Isolation and incidence of pleuropneumonia-like organisms from the human oral cavity.

Shklair, I. L. (U. S. Naval Training Center, Great Lakes, Ill.), M. A. Mazzarella, R. R. Gutekunst, and E. M. Kiggins. Isolation and incidence of pleuropneumonia-like organisms from the human oral cavity. J. Bacteriol. 83:785-788. 1962.-Pleuropneumonia-like organisms (PPLO) were isolated from the oral cavity of 87.2% (184 of 211) of young male naval recruits, by use of an enriched medium under anaerobic conditions. Aerobically, the organisms were isolated from 75% (78 of 104) of the subjects. However, aerobic cultivation was not the method of choice for the isolation of these organisms, as only a few colonies of PPLO were found. These colonies were atypical, or incomplete, and could not be further subcultured either aerobically or anaerobically. With anaerobic procedures, typical PPLO colonies developed and they could be subcultured anaerobically. The PPLO were isolated by adding saliva or gingival scrapings to 8 ml of PPLO broth enriched with 10% horse serum and 1% yeast autolysate. In addition, thallium acetate (1:2,000) and penicillin (3,000 units/ml) were added to prevent bacterial overgrowth. The broth was incubated at 37 C for 48 hr; 0.1 ml was then spread on PPLO agar enriched with the above nutrients and thallium acetate. The plates were incubated at 37 C for 48 hr. The broth and agar plates were adjusted to a pH of 7.8 to 8.0. Both PPLO and L forms were isolated by the above procedure.