Secreted antigens as virulence-associated markers in Staphylococcus aureusstrains from rabbits

Western blot analysis was performed from the culture supernatant of 59 rabb it Staphylococcus aureus strains, classified as high and low virulence stra ins according to their epidemiological behaviour in commercial rabbitries, bio-, phage- and RAPD-type. Fourteen extracellular antigen bands (A-N) were recognised using sera of rabbits immunised with washed, viable high virule nce S. aureus bacteria. Eleven of these bands were found in high virulence as well as in low virulence strains. The band A, approximately 78 kDa, was not seen in any of the 27 high virulence strains, except for one strain whi ch was also typical in other aspects, was detected in all, but one of the l ow virulence strains. The M and N bands with molecular masses of approximat ely 29 and 27 kDa, respectively, were recognised in all high virulence stra ins except for the atypical strain. but in none of the low virulence strain s. This indicates that the latter two antigens may be virulence-associated markers for S. aureus strains from rabbits. (C) 2001 Elsevier Science B.V. All rights reserved.