Antibiotic use during coronavirus disease 2019 intensive care unit shape multidrug resistance bacteriuria: A Swedish longitudinal prospective study.

Objectives: High frequency of antimicrobial prescription and the nature of prolonged illness in COVID-19 increases risk for complicated bacteriuria and antibiotic resistance. We investigated risk factors for bacteriuria in the ICU and the correlation between antibiotic treatment and persistent bacteria. Methods: We conducted a prospective longitudinal study with urine from indwelling catheters of 101 ICU patients from Uppsala University Hospital, Sweden. Samples were screened and isolates confirmed with MALDI-TOF and whole genome sequencing. Isolates were analyzed for AMR using broth microdilution. Clinical data were assessed for correlation with bacteriuria. Results: Length of stay linearly correlated with bacteriuria (R2 = 0.99, p ≤ 0.0001). 90% of patients received antibiotics, primarily the beta-lactams (76%) cefotaxime, piperacillin-tazobactam, and meropenem. We found high prevalence of Enterococcus (42%) being associated with increased cefotaxime prescription. Antibiotic-susceptible E. coli were found to cause bacteriuria despite concurrent antibiotic treatment when found in co-culture with Enterococcus. Conclusion: Longer stays in ICUs increase the risk for bacteriuria in a predictable manner. Likely, high use of cefotaxime drives Enterococcus prevalence, which in turn permit co-colonizing Gram-negative bacteria. Our results suggest biofilms in urinary catheters as a reservoir of pathogenic bacteria with the potential to develop and disseminate AMR.

Elastase- and LPS-Exposed Cpa3Cre/+ and ST2-/- Mice Develop Unimpaired Obstructive Pulmonary Disease.

IL-33 and its receptor ST2, as well as mast cells and their mediators, have been implicated in the development of chronic obstructive pulmonary disease (COPD). However, whether mast cells and the ST2 receptor play a critical role in COPD pathophysiology remains unclear. Here, we performed repeated intranasal administrations of porcine pancreatic elastase and LPS for four weeks to study COPD-like disease in wildtype, ST2-deficient, and Cpa3Cre/+ mice, which lack mast cells and have a partial reduction in basophils. Alveolar enlargement and changes in spirometry-like parameters, e.g. increased dynamic compliance and decreased expiratory capacity, were evident one day after the final LPS challenge and worsened over time. The elastase/LPS model also induced mild COPD-like airway inflammation, which encompassed a transient increase in lung mast cell progenitors, but not in mature mast cells. While ST2-deficient and Cpa3Cre/+ mice developed reduced pulmonary function uninterruptedly, they had a defective inflammatory response. Importantly, both ST2-deficient and Cpa3Cre/+ mice had fewer alveolar macrophages, known effector cells in COPD. Elastase/LPS instillation in vivo also caused increased bronchiole contraction in precision cut lung slices challenged with methacholine ex vivo, which occurred in a mast cell-independent fashion. Taken together, our data suggest that the ST2 receptor and mast cells play a minor role in COPD pathophysiology by sustaining alveolar macrophages.

Fluid deficits during prolonged overnight fasting in young healthy adults.

BACKGROUND: Overnight fasting is often prolonged before scheduled surgery, and the extent of perioperative fluid replacement may influence outcome. In clinical practice, basic requirements are estimated at 1.2-2.0 mL·kg-1 ·h-1 , but there is little contemporary clinical data on what deficits result from complete fasting. This prospective preclinical study was designed to determine total fluid loss during overnight fasting, prolonged during daytime. METHODS: Twenty (10 female) healthy adult volunteers, aged 24 (range 21-46) years, fasted from 22:00 until 16:00, and had their body weight and urine output measured at predefined time intervals. RESULTS: The median (interquartile range) fluid deficits were 0.82 (0.73-1.00) kg, corresponding to 1.26 (1.11-1.41) g·kg-1 ·h-1 for the initial overnight fasting period, 0.59 (0.40-0.70) kg and 0.99 (0.83-1.31) g·kg-1 ·h-1 for the consecutive daytime period, and 1.47 (1.27-1.64) kg and 1.19 (1.05-1.28) g·kg-1 ·h-1 for the total period of fasting. Urine output accounted for 52% of total weight loss and was 36% of the baseline hourly level during the last four-hour period of fasting. CONCLUSIONS: Ten hours of overnight fasting in young adults induces fluid deficits at the lower limit of estimated intervals referred to in clinical practice, and hourly weight loss gradually decreases further during prolonged daytime fasting. These findings indicate that current routine procedures do slightly overestimate fluid deficits resulting from prolonged fasting in perioperative clinical practice.

A methodological study of locus coeruleus degeneration in dementing disorders.

BACKGROUND: Degeneration of the locus coeruleus (LC) of the brain stem is a recognized phenomenon in Alzheimer's disease (AD), in dementia with Lewy bodies (DLB), and in Parkinson's disease with dementia (PDD). Prior studies have suggested that LC degeneration can be used to differentiate various dementing disorders histologically, but the paucity of methodological data may hamper systematic research on this nucleus. PURPOSE: The purpose of this study was to evaluate various approaches to quantifying LC degeneration in dementing disorders, and to inform future decisions regarding the most appropriate method for diagnostics and research. METHODS: 105 LCs from brains of demented individuals with AD, DLB/PDD, vascular dementia (VaD), mixed dementia (AD+VaD), or frontotemporal lobar degeneration (FTLD) were examined, and the extent of LC degeneration was assessed using macroscopic evaluation, cell counting, and two degeneration scales. Scores were compared across diagnostic categories; diagnostic utility and intra- and interobserver reliability were assessed. RESULTS: AD and DLB/PDD were associated with greater LC damage using either assessment method, significantly different from VaD and FTLD. Macroscopic appearance was informative, but cell counting was more sensitive and specific. The degeneration scales did not add significant diagnostic value over cell counting and were associated with greater observer variability. CONCLUSIONS: The LC degenerates in certain dementia subtypes, especially in AD and DLB/PDD. Macroscopic assessment of the LC postmortem can be used to differentiate between disorders associated with degeneration (AD, DLB/PDD) or sparing (VaD) of the LC, but counting LC cells in a representative pontine section is the most appropriate method by which to assess LC degeneration.

Interleukin-1 system in CNS stress: seizures, fever, and neurotrauma.

Proteins of the interleukin-1 (IL-1) system include the secreted agonist IL-1beta, and the receptor antagonist IL-1ra, both competing for binding to the IL-1 receptor (IL-1R). IL-1beta and IL-1ra are highly inducible under different forms of stress, such as excitatory neurotransmitter excess occurring during seizures, in infection and inflammation, and during neurotrauma. In each of these conditions induction of IL-1beta precedes that of IL-1ra, resulting in up to 10-20-fold elevation of IL-1beta concentrations. Consequently, IL-1beta induces the elevation of other proinflammatory molecules, including IL-6, IL-1R1, COX2, and iNOS, as well as of IL-1ra. Elevation of IL-1ra is of key importance for quenching the inflammatory response at the IL-1R1 as part of an autoregulatory loop. In seizures, IL-1ra is a strong anticonvulsant and in IL-1beta-dependent fever, a powerful antipyretic. In traumatic brain injury (TBI), the ability of patients to mount an IL-1ra response, as measured in the CSF, strongly correlated with the neurological outcome. Selective induction or pharmacological application of IL-1ra may be sparing neurons in seizures and neurotrauma.