Patient-Centred Outcomes Following Tracheostomy in Critical Care.

INTRODUCTION: Around 20% of intensive care unit (ICU) patients undergo tracheostomy insertion and expect high-quality care concentrating on patient-centered outcomes including communication, oral intake, and mobilization. The majority of data has focused on timing, mortality, and resource utilization, with a paucity of information on quality of life following tracheostomy. METHODS: Single center retrospective study including all patients requiring tracheostomy from 2017 to 2019. Information collected on demographics, severity of illness, ICU and hospital length of stay (LOS), ICU and hospital mortality, discharge disposition, sedation, time to vocalization, swallow and mobilization. Outcomes were compared for early versus late tracheostomy (early =

Bacterial Staining and Profiling for Glycan Interactions on Glycan Microarrays for t-Test Calculation.

The use of glycan microarrays to study carbohydrate interactions of bacterial cells is of great interest owing to the key roles these interactions play in bacterial colonization and infection of a host. In this chapter, the methods to fluorescently stain Gram-positive or Gram-negative bacteria and profiling them for glycan interactions using glycan microarrays are described in detail. The application of the Student's t-test to glycan microarray data using an example data set comparing glycan microarray binding of an Acinetobacter baumannii wild type and mutant strain is also described in step-by-step detail.

Glycomics Microarrays Reveal Differential In Situ Presentation of the Biofilm Polysaccharide Poly-N-acetylglucosamine on Acinetobacter baumannii and Staphylococcus aureus Cell Surfaces.

The biofilm component poly-N-acetylglucosamine (PNAG) is an important virulence determinant in medical-device-related infections caused by ESKAPE group pathogens including Gram-positive Staphylococcus aureus and Gram-negative Acinetobacter baumannii. PNAG presentation on bacterial cell surfaces and its accessibility for host interactions are not fully understood. We employed a lectin microarray to examine PNAG surface presentation and interactions on methicillin-sensitive (MSSA) and methicillin-resistant S. aureus (MRSA) and a clinical A. baumannii isolate. Purified PNAG bound to wheatgerm agglutinin (WGA) and succinylated WGA (sWGA) lectins only. PNAG was the main accessible surface component on MSSA but was relatively inaccessible on the A. baumannii surface, where it modulated the presentation of other surface molecules. Carbohydrate microarrays demonstrated similar specificities of S. aureus and A. baumannii for their most intensely binding carbohydrates, including 3' and 6'sialyllactose, but differences in moderately binding ligands, including blood groups A and B. An N-acetylglucosamine-binding lectin function which binds to PNAG identified on the A. baumannii cell surface may contribute to biofilm structure and PNAG surface presentation on A. baumannii. Overall, these data indicated differences in PNAG presentation and accessibility for interactions on Gram-positive and Gram-negative cell surfaces which may play an important role in biofilm-mediated pathogenesis.

Assessing Bacterial Interactions Using Carbohydrate-Based Microarrays.

Carbohydrates play a crucial role in host-microorganism interactions and many host glycoconjugates are receptors or co-receptors for microbial binding. Host glycosylation varies with species and location in the body, and this contributes to species specificity and tropism of commensal and pathogenic bacteria. Additionally, bacterial glycosylation is often the first bacterial molecular species encountered and responded to by the host system. Accordingly, characterising and identifying the exact structures involved in these critical interactions is an important priority in deciphering microbial pathogenesis. Carbohydrate-based microarray platforms have been an underused tool for screening bacterial interactions with specific carbohydrate structures, but they are growing in popularity in recent years. In this review, we discuss carbohydrate-based microarrays that have been profiled with whole bacteria, recombinantly expressed adhesins or serum antibodies. Three main types of carbohydrate-based microarray platform are considered; (i) conventional carbohydrate or glycan microarrays; (ii) whole mucin microarrays; and (iii) microarrays constructed from bacterial polysaccharides or their components. Determining the nature of the interactions between bacteria and host can help clarify the molecular mechanisms of carbohydrate-mediated interactions in microbial pathogenesis, infectious disease and host immune response and may lead to new strategies to boost therapeutic treatments.