Bacterial flora of nose and throat in health and upper respiratory infection.

Abstract

In searching for the causative agent in respiratory disease, the problem is seriously complicated by the fact that the nose and throat normally harbor a variety of bacteria, some constantly present and others more or less transient. Correct interpretation, therefore, of the importance of organisms found in respiratory disease is dependent upon comprehensive familiarity with the bacterial flora in health. In the present study, a preliminary in an investigation of the Common Cold being undertaken by us, observations have been made of the bacterial flora of the nose and throat in a group of normals over a comparatively long period, and qualitative and quantitative changes occurring in the course of upper respiratory infections appearing in the group have been noted.

Thirteen individuals were studied for periods ranging from five to nine months. Aerobic and anaerobic cultures were made from the nose and throat infections weekly in health, and daily in the course of colds and throat infections. All organisms present were carefully identified and their prominence noted.

Our results may be summarized briefly as follows: The normal basic nasal flora includes staphylococcus albus, diphtheroids, and for certain individuals, staphylococcus aureus and citreas; occasional transients are gram-negative cocci and non-hemolytic streptococci. The normal basic throat flora includes gram-negative cocci, non-hemolytic streptococci, and for certain individuals large gram-positive cocci, B. pfeifferi, both non-hemolytic and hemolytic, and diphtheroids; transients are staphyylococcus albus, staphylococcus aureus, hemolytic sterptococci, staphylococcus citreus and pneumococci.

Certain of these organisms have been assumed to play pathogenic roles. Such so-called potential pathogens are hemolytic streptocci, staphylococcus anreus, pneumococci, and B. pfeifferi. In the nose, hemolytic streptococci were found once without associated untoward symptoms. In the throat, hemolytic streptococci had a high incidence in four cases, of whom two had no associated symptoms and two had more or less continuous subacute inflammation of their throats.