The viridans group streptococci (VGS) are an extremely diverse range of organisms within the genus Streptococcus, which are characterized by a greening of the blood in blood agar, on which they are normally grown. Oral streptococci largely comprise members of the VGS, which currently include 20 species, which are commensal inhabitants of the oropharyngeal cavity, and the gastrointestinal and genital tracts of mammals. On the basis of 16S rRNA sequence homology, these bacteria are categorised into four groups: the salivarius rRNA homology group, including Streptococcus thermophilus, Streptococcus vestibularis and Streptococcus salivarius; the mitis group, including Streptococcus cristatus, Streptococcus gordonii, Streptococcus oralis, Streptococcus mitis, Streptococcus pneumoniae, Streptococcus sanguinis and Streptococcus parasanguinis; the anginosus group, including Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius; and the mutans group, including Streptococcus mutans, Streptococcus criceti, Streptococcus downei, Streptococcus ferus, Streptococcus macacae, Streptococcus ratti and Streptococcus sobrinus. This review aims at comparing conventional and molecular detection methods and the emergence of antibiotic resistance within the VGS.
aNorthern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast, UK
bSchool of Biomedical Sciences, University of Ulster, Coleraine, UK
cSchool of Dentistry, Queen's University of Belfast, Royal Group of Hospitals, Belfast, Northern Ireland, UK.
Received 26 April, 2010
Accepted 24 May, 2010
Correspondence to Professor John E. Moore, Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Belfast BT9 7AD, Northern Ireland, UK. Tel: +44 28 9026 3554; fax: +44 28 9026 3991; e-mail: firstname.lastname@example.org