Wall-less microbial isolate from a human renal biopsy.

An orgainsm was isolated from a kidney biopsy of a patient with renal failure. Electron microscopy revealed an ultrastructure very similar to that of a bacterial L-form or mycoplasma. But macroscopically, its colonial morphology was unusual and distinct from that ascribed to these wall-less organisms. This isolate lacked a rigid cell wall and required a hypertonic medium with serum for growth. Also, a long incubation period was essential for its growth, and use of hand lens was necessary for detection on solid medium.