Louis B Rice, MD
Professor of Medicine
Chief, Medical Service
Louis Stokes Cleveland VA Medical Center
Phone: (216) 791-3800 ext 4806
Fax: (216) 231-3482
E-mail: louis.rice@med.va.gov
Education
AB- Harvard University, 1977
MD- Columbia University College of Physicians and Surgeons, 1983
Residency- New York University Medical Center, 1988
Clinical and Research Fellow in Infectious Diseases- New England Deaconess Hospital and Harvard Medical School, 1990
Research
There are four primary foci of research in my laboratory, some of which is performed in collaboration with my colleagues Robert Bonomo, M.D. and Curtis Donskey, M.D.
The first focus is on the mechanisms of transfer of resistance to antimicrobial agents in enterococci. Specifically, we are investigating the mechanisms by which Enterococcus faecium exchanges genetic copies of ampicillin and vancomycin resistance genes. We believe such genetic exchange has played a significant role in the rapid increase in prevalence of these organisms in U.S. hospitals over the past decade.
The second focus is on the mechanisms by which ampicillin resistance in E. faecium is regulated. Expression of ampicillin resistance in E. faecium is primarily related to mutations found within the low-affinity PBP5. However, levels of resistance expression may vary between strains with identical PBP5s. We are trying to determine the other factors involved in this resistance expression.
The third focus is on the impact of antimicrobial agents in colonization of the gastrointestinal tract with multi-resistant enterococci. Using our mouse model of colonization, we have shown that the tendency of a beta-lactam antibiotic to promote colonization is related to the antibiotics biliary concentration and to its intrinsic anti-enterococcal activity. These findings help explain some of the associations that have been observed in the clinical setting.
The fourth focus is on the mechanisms of resistance to extended spectrum cephalosporins in Enterobacteriaciae. In particular we study the impact of extended-spectrum beta-lactamases on resistance.
NIH Biosketch
Selected References:
• Carias, L.L., Rudin, S.D., Donskey, C.J., Rice, L.B. Genetic linkage and co-transfer of a novel, vanB-containing transposon (Tn5382) and a low-affinity penicillin-binding protein 5 gene in a clinical vancomycin-resistant Enterococcus faecium isolate. J. Bacteriol. 1998 180: 4426-4434.
• Donskey, C. J., Chowdhry, T. K., Hecker, M. T., Hoyen, C. K., Hanrahan, J. A., Hujer, A. M., Hutton-Thomas, R. A., Whalen, C. C., Bonomo, R. A., Rice, L. B. Effect of Antibiotic Therapy on the Density of Vancomycin-Resistant Enterococci in the Stool of Colonized Patients. 2000. N. Eng. J. Med. 343: 1925-32.
• Lobritz, M., Hutton-Thomas, R., Marshall, S., Rice, L.B. Recombination proficiency influences frequency and locus of mutational resistance to linezolid in Enterococcus faecalis. Antimicrob. Agents Chemother. 2003 47: 3318-20.
• Rice, L.B., Carias, L.L., Hutton-Thaomas, R., Bonomo, R.A., Caspers, P., Page, Malcolm G.P., Bellay, S., Gutmann, L. Impact of specific pbp5 mutations on expression of â-lactam resistance in Enterococcus faecium. 2004. Antimicrob. Agents Chemother. 48:3028-32.
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