Jose A. Lemos, Ph.D.

Jose A. Lemos, Ph.D.

Contact Information

University of Rochester Medical Center
School of Medicine and Dentistry
601 Elmwood Ave, Box 611
Rochester, NY 14642

Office: (585) 275-1850
Lab: (585) 275-1433
Fax: (585) 276-0190

Lab Information

Molecular Genetics and Physiology of the Response to Environmental Stresses by Oral Bacteria.

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Research Bio

Research: Molecular Genetics and Physiology of the Response to Stresses by Streptococci and Enterococci.

The research in my laboratory is focused on characterization of the stress responses by streptococci and enterococci. To accomplish our goals, we use a variety of state-of-the-art molecular and biochemical techniques, that include physiologic, enzymatic, genomic and proteomic approaches. The specific projects in the laboratory are divided in two major areas; (i) the role of the Streptococcus mutans stress regulon in biofilm formation, persistence and virulence, and (ii) characterization of the stringent response of Enterococcus faecalis.

1. Streptococcus mutans
Streptococcus mutans, a common inhabitant of dental biofilms, is recognized as a major etiologic agent of human dental caries. Despite significant progress in treatment and prevention, dental caries remains among the most common infectious diseases afflicting humans and results in an enormous health and economic burden worldwide. The virulence of S. mutans resides in three core attributes; its abilities to adhere and form biofilms on tooth surfaces, to produce large quantities of organic acids from a wide range of carbohydrates, and to tolerate environmental stresses, particularly low pH. Because stress tolerance is intertwined with S. mutans virulence, the dissection of the mechanisms that allow these bacteria to thrive in oral biofilms during stressful conditions is central for a complete understanding of the pathogenesis of dental caries. Our current efforts focus on the characterization of the Spx global regulator, and its role in controlling stress response and biofilm formation in S. mutans.

2. Enterococcus faecalis
The opportunistic pathogen Enterococus faecalis, a natural inhabitant of the human intestinal flora, is one of the leading causes of hospital-acquired infections, including endocarditis, bacteremia, and urinary tract and soft tissue infections. This organism has a remarkable ability to thrive in a variety of adverse environments, including an innate and acquired resistance to multiple antibiotics. Recently, we found that the stringent response, a key bacterial system for adaptation to changing environments, plays a key role in the ability of E. faecalis to tolerate the human host defenses and antimicrobial therapies. The objective of this study is to fully understand how, and to what extent, the stringent response controls the expression of virulence factors, and of antibiotic tolerance in E. faecalis.

Recent Journal Articles

Showing the 5 most recent journal articles. 32 available »

2012 Aug
Gaca AO, Abranches J, Kajfasz JK, Lemos J. "Global transcriptional analysis of the stringent response in Enterococcus faecalis." Microbiology. 2012 Aug; 158(Pt 8):1994-2004. Epub 2012 May 31.
2012 Jul
Kajfasz JK, Mendoza JE, Gaca AO, Miller JH, Koselny KA, Giambiagi-Demarval M, Wellington M, Abranches J, Lemos JA. "The Spx regulator modulates stress responses and virulence in Enterococcus faecalis." Infection and immunity. 2012 Jul; 80(7):2265-75. Epub 2012 Apr 16.
2012 Mar
Chávez de Paz LE, Lemos JA, Wickström C, Sedgley CM. "Role of (p)ppGpp in biofilm formation by Enterococcus faecalis." Applied and environmental microbiology. 2012 Mar; 78(5):1627-30. Epub 2011 Dec 16.
2011 Oct
Kajfasz JK, Abranches J, Lemos JA. "Transcriptome analysis reveals that ClpXP proteolysis controls key virulence properties of Streptococcus mutans." Microbiology. 2011 Oct; 157(Pt 10):2880-90. Epub 2011 Aug 04.
2011 Jun
Abranches J, Miller JH, Martinez AR, Simpson-Haidaris PJ, Burne RA, Lemos JA. "The collagen-binding protein Cnm is required for Streptococcus mutans adherence to and intracellular invasion of human coronary artery endothelial cells." Infection and immunity. 2011 Jun; 79(6):2277-84. Epub 2011 Mar 21.


PhD | Medical Microbiology | Brazil-Federal U, Rio de Janeiro2000
MS | Microbiology | Brazil-Federal U, Rio de Janeiro1995
BS | Biology | Brazil-Santa Ursula University1990

Post-Doctoral Training & Residency

Postdoctoral Fellow, Department of Oral Biology, University of Florida, Gainesville, FL 2002
Postdoctoral Fellow, Center for Oral Biology, University of Rochester, Rochester, NY. 2001