This Article
Right arrow Full Text
Right arrow Full Text (PDF)
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 arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhang, S.
Right arrow Articles by Maddox, C. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, S.
Right arrow Articles by Maddox, C. W.

 Previous Article  |  Next Article 

Infection and Immunity, March 2000, p. 1102-1108, Vol. 68, No. 3
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Cytotoxic Activity of Coagulase-Negative Staphylococci in Bovine Mastitis

Songlin Zhang and Carol W. Maddox*

Animal Diagnostic Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802

Received 22 July 1999/Returned for modification 28 September 1999/Accepted 23 November 1999

Secreted toxins play important roles in the pathogenesis of bacterial infections. In this study, we examined the presence of secreted cytotoxic factors of coagulase-negative staphylococci (CoNS) from bovine clinical and subclinical mastitis. A 34- to 36-kDa protein with cell-rounding cytotoxic activity was found in many CoNS strains, especially in Staphylococcus chromogenes strains. The protein caused cell detachment and cell rounding in several cell lines, including HEp-2, Int 407, CHO-K1, and Y-1 cells. Native protein recovered from nondenatured polyacrylamide gel electrophoresis showed both cytotoxic activity and casein hydrolysis activity. The purified protein had a pH optimal at 7.2 to 7.5 and a pI of 5.1 and was heat labile. The proteolytic activity could be inhibited by zinc and metal specific inhibitors such as 1,10-phenanthroline and EDTA, indicating that it is a metalloprotease. Protein mass analysis and peptide sequencing indicated that the protein is a novel metalloprotease. Different bacterial strains expressed variable levels of 34- to 36-kDa protease, which may provide an indication of strain virulence.

* Corresponding author. Mailing address: Animal Diagnostic Laboratory, The Pennsylvania State University, University Park, PA 16802. Phone: (814) 863-0838. Fax: (814) 865-3907. E-mail: cwm5{at}psu.edu.

Infection and Immunity, March 2000, p. 1102-1108, Vol. 68, No. 3
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Nemati, M., Hermans, K., Vancraeynest, D., De Vliegher, S., Sampimon, O. C., Baele, M., De Graef, E. M., Pasmans, F., Haesebrouck, F. (2008). Screening of bovine coagulase-negative staphylococci from milk for superantigen-encoding genes. Vet Rec. 163: 740-743 [Abstract] [Full Text]  
  • Fernandez, L., Delgado, S., Herrero, H., Maldonado, A., Rodriguez, J. M. (2008). The Bacteriocin Nisin, an Effective Agent for the Treatment of Staphylococcal Mastitis During Lactation. J Hum Lact 24: 311-316 [Abstract]  
  • Jimenez, E., Fernandez, L., Maldonado, A., Martin, R., Olivares, M., Xaus, J., Rodriguez, J. M. (2008). Oral Administration of Lactobacillus Strains Isolated from Breast Milk as an Alternative for the Treatment of Infectious Mastitis during Lactation. Appl. Environ. Microbiol. 74: 4650-4655 [Abstract] [Full Text]  
  • Taponen, S., Koort, J., Bjorkroth, J., Saloniemi, H., Pyorala, S. (2007). Bovine Intramammary Infections Caused by Coagulase-Negative Staphylococci May Persist Throughout Lactation According to Amplified Fragment Length Polymorphism-Based Analysis. J DAIRY SCI 90: 3301-3307 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»