Table 3 Virulence genes among 124 S. aureus isolates from bulk tank milk of 189 U.S. dairy farms
Genes | Protein | Number of isolates (%) |
|---|---|---|
Hemolysins and Leukocidins | ||
 hlgA | Gamma hemolysin chain II precursor | 123 (99.2) |
 hlgB | Gamma hemolysin component B | 124 (100.0) |
 hlgC | Gamma hemolysin component C | 123 (99.2) |
 hlb | Beta hemolysin | 123 (99.2) |
 lukD | Leukocidin D component | 117 (94.3) |
 lukE | Leukocidin E component | 119 (95.9) |
Proteases | ||
 aur | Aureolysin | 124 (100.0) |
 splA | Serine protease A | 110 (88.7) |
 splB | Serine protease B | 97 (78.2) |
 splE | Serine protease E | 41 (33.1) |
Superantigenic toxins | ||
 seb | Enterotoxin B | 2 (1.6) |
 sec | Enterotoxin C | 17 (13.7) |
 sed | Enterotoxin D | 8 (6.4) |
 seg | Enterotoxin G | 41 (33.1) |
 seh | Enterotoxin H | 1 (0.8) |
 sei | Enterotoxin I | 44 (35.5) |
 sek | Enterotoxin K | 1 (0.8) |
 sel | Enterotoxin L | 17 (13.7) |
 sem | Enterotoxin M | 44 (35.5) |
 sen | Enterotoxin N | 47 (37.9) |
 seo | Enterotoxin O | 37 (29.8) |
 seq | Enterotoxin Q | 1 (0.8) |
 seu | Enterotoxin U | 32 (25.8) |
 tst | Toxic shock syndrome toxin 1 | 13 (10.5) |
Others | ||
 sak | Staphylokinase | 1 (0.8) |
 scn | Staphylococcal complement inhibitor | 1 (0.8) |