Chromosomal inversion between rrn operons among Streptococcus mutans serotype c oral and blood isolates.
Streptococcus mutans causes dental caries and infective endocarditis. The aim of this study was to determine genomic diversity among serotype c S. mutans laboratory and clinical strains and to characterize the genetic events involved. A genome-based approach using PFGE coupled with Southern hybridization was employed to examine a total of 58 serotype c oral and blood isolates and seven laboratory strains and to compare them with S. mutans UA159. No significant differences were found in the phenotypic characteristics of the strains tested, except that some of the strains exhibited smooth rather than rough colony morphology. In contrast, PFGE profiles of clinical isolates, from either diseased or healthy subjects, exhibited diverse patterns, suggesting that recombination or point mutations occurred frequently in vivo. Diverse PFGE patterns, with various lengths of insertions and deletions, could be detected even within a localized chromosomal region between rRNA operons. Comparative analysis using Southern hybridization with specific markers revealed that a large chromosomal inversion had also occurred between rrn operons in 25 strains.
Huang
Wen-Chuan
WC
Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
Chen
Yi-Ywan M
YM
Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taipei, Taiwan, ROC.
Teng
Lee-Jene
LJ
Department of Clinical Laboratory Sciences and Medical Biotechnology, Taipei, Taiwan, ROC.
Lien
Huwei-Ting
HT
Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
Chen
Jen-Yang
JY
National Health Research Institute, Taipei, Taiwan, ROC.|Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
Chia
Jean-San
JS
Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan, ROC.|Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
D016470:Bacteremia / Q000382:microbiology; D001769:Blood / Q000382:microbiology*; D015139:Blotting, Southern; D007446:Chromosome Inversion / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D009055:Mouth / Q000382:microbiology*; D016254:Mutagenesis, Insertional; D017384:Sequence Deletion; D013290:Streptococcal Infections / Q000382:microbiology*; D013295:Streptococcus mutans / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D012407:rRNA Operon / Q000235:genetics*
D004269:DNA, Bacterial