JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J. Dairy Sci. 2009. 92:5467-5475. doi:10.3168/jds.2009-2223
© 2009 American Dairy Science Association ®
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Interpretive Summary
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Pryor, S. M.
Right arrow Articles by Lacy-Hulbert, S. J.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pryor, S. M.
Right arrow Articles by Lacy-Hulbert, S. J.

Experimentally induced intramammary infection with multiple strains of Streptococcus uberis

S. M. Pryor*,{dagger}, R. T. Cursons*, J. H. Williamson{dagger} and S. J. Lacy-Hulbert{dagger},1

* University of Waikato, Hamilton 3240, New Zealand
{dagger} DairyNZ, Private Bag 3221, Hamilton 3240, New Zealand

1 Corresponding author: jane.lacyhulbert{at}dairynz.co.nz

The effect of infusing a mixture of 5 Streptococcus uberis strains into mammary quarters of 10 lactating cows was investigated. All 5 strains, which included 2 originally isolated from the dairy environment and 3 from clinical cases of mastitis, were capable of establishing an intramammary infection when infused individually. However, when the 5 strains were infused together, a single strain predominated in 7 out of 10 quarters. One strain in particular prevailed in 4 mammary quarters and was also found to inhibit the growth of the other 4 strains with deferred antagonism on esculin blood agar. The genes required for the production of bacteriocins nisin U and uberolysin were identified in this strain, whereas the other 4 strains contained only uberolysin genes. Direct competition may have occurred between strains within the mammary gland but competition was not apparent when cultured together in UHT milk, where no strain predominated. Although the mechanism is unknown, these results imply that a selection process can occur within the mammary gland, leading to a single strain that is detected upon diagnosis of mastitis.

Key Words: Streptococcus uberis • mastitis • strain • bacteriocin






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by the American Dairy Science Association ®.