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[AM]  Dr Akira Matsumoto: Ultrastructure of chlamydial EBs and RBs and the developmental cycle

MEW writes: "Dr Akira Matsumoto is in the Department of Urology at Okayama University Medical School, in Japan. His electron micrographs of chlamydial ultrastructure are much admired by chlamydiologists world wide. Initial work published in 1970 with G Manire described the effect of penicillin on the morphology of C. psittaci. This was followed by studies of the ultrastructure of the envelope of chlamydial EBs and RBs using, initially, negative stain techniques and subsequently freeze etch carbon replica methodology. Careful observations of thin sections of C. psittaci revealed the presence of small projections from the surface of the organism. This finding was published in the Journal of Electron Microscopy (Tokyo) in 1976. Subsequently it was found these projections were surrounded by a rosette, whose periodicity was determined by analysis of the rotational symmetry. His careful observations culminated in an overall model of the morphology of the outer envelope which has stood the test of time and assumed even greater importance in recent years with the realisation that the projections may be part of a type III protein secretion mechanism used by many bacterial pathogens to subvert the host cell.

Dr Matsumoto's work is very much a part of the tradition of high quality electron microscopy for which Japan is famous. It was this which lead me to visit Japan in 1985 as chair of an electron microscopy unit, to purchase a transmission and a field emission scanning electron microscope. These purchases were very successful and are still in use 17 years later. I am grateful to Dr Matsumoto for making his electron micrographs available, including some previously unpublished pictures."