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Bergenman O, Nilson B, Rasmussen M. Risk of infective endocarditis and complicated infection in Staphylococcus aureus bacteremia - a retrospective cohort study on the role of bacteriuria. Eur J Clin Microbiol Infect Dis 2024:10.1007/s10096-024-04850-7. [PMID: 38771404 DOI: 10.1007/s10096-024-04850-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/09/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE S. aureus bacteremia (SAB) is a common and severe infection with high mortality and morbidity. The clinical relevance of the finding of concurrent S. aureus bacteriuria (SABU) is debated. The goal of this study was to analyze whether a concurrent SABU is associated with complicated SAB, infective endocarditis (IE) and mortality. METHODS We conducted a retrospective cohort study, reviewing medical charts of all episodes of SAB in patients > 18 years in the region of Skåne, Sweden, between 1st of January and 31st of June 2020. Episodes where a concurrent urine culture was performed were included for analysis. An episode was considered as complicated SAB if there was either attributable mortality, recurrent infection, embolic stroke, or occurrence of a complicated focus of infection. RESULTS During the study period, there were 279 episodes of SAB. 154 episodes met the eligibility criteria, of whom 37 (24%) had concurrent SABU. In 78 episodes (51%), the patients had a complicated SAB. There was a significantly lower proportion of complicated SAB for episodes with concurrent SABU (32%), compared to episodes without concurrent SABU (56%), p-value 0.014. Moreover, in the cohort there were 11 episodes (7.1%) of IE and a 30 days mortality rate of 16%, with no difference between the groups with or without SABU. CONCLUSIONS There is an association between concurrent SABU and a decreased risk for complicated SAB among patients with SAB. This study found no significant association between SABU and neither IE nor mortality for patients with SAB.
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Affiliation(s)
- Oskar Bergenman
- Kalmar Regional Hospital, Kalmar, Sweden.
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14 SE-221 84, Lund, Sweden.
| | - Bo Nilson
- Clinical Microbiology, Office for Medical Services, Infection Prevention and Control, Region Skåne, Lund, Sweden
- Division of Medical Microbiology, Department of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14 SE-221 84, Lund, Sweden.
- Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden.
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2
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Bläckberg A, Holm K, Liderot K, Nilson B, Sunnerhagen T. Eubacterium bacteremia - a retrospective observational study of a seldom found anaerobic pathogen. Diagn Microbiol Infect Dis 2024; 108:116185. [PMID: 38232640 DOI: 10.1016/j.diagmicrobio.2024.116185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/28/2023] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
BACKGROUND Human infections due to Eubacterium are rare and knowledge of the condition is limited. This study aimed to describe clinical characteristics and outcome in patients with Eubacterium bacteremia. METHODS Episodes of Eubacterium bacteremia were identified through the clinical microbiology laboratory in Lund, Sweden. Medical records were retrospectively reviewed. Blood isolates of Eubacterium were collected and antibiotic susceptibility testing was performed with agar dilution. RESULTS Seventeen patients with Eubacterium bacteremia were identified of whom six had monomicrobial bacteremia. The incidence was 1.7 cases of Eubacterium bacteremia per million inhabitants and year. The median age was 67 years (interquartile range 63-79 years), and six patients had some form of malignancy. Most of the patients an abdominal focus of infection and the 30-day mortality was low (n = 1). CONCLUSIONS Invasive infections with Eubacterium have a low incidence. The condition has a low mortality and an abdominal focus of infection, and malignancy, is common.
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Affiliation(s)
- Anna Bläckberg
- Department of Infectious Diseases, Skåne University Hospital Lund, Sweden; Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University Sweden
| | - Karin Holm
- Department of Infectious Diseases, Skåne University Hospital Lund, Sweden; Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University Sweden
| | - Karin Liderot
- Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Bo Nilson
- Clinical Microbiology, Infection Prevention and Control, Office for Medical Services, Lund, Sweden; Division of Medical Microbiology, Department of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | - Torgny Sunnerhagen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University Sweden; Clinical Microbiology, Infection Prevention and Control, Office for Medical Services, Lund, Sweden.
