Plasmid-encoded gene duplications of extended-spectrum ß-lactamases in clinical bacterial isolates.

Introduction: The emergence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae is an urgent and alarming One Health problem. This study aimed to investigate duplications of plasmid-encoded ESBL genes and their impact on antimicrobial resistance (AMR) phenotypes in clinical and screening isolates. Methods: Multi-drug-resistant bacteria from hospitalized patients were collected during routine clinical surveillance from January 2022 to June 2023, and their antimicrobial susceptibility patterns were determined. Genotypes were extracted from long-read whole-genome sequencing data. Furthermore, plasmids and other mobile genetic elements associated with ESBL genes were characterized, and the ESBL genes were correlated to ceftazidime minimal inhibitory concentration (MIC). Results: In total, we identified four cases of plasmid-encoded ESBL gene duplications that match four genetically similar plasmids during the 18-month surveillance period: five Escherichia coli and three Klebsiella pneumoniae isolates. As the ESBL genes were part of transposable elements, the surrounding sequence regions were duplicated as well. In-depth analysis revealed insertion sequence (IS)-mediated transposition mechanisms. Isolates with duplicated ESBL genes exhibited a higher MIC for ceftazidime in comparison to isolates with a single gene copy (3-256 vs. 1.5-32 mg/L, respectively). Conclusion: ESBL gene duplications led to an increased phenotypic resistance against ceftazidime. Our data suggest that ESBL gene duplications by an IS-mediated transposition are a relevant mechanism for how AMR develops in the clinical setting and is part of the microevolution of plasmids.

Characterization of blaOXA-48-carrying plasmids and small non-AMR-coding plasmids collected from Ukrainian patients.

PURPOSE: Carbapenemase-producing Enterobacterales (CPE) pose a serious threat for healthcare facilities worldwide, yet the mode of transmission is often unclear. Recently, we recorded an increase of blaOXA-48-harboring isolates at our hospital associated with patients with previous medical treatment in the Ukraine. We used long-read whole genome sequencing (lrWGS) to characterize these isolates including their plasmids. METHODS: Samples were collected as part of clinical routine diagnostic or screening of multi-drug resistance bacteria (MDRB). Antimicrobial susceptibility testing was performed and all MDRB (n = 10) were sequenced by lrWGS for genotyping, identification of antimicrobial resistance (AMR) genes, and characterization of plasmids. RESULTS: While routine analysis of core genome multilocus sequence typing (cgMLST) did not show any genetic similarities between isolates, we found an unexpected high similarity in the plasmid diversity of different Enterobacterales in patients with previous medical treatment in the Ukraine. This included an IncL/M plasmid carrying blaOXA-48 and additional small non-AMR-coding plasmids. CONCLUSION: Our results show that lrWGS can be used in the routine setting to uncover similarities in plasmids and may give further information about potential epidemiologic associations. In the future, analysis of both AMR and non-AMR plasmids may provide an additional layer of information for molecular surveillance of CPE.

Effects of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) on the Glucose and Fat Metabolism Biomarkers Leptin and Fructosamine.

(1) Background: Heart failure with reduced ejection fraction (HFrEF) remains a major health burden. Angiotensin-Receptor-Neprilysin-Inhibitors (ARNIs) are an established HFrEF therapy which increases natriuretic peptide levels by inhibiting neprilysin. Leptin is a lipid metabolism parameter, which is also involved in glucose metabolism and is suggested to correlate with HF burden. While the hormone also seems to interact with neprilysin, potential associations with ARNI therapy have not been investigated yet. (2) Methods: To study this issue, we measured levels of leptin and fructosamine in consecutive 72 HFrEF patients before initiation of ARNI therapy and 3-6 months after initiation of therapy in two European centers. Biomarker levels were correlated with clinical parameters including ejection fraction, LVEF, and NYHA class. (3) Results: During a follow-up of up to 6 months, clinical parameters improved significantly (LVEF: 30.2 ± 7.8% to 37.6 ± 10.0%, (p < 0.001) and a significant improvement of the mean NYHA class with initial 32 patients in NYHA III or IV and 8 patients in NYHA class III/IV during the follow up (p < 0.001). The initial NT-proBNP levels of 2251.5 ± 2566.8 pg/mL significantly improved to 1416.7 ± 2145 pg/mL, p = 0.008) during follow up. ARNI therapy was also associated with an increase in leptin levels (17.5 ± 23.4 µg/L to 22.9 ± 29.3, p < 0.001) and furthermore, affected glucose metabolism indicated by elevation of fructosamine values (333.9 ± 156.8 µmol/L to 454.8 ± 197.8 µmol/L, p = 0.013). (4) Conclusion: while in the early phase of therapy, ARNI promotes clinical improvement of HFrEF, and it also seems to affect fat and glucose parameters, indicating significant metabolic implications of this therapy regime.

Gender-Specific Differences in the Intensive Care Treatment of COVID-19 Patients.

