Identification of a secreted cholesterol-dependent cytolysin (mitilysin) from Streptococcus mitis.
We have detected a cholesterol-dependent cytolysin, which we have named mitilysin, in a small number of Streptococcus mitis isolates. We have sequenced the mitilysin gene from seven isolates of S. mitis. Comparisons with the pneumococcal pneumolysin gene show 15 amino acid substitutions. S. mitis appear to release mitilysin extracellularly. Certain alleles of mitilysin are not recognized by a monoclonal antibody raised to the related toxin pneumolysin. Based on enzyme-linked immunosorbent assay and neutralization assay results, one isolate of S. mitis may produce a further hemolytic toxin in addition to mitilysin. As genetic exchange is known to occur between S. mitis and Streptococcus pneumoniae, this finding may have implications for the development of vaccines or therapies for pneumococcal disease that are based on pneumolysin.
Jefferies
Johanna
J
Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow G12 8TA, UK.
Nieminen
Leena
L
Kirkham
Lea-Ann
LA
Johnston
Calum
C
Smith
Andrew
A
Mitchell
Tim J
TJ
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002784:Cholesterol / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D034361:Streptococcus mitis / Q000235:genetics* / Q000378:metabolism*; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism; D013301:Streptolysins / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D013301:Streptolysins; C517494:mitilysin, Streptococcus mitis; C032290:plY protein, Streptococcus pneumoniae; D002784:Cholesterol