Direct observation of Mycoplasma mobile in liquid using the ASEM Atmospheric Scanning Electron Microscope

We directly observed the model species Mycoplasma Mobile in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). Quick, in-solution EM observation of mycoplasma should aid in the early diagnosis of various mycoplasma-induced diseases.

Sato C, Manaka S, Nakane D, Nishiyama H, Suga M, Nishizaka T, Miyata M, Maruyama Y.


Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM).

Abstract from: Biochem Biophys Res Commun. [2012, vol 417: 1213-1218]

Mycoplasma is a genus of bacteria including pathogens that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3μm-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

PubMed Link

We investigate the structure of proteins and molecular complexes at the macromolecular level, using a combination of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Optical Microscopy (OM).