Staph aureus facts
Staphylococcus aureus is one of the most common causes of mastitis in US dairy herds. It is a major source of expense and lost revenues on many dairies. Most commonly, Staph aureus mastitis exists as a very chronic, subclinical infection, but it is also a leading cause of clinical mastitis. Staph aureus udder infections are notable for the difficulty in achieving full bacteriological cures even with intensive antimicrobial treatment.This fact is well recognized by all universities and other organizations (see Fact Sheet)
The University of Washington disclosed the fact that even with the best of milking procedures that Staph aureus is a major problem in their herd (see JDS 84:1976-1978).
The US government has been investigating methods of genetically modifying dairy cows to make them more resistant to staph aureus infections. The introduction of milk into the consumer market will first require FDA approval and consumer acceptance of the taste. The approach is to genetically modify the cows to cause them to secrete a substance into the udder and milk that will kill the Staph aureus bacteria.
"There have been efforts aimed at developing a vaccine against Staph aureus bacteria, which tend to produce a very difficult to eliminate type of mastitis. The general experience has been of limited value to date although there have been reports that vaccinating heifers with a particular product appears to boost their resistance to the organism. Staph aureus mastitis in first calf heifers is a significant issue in some herds and if there is a possibility, through vaccination programs, to reduce this problem then it may well be worth the expense. It is a very expensive proposition to raise a calf to calving age and then possibly lose all the investment to mastitis before the animal has any opportunity to be productive." (see Environmental Mastitis-Source and Causes)
Staph aureus is not very heat sensitive and therefore the endotoxins are not all destroyed by the HTST pasteurization process.
In June/July 2000, at least 14,000 people were sickened in Japan by Staph aureus enterotoxins. (see JDS 84:1-11)
Deformed udder caused by mastitis.
This cow has been milking for less than two years and has had mastitis infections so severe that the right rear teat has been destroyed. Note the dead teat flesh hanging from the udder and the severely deformed udder.