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|Title:||Characterization of Staphylococcus Aureus of Bovine Origin|
|Department / Program:||Dairy Science|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Agriculture, Animal Pathology|
|Abstract:||The incidence of mastitis caused by Staphylococcus aureus was of the same order as that reported by other investigators. However, the strains isolated were not all of the bovine biotype. The strains isolated from the mammary gland and nasal cavity, although mostly of bovine biotype, differed in their lytic spectra. It is speculated that these differences are due to basic differences between these two ecological niches (mammary gland and nasal cavity).
Investigations into the nature of the nontypeable strains showed that neither encapsulation nor protein A could have been the reasons for untypeability. It is speculated that these strains were in a state of lysogenic immunity. Further work is needed to determine whether lysogeny was in fact the reason for untypeability.
The methods described for typing the untypeable strains are unlikely to gain general acceptance because of the additional labor involved and the high phage titer required. However, if the percentage of untypeable strains were to increase, these methods might prove useful.
Thermal stressing of the untypeable strains at various temperatures for various time intervals had a profound effect on the production of delta hemolysin by the strains studied. There was a negative correlation between endogenous delta hemolysin and plaque forming units.
Addition of purified (delta)-hemolysin to the typing medium produced a decrease in plaque forming units in both stressed and unstressed Staphylococcus aureus strains investigated. It is speculated that (delta)-hemolysin, in view of its detergent-like property, was inactivating the phage used.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-14|