Identification of the capsular polysaccharides in Staphylococcus aureus clinical isolates by PCR and agglutination tests.
Staphylococcus aureus is a major cause of nosocomial and community-acquired infections. The predominance of two capsular polysaccharides, types 5 and 8, on the surface of clinical isolates led to the development of a conjugate vaccine (StaphVAX) based on capsular polysaccharides types 5 and 8 conjugated to a carrier protein. We have studied the capsular phenotypes and genotypes of 195 isolates representative of all clinical syndromes that encompassed both hospital and community-acquired infections. These isolates were mainly detected in France between January 2001 and December 2004. In this population, most of clinical isolates (87%) expressed either capsular polysaccharide type 5 (42%) or 8 (45%), whereas 13% were nontypeable by the serotyping method with antibodies specific to capsular polysaccharide type 5 or 8. These 26 nontypeable strains were further serotyped and were demonstrated to express the cell wall surface antigen 336, a polyribitol phosphate N-acetylglucosamine, which resembles cell wall teichoic acid. Among methicillin-resistant Staphylococcus aureus (MRSA) strains, we found a predominance of serotype 5 for 64% of strains, whereas MSSA isolates were predominantly capsular serotype 8 (60%). All S. aureus clinical isolates included in the present study have been investigated by PCR method, demonstrating that all isolates carried either the cap5 or the cap8 locus.
Verdier
Isabelle
I
INSERM, E0230, Lyon, F-69008, France.
Durand
Geraldine
G
Bes
Michele
M
Taylor
Kimberly L
KL
Lina
Gerard
G
Vandenesch
François
F
Fattom
Ali I
AI
Etienne
Jerome
J
D000372:Agglutination Tests / Q000379:methods*; D016667:Bacterial Capsules / Q000235:genetics; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D005602:France; D006801:Humans; D016106:Methicillin Resistance; D016133:Polymerase Chain Reaction / Q000379:methods*; D011135:Polysaccharides, Bacterial / Q000145:classification* / Q000235:genetics; D012703:Serotyping; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification
D011135:Polysaccharides, Bacterial; C054106:capsular polysaccharide, type 5, Staphylococcus aureus; C064836:capsular polysaccharide, type 8, Staphylococcus aureus