BACKGROUND: Gender-specific differences in the outcome of COVID-19 patients requiring intensive care treatment have been reported. However, a potential association with ICU therapy remains elusive. METHODS: A total of 224 consecutive patients (63 women) treated for severe COVID-19 disease requiring mechanical ventilation were screened for the study. After propensity score matching for gender, 40 men and 40 women were included in the study. Comparative analysis was conducted for laboratory parameters, ICU therapy and complications (pulmonary embolism, thrombosis, stroke, and ventricular arrhythmias), and outcome (mortality). RESULTS: Male patients had significantly higher levels of CRP (p = 0.012), interleukin-6 (p = 0.020) and creatinine (p = 0.027), while pH levels (p = 0.014) were significantly lower compared to females. Male patients had longer intubation times (p = 0.017), longer ICU stays (p = 0.022) and higher rates of catecholamine dependence (p = 0.037). Outcome, complications and ICU therapy did not differ significantly between both groups. CONCLUSION: The present study represents the first matched comparison of male and female COVID-19 patients requiring intensive care treatment. After propensity matching, male patients still displayed a higher disease severity. This was reflected in higher rates of vasopressors, duration of ICU stay and duration of intubation. In contrast, no significant differences were observed in mortality rates, organ replacement therapy and complications during ICU stay.

The Use of Long-Read Sequencing Technologies in Infection Control: Horizontal Transfer of a blaCTX-M-27 Containing lncFII Plasmid in a Patient Screening Sample.

Plasmid transfer is one important mechanism how antimicrobial resistance can spread between different species, contributing to the rise of multidrug resistant bacteria (MDRB) worldwide. Here were present whole genome sequencing (WGS) data of two MDRB isolates, an Escherichia coli and a Klebsiella quasipneumoniae, which were isolated from a single patient. Detailed analysis of long-read sequencing data identified an identical F2:A-:B- lncFII plasmid containing blaCTX-M-27 in both isolates, suggesting horizontal plasmid exchange between the two species. As the plasmid of the E. coli strain carried multiple copies of the resistance cassette, the genomic data correlated with the increased antimicrobial resistance (AMR) detected for this isolate. Our case report demonstrates how long-read sequencing data of MDRB can be used to investigate the role of plasmid mediate resistance in the healthcare setting and explain resistance phenotypes.

Dexamethasone Improves Cardiovascular Outcomes in Critically Ill COVID-19, a Real World Scenario Multicenter Analysis.

BACKGROUND: Severe COVID-19 pneumonia requiring intensive care treatment remains a clinical challenge to date. Dexamethasone was reported as a promising treatment option, leading to a reduction of mortality rates in severe COVID-19 disease. However, the effect of dexamethasone treatment on cardiac injury and pulmonary embolism remains largely elusive. METHODS: In total 178 critically ill COVID-19 patients requiring intensive care treatment and mechanical ventilation were recruited in three European medical centres and included in the present retrospective study. One hundred thirteen patients (63.5%) were treated with dexamethasone for a median duration of 10 days (IQR 9-10). Sixty five patients (36.5%) constituted the non-dexamethasone control group. RESULTS: While peak inflammatory markers were reduced by dexamethasone treatment, the therapy also led to a significant reduction in peak troponin levels (231 vs. 700% indicated as relative to cut off value, p = 0.001). Similar, dexamethasone resulted in significantly decreased peak D-Dimer levels (2.16 mg/l vs. 6.14 mg/l, p = 0.002) reflected by a significant reduction in pulmonary embolism rate (4.4 vs. 20.0%, p = 0.001). The antithrombotic effect of dexamethasone treatment was also evident in the presence of therapeutic anticoagulation (pulmonary embolism rate: 6 vs. 34.4%, p < 0.001). Of note, no significant changes in baseline characteristics were observed between the dexamethasone and non-dexamethasone group. CONCLUSION: In severe COVID-19, anti-inflammatory effects of dexamethasone treatment seem to be associated with a significant reduction in myocardial injury. Similar, a significant decrease in pulmonary embolism, independent of anticoagulation, was evident, emphasizing the beneficial effect of dexamethasone treatment in severe COVID-19.

Rapid detection of carbapenemase-producing Acinetobacter baumannii and carbapenem-resistant Enterobacteriaceae using a bioluminescence-based phenotypic method.

Accurate detection of carbapenem-resistant Enterobacteriaceae (CRE) and carbapenemase-producing carbapenem-resistant Acinetobacter spp. (CP-CRA) constitutes a major challenge in laboratory diagnostics. We developed a bioluminescence-based carbapenem susceptibility detection assay (BCDA) which allows identification of CRE (carbapenemase-producing-CRE (CP-CRE) as well as non-carbapenemase-producing-CRE (non-CP-CRE) and CP-CRA in 2.5 h from culture media. This laboratory method was evaluated with CP-CRE and CP-CRA isolates producing different ß-lactamases of different Ambler classes (A, n = 16; B, n = 25; D, n = 67) and 22 non-CP-CRE. The results were correlated with those obtained by BD Phoenix™ and genotypic analysis results. The performance of BCDA on 123 validated CRE (except C. freundii isolates) and CP-CPA isolates revealed that 122 of 123 isolates were identified correctly. Only one OXA-48-producing Klebsiella pneumoniae was falsely classified. Among 45 meropenem susceptible Enterobacteriaceae (except C. freundii isolates) and meropenem susceptible Acinetobacter spp. strains tested, 44 were confirmed as susceptible by our BCDA. Overall, our BCDA had a sensitivity of 99% and a specificity of 98% and is a rapid and accurate assay which distinguished CRE/CP-CRA from meropenem susceptible Enterobacteriaceae and Acinetobacter spp.