Oligotrophic bacteria isolated from clinical materials.

Oligotrophic bacteria (oligotrophs) are microorganisms that grow in extremely nutritionally deficient conditions in which the concentrations of organic substances are low. Many oligotrophic bacteria were isolated from clinical materials including urine, sputum, swabbings of the throat, vaginal discharges, and others. Seventy-seven strains of oligotrophic bacteria from 871 samples of clinical material were isolated. A relatively higher frequency of isolation of oligotrophic bacteria was shown in drainage, sputum, and throat specimens. Eleven strains of the obligate oligotrophic bacteria recovered showed scant growth on enriched medium, blood agar, and nutrient agar. Oligotrophic bacteria were isolated from a variety of materials but were not found in routine bacteriologic examinations in the hospital laboratory. The clinical significance of such oligotrophic bacteria is uncertain.