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.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI042135-13
Application #
7805587
Study Section
Host Interactions with Bacterial Pathogens Study Section (HIBP)
Program Officer
Huntley, Clayton C
Project Start
1998-06-01
Project End
2014-04-30
Budget Start
2010-05-01
Budget End
2011-04-30
Support Year
13
Fiscal Year
2010
Total Cost
$469,260
Indirect Cost
Name
Sloan-Kettering Institute for Cancer Research
Department
Type
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10065
Pamer, Eric G (2017) Microbial Tuning of the Mammalian Immune System. Trends Mol Med 23:379-380
Caballero, Silvia; Kim, Sohn; Carter, Rebecca A et al. (2017) Cooperating Commensals Restore Colonization Resistance to Vancomycin-Resistant Enterococcus faecium. Cell Host Microbe 21:592-602.e4
Becattini, Simone; Littmann, Eric R; Carter, Rebecca A et al. (2017) Commensal microbes provide first line defense against Listeria monocytogenes infection. J Exp Med 214:1973-1989
Weber, Daniela; Jenq, Robert R; Peled, Jonathan U et al. (2017) Microbiota Disruption Induced by Early Use of Broad-Spectrum Antibiotics Is an Independent Risk Factor of Outcome after Allogeneic Stem Cell Transplantation. Biol Blood Marrow Transplant 23:845-852
Dubin, Krista; Callahan, Margaret K; Ren, Boyu et al. (2016) Intestinal microbiome analyses identify melanoma patients at risk for checkpoint-blockade-induced colitis. Nat Commun 7:10391
Westblade, Lars F; van Belkum, Alex; Grundhoff, Adam et al. (2016) Role of Clinicogenomics in Infectious Disease Diagnostics and Public Health Microbiology. J Clin Microbiol 54:1686-93
Lewis, Brittany B; Carter, Rebecca A; Pamer, Eric G (2016) Bile acid sensitivity and in vivo virulence of clinical Clostridium difficile isolates. Anaerobe 41:32-36
Abt, Michael C; McKenney, Peter T; Pamer, Eric G (2016) Clostridium difficile colitis: pathogenesis and host defence. Nat Rev Microbiol 14:609-20
Pamer, Eric G (2016) Resurrecting the intestinal microbiota to combat antibiotic-resistant pathogens. Science 352:535-8
Becattini, Simone; Taur, Ying; Pamer, Eric G (2016) Antibiotic-Induced Changes in the Intestinal Microbiota and Disease. Trends Mol Med 22:458-78

Showing the most recent 10 out of 61 publications