| 1. |
- Aldman, Malin Hagstrand, et al.
(author)
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Endocarditis due to Staphylococcus lugdunensis-a retrospective national registry-based study
- 2021
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In: European Journal of Clinical Microbiology & Infectious Diseases. - : Springer Science and Business Media LLC. - 0934-9723 .- 1435-4373. ; 40, s. 1103-1106
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Journal article (peer-reviewed)abstract
- We present characteristics of infective endocarditis (IE) caused by Staphylococcus lugdunensis and compare with IE caused by Staphylococcus aureus and other CoNS, in the National Swedish Registry of IE (2008-2018). Thirty episodes of S. lugdunensis IE were registered, of which 21 cases affected native valves, and 7 patients were subjected to surgery. The mortality rate at 30 days was significantly higher for S. lugdunensis IE (20%, n = 6), than for IE caused by other CoNS (7%) or S. aureus (9%) p = 0.016. Septic embolisation was only reported in two cases (7%). The most common treatment was isoxazolyl penicillin (n = 18).
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| 2. |
- Björck, Viveka, et al.
(author)
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Commercial albumin solution enhances endotoxin-induced vasoplegia and inflammation
- 2020
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In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 64:7, s. 982-991
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Journal article (peer-reviewed)abstract
- BACKGROUND: The Gram-negative bacterium Escherichia coli, commonly involved in severe sepsis and septic shock, shed endotoxin that upon detection by the host triggers an inflammatory cascade. Efficiency of albumin solutions to restore hypovolemia during sepsis has been debated. To aid identification of subgroups of sepsis patients that may respond positively or negatively to treatment with albumin we investigated if preparations of albumin for medical use could affect endotoxin-induced inflammatory response.METHODS: Isolated human omental arteries obtained during surgery were incubated with endotoxin in the presence or absence of albumin solution. Isolated human monocytes were incubated with endotoxin in the presence or absence of five different commercially available albumin solutions. Vascular contractile response to noradrenaline and release of interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α were measured.RESULTS: Incubation with albumin together with endotoxin decreased median maximum contraction and increased release of IL-6 and IL-8 from the arteries compared to incubation with endotoxin alone. All albumin solutions except one significantly increased endotoxin-induced TNF-α release from monocytes. IL-6 and IL-10 were also increased and no concentration dependency of TNF-α release was observed above 2 mg mL-1 . Incubation with albumin alone did not affect contraction or release of cytokines while no potentially endotoxin-enhancing contaminant could be identified.CONCLUSION: We have shown that albumin solution in combination with endotoxin cause vasoplegia in human omental arteries, paralleled by an inflammatory response. This finding could explain the variable efficiency of albumin solutions for sepsis treatment.
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| 3. |
- Björck, Viveka, et al.
(author)
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Morbidity and mortality in critically ill patients with invasive group A streptococcus infection : an observational study
- 2020
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In: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535. ; 24:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Group A streptococci (GAS) are known to cause serious invasive infections, but little is known about outcomes when patients with these infections are admitted to intensive care. We wanted to describe critically ill patients with severe sepsis or septic shock due to invasive GAS (iGAS) and compare them with other patients with severe sepsis or septic shock. METHODS: Adult patients admitted to a general intensive care unit (ICU) in Sweden (2007-2019) were screened for severe sepsis or septic shock according to Sepsis 2 definition. Individuals with iGAS infection were identified. The outcome variables were mortality, days alive and free of vasopressors and invasive mechanical ventilation, maximum acute kidney injury score for creatinine, use of continuous renal replacement therapy and maximum Sequential Organ Failure Assessment score during the ICU stay. Age, Simplified Acute Physiology Score (SAPS 3) and iGAS were used as independent, explanatory variables in regression analysis. Cox regression was used for survival analyses. RESULTS: iGAS was identified in 53 of 1021 (5.2%) patients. Patients with iGAS presented a lower median SAPS 3 score (62 [56-72]) vs 71 [61-81]), p < 0.001), had a higher frequency of cardiovascular cause of admission to the ICU (38 [72%] vs 145 [15%], p < 0.001) and had a higher median creatinine score (173 [100-311] vs 133 [86-208] μmol/L, p < 0.019). Of the GAS isolates, 50% were serotyped emm1/T1 and this group showed signs of more pronounced circulatory and renal failure than patients with non-emm1/T1 (p = 0.036 and p = 0.007, respectively). After correction for severity of illness (SAPS 3) and age, iGAS infection was associated with lower mortality risk (95% confidence interval (CI) of hazard ratio (HR) 0.204-0.746, p < 0.001). Morbidity analyses demonstrated that iGAS patients were more likely to develop renal failure. CONCLUSION: Critically ill patients with iGAS infection had a lower mortality risk but a higher degree of renal failure compared to similarly ill sepsis patients. emm1/T1 was found to be the most dominant serotype, and patients with emm1/T1 demonstrated more circulatory and renal failure than patients with other serotypes of iGAS.
