[Microbiological diagnosis of microorganisms tentatively designated as "SP organisms"].

The authors describe the biochemical characteristics of two strains described as "SP organism". This microorganism incertae sedis resembles from the biochemical aspect (oxidase+, mannite-, dextrose+ with gas) the species Pasteurella aerogenes; contrary to the latter it does not break down urea and differs also as regards the morphology of colonies, which on blood agar are coarser; it also has a higher content of G + C in DNA than Pasteurella. It is a pathogen of rodents.

Rarely occurring Shigella serovars.

In addition to the predominant Shigella sonnei, also rarely occurring Shigella serovars have been found in Czechoslovakia: 4 serovars of subgroup A (S. dysenteriae 3, 4, 7 and 12) and 11 serovars of subgroup C (S. boydii 2, 3, 5, 7, 9 lactose-positive, 10, 13, 14 aerogenic, mannitol-negative, 15, 16 and the provisional serovar E 16553).