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3
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Öberg J, Inghammar M, Nilson B. Improved identification of Streptococcus bovis-Streptococcus equinus-complex species and subspecies by MALDI-TOF MS using a novel library. Diagn Microbiol Infect Dis 2023; 107:116045. [PMID: 37598592 DOI: 10.1016/j.diagmicrobio.2023.116045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/06/2023] [Accepted: 07/28/2023] [Indexed: 08/22/2023]
Abstract
OBJECTIVES To develop an in-house matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) library for improved identification of species and subspecies of the Streptococcus bovis/Streptococcus equinus-complex (SBSEC). METHODS A total of 236 SBSEC isolates from blood stream infections and culture collections, determined by whole genome sequencing to subspecies level, were grown in brain heart infusion broth. Mass spectra were collected using the Bruker MALDI Biotyper system after ethanol-formic acid extraction. Main spectral profiles from 117 isolates were used to create the "SBSEC-CMRS library." The remaining 119 spectra were used for evaluation of Bruker MALDI Biotyper (MBT) Compass Library Revision K (2022) and the SBSEC-CMRS library. RESULTS The Bruker library correctly identified species and subspecies in 72 of 119 (61 %) isolates, while the SBSEC-CMRS library identified 116 of 119 (97 %), using a cutoff score of ≥2.0. CONCLUSIONS The SBSEC-CMRS library showed sufficient diagnostic accuracy, and can be implemented in clinical practice for SBSEC species and subspecies identification.
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Affiliation(s)
- Jonas Öberg
- Department of Clinical Sciences Lund, Section for Infection Medicine, Lund University, Lund, Sweden; Department of Infectious Diseases, Helsingborg Hospital, Helsingborg, Sweden.
| | - Malin Inghammar
- Department of Clinical Sciences Lund, Section for Infection Medicine, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden; Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
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Beusch CM, Simonson OE, Wedin JO, Sabatier P, Felldin U, Kadekar S, Österholm C, Végvári Á, Zubarev RA, Fromell K, Nilson B, James S, Ståhle E, Grinnemo KH, Rodin S. Analysis of local extracellular matrix identifies different aetiologies behind bicuspid and tricuspid aortic valve degeneration and suggests therapies. Cell Mol Life Sci 2023; 80:268. [PMID: 37632572 PMCID: PMC10460373 DOI: 10.1007/s00018-023-04926-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/28/2023]
Abstract
Aortic valve degeneration (AVD) is a life-threatening condition that has no medical treatment and lacks individual therapies. Although extensively studied with standard approaches, aetiologies behind AVD are unclear. We compared abundances of extracellular matrix (ECM) proteins from excised valve tissues of 88 patients with isolated AVD of normal tricuspid (TAV) and congenital bicuspid aortic valves (BAV), quantified more than 1400 proteins per ECM sample by mass spectrometry, and demonstrated that local ECM preserves molecular cues of the pathophysiological processes. The BAV ECM showed enrichment with fibrosis markers, namely Tenascin C, Osteoprotegerin, and Thrombospondin-2. The abnormal physical stress on BAV may cause a mechanical injury leading to a continuous Tenascin C-driven presence of myofibroblasts and persistent fibrosis. The TAV ECM exhibited enrichment with Annexin A3 (p = 1.1 × 10-16 and the fold change 6.5) and a significant deficit in proteins involved in high-density lipid metabolism. These results were validated by orthogonal methods. The difference in the ECM landscape suggests distinct aetiologies between AVD of BAV and TAV; warrants different treatments of the patients with BAV and TAV; elucidates the molecular basis of AVD; and implies possible new therapeutic approaches. Our publicly available database (human_avd_ecm.surgsci.uu.se) is a rich source for medical doctors and researchers who are interested in AVD or heart ECM in general. Systematic proteomic analysis of local ECM using the methods described here may facilitate future studies of various tissues and organs in development and disease.
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Affiliation(s)
- Christian M Beusch
- Division of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Oscar E Simonson
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - Johan O Wedin
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - Pierre Sabatier
- Division of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Ulrika Felldin
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - Sandeep Kadekar
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
| | - Cecilia Österholm
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Ákos Végvári
- Division of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Roman A Zubarev
- Division of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Karin Fromell
- Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Bo Nilson
- Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, 751 85, Uppsala, Sweden
| | - Stefan James
- Department of Medical Sciences, Uppsala University, 752 37, Uppsala, Sweden
| | - Elisabeth Ståhle
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - Karl-Henrik Grinnemo
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden
| | - Sergey Rodin
- Cardio-Thoracic Translational Medicine (CTTM) Lab, Department of Surgical Sciences, Uppsala University, 752 37, Uppsala, Sweden.