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| 4. |
- Björck, Viveka, et al.
(author)
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Streptococcal M1 protein induces hyporesponsiveness and cytokine release from human arteries in a fibrinogen-dependent manner : A translational study
- 2018
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In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : Springer Science and Business Media LLC. - 1757-7241. ; 26:1
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Journal article (peer-reviewed)abstract
- Background: Streptococcus pyogenes is a Gram positive bacterial species commonly involved in sepsis. Invasive strains express virulence factors such as the M1 protein. M1 protein forms complexes with fibrinogen leading to a cytokine storm in plasma contributing to the development of septic shock and organ failure. In experimental animals M1 protein causes vascular nitric oxide production and hyporesponsiveness to pressors, but it is not known whether it affects the human vascular wall. Methods: Human omental arteries obtained during surgery were incubated in vitro with M1 protein or lipopolysaccharide (LPS) as positive control, with or without plasma. After 48h, contractile response to noradrenaline was measured, and levels of nitrite/nitrate and the cytokines interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α in the incubation medium were measured. A second set of arteries were incubated with or without main components of plasma (immunoglobulin G, albumin or fibrinogen), in the presence of M1 protein followed by cytokine measurement. Results: Artery segments incubated with M1 protein and plasma contracted weaker in response to noradrenaline, and levels of IL-6 and IL-8 were significantly higher compared to after incubation with M1 protein alone. Incubation with M1 protein and fibrinogen resulted in elevated levels of IL-6 and IL-8, while incubation with M1 protein and albumin or immunoglobulin G did not affect the levels. Neither any of the other cytokines nor nitrite/nitrate was detected in the medium in any of the incubation conditions. Conclusions: The study shows that M1 protein of Streptococcus pyogenes has a direct effect on the human vascular wall in the presence of plasma, demonstrated both as a diminished contractile response to noradrenaline and increased cytokine production. The effect of plasma was attributed to fibrinogen. The findings suggest that M1 protein contributes to the development of septic shock through impairment of the contractility of the vascular wall.
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| 5. |
- Blomquist, Axel, et al.
(author)
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Persistent Aspergillus fumigatus infection in cystic fibrosis : impact on lung function and role of treatment of asymptomatic colonization-a registry-based case-control study
- 2022
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In: BMC Pulmonary Medicine. - : Springer Science and Business Media LLC. - 1471-2466. ; 22:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Aspergillus fumigatus is the most common filamentous fungus isolated from the airways of people with cystic fibrosis (CF). The aim of this study was to investigate how chronic A. fumigatus colonization affects lung function in people with CF, to identify risk factors for colonization, and to evaluate antifungal treatment of asymptomatic Aspergillus colonization.METHODS: Data from 2014-2018 was collected from the Swedish CF registry and medical records. Baseline data before the start of A. fumigatus colonization was compared with the two succeeding years to evaluate how colonization and treatment affected lung function and other clinical aspects.RESULTS: A total of 437 patients were included, of which 64 (14.6%) became colonized with A. fumigatus during the study period. Inhaled antibiotics was associated with A. fumigatus colonization (adjusted OR 3.1, 95% CI 1.6-5.9, p < 0.05). Fungal colonization was not associated with a more rapid lung function decline or increased use of IV-antibiotics compared to the non-colonized group, but patients with A. fumigatus had more hospital days, a higher increase of total IgE, and higher eosinophil counts. In the Aspergillus group, 42 patients were considered to be asymptomatic. Of these, 19 patients received antifungal treatment. Over the follow up period, the treated group had a more pronounced decrease in percent predicted Forced Expiratory Volume in one second (ppFEV1) compared to untreated patients (- 8.7 vs - 1.4 percentage points, p < 0.05).CONCLUSION: Inhaled antibiotics was associated with A. fumigatus colonization, but no association was found between persistent A. fumigatus and subsequent lung function decline. No obvious benefits of treating asymptomatic A. fumigatus colonization were demonstrated.
