Multidrug-Resistant Bacteria and Immunocompromised Patients
The Center for Disease Control and Prevention considers multidrug-resistant (MDR) bacteria major threats to public health. Examples include carbapenem-resistant Enterobacteriaceae and vancomycin-resistant Enterococci. The organisms are particularly problematic in immunocompromised hosts, such as patients with neutropenia, low white blood cell counts, and hematologic malignancies. These patients rely on immediate, active antimicrobial therapy to combat infections, making drug-resistant bacteria potentially lethal. Most pathogenic MDR bacteria arise from the gastrointestinal and respiratory tracts, where they reside with large numbers of non-pathogenic and non-cultivatable bacteria. The non-pathogenic bacteria of the microbiome serve as reservoirs for the acquisition and transfer of antibiotic resistance (AR) genes. The understanding of the dynamic process of horizontal gene transfer within the microbiome, however, is limited.
Ilana L. Brito, Meinig School of Biomedical Engineering, is developing novel tools to characterize the presence, abundance, and horizontal transfer of AR genes among pathogenic and non-pathogenic bacteria within the human microbiome. She is collaborating with Michael J. Satlin, Infectious Diseases at Weill Cornell Medicine, to study the spread of AR genes within the microbiomes of neutropenic patients with hematologic malignancies. Examining AR gene carriage in this patient population offers a unique setting to assess the horizontal transfer of AR genes in response to antibiotics, since these patients have prolonged hospitalizations and receive frequent courses of antimicrobial therapy. This population is at very high risk of developing life-threatening infections due to MDR bacteria that they harbor in their gastrointestinal and respiratory tracts.