Studies on a Non-Hemolytic Streptococcus Isolated From the Respiratory Tract of Human Beings

Abstract

In the course of an investigation of the etiology of primary atypical pneumonia attempts were made to isolate infectious agents from specimens obtained from patients with this clinical syndrome. Not only were efforts made to recover virus-like agents from such specimens but also the various bacterial species encountered were studied. From lung tissues obtained from two fatal cases of primary atypical pneumonia a non-hemolytic streptococcus was isolate& In a preliminary communication (1) the results of certain studies carried out with this microorganism were reported. It was shown that some patients with primary atypical pneumonia developed in their serum during convalescence antibodies which agglutinated this streptococcus and also yielded precipitates with appropriate extracts derived from the bacterial cells. In most instances similar antibodies were found not to develop during convalescence from other acute infectious diseases.Since this non-hemolytic streptococcus appeared to possess certain interesting properties it has been studied in detail. Efforts have been directed toward determining its relationship to other streptococci. Moreover, attempts have

Emended Descriptions and Recognition of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus as Distinct Species

“…The species Streptococcus anginosus (1) as currently recommended by Coykendall et al (5) includes streptococcal strains that have been referred to previously as the "minute-colony-forming streptococci of Lancefield groups F and G" (2, 21), "Streptococcus MG" (24), "Streptococcus milleri" (15), the "Streptococcus milleri group" (14, 16), Streptococcus constellatus (17), Streptococcus intermedius (17), " and " . These strains have been isolated from mouths, nasopharynges, gastrointestinal tracts, and vaginas and are of clinical significance because of their association with pyogenic infections involving the central nervous system, chest, or abdomen (14,28).…”

“…anginosus have long been a source of disagreement and confusion. Colman and Williams (3) grouped the strains previously called "Streptococcus MG" (24), the minute-colony-forming streptococci of Lancefield groups F and G (2, 21), and the hemolytic and nonhemolytic streptococci possessing the type antigens of Lancefield group F (26) into " S . milleri" because these organisms closely resemble the nonhemolytic streptococci isolated from oral abscesses and originally given that name by Guthof (15).…”

“…milleri" because these organisms closely resemble the nonhemolytic streptococci isolated from oral abscesses and originally given that name by Guthof (15). However, Facklam also noted a high degree of similarity among "Streptococcus MG" (24), S . intermedius (17), and S .…”

Studies on Primary Atypical Pneumonia. I. Clinical Features and Results of Laboratory Investigations 12

“…The characteristics of this microorganism, which has been designated streptococcus MG, have been investigated intensively. The results of these studies are presented in separate communications (20,21). In the accompanying paper (22) …”

“…For convenience in reference, this microorganism has been designated streptococcus MG. Because of the possibility that streptococcus MG might have more than an incidental association with primary atypical pneumonia, the properties of this microorganism and its relation to the disease were investigated. The bacteriological and serological characteristics of streptococcus MG are described in separate communications (20,21). The special techniques for isolating streptococcus MG from the respiratory tract of human beings and an extension of the original observations concerning the relation of this microorganism to primary atypical pneumonia are described in the accompanying paper (22).…”