 Ph.D. (1996) |
Michelle
Dziejman
Assistant Professor of Microbiology & Immunology Primary Appointment: GEBS Cluster Affiliations: |
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| Contact Information | ||
| University of Rochester School of Medicine and Dentistry 601 Elmwood Ave, Box 672 Rochester, New York 14642 |
Medical Center 2-3005 Phone: (585) 273-4459 Fax: (585) 473-9573 E-Mail: michelle_dziejman@urmc.rochester.edu |
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- Research Focus
- Vibrio cholerae as an evolving pathogen; Using genomics to identify pandemic specific genes.
- Research Overview
- Vibrio cholerae is a diverse species found in aquatic environments worldwide, and can be classified according to serogroup and biotype. While many strains are considered non-pathogenic environmental isolates, certain strains are capable of causing the severe diarrheal disease known as cholera. Although the first six pandemics were caused by strains of the O1 serogroup and classical biotype, the 7th pandemic (beginning in 1961) was caused by O1 strains of the El Tor biotype. In 1992, strains of the O139 serogroup emerged as the cause of epidemic disease, further demonstrating the ability of this bacterium to evolve as a reemerging pathogen. Pathogenic O1 and O139 strains contain known virulence factors for colonization (TCP, toxin co-regulated pilus) and toxin production (CTX, cholera toxin phage), and cause epidemic disease in seasonal patterns. A significant amount of sporadic disease is caused by non-O1/non-O139 strains, however. While these strains are easily isolated from environmental reservoirs, they do not usually contain TCP and CTX, and therefore must colonize and cause disease by other mechanisms.
- The completion of the genomic sequence of 7th pandemic O1 El Tor strain N16961 in 2000 facilitated the study of V. cholerae at the genomic level. Using a spotted microarray representing the 3,885 open reading frames (ORFs) defined by the sequencing project, we conducted comparative genomic studies using diverse strains isolated over the past 100 years. This resulted in the identification of ORFs unique to 7th pandemic strains. Many of these ORFs encode a number of hypothetical proteins, but are predicted to encode transcriptional regulators, proteins involved in chemotaxis and DNA repair, a pilin and a phospholipase. Further study will include understanding the expression pattern of these genes and the function of their encoded products. Other studies in the laboratory focus on the role of a recently identified Type Three Secretion System in the pathogenesis of TCP-CT- non-O1/non-O139 strains.
- Recent Publications
- Tam VC, Serruto D, Dziejman M, Brieher W, Mekalanos JJ "A Type III Secretion System in Vibrio cholerae Translocates a Formin/Spire Hybrid-like Actin Nucleator to Promote Intestinal Colonization." Cell Host Microbe. 2007 Apr 19;1(2):95-107
- Faruque SM, Tam VC, Chowdhury N, Diraphat P, Dziejman M, Heidelberg JF, Clemens JD, Mekalanos JJ, Nair "Genomic analysis of the Mozambique strain of Vibrio cholerae O1 reveals the origin of El Tor strains carrying classical CTX prophage." Proc Natl Acad Sci U S A. 2007 Mar 12;
- Larocque RC, Harris JB, et al. "Transcriptional profiling of Vibrio cholerae recovered directly from patient specimens during early and late stages of human infection." Infect Immun. 2005 Aug;73(8):4488-93.
- Dziejman, M., D. Serruto, et al. "Genomic characterization of non-O1, non-O139 Vibrio cholerae reveals genes for a type III secretion system." Proc Natl Acad Sci U S A 102(9): 3465-70, 2005.
- Larocque, R. C., J. B. Harris, et al. "Transcriptional profiling of Vibrio cholerae recovered directly from patient specimens during early and late stages of human infection." Infect Immun 73(8): 4488-93, 2005.
- Faruque SM, Chowdhury N, Kamruzzaman M, Dziejman M, Rahman MH, Sack DA, Nair GB, Mekalanos JJ. "Genetic diversity and virulence potential of environmental Vibrio cholerae population in a cholera-endemic area." Proc Natl Acad Sci U S A. 2004 Feb 17;101(7):2123-8.
- Bina J, Zhu J, Dziejman M, Faruque S, Calderwood S, Mekalanos J. ToxR regulon of Vibrio cholerae and its expression in vibrios shed by cholera patients. Proc Natl Acad Sci U S A. 2003 Mar 4;100(5):2801-6.
- Xu Q, Dziejman M, Mekalanos JJ. Determination of the transcriptome of Vibrio cholerae during intraintestinal growth and midexponential phase in vitro. Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):1286-91.
- Zhu J, Miller MB, Vance RE, Dziejman M, Bassler BL, Mekalanos JJ. Quorum-sensing regulators control virulence gene expression in Vibrio cholerae. Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):3129-34.
- Dziejman M, Balon E, Boyd D, Fraser CM, Heidelberg JF, Mekalanos JJ. Comparative genomic analysis of Vibrio cholerae: genes that correlate with cholera endemic and pandemic disease. Proc Natl Acad Sci U S A. 2002 Feb 5;99(3):1556-61.