- Department of Cardio-Thoracic Surgery and Anesthesia, Uppsala University Hospital, 751 85, Uppsala, Sweden.
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Bläckberg A, Lundberg K, Svedevall S, Nilson B, Rasmussen M. Time to positivity of blood cultures in bloodstream infections with Streptococcus dysgalactiae and association with outcome. Infect Dis (Lond) 2023; 55:333-339. [PMID: 36847483 DOI: 10.1080/23744235.2023.2182910] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
PURPOSE Invasive infections with Streptococcus dysgalactiae predominantly occur in persons of older age with substantial morbidity and mortality. Time to positivity from blood cultures (TTP) has been shown to be a prognostic indicator in bloodstream infections caused by other beta-haemolytic streptococci. This study aimed to determine any possible association between TTP and outcome in invasive infections due to S. dysgalactiae. MATERIALS AND METHODS Episodes of S. dysgalactiae bacteraemia, that occurred during 2015-2018 in the Region of Skåne, Sweden, were identified through the laboratory database and retrospectively studied. Any association with TTP and the primary outcome, death within 30 days and the development of sepsis or disease deterioration within 48 hours from blood culturing as secondary outcomes were investigated. RESULTS Among the 287 episodes of S. dysgalactiae bacteraemia, 30-day mortality rate was 10% (n = 30). Median TTP was 9.3 h (interquartile range 8.0-10.3 h). Median TTP was statistically significantly shorter in patients who died within 30 days compared to surviving patients (7.7 vs 9.3 h, p = .001, Mann-Whitney U test). Short TTP(≤ 7.9 h) was still associated with 30-day mortality when adjusting for age, (OR 4.4, 95% CI 1.6-12.2, p = .004). Associations between secondary outcomes and levels of TTP were not observed. CONCLUSION TTP may be an important prognostic indicator for 30-day mortality in patients with bloodstream infections due to S. dysgalactiae.
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Affiliation(s)
- Anna Bläckberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden
| | - Katrina Lundberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Stina Svedevall
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Lund, Sweden.,Division of Medical Microbiology, Department of Experimental Medicine Lund, Lund University, Office for Medical Services, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden
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Pernow G, Shannon O, Öberg J, Nilson B, Rasmussen M. Platelet Activation and Aggregation Induced by Streptococcus bovis /Streptococcus equinus Complex. Microbiol Spectr 2022; 10:e0186122. [PMID: 36374116 PMCID: PMC9769897 DOI: 10.1128/spectrum.01861-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a common cause of infective endocarditis (IE). For IE-pathogens, the capacity to activate and aggregate platelets is believed to be an important virulence mechanism. While the interactions between bacteria and platelets have been described in detail for many Gram-positive pathogens, little research has been carried out with SBSEC in this respect. Twenty-six isolates of the four most common species and subspecies of SBSEC identified in bacteremia were collected, and interactions with platelets were investigated in platelet rich plasma (PRP) from three donors. Aggregation was studied using light-transmission aggregometry and platelet activation using flow cytometry detecting surface upregulation of CD62P. Platelets and serum were treated with different inhibitors to determine mechanisms involved in platelet aggregation and activation. Twenty-two of 26 isolates induced aggregation in at least one donor, and four isolates induced aggregation in all three donors. In PRP from donor 1, isolate SL1 induced a rapid aggregation with a median time of 70 s to reach 50% aggregation. Blockade of the platelet Fc-receptor or enzymatic cleavage of IgG abolished platelet activation and aggregation. The capacity for bacteria-induced platelet aggregation was also shown to be transferable between donors through serum. SBSEC mediates platelet aggregation in an IgG and IgG-Fc-receptor dependent manner. Bacterial activation of platelets through this pathway is common for many bacteria causing IE and could be a potential therapeutic target for the prevention and treatment of this infection. IMPORTANCE The capacity of bacteria to activate and aggregate platelets is believed to contribute to the pathogenesis of IE. The Streptococcus bovis/Streptococcus equinus complex (SBSEC) contains known IE-pathogens, but there is limited research on the different subspecies ability to interact with platelets and what signaling pathways are involved. This study reports that 22 of 26 tested isolates of different subspecies within SBSEC can induce aggregation, and that aggregation is host dependent. The Fc-IgG-receptor pathway was shown essential for platelet activation and aggregation. To the best of our knowledge, this is the first study that reports on platelet interactions of SBSEC-isolates other than Streptococcus gallolyticus subspecies gallolyticus as well as the first study to report of mechanisms of platelet interaction of SBSEC-isolates. It adds SBSEC to a group of bacteria that activate and aggregate platelets via the platelet Fc-receptor. This could be a potential therapeutic target for prevention of IE.
