据
维普
