Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/1998
Publication Date: N/A
Interpretive Summary: Development of an effective vaccine against bovine Staphylococcus aureus mastitis has eluded researchers for decades. The currently available S. aureus vaccines are only partially effective. This suggested to us that the vaccine formulation lacked complete coverage of the S. aureus strains present in the field. We collected S. aureus from mastitic cows throughout the US and found that the organism used to formulate the vaccines represented only 41% for the S. aureus causing bovine mastitis in the US. We have since identified a strain of S. aureus that accounts for the 59% not represented in the currently available vaccines. Inclusion of the newly identified S. aureus strain will afford complete coverage of the types of S. aureus responsible for bovine mastitis in the US. Inclusion of this new strain in vaccine formulations should greatly improve their effectiveness in protecting dairy cattle against mastitis.
Technical Abstract: Development of a Staphylococcus aureus vaccine for bovine mastitis has eluded researchers for decades. The ability of S. aureus to form a protective exopolysaccharide has posed a major obstacle because of multiple capsule serotypes and the poor immune response elicited by exopolysaccharides. Methods have been developed to increase the immunogenicity of exopolysaccharides, but the S. aureus capsule serotypes causing bovine mastitis are still in question. In a previous study we characterized S. aureus serotypes isolated from cases of bovine mastitis obtained from veterinary diagnostic laboratories that screen 44% of the dairy cattle in the United States and found that 59% of the isolates were nontypeable with the classical serotyping antisera. The current study reports an antisera that identifies 100% of the S. aureus in the US and 98% of S. aureus in Europe. Inclusion of the newly identified S. aureus capsular serotype to vaccines currently being tested in the bovine would increase their effectiveness significantly.