A Yersiniabactin-producing Klebsiella aerogenes Strain Causing an Outbreak in an Austrian Neonatal Intensive Care Unit.

BACKGROUND: Yersiniabactin, a siderophore with a high affinity to iron, has been described as a potential virulence factor in Enterobacteriaceae. Klebsiella aerogenes is a Gram-negative rod known to cause invasive infection in very low birth weight infants but is an unusual pathogen to cause outbreaks in neonatal intensive care units (NICU). METHODS: We performed a retrospective analysis of all patients colonized with K. aerogenes in our NICU from September to December 2018. Each infant with an occurrence of K. aerogenes in any microbiological culture was defined as a case. Clinical data were taken from medical charts. K. aerogenes isolates were genotyped using whole-genome sequencing combined with core genome multilocus sequencing type analysis. Yersiniabactin production was evaluated by luciferase assay. RESULTS: In total 16 patients were colonized with K. aerogenes over the 3-month period and 13 patients remained asymptomatic or developed late-onset neonatal sepsis from another pathogen. Three patients developed necrotizing enterocolitis, 2 complicated by sepsis and 1 of them died. All symptomatic patients were premature infants with low birth weight. Genetic sequencing confirmed an outbreak with the same strain, all samples expressed the high-pathogenicity island, necessary for the production of yersiniabactin. Six exemplary cases were proven to produce yersiniabactin in vitro. CONCLUSION: This is the first report of an outbreak of a yersiniabactin-producing K. aerogenes strain causing invasive infection in preterm infants. We hypothesize that, due to improved iron uptake, this strain was associated with higher virulence than non-yersiniabactin-producing strains. Extended search for virulence factors and genetic sequencing could be pivotal in the management of NICU outbreaks in the future.

Improvement of outcome prediction of hospitalized patients with COVID-19 by a dual marker strategy using high-sensitive cardiac troponin I and copeptin.

BACKGROUND: COVID-19 has been associated with a high prevalence of myocardial injury and increased cardiovascular morbidity. Copeptin, a marker of vasopressin release, has been previously established as a risk marker in both infectious and cardiovascular disease. METHODS: This prospective, observational study of patients with laboratory-confirmed COVID-19 infection was conducted from June 6th to November 26th, 2020 in a tertiary care hospital. Copeptin and high-sensitive cardiac troponin I (hs-cTnI) levels on admission were collected and tested for their association with the primary composite endpoint of ICU admission or 28-day mortality. RESULTS: A total of 213 eligible patients with COVID-19 were included of whom 55 (25.8%) reached the primary endpoint. Median levels of copeptin and hs-cTnI at admission were significantly higher in patients with an adverse outcome (Copeptin 29.6 pmol/L, [IQR, 16.2-77.8] vs 17.2 pmol/L [IQR, 7.4-41.0] and hs-cTnI 22.8 ng/L [IQR, 11.5-97.5] vs 10.2 ng/L [5.5-23.1], P < 0.001 respectively). ROC analysis demonstrated an optimal cut-off of 19.3 pmol/L for copeptin and 16.8 ng/L for hs-cTnI and an increase of either biomarker was significantly associated with the primary endpoint. The combination of raised hs-cTnI and copeptin yielded a superior prognostic value to individual measurement of biomarkers and was a strong prognostic marker upon multivariable logistic regression analysis (OR 4.274 [95% CI, 1.995-9.154], P < 0.001). Addition of copeptin and hs-cTnI to established risk models improved C-statistics and net reclassification indices. CONCLUSION: The combination of raised copeptin and hs-cTnI upon admission is an independent predictor of ICU admission or 28-day mortality in hospitalized patients with COVID-19.

Red Cell Distribution Width Upon Hospital Admission Predicts Short-Term Mortality in Hospitalized Patients With COVID-19: A Single-Center Experience.

