Proteomic analysis using an unfinished bacterial genome: The effects of subminimum inhibitory concentrations of antibiotics on Mannheimia haemolytica virulence factor expression

Bindu Nanduri, Mark L. Lawrence, Sucharith Vanguri, Shane C. Burgess

Research output: Contribution to journalArticle

43 Scopus citations


Here we identify, using nonelectrophoretic proteomics, effects of subminimum inhibitory concentrations (subMIC) of two antibiotic preparations, chlortetracycline (CTC), and chlortetracycline-sulfamethazine (CTC + SMZ), on protein expression in the bovine respiratory pathogen Mannheimia haemolytica. The M. haemolytica genome is currently in draft form, and annotation is incomplete. Relying on the principle of gene sequence conservation across species, we used annotated genomes from closely related species to identify, confirm, and functionally annotate 495 M. haemolytica proteins. To conduct quantitative comparative proteomics, we developed a protein quantitation method based on the cross correlation function of the SEQUEST algorithm. When M. haemolytica was cultivated in the presence of 1/4 MIC of CTC and CTC + SMZ, expression of proteins involved in energy production, nucleotide metabolism, translation, and the bacterial stress response (chaperones) were affected. The most notable subMIC effect was a significant decrease in the expression of leukotoxin A, which is an important M. haemolytica virulence factor. Reduction in leukotoxin expression could be one of the molecular mechanisms responsible for the efficacy of these antibiotics against bovine respiratory disease.

Original languageEnglish (US)
Pages (from-to)4852-4863
Number of pages12
Issue number18
StatePublished - Dec 2005
Externally publishedYes



  • Leukotoxin
  • Mannheimia haemolytica
  • Mass spectrometry
  • Protein quantitation
  • Subminimum inhibitory concentration

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Cite this