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| 6. |
- Cabak, Andrea, et al.
(author)
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Activity of airway antimicrobial peptides against cystic fibrosis pathogens
- 2020
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In: Pathogens and Disease. - : Oxford University Press. - 2049-632X. ; 78:7
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Journal article (peer-reviewed)abstract
- Antimicrobial peptides are important players of the innate host defence against invading microorganisms. The aim of this study was to evaluate the activity of airway antimicrobial peptides against the common cystic fibrosis (CF) pathogen Pseudomonas aeruginosa, and to compare it to the emerging multi-drug resistant CF pathogens Achromobacter xylosoxidans and Stenotrophomonas maltophilia. Clinical bacterial isolates from CF patients were used, and the antimicrobial activity of human beta-defensin 2 and 3, LL37 and lysozyme was evaluated using radial diffusion assay and viable counts. The cell surface zeta potential was analysed to estimate the net charge at the bacterial surface. Of the bacterial species included in the study, A. xylosoxidans was the most resistant to antimicrobial peptides, whereas P. aeruginosa was the most susceptible. The net charge of the bacterial surface was significantly more negative for P. aeruginosa compared to A. xylosoxidans, which may in part explain the differences in susceptibility.
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| 7. |
- Hagstrand Aldman, Malin, et al.
(author)
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Biofilm formation is associated with poor outcome in prosthetic joint infections caused by Staphylococcus lugdunensis
- 2023
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In: Infectious Diseases. - : Informa UK Limited. - 2374-4235 .- 2374-4243. ; 55:5, s. 328-332
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Journal article (peer-reviewed)abstract
- Background: Staphylococcus lugdunensis has been described as a pathogen of increasing importance in prosthetic joint infections (PJI). Our aim was to describe the clinical presentation of PJI caused by S. lugdunensis, and to correlate the biofilm-forming ability of the bacterial isolates to clinical outcome. Method: S. lugdunensis isolates from PJI episodes during 2015–2019 were included and analysed for biofilm formation using a microtiter plate assay. Medical records from the corresponding patients were reviewed. Results: We identified 36 patients with PJI caused by S. lugdunensis during the study period. Early postoperative PJIs were most frequent (n = 20, 56%). Surgical intervention was performed in a majority of the patients (n = 33, 92%), and the dominating type of antibiotic treatment was a combination of rifampicin and ciprofloxacin (n = 27, 75%). The treatment success-rate was 81% (n = 29). All isolates causing PJI were able to form biofilm in vitro. Biofilm formation was significantly stronger in isolates causing relapsing vs non-relapsing PJI (mean OD550 3.1 ± 0.23 vs 1.14 ± 0.73 p =.001) and strong biofilm formation was also associated with late acute hematogenic PJI (mean OD550 1.8 ± 0.93 vs. 0.93 ± 0.81, p =.01). Conclusion: Strong biofilm production in S. lugdunensis isolates was associated with relapse in PJI.
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| 8. |
- Hagstrand Aldman, Malin, et al.
(author)
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Evaluation of penicillin G susceptibility testing methods for Staphylococcus lugdunensis
- 2020
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In: The Journal of antimicrobial chemotherapy. - : Oxford University Press (OUP). - 1460-2091 .- 0305-7453. ; 75:5, s. 1206-1211
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Journal article (peer-reviewed)abstract
- BACKGROUND: Staphylococcus lugdunensis belongs to the CoNS group, but is regarded to be more virulent than most other CoNS. It is also remarkably susceptible to antibiotics, including penicillin G. OBJECTIVES: To evaluate different methods for penicillin susceptibility testing, to assess penicillin susceptibility rates among S. lugdunensis and to describe the clinical presentation including antibiotic treatment. METHODS: Clinical isolates of S. lugdunensis were tested for penicillin susceptibility using disc diffusion according to CLSI (10 U disc) and EUCAST (1 U disc), assessment of zone-edge appearance, nitrocefin test and Etest for MIC determination. PCR of the blaZ gene was used as a reference method. RESULTS: Of the 112 isolates included in the study, 67% were susceptible to penicillin G according to blaZ PCR. The EUCAST disc diffusion test had 100% sensitivity, whereas the CLSI method had one very major error with a false-susceptible isolate. When zone-edge appearance was included in the assessment, the false-susceptible isolate was correctly classified as resistant. Foreign-body infection was the most common focus of infection, affecting 49% of the participants. Only 4% of the patients were treated with penicillin G. CONCLUSIONS: Penicillin susceptibility is common in S. lugdunensis and the disc diffusion method according to EUCAST had a higher sensitivity than that of CLSI. Assessment of zone-edge appearance could increase the sensitivity of the disc diffusion test. Penicillin susceptibility testing and treatment should be considered in S. lugdunensis infections.