Background: Coronavirus disease (COVID-19) was first described at the end of 2019 in China and has since spread across the globe. Red cell distribution width (RDW) is a potent prognostic marker in several medical conditions and has recently been suggested to be of prognostic value in COVID-19. Methods: This retrospective, observational study of consecutive patients with COVID-19 was conducted from March 12, 2020 to December 4, 2020 in the Wilhelminenhospital, Vienna, Austria. RDWlevels on admission were collected and tested for their predictive value of 28-day mortality. Results: A total of 423 eligible patients with COVID-19 were included in the final analyses and 15.4% died within 28 days (n = 65). Median levels of RDWwere significantly higher in non-survivors compared to survivors [14.6% (IQR, 13.7-16.3) vs. 13.4% (IQR, 12.7- 14.4), P < 0.001]. Increased RDW was a significant predictor of 28-day mortality [crude odds ratio (OR) 1.717, 95% confidence interval (CI) 1.462-2.017; P = < 0.001], independent of clinical confounders, comorbidities and established prognostic markers of COVID-19 (adjusted OR of the final model 1.368, 95% CI 1.126-1.662; P = 0.002). This association remained consistent upon sub-group analysis. Our study data also demonstrate that RDW levels upon admission for COVID-19 were similar to previously recorded, non-COVID-19 associated RDW levels [14.2% (IQR, 13.3-15.7) vs. 14.0% [IQR, 13.2-15.1]; P = 0.187]. Conclusions: In this population, RDWwas a significant, independent prognostic marker of short-term mortality in patients with COVID-19.

Mid-regional pro-atrial natriuretic peptide independently predicts short-term mortality in COVID-19.

BACKGROUND: Mid-regional pro-atrial natriuretic peptide (MR-proANP) is a strong prognostic marker in several inflammatory, respiratory and cardiovascular conditions, but has not been studied in COVID-19 yet. METHODS: This prospective, observational study of patients with COVID-19 infection was conducted from 6 June to 26 November 2020 in different wards of a tertiary hospital. MR-proANP, N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitive cardiac troponin I levels on admission were collected and tested for their association with disease severity and 28-day mortality. RESULTS: A total of 213 eligible patients with COVID-19 were included in the final analyses of whom 13.2% (n = 28) died within 28 days. Median levels of MR-proANP at admission were significantly higher in nonsurvivors (307 pmol/L IQR, [161 - 532] vs 75 pmol/L [IQR, 43 - 153], P < .001) compared to survivors and increased with disease severity and level of hypoxaemia. The area under the ROC curve for MR-proANP predicting 28-day mortality was 0.832 (95% CI 0.753 - 0.912, P < .001). An optimal cut-off point of 160 pmol/L yielded a sensitivity of 82.1% and a specificity of 76.2%. MR-proANP was a significant predictor of 28-day mortality independent of clinical confounders, comorbidities and established prognostic markers of COVID-19 (HR 2.77, 95% CI 1.21 - 6.37; P = .016), while NT-proBNP failed to independently predict 28-day mortality and had a numerically lower AUC compared to MR-proANP. CONCLUSION: Higher levels of MR-proANP at admission are associated with disease severity of COVID-19 and act as a powerful and independent prognostic marker of 28-day mortality.

Decreasing Clostridium difficile infections by an antimicrobial stewardship program that reduces moxifloxacin use.

Clostridium difficile infections (CDI) in hospitalized patients are known to be closely related to antibiotic exposure. Although several substances can cause CDI, the risk differs between individual agents. In Vienna and other eastern parts of Austria, CDI ribotype 027 is currently highly prevalent. This ribotype has the characteristic of intrinsic moxifloxacin resistance. Therefore, we hypothesized that moxifloxacin restriction can decrease the number of CDI cases in hospitalized patients. Our antibiotic stewardship (ABS) group applied an information campaign on CDI and formal restriction of moxifloxacin in Wilhelminenspital (Vienna, Austria), a 1,000- bed tertiary care hospital. The preintervention period (period 1) was January through May 2013, and the intervention period (period 2) was June through December 2013. We recorded the defined daily doses (DDD) of moxifloxacin and the number of CDI patients/month. Moxifloxacin use was reduced from a mean (±standard error of the mean [SEM]) of 1,038±109 DDD per month (period 1) to 42±10 DDD per month (period 2) (P=0.0045). Total antibiotic use was not affected. The mean (±SEM) numbers of CDI cases in period 1 were 59±3 per month and in period 2 were 32±3 per month (46% reduction; P=0.0044). Reducing moxifloxacin use in combination with providing structured information on CDI was associated with an immediate decrease in CDI rates in this large community teaching hospital.