The continued and inevitable emergence of antibiotic resistance demands a vigorous and sustained effort to identify fundamentally new targets and strategies for innovative antimicrobial therapeutics. Antibiotic-resistant enterococci are major causes of hospital-acquired infections. Enterococci are successful hospital-acquired pathogens in part because of their intrinsic resistance to commonly used antibiotics that target the bacterial cell envelope, such as cephalosporins. However, many questions remain regarding the genetic and biochemical basis for cephalosporin resistance in enterococci. In preliminary studies we identified two widely conserved genes encoding ?conserved hypothetical? proteins of unknown function (termed IreB and IreC) that modulate intrinsic enterococcal cephalosporin resistance. IreB acts as a negative regulator of cephalosporin resistance, while IreC promotes resistance. However, the mechanisms by which IreB and IreC influence cephalosporin resistance are unknown, and few clues are available to guide the development of hypotheses to explain their roles. The research proposed here is designed to elucidate new insights into the roles of IreB and IreC in the biological processes that drive enterococcal cephalosporin resistance. To do so, we will use unbiased, genome-wide genetic approaches to identify cellular factors that influence cephalosporin resistance in cooperation with IreB and IreC. By doing so, the research proposed here will provide new insights into the fundamental biological processes that drive key antibiotic resistance in enterococci and may define new targets for innovative therapeutics designed to impair enterococcal antibiotic resistance.

Public Health Relevance

Antibiotic-resistant bacteria, such as vancomycin-resistant enterococci (VRE) and methicillin- resistant Staphylococcus aureus (MRSA), are major causes of hospital-acquired infections and contribute to an escalating healthcare crisis. The research proposed here promises to reveal new insights into the biological processes driving antibiotic resistance that will facilitate the development of new treatments for infections caused by drug-resistant pathogens. In particular, this work promises to define new targets for innovative therapeutics with potentially unique modes of action.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI132927-02
Application #
9524780
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Huntley, Clayton C
Project Start
2017-07-06
Project End
2019-06-30
Budget Start
2018-07-01
Budget End
2019-06-30
Support Year
2
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Medical College of Wisconsin
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
937639060
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Banla, Leou Ismael; Salzman, Nita H; Kristich, Christopher J (2018) Colonization of the mammalian intestinal tract by enterococci. Curr Opin Microbiol 47:26-31