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| 9. |
- Hagstrand Aldman, Malin, et al.
(author)
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Penicillin-susceptible Staphylococcus aureus : susceptibility testing, resistance rates and outcome of infection
- 2017
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In: Infectious Diseases. - : Informa UK Limited. - 2374-4235 .- 2374-4243. ; 49:6, s. 454-460
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Journal article (peer-reviewed)abstract
- Background: Staphylococcus aureus (SA) is an important human pathogen that causes both superficial and invasive infections. Penicillin is now rarely used in the treatment of SA infections due to widespread resistance and a concern about the accuracy of existing methods for penicillin susceptibility testing. The aims of the present study were to determine the frequency of penicillin-susceptible SA isolates from blood and wound cultures in Lund, Sweden, and to evaluate methods for penicillin testing in SA. We also wanted to investigate if penicillin-susceptible isolates are associated with higher mortality. Methods: Hundred blood culture isolates collected 2008/2009, 140 blood culture isolates from 2014/2015, and 141 superficial wound culture strains from 2015 were examined. Penicillin susceptibility was tested with disk diffusion according to EUCAST guidelines, and results were confirmed with a cloverleaf assay and PCR amplification of the BlaZ gene. Patient data for all bacteraemia cases were extracted from medical records. Results: The disk diffusion method with assessment of both zone size and zone edge appearance had high accuracy in our study. About 57% of bacteraemia isolates from 2008/2009 were sensitive to penicillin compared to 29% in 2014/2015 (p < .0001). In superficial wound cultures, 21% were penicillin susceptible. There was no difference in co-morbidity or mortality rates between patients with penicillin resistant and penicillin sensitive SA bacteraemia. Conclusion: Disk-diffusion is a simple and reliable method to detect penicillin resistance in SA, and susceptibility rates are significant. Penicillin has many theoretical advantages and should be considered in the treatment of SA bacteraemia when susceptible.
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| 10. |
- Hovold, Gisela, et al.
(author)
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BPI-ANCA is expressed in the airways of cystic fibrosis patients and correlates to platelet numbers and Pseudomonas aeruginosa colonization
- 2020
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In: Respiratory Medicine. - : Elsevier BV. - 0954-6111. ; 170
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Journal article (peer-reviewed)abstract
- Background: Autoantibodies to bactericidal/permeability-increasing protein (BPI), BPI-ANCA, are often present in serum of patients with cystic fibrosis (CF), and correlate to airway colonization with Pseudomonas aeruginosa. The aim of the study was to investigate if BPI-ANCA IgA is also present in the airways of CF patients, and if its presence correlates with neutrophil counts, platelets, and P. aeruginosa DNA in sputum. Methods: BPI-ANCA IgA was quantified in serum and sputum samples from adult CF patients (n = 45) by ELISA. Sputum neutrophil counts, platelets, and platelet-neutrophil complexes were assessed by flow cytometry, and P. aeruginosa DNA was analysed with RT-PCR. Results: Serum BPI-ANCA IgA was present in 44% of the study participants, and this group also had significantly enhanced BPI-ANCA levels in sputum compared to serum negative patients. Sputum levels of BPI-ANCA IgA correlated with P. aeruginosa DNA (r = 0.63, p = 0.0003) and platelet counts in sputum (r = 0.60, p = 0.0002). Conclusions: BPI-ANCA is expressed in the airways of CF patients and correlates with P. aeruginosa load and platelet counts, suggesting a link to airway inflammation and mucosal immunity.
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