Steven Clegg, Ph.D.
Ph.D., University of Dundee (Scotland), 1978 |
Professor of Microbiology Campus address: 3-334 BSB Mailing address: 51 Newton Rd. 3-334 Bowen Science Building Iowa City, IA 52242 Phone: 319-335-7778 Email: |
The Fimbriae of Enterobacteria
In both intestinal and extraintestinal infections due to enterobacteria, adhesion of the bacteria to the host tissue is a necessary prerequisite to colonization and infection. Current research projects involve
- analysis of the genetic control of fimbrial expression in enteric bacteria,
- the construction of recombinant plasmids encoding functional fimbriae (pili) and examination of gene products,
- cloning, by recombinant DNA technology, fimbrial genes from members of the enterobacteriaceae, and
- examination of recombinant strains for the acquisition of enhanced virulence properties.
Using the techniques of molecular biology the genes coding for fimbrial expression are being studied. Comparison of the structural and regulatory components of this genetic system in different genera of enterobacteria possessing diverse fimbrial antigens is being performed. Many genera of the enteric group of bacteria possess fimbriae which are antigenically distinct, and are expressed only under defined conditions in vitro. A comparison of the genetic elements encoding different types of fimbriae is being performed using gene cloning, DNA sequencing and hybridization, recombinant plasmids and DNA fusion molecules.
Recent publications
Johnson, J.G., C.N. Murphy, J. Sippy, T.J. Johnson, and S. Clegg. 2011. Type 3 fimbriae and biofilm formation are regulated by the transcriptional regulators MrkHI in Klebsiella pneumoniae. J. Bact. 193:3453-3460.
Clegg, S., J. Wilson, and J. Johnson. 2011. More than one way to control hair growth: Regulatory mechanisms in Enterobacteria that affect fimbriae assembled by the chaperone/usher pathway (Minireview). J. Bact. 193:2089-2096.
Johnson, J.G., and S. Clegg. 2010. Role of MrkJ, a phosphodiesterase, in type 3 fimbrial expression and biofilm formation in Klebsiella pneumoniae. J. Bact. 192:3944-3950.