THE POTENTIAL HAZARD OF STAPHYLOCOCCI AND MICROCOCCI TO HUMAN SUBJECTS IN A LIFE SUPPORT SYSTEMS EVALUATOR WITH ELEVATED CABIN TEMPERATURE.

Four human male subjects participated in a 6-week simulated aerospace study and were confined under controlled metabolic conditions. During this time 28 consecutive days were spent in a Life Support Systems Evaluator. The subjects ate a diet composed of fresh foods while exposed to simulated aerospace stress of confinement, wearing an unpressurized pressure suit, increased environmental temperature, experimental diet, and mimimal personal hygienic conditions. Body and environmental areas were sampled and catalase-positive, gram-positive cocci isolated were tested for production of coagulase, deoxyribonuclease, hemolysin, gelatinase, and utilization of mannitol. The results showed no significant differences in frequency of occurrence of biochemical types among subjects and among environmental areas during the chamber period. There were significant differences in the frequency of occurrence of biochemical types on nose, throat, gingiva, axilla, groin, glans penis, anus, and toe. There was no buildup of biochemical types with time in any test condition. Though 3 phage types, 29, 675383a, and 6, were recovered initially from 2 subjects, only one subject had transmitted astaphylococcus to other subjects and the environment. In the concurrent metabolic studies the physiological, biochemical and nutritional parameters investigated were all in the normal range of clinical values. Confinement under simulated aerospace conditions for at least 28 consecutive days and conditions of minimal personal hygiene show that no unique set of circumstances are operable that would require the establishment of special biomedical criteria.