title: Presence of nonhemolytic pneumolysin in serotypes of Streptococcus pneumoniae associated with disease outbreaks.
abstract: Pneumolysin is an important virulence factor of the human pathogen Streptococcus pneumoniae. Sequence analysis of the ply gene from 121 clinical isolates of S. pneumoniae uncovered a number of alleles. Twenty-two strains were chosen for further analysis, and 14 protein alleles were discovered. Five of these had been reported previously, and the remaining 9 were novel. Cell lysates were used to determine the specific hemolytic activities of the pneumolysin proteins. Six strains showed no hemolytic activity, and the remaining 16 were hemolytic, to varying degrees. We report that the nonhemolytic allele reported previously in serotype 1, sequence type (ST) 306 isolates is also present in a number of pneumococcal isolates of serotype 8 that belong to the ST53 lineage. Serotype 1 and 8 pneumococci are known to be associated with outbreaks of invasive disease. The nonhemolytic pneumolysin allele is therefore associated with the dominant clones of outbreak-associated serotypes of S. pneumoniae.
authors: Institute of Biomedical and Life Sciences, Division of Infection and Immunity, University of Glasgow, Glasgow, United Kingdom.
authors: Johanna M C
authors: JM
authors: Jefferies
authors: Calum H G
authors: CH
authors: Johnston
authors: Lea-Ann S
authors: LA
authors: Kirkham
authors: Graeme J M
authors: GJ
authors: Cowan
authors: Kirsty S
authors: KS
authors: Ross
authors: Andrew
authors: A
authors: Smith
authors: Stuart C
authors: SC
authors: Clarke
authors: Angela B
authors: AB
authors: Brueggemann
authors: Robert C
authors: RC
authors: George
authors: Bruno
authors: B
authors: Pichon
authors: Gerd
authors: G
authors: Pluschke
authors: Valentin
authors: V
authors: Pfluger
authors: Tim J
authors: TJ
authors: Mitchell
mesh_terms: D000483:Alleles; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000633:toxicity; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D005838:Genotype; D006461:Hemolysis; D006801:Humans; D008969:Molecular Sequence Data; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D013301:Streptolysins / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D013301:Streptolysins; D037521:Virulence Factors; C032290:plY protein, Streptococcus pneumoniae