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Affiliation(s)
- Gustav Pernow
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Helsingborg Hospital, Lund, Sweden
| | - Oonagh Shannon
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Jonas Öberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Helsingborg Hospital, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
- Division of Medical Microbiology, Department of Laboratory Medicine Lund, Medical Faculty, Lund University, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
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Öberg J, Nilson B, Gilje P, Rasmussen M, Inghammar M. Bacteraemia and infective endocarditis with Streptococcus bovis-Streptococcus equinus-complex: a retrospective cohort study. Infect Dis (Lond) 2022; 54:760-765. [PMID: 35730935 DOI: 10.1080/23744235.2022.2089730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Streptococcus bovis/equinus complex (SBSEC) comprise several species and subspecies and is a common cause of infective endocarditis (IE). S. gallolyticus subsp. gallolyticus (Sg gallolyticus) accounts for a majority of SBSEC IE, but the risk of IE for other subspecies is largely unknown. We aimed to investigate the clinical presentation of bacteraemia, and proportion of patients with IE in bacteraemia with the most common subspecies. METHODS A retrospective cohort study of SBSEC-bacteraemia identified in clinical laboratory databases, in Skåne Region, Sweden, 2003-2018. Bacteraemia with Sg gallolyticus, S. gallolyticus subsp. pasteurianus (Sg pasteurianus), S. lutetiensis and S. infantarius subsp. infantarius (Si infantarius) were included. Subspecies was identified by whole genome sequencing. Medical charts were reviewed according to a predetermined protocol, IE was defined by the criteria from European Society of Cardiology. RESULTS In total, 210 episodes of SBSEC-bacteraemia were included. Definite IE was identified in 28/210 (13%) episodes. Of these, 7/28 (25%) were prosthetic valve-IE, 1/28 (4%) related to a cardiovascular implantable electronic device and 10/28 (36%) required heart valve surgery. The proportions of IE among different subspecies were: Sg gallolyticus 17/52 (33%), Si infantarius 5/31 (16%), Sg pasteurianus 4/83 (5%) and S. lutetiensis 2/44 (5%) (p < 0.001). Sg pasteurianus and S. lutetiensis were more often associated with intra-abdominal- and polymicrobial infection. CONCLUSION The proportion of IE in SBSEC-bacteraemia varies substantially depending on subspecies. Echocardiography should always be considered in bacteraemia with Sg gallolyticus and Si infantarius, and can sometimes be omitted in bacteraemia with Sg pasteurianus and S. lutetiensis.
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Affiliation(s)
- Jonas Öberg
- Department of Clinical Sciences Lund, Section for Infection Medicine, Helsingborg Hospital, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Division of Medical Microbiology, Office for Medical Services, Lund University, Region Skåne, Lund, Sweden.,Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Patrik Gilje
- Department of Cardiology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Department of Clinical Sciences Lund, Section for Infection Medicine, Skåne University Hospital, Lund University, Lund, Sweden
| | - Malin Inghammar
- Department of Clinical Sciences Lund, Section for Infection Medicine, Skåne University Hospital, Lund University, Lund, Sweden
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Toth N, Nilson B, Berge A, Rasmussen M. Treatment strategies and risk of recurrence in patients with heart valve prosthesis, Staphylococcus aureus bacteraemia and possible endocarditis – A retrospective cohort study. Open Forum Infect Dis 2022; 9:ofac207. [PMID: 35794933 PMCID: PMC9251659 DOI: 10.1093/ofid/ofac207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 04/13/2022] [Indexed: 11/15/2022] Open
Abstract
Patients with heart valve prosthesis (HVP) and Staphylococcus aureus bacteremia (SAB) are at risk for endocarditis. In this retrospective, population-based cohort study of 134 patients with SAB and HVP, 97 patients (72%) were diagnosed with possible endocarditis. Despite that most patients with possible endocarditis received short antibiotic treatment, only 3 patients suffered recurrent SAB.
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Affiliation(s)
- Nikita Toth
- Skåne University Hospital, Lund, Sweden
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medial Services, Region Skåne, Lund, Sweden
- Division of Medical Microbiology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Andreas Berge
- Unit of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Magnus Rasmussen
- Skåne University Hospital, Lund, Sweden
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Bläckberg A, Svedevall S, Lundberg K, Nilson B, Kahn F, Rasmussen M. Time to blood culture positivity- an independent predictor of mortality in Streptococcus pyogenes bacteraemia. Open Forum Infect Dis 2022; 9:ofac163. [PMID: 35615297 PMCID: PMC9126491 DOI: 10.1093/ofid/ofac163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/01/2022] [Indexed: 11/26/2022] Open
Abstract
Background Streptococcus pyogenes bacteremia is a severe condition with high mortality. Time to blood culture positivity (TTP) is known to predict the outcome in bacteremia with other pathogens. This study aimed to determine the association between TTP and outcome in S pyogenes bacteremia. Methods This retrospective observational cohort study comprised adults with S pyogenes bacteremia, identified through the laboratory database between 2015 and 2018, in the Region of Skåne, Sweden. Correlations between TTP and outcomes were investigated. Primary outcome was death within 30 days, and secondary outcomes were presence of sepsis or disease deterioration within the first 48 hours. Results A total of 347 episodes of S pyogenes bacteremia were identified, of which 61 were excluded, resulting in 286 included episodes. Median TTP was 10.4 (interquartile range, 8.4–11.4) hours. Thirty-day mortality was 10%. Median TTP was shorter in patients who died within 30 days compared to survivors (8.6 vs 10.4 hours; P < .001). In a multivariable logistic regression, shorter TTP was associated with 30-day mortality when adjusting for age, Charlson Comorbidity Index, and focus of infection (odds ratio, 3.7 [95% confidence interval, 1.2–11.3]; P = .02). There was no statistically significant difference in TTP between patients with sepsis within 48 hours and those who did not have sepsis. Additionally, there was no statistically significant difference in TTP between patients with disease deterioration compared to those who did not deteriorate. Conclusions Knowledge on TTP might be a tool to determine the prognosis of a given patient with S pyogenes bacteremia.
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Affiliation(s)
- Anna Bläckberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden
| | - Stina Svedevall
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Katrina Lundberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
- Division of Medical Microbiology, Department of Experimental Medicine Lund, Lund University, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Fredrik Kahn
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Infectious Diseases, Skåne University Hospital, Lund, Sweden
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Berge A, Strand R, Nilson B, Naucler P, Rasmussen M. Staphylococcus aureus bacteremia, cardiac implantable electronic device, extraction, and the risk of recurrence. J Infect 2022; 84:e67-e69. [PMID: 35202610 DOI: 10.1016/j.jinf.2022.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 10/19/2022]
Affiliation(s)
- Andreas Berge
- Unit of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, SE-171 76, Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, SE-171 76, Stockholm, Sweden.
| | - Rasmus Strand
- Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, SE-221 00, Lund, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, SE-221 00, Lund, Sweden; Clinical Microbiology, Labmedicin, Region Skåne, SE-221 00, Lund, Sweden
| | - Pontus Naucler
- Unit of Infectious Diseases, Department of Medicine, Solna, Karolinska Institutet, SE-171 76, Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, SE-171 76, Stockholm, Sweden
| | - Magnus Rasmussen
- Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, SE-221 00, Lund, Sweden; Skåne University Hospital, Division for Infectious Diseases, SE-221 00, Lund, Sweden.
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11
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Kahn F, Resman F, Bergmark S, Filiptsev P, