Deoxyribonucleic Acid Hybridizations Among Strains of Streptococcus salivarius and Streptococcus bovis

Abstract

The genetic relationships among 33 streptococci that were identified as Streptococcus salivarius or Streptococcus bovis and were isolated from humans were determined by deoxyribonucleic aciddeoxyribonucleic acid hybridization on membrane filters. The phenotypic characteristics of these bacteria were determined by their action on 20 substrates in a commercially prepared system, as well as by colony morphology and conventional tests. The S . sulivurius strains were biochemically heterogeneous but genetically homogeneous. Although there were some phenotypic similarities between S . bovis and S . salivarius, these two species were genetically distinct. Within S. bovis there was genetic heterogeneity. Typical S . bovis strains (S. bovis biotype I) were genetically homologous with some, but not all, of the S . bovis variant strains ( S . bovis biotype 11). Other S . bovis biotype I1 strains formed a separate genetic group, the members of which were biochemically somewhat different from other S . bovis biotype I1 strains.Streptococcus bovis has become medically important since it was discovered to be a frequent cause of endocarditis (13,19,20,30,35) and to be more common in the bowels of patients with colon diseases, including carcinomas (23 , 24,31,36). Isolates from such human sources ferment mannitol, usually ferment inulin, and produce an extracellular glucan from sucrose (13, 34). These typical strains are called Streptococcus bovis biotype I to differentiate them from strains of a variant type called Streptococcus bovis biotype 11, which do not ferment mannitol or inulin and do not produce glucan (13, 34). As is usual with such divisions, there are strains whose characteristics put them midway between the biotypes (for example, mannitol fermentation but no glucan production). In addition, some members of the common human commensal Streptococcus salivarius resemble Streptococcus bovis because they have similar biochemical traits and may react with Lancefield group D antiserum or grow on bile-esculin agar (37) or both. Like Streptococcus bovis, Streptococcus salivarius produces a polymer, usually levan (21, 32), from sucrose, and the two species can produce similar colonies on sucrose agar.To clarify the relationships among strains identified as Streptococcus salivarius, Streptococcus bovis biotype I, andStreptococcus bovis biotype 11, we compared the base sequence similarities of their deoxyribonucleic acids (DNAs) by using DNA-DNA hybridization. MATERIALS AND METHODSThe strains used in this study are listed in the tables (see below). Strains whose designations begin with CDC were obtained from the Centers for Disease Control, Atlanta, Ga. ; strains whose designations begin with COL were obtained from the Central Public Health Laboratories, Colindale, England; and strains whose designations begin with MG were obtained from The Massachusetts General Hospital, Boston. Other strains were obtained from clinics at the University of Connecticut Health Center, Farmington. Strain 13419 was a subculture of Streptococcus sa...

Reappraisal of the taxonomy of the Streptococcus bovis/Streptococcus equinus complex and related species: description of Streptococcus gallolyticus subsp. gallolyticus subsp. nov., S. gallolyticus subsp. macedonicus subsp. nov. and S. gallolyticus subsp. pasteurianus subsp. nov.

“…The DNA relatedness ranged from 48 to 93 % (DT m <6 uC) between different subgroups. The levels of hybridization of total DNA between S. gallolyticus and S. bovis biotype II.2 are similar to the results of Coykendall & Gustafson (1985), Garvie & Bramley (1979) and Osawa et al (1995). Only a few biochemical characteristics (acidification of arbutin and melibiose) distinguish S. macedonicus from S. waius.…”

“…However, phenotypic heterogeneity was recognized among isolates in terms of carbohydrate fermentation, starch hydrolysis and production of glucan from sucrose. These variations led to the description of 'variant strains' of S. bovis by different authors (Coykendall & Gustafson, 1985;Facklam, 1972;Knight & Shlaes, 1985;Nelms et al, 1995). The species S. alactolyticus, S. suis, S. gallolyticus, S. macedonicus, S. waius and S. infantarius were further described.…”

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

“…Preparation of DNA. Bacteria were grown and lysed, and the DNA was isolated as described previously (8). Briefly, the cells were harvested from cultures grown in 1 liter of Todd-Hewitt broth with 1% extra glucose.…”

The Role of Infectious Agents in Colorectal Carcinogenesis

“…bovis, a nonenterococcal lancefield group D streptococcus, is a transient colonic commensal with fecal carriage rate of 5 -13 % in healthy adults (Potter et al, 1998;Dubrow et al, 1991), and accounts for 11-12% of infective endocarditis (Ballet et al, 1995;Kupferwasser et al, 1998). Traditionally, S. bovis has been classified into three distinct biotypes; I, II/1, and II/2, www.intechopen.com based on phenotypical and genetic characteristics (Coykendall & Gustafson, 1985). Further studies using phylogenetic analysis allowed clear and unambiguous differentiation of human clinical isolates and indicated that all strains of S. bovis I and II/2 be identified as S. gallolyticus (Schlegel et al, 2003).…”