3FNC1†Present address: MRC Molecular Pathogenesis Group, Department of Medical Microbiology, St Bartholomew's & The Royal London School of Medicine and Dentistry, 2 Newark Street, London E1 2AA, UK.
3FNC2‡Present address: School of Biological Sciences, University of Birmingham, Birmingham B15 2TT, UK.
Capsule phase variants were isolated from serotype 8 and serotype 37 pneumococcal sorbarods. Sequence duplications within the essential capsule genes – cap8E (type 8) and tts (type 37) – were found to introduce frameshifts and generate acapsular phenotypes. Capsular revertants possessed wild-type cap8E and tts genes, indicating the precise excision of these duplications. Reversion frequencies (OFF–ON) fit a linear relationship between log(frequency of reversion) and log(length of duplication), previously found for serotype three pneumococci [Waite, R. D., Struthers, J. K. & Dowson, C. G. (2001). Mol Microbiol 42, 1223–1232]. This study provides evidence that capsule phase variation can occur in pneumococcal serotypes with either simple (one to three genes) or complex capsule-encoding loci (12 genes). Given the key role of CapE (the first monosaccharide transferase) in other clinically important pneumococci, such as serotypes 14 and 19F with complex capsular loci, the observed duplication within cap8E suggests that capsule phase variation could be controlled by tandem sequence duplication in capE homologues in other pneumococcal serotypes that construct their capsules through polymerization of lipid-linked intermediates.
AdamouJ. E,
WizemannT. M,
BarrenP.,
LangermannS.
1998; Adherence of Streptococcus pneumoniae to human bronchial epithelial cells (BEAS-2B). Infect Immun 66:820–822
AppelbaumP. C,
GladkovaC,
HryniewiczW.10 other authors1996; Carriage of antibiotic-resistant Streptococcus pneumoniae by children in eastern and central Europe – a multicenter study with use of standardized methods. Clin Infect Dis 23:712–717
ArrecubietaC,
LopezR.,
GarciaE.
1996; Type 3-specific synthase of Streptococcus pneumoniae (Cap3B) directs type 3 polysaccharide biosynthesis in Escherichia coli and in pneumococcal strains of different serotypes. J Exp Med 184:449–455
ButlerJ. C,
DowellS. F.,
BreimanR. F.
1998; Epidemiology of emerging pneumococcal drug resistance: implications for treatment and prevention. Vaccine 16:1693–1697
DillardJ. P,
VanderseaM. W.,
YotherJ.
1995; Characterisation of the cassette containing genes for type 3 capsular polysaccharide biosynthesis in Streptococcus pneumoniae
. J Exp Med 181:973–983
ErtugrulN,
Rodriguez-BarradasM. C,
MusherD. M,
RyanM. A,
AginC. S,
MurphyS. J,
ShayeganiM.,
WatsonD. A.
1997; BOX-polymerase chain reaction-based DNA analysis of non-serotypeable Streptococcus pneumoniae implicated in outbreaks of conjunctivitis. J Infect Dis 176:1401–1405
HammerschmidtS,
MullerA,
SillmannH.7 other authors1996b; Capsule phase variation in Neisseria meningitidis serogroup B by slipped-strand mispairing in the polysialyltransferase gene ( siaD ): correlation with bacterial invasion and the outbreak of meningococcal disease. Mol Microbiol 20:1211–1220
JiangS. M,
WangL.,
ReevesP. R.
2001; Molecular characterisation of Streptococcus pneumoniae type 4, 6B, 8, and 18C capsular polysaccharide gene clusters. Infect Immun 69:1244–1255
KimJ. O.,
WeiserJ. N.
1998; Association of intrastrain phase variation in quantity of capsular polysaccharide and teichoic acid with the virulence of Streptococcus pneumoniae
. J Infect Dis 177:368–377
KoeuthT,
VersalovicJ.,
LupskiJ. R.
1995; Differential subsequence conservation of interspersed repetitive Streptococcus pneumoniae Box elements in diverse bacteria. Genome Res 5:408–418
KolkmanM. A,
MorrisonD. A,
Van Der ZeijstB. A.,
NuijtenP. J.
1996; The capsule polysaccharide synthesis locus of Streptococcus pneumoniae serotype 14: identification of the glycosyl transferase gene cps14E
. J Bacteriol 178:3736–3741
KolkmanM. A,
WakarchukW,
NuijtenP. J.,
van der ZeijstB. A.
1997a; Capsular polysaccharide synthesis in Streptococcus pneumoniae serotype 14: molecular analysis of the complete cps locus and identification of genes encoding glycosyltransferases required for the biosynthesis of the tetrasaccharide subunit. Mol Microbiol 26:197–208
KolkmanM. A,
van der ZeijstB. A.,
NuijtenP. J.
1997b; Functional analysis of glycosyltransferases encoded by the capsular polysaccharide biosynthesis locus of Streptococcus pneumoniae serotype 14. J Biol Chem 272:19502–19508
KolkmanM. A,
van der ZeijstB. A.,
NuijtenP. J.
1998; Diversity of capsular polysaccharide synthesis gene clusters in Streptococcus pneumoniae
. J Biochem (Tokyo) 123:937–945
LlullD,
LopezR,
GarciaE.,
MunozR.
1998; Molecular structure of the gene cluster responsible for the synthesis of the polysaccharide capsule of Streptococcus pneumoniae type 33F. Biochim Biophys Acta1443217–224
LlullD,
MunozR,
LopezR.,
GarciaE.
1999; A single gene ( tts ) located outside the cap locus directs the formation of Streptococcus pneumoniae type 37 capsular polysaccharide. Type 37 pneumococci are natural, genetically binary strains. J Exp Med 190:241–251
LlullD,
GarciaE.,
LopezR.
2001; Tts, a processive beta-glucosyltransferase of Streptococcus pneumoniae , directs the synthesis of the branched type 37 capsular polysaccharide in pneumococcus and other gram-positive species. J Biol Chem 276:21053–21061
MoronaJ. K,
MoronaR.,
PatonJ. C.
1997a; Characterization of the locus encoding the Streptococcus pneumoniae type 19F capsular polysaccharide biosynthetic pathway. Mol Microbiol 23:751–763
MoronaJ. K,
MoronaR.,
PatonJ. C.
1997b; Molecular and genetic characterization of the capsule biosynthesis locus of Streptococcus pneumoniae type 19B. J Bacteriol 179:4953–4958
MoronaJ. K,
MoronaR.,
PatonJ. C.
1999; Analysis of the 5′ portion of the type 19A capsule locus identifies two classes of cpsC , cpsD , and cpsE genes in Streptococcus pneumoniae
. J Bacteriol 181:3599–3605
Muller-GrafC. D,
WhatmoreA. M,
KingS. J.7 other authors1999; Population biology of Streptococcus pneumoniae isolated from oropharyngeal carriage and invasive disease. Microbiology 145:3283–3293
MunozR,
MollerachM,
LopezR.,
GarciaE.
1997; Molecular organisation of the genes required for the synthesis of type 1 capsular polysaccharide of Streptococcus pneumoniae : formation of binary encapsulated pneumococci and identification of cryptic dTDP-rhamnose biosynthesis genes. Mol Microbiol 25:79–92
MunozR,
MollerachM,
LopezR.,
GarciaE.
1999; Characterisation of the type 8 capsular gene cluster of Streptococcus pneumoniae
. J Bacteriol 181:6214–6219
MusherD. M,
DowellM. E,
ShortridgeV. D,
FlammR. K,
JorgensenJ. H,
Le MagueresP.,
KrauseK. L.
2002; Emergence of macrolide resistance during treatment of pneumococcal pneumonia. N Engl J Med 346:631–632
PatonJ. C,
AndrewP. W,
BoulnoisG. J.,
MitchellT. J.
1993; Molecular analysis of the pathogenicity of Streptococcus pneumoniae : the role of pneumococcal proteins. Annu Rev Microbiol 47:89–115
RamirezM.,
TomaszA.
1998; Molecular characterisation of the complete 23F capsular polysaccharide locus of Streptococcus pneumoniae
. J Bacteriol 180:5273–5278
RingA,
WeiserJ. N.,
TuomanenE. I.
1998; Pneumococcal trafficking across the blood–brain barrier. Molecular analysis of a novel bidirectional pathway. J Clin Invest 102:347–360
SalujaS. K.,
WeiserJ. N.
1995; The genetic basis of colony opacity in Streptococcus pneumoniae : evidence for the effect of box elements on the frequency of phenotypic variation. Mol Microbiol 16:215–227
SungR. Y. T,
LingJ. M,
FungS. M,
OppenheimerS. J,
CrookD. W,
LauJ. T. F.,
ChengA. F. B.
1995; Carriage of Haemophilus influenzae and Streptococcus pneumoniae in healthy Chinese and Vietnamese children in Hong Kong. Acta Paediatr 84:1262–1267
ThroupJ. P,
KoretkeK. K,
BryantA. P.9 other authors2000; A genomic analysis of two-component signal transduction in Streptococcus pneumoniae
. Mol Microbiol 35:566–576
van DamJ. E,
FleerA.,
SnippeH.
1990; Immunogenicity and immunochemistry of Streptococcus pneumoniae capsular polysaccharides. Antonie Leeuwenhoek 58:1–47
WaiteR. D,
StruthersJ. K.,
DowsonC. G.
2001; Spontaneous sequence duplication within an open reading frame of the pneumococcal type 3 capsule locus causes high-frequency phase variation. Mol Microbiol 42:1223–1232
WatsonD. A.,
MusherD. M.
1990; Interruption of capsule production in Streptococcus pneumoniae serotype 3 by insertion of transposon Tn 916. Infect Immun. 583135–3138
WhatmoreA. M,
KingS. J,
DohertyN. C,
SturgeonD,
ChanterN.,
DowsonC. G.
1999; Molecular characterisation of equine isolates of Streptococcus pneumoniae : natural disruption of genes encoding the virulence factors pneumolysin and autolysin. Infect Immun 67:2776–2782