"Streptococcus milleri" Streptococcus constellatus, and Streptococcus intermedius Are Later Synonyms of Streptococcus anginosus

Abstract

Streptococci that produced acetoin and alkaline phosphatase, hydrolyzed arginine, and fermented trehalose but did not produce pyrrolidonylarylamidase or P-glucuronidase, split hippurate, or ferment ribose or glycogen were collected and compared, These streptococci were considered members of the unapproved species 'LStreptococcus millen'," but most of them would fit the description of one of three approved species: Streptococcus anginosus, Streptococcus constellatus, or Streptococcus intermedius. Most were recent clinical isolates. Some hydrolyzed esculin and fermented lactose, while others did pot. Some fermented mannitol and rafknose. Many were beta-hemolytic, and several reacted to antiserum of Lancefield group A, C, F, or G. From a total of 111 strains, 40 were selected for comparison of their deoxyribbnucleic acid (DNA) base sequence similarities by DNA-DNA hybridization on membrane Filters. All biotypes, hemolytic types, and serotypes were included, as well as the type strains of S. anginosus, S. constellatus, and S . intermedius, and Lancefield group F Streptococcus sp., plus two strains derived from GuthoPs '(S. millen'" isolates. The results showed considerable genetic similarity within the group. DNA from most strains hybridized at a level of 70% or more of the homologous control, even under very stringent conditions. There was somewhat less homology between DNAs of some of the least reactive strains (lactose, mannitol, and esculin negative) and the most reactive strains (lactose, mannitol, and esculin positive). The Lancefield F strain and the type strains of S. anginosus and S.constellatus were genetically similar. Traits such as hemolysis and lactose fermentation could not be ascribed to plasmids. The results support the unification of these streptococci into a single species.

Physiological Characteristics and Deoxyribonucleic Acid Relatedness of Streptococcus intermedius Strains

“…We were not, therefore, limited to biotypes identified by the API Rapid Strep Identification system. In addition, the method we used for DNA-DNA hybridization is probably more stringent than that used by Coykendall et al (7) and is similar to the method used by Kilpper-Balz et al (20). This may partly explain the similarity of our results to those of the latter workers, who identified three homology groups among their collection of reference strains.…”

Whole-cell protein electrophoretic analysis of viridans streptococci: evidence for heterogeneity among Streptococcus mitis biovars

“…We conclude that our analysis of whole-cell protein patterns supports the viewpoint that these three taxa constitute a single species which should be referred to as S. anginosus (6).…”

“…One view is that these three taxa are phenotypically virtually indistinguishable and that, in spite of some genotypic heterogeneity, they constitute a single species, S. anginosus (6). The other view is that there are sufficient differential phenotypic characteristics between these three taxa and that the DNA-DNA hybridization levels between the three groups are sufficiently low to warrant their classification as three distinct species (20).…”

Identification of chromosomal antibiotic resistance genes in Streptococcus anginosus ("S. milleri")

“…strain MGintermedius, and S. anginosus-constellatus (42). A single taxon that is now officially called S. anginosus is recognized on the basis of DNA-DNA hybridization (14); it includes a group of streptococci that are phenotypically heterogeneous with respect to physiological characteristics, beta-hemolysis, and the presence of Lancefield group antigens (A, C, F, or G).…”