Masaroh Matsuura

Isolation and serological typing of ureaplasma in human saliva

Ureaplasmas were detected in the saliva of 3.5 per cent (12/342) of subjects. A total of 60 isolated strains did not revert to bacterial forms on repeated subculture in antibacterial agent-free media, failed to grow in serum-free media, were inhibited by digitonin and hydrolysed urea but not glucose or arginine. Twenty-five strains were divided into serotypes: I (5), II (3), III (5), IV (4) and VI (8 strains). Ureaplasmas of serotype I, II, III, IV and VI were harboured by 2, 1, 1, 1 and 3 subjects respectively and the remaining 4 subjects harboured 2 different serotypes. Ureaplasma-positive subjects were young and middle-aged and, except for 1 subject with mandibular arthrosis, suffered from periodontitis, pericoronitis, gingivitis and maxillary sinusitis. These accounted for only 6.1 per cent (11/180) of the series of subjects examined.

Ammonia production as a virulence expression by Mycoplasma salivarium.

Rabbits were inoculated intracutaneously with M. salivarium (ATCC 23064) cells. The size of the resulting swelling was significantly larger in 1) the sites inoculated with viable cells (7.5 × 109 CFU) suspended in a medium with arginine (arginine medium) than in those inoculated with killed cells, and in 2) those inoculated with cells suspended in arginine medium than with cells suspended in arginine‐free medium. The swelling was enhanced when rabbits had previously been immunized with the organism. This effect was concluded to be due to ammonia which the organism produced by the hydrolysis of arginine through the arginine‐dihydrolase pathway.