Infections caused by highly antibiotic-resistant microbes are an increasing problem in hospitalized patients. Many of these infections occur following antibiotic therapy, an intervention that promotes colonization with highly antibiotic-resistant bacteria. Although elimination of commensal bacteria opens up physical and nutrient niches that enhance growth of antibiotic resistant microbes, results from our laboratory suggest that antibiotics also compromise innate immune defenses on mucosal surfaces by interfering with homeostatic stimulation of innate immune receptors by commensal flora. The focus of this application is to characterize the relationship between intestinal microbes and the mucosal innate immune system. Our experimental approach will be to manipulate the commensal flora or the innate immune system and measure the host's ability to resist colonization and infection by Vancomycin-resistant enterococcus (VRE) and carbapenem-resistant Klebsiella pneumoniae (KPC), two highly antibiotic resistant bacteria that are emerging causes of severe, frequently lethal infections.
Our first aim i s to characterize the effect of distinct antibiotics on the commensal flora of the murine gut and the downstream effect of antibiotics on the expression of innate immune effector molecules by the intestinal epithelium.
The second aim of our studies is to determine the effect of innate immune receptor deficiencies on the flora of the murine intestinal tract. These studies will take advantage of a large panel of TLR and signaling adaptor mutant mouse strains in our animal colony.
Our third aim i s to test the ability of different microbial molecules or analogs to stimulate innate immune defense against VRE and KPC in mice depleted of commensal flora by antibiotic treatment. We believe these studies will provide important insights into the two-way relationship between the microbial flora and the intestinal epithelium. Our studies are likely to provide new approaches to prevent or limit infections caused by highly antibiotic-resistant bacteria.

Public Health Relevance

Infections with highly antibiotic-resistant bacteria are an increasingly common problem in patients being treated with antibiotics. We have discovered that antibiotics, by eliminating normal bacteria inhabiting the intestine, compromise the ability of the intestinal lining to resist attack by antibiotic-resistant bacteria. Our experiments will determine which normal intestinal bacteria are important for the maintenance of antimicrobial resistance in the intestine, and which mammalian molecules are responsible for detecting normal bacteria in the intestine.
Our third aim i s to discover whether administration of molecules derived from bacteria can reverse the increased susceptibility to infection induced by antibiotic administration.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Host Interactions with Bacterial Pathogens Study Section (HIBP)
Program Officer
Huntley, Clayton C
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Sloan-Kettering Institute for Cancer Research
New York
United States
Zip Code
Pickard, Joseph M; Maurice, Corinne F; Kinnebrew, Melissa A et al. (2014) Rapid fucosylation of intestinal epithelium sustains host-commensal symbiosis in sickness. Nature 514:638-41
Abt, Michael C; Pamer, Eric G (2014) Commensal bacteria mediated defenses against pathogens. Curr Opin Immunol 29:16-22
Pamer, E G (2014) Fecal microbiota transplantation: effectiveness, complexities, and lingering concerns. Mucosal Immunol 7:210-4
Kinnebrew, Melissa A; Lee, Yeon Joo; Jenq, Robert R et al. (2014) Early Clostridium difficile infection during allogeneic hematopoietic stem cell transplantation. PLoS One 9:e90158
Taur, Ying; Jenq, Robert R; Perales, Miguel-Angel et al. (2014) The effects of intestinal tract bacterial diversity on mortality following allogeneic hematopoietic stem cell transplantation. Blood 124:1174-82
van Heijst, Jeroen W J; Ceberio, Izaskun; Lipuma, Lauren B et al. (2013) Quantitative assessment of T cell repertoire recovery after hematopoietic stem cell transplantation. Nat Med 19:372-7
Taur, Ying; Pamer, Eric G (2013) The intestinal microbiota and susceptibility to infection in immunocompromised patients. Curr Opin Infect Dis 26:332-7
Ubeda, Carles; Bucci, Vanni; Caballero, Silvia et al. (2013) Intestinal microbiota containing Barnesiella species cures vancomycin-resistant Enterococcus faecium colonization. Infect Immun 81:965-73
Buffie, Charlie G; Pamer, Eric G (2013) Microbiota-mediated colonization resistance against intestinal pathogens. Nat Rev Immunol 13:790-801
Buffie, Charlie G; Jarchum, Irene; Equinda, Michele et al. (2012) Profound alterations of intestinal microbiota following a single dose of clindamycin results in sustained susceptibility to Clostridium difficile-induced colitis. Infect Immun 80:62-73

Showing the most recent 10 out of 37 publications