Host-Pathogen Interface: Progress in Understanding the Pathogenesis of Infection Due to Multidrug-Resistant Bacteria in the Intensive Care Unit

Abstract

The diverse responses of critically ill patients to infection with multi-drug resistant (MDR) bacteria are determined by many complex factors. These include the nature of the immune response activated by specific organisms. Properties unique to each organism such as adherence proteins, microvesicle formation, toxin production and the propensity to form biofilms are important factors in pathogenesis. Equally important is the variability in the host immune response, whether due to genetic or iatrogenic factors, including the presence of major comorbidities, treatment with immunomodulatory therapy and disruption of the microbiome. Future approaches in treating infections caused by MDR bacteria will be heavily influenced by a precision medicine approach, with rapid diagnostic techniques of both bacterial and host factors and high throughput screening of novel therapeutics becoming the mainstay of treatment.

Keywords: ICU; MDR-bacteria; pathogenesis; therapeutics.

Figure 1.

(A) Murine model of green fluorescent protein (GFP)–labeled carbapenemase-producing Klebsiella pneumoniae ST258 in the alveoli as seen with in vivo confocal microscopy. (B) Magnified image of the dashed box in Panel A. Red represents calcein red; green, GFP-labeled K. pneumoniae. (Courtesy of Jaime Hook, MD, Columbia University Medical Center.)