In strain HK187 ( Streptococcus faecalis subsp. liquefaciens ) four plasmids were isolated. The molecular weights, as analyzed in neutral sucrose gradients and by electron microscopy, were found to be about 36 × 10 6 , 31 × 10 6 , 26 × 10 6 , and 4 × 10 6 . Plasmid 3, also designated pFK14, with a molecular weight of 26 × 10 6 , was found to be responsible for resistance to chloramphenicol and erythromycin and also for high-level resistance to streptomycin and lincomycin. In mixed cultures these four resistances could be transferred with high frequency to a plasmid-free recipient, S. faecalis strain JH2-2.

Spirochaetes were isolated from rectal biopsies of three patients and successfully cultured. Enzymatic reactions and electron microscopy revealed spirochaetes resembling Brachyspira aalborgi. Examination of ultrathin sections of centrifugates of cultured spirochaetes yielded unusual cyst-like structures with an outer double membrane containing spirochaetes in different developmental stages. The protoplasmic cylinders seemed to originate from a large electron-dense focus in the cyst-like structures. The axial fibrils occurred as loosely distributed solitary structures in the cyst-like structures. Cysts were not found in the biopsy tissue. The encystment of the spirochaetes could be related to their protection, multiplication, spread and transmission.

No abstract

No abstract