Impact of dementia on 30-, 180-, and 365-day mortality during the first pandemic wave in older adults seen in spanish emergency departments diagnosed with or without COVID-19

OBJECTIVES

To assess whether dementia is an independent predictor of death after a hospital emergency department (ED) visit by older adults with or without a COVID-19 diagnosis during the first pandemic wave.

METHOD

We used data from the EDEN-Covid (Emergency Department and Elderly Needs during Covid) cohort formed by all patients ≥65 years seen in 52 Spanish EDs from March 30 to April 5, 2020. The association of prior history of dementia with mortality at 30, 180 and 365 d was evaluated in the overall sample and according to a COVID-19 or non COVID diagnosis.

RESULTS

We included 9,770 patients aged 78.7 ± 8.3 years, 51.1% men, 1513 (15.5%) subjects with prior history of dementia and 3055 (31.3%) with COVID-19 diagnosis. 1399 patients (14.3%) died at 30 d, 2008 (20.6%) at 180 days and 2456 (25.1%) at 365 d. The adjusted Hazard Ratio (aHR) for age, sex, comorbidity, disability and diagnosis for death associated with dementia were 1.16 (95% CI 1.01-1.34) at 30 d; 1.15 at 180 d (95% CI 1.03-1.30) and 1.19 at 365 d (95% CI 1.07-1.32), p < .001. In patients with COVID-19, the aHR were 1.26 (95% CI: 1.04-1.52) at 30 days; 1.29 at 180 d (95% CI: 1.09-1.53) and 1.35 at 365 d (95% CI: 1.15-1.58).

CONCLUSION

Dementia in older adults attending Spanish EDs during the first pandemic wave was independently associated with 30-, 180- and 365-day mortality. This impact was lower when adjusted for age, sex, comorbidity and disability, and was greater in patients diagnosed with COVID-19.

Quorum sensing signal profile of Acinetobacter strains from nosocomial and environmental sources

A set of 43 strains corresponding to 20 classified and unclassified genomic Acinetobacter species was analyzed for the production of typical N-acyl homoserine lactone quorum sensing molecules in culture broths. A large percentage of the strains (74%) displayed quorum sensing signals that could be separated into three statistically significantly different chromatographic groups (p < 0.001) based on their retention factor in TLC, i.e., Rf1 (0.22 +/- 0.02); Rf2 (0.40 +/- 0.02) and Rf3 (0.54 +/- 0.02). Noteworthy, 63% of the strains tested produced more than one quorum signal. The frequency of signal appearance was Rf3 > Rf2 > Rf1. None of the three signals could be specifically assigned to a particular species in the genus; furthermore, no distinction could be made between the quorum sensing signals secreted by typical opportunistic strains of the A. calcoaceticus-A. baumannii complex, isolated from patients, with respect to the other species of the genus, except for the Rf1 signal which was present in all the QS positive strains belonging to this complex and DNA group 13 TU. In conclusion, quorum sensors in Acinetobacter are not homogenously distributed among species and one of them is present in most of the A. calcoaceticus-baumannii complex.

Detection and characterization of quorum sensing signal molecules in Acinetobacter strains

Quorum sensing is a widespread regulatory mechanism among Gram-negative bacteria. In this study, Acinetobacter strains were assayed for the presence of quorum sensing signal molecules capable of activating N-acylhomoserine lactone biosensors. By using an Agrobacterium tumefaciens reporter strain it was shown that all the cultures produced two to four detectable signal molecules with different chromatographic patterns. In A. calcoaceticus BD413 supernatants four compounds were detected in a time-dependent manner, and maximal activity was reached at stationary phase. The number of signal molecules was dependent on medium composition; typically, cultures in minimal medium displayed one or two more signals, as compared to complex medium. None of the Acinetobacter supematants showed autoinduction activity with an Chromobacterium violaceum reporter strain, neither in direct or competition assays.