Identification of Clinically Relevant Viridans Streptococci by an Oligonucleotide Array

• Published in: Journal of Clinical Microbiology Vol. 43; no. 4; pp. 1515 - 1521
• Main Authors: Chen, Chao Chien, Teng, Lee Jene, Kaiung, Seng, Chang, Tsung Chain
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.04.2005
• Subjects: Bacteriology; Biological and medical sciences; DNA, Bacterial - analysis; DNA, Ribosomal Spacer - analysis; Fundamental and applied biological sciences. Psychology; Humans; Infectious diseases; Medical sciences; Microbiology; Oligonucleotide Array Sequence Analysis - methods; Polymerase Chain Reaction - methods; RNA, Ribosomal, 16S; RNA, Ribosomal, 23S; Species Specificity; Streptococcal Infections - diagnosis; Streptococcal Infections - microbiology; Streptococcus anginosus; Streptococcus constellatus; Streptococcus gordonii; Streptococcus intermedius; Streptococcus mitis; Streptococcus mutans; Streptococcus oralis; Streptococcus parasanguinis; Streptococcus salivarius; Streptococcus sanguinis; Streptococcus uberis; Viridans Streptococci - classification; Viridans Streptococci - genetics; Viridans Streptococci - isolation & purification; Microbiology; Identification
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/JCM.43.4.1515-1521.2005

Viridans streptococci (VS) are common etiologic agents of subacute infective endocarditis and are capable of causing a variety of pyogenic infections. Many species of VS are difficult to differentiate by phenotypic traits. An oligonucleotide array based on 16S-23S rRNA gene intergenic spacer (ITS) sequences was developed to identify 11 clinically relevant VS. These 11 species were Streptococcus anginosus, S. constellatus, S. gordonii, S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguinis, S. salivarius, S. sanguinis, and S. uberis. The method consisted of PCR amplification of the ITS regions by using a pair of universal primers, followed by hybridization of the digoxigenin-labeled PCR products to a panel of species-specific oligonucleotides immobilized on a nylon membrane. After 120 strains of the 11 species of VG and 91 strains of other bacteria were tested, the sensitivity and specificity of the oligonucleotide array were found to be 100% (120 of 120 strains) and 95.6% (87 of 91 strains), respectively. S. pneumoniae cross-hybridized to the probes used for the identification of S. mitis, and simple biochemical tests such as optochin susceptibility or bile solubility should be used to differentiate S. pneumoniae from S. mitis. In conclusion, identification of species of VS by use of the present oligonucleotide array is accurate and could be used as an alternative reliable method for species identification of strains of VS.