Abstract
The pathogenic staphylococci are well known Cor their ability to elaborate a wide variety of antigenic substances, many of which have been designated as exo-toxins. One of these is coagulase. This substance has long been thought to be an important factor affecting the disease producing capabilities of the staphylococci, thus this substance has always been associated with virulence of the staphylococci. The absence of coagulase is usually interpreted as being evidence of a lack of pathogenicity on the part of the staphylococci. | In nature, the staphylococcus exists as a parasite on the mucosa of the nasopharynx and skin of man. | Under certain conditions these organisms may produce characteristic destructive localized lesions and sometimes generalized systemic Infections. Therefore, it does not seem unreasonable to assume that it the main reservoir in nature is in the nasopharynx of man, One group characteristics of strains Isolated from this site would carry the entire range of those factors, mainly coagulase, related to virulence. furthermore, staphylococcal strains which can survive, multiply, and, in some cases, produce necrotic lesions must possess those factors related to virulence. | Since most staphylococcal infections yield organisms of the coagulase producing type, the question arises as to their source. The possibility that such organisms could emerge from the normal saprophytic flora of the nasopharynx and skin exists. | With this in mind, this investigation was undertaken to determine the stability of coagulase-negative strains of staphylococci and to obtain information on the possible spontaneous emergence of coagulase-positive variants from the coagulase-negative strains. Coagulase production, a peculiar property of virulent staphylococci, has been one of the moat reliable tests for the identification of the pathogenic strains. It was this investigator's belief and trust in this test that formed the basis for his experimental research. This work could result in information that would markedly change our concept regarding the control of staphylococcal infections.