Production of muraminidase-released protein (MRP), extracellular factor (EF) and suilysin by field isolates of Streptococcus suis capsular types 2, 1/2, 9, 7 and 3 isolated from swine in France.
A total of 323 isolates of Streptococcus suis recovered from diseased or healthy pigs in France were serotyped. The presence of virulence-related proteins, Muraminidase-Released Protein (MRP), Extracellular Factor (EF) and Suilysin was also studied in 122 isolates of capsular types 2, 1/2, 9, 7 and 3 to evaluate their implication in virulence of S. suis. Capsular types 2, 1/2, 9, 7 and 3 were the most frequently detected (93%), with 69% for the capsular type 2 alone. Capsular types 2, 1/2, 9, 7, 3, 1, 4, 8, 18, 10 and 12 were isolated from diseased pigs, whereas types 2, 7, 9, 1/2, and 3 originated from the nasal cavities or tonsils of healthy animals. Most of the S. suis type 2 isolates recovered from diseased pigs carried MRP+ EF- Suilysin- (46%) or MRP+ EF+ Suilysin+ (28%) phenotypes. The MRP+ EF- Suilysin- phenotype was also detected in 67% of S. suis type 2 strains isolated from healthy pigs. The production of the virulence-related proteins was less frequently found in S. suis types 1/2, 9, 7 and 3 recovered either from diseased or healthy pigs. In this study, all the capsular type 1/2 strains were MRP+ EF- Suilysin- and all the S. suis type 7 harboured an MRP- EF- Suilysin- phenotype. The MRP- EF- Suilysin- phenotype was found in S. suis types 2, 3, 7 and 9 isolated from septicaemia, meningitis, pneumonia, and pleurisy. These results suggest that the presence of these proteins should not be used as a single condition for classifying the virulence of a field isolate in France.
Berthelot-Hérault
F
F
Agence Française de Sécurité Sanitaire des Aliments, Unité Mycoplasmologie-Bactériologie, Ploufragan, France.
Morvan
H
H
Kéribin
A M
AM
Gottschalk
M
M
Kobisch
M
M
D000818:Animals; D000942:Antigens, Bacterial; D016667:Bacterial Capsules / Q000145:classification; D001426:Bacterial Proteins / Q000096:biosynthesis*; D015153:Blotting, Western; D004586:Electrophoresis; D005602:France; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D009930:Organic Chemicals; D010641:Phenotype; D012703:Serotyping; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary*; D017011:Streptococcus suis / Q000145:classification / Q000378:metabolism / Q000472:pathogenicity*; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D014774:Virulence
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C082316:Epf protein, Streptococcus suis; D006460:Hemolysin Proteins; C421489:MRP protein, Streptococcus suis; D009930:Organic Chemicals; C104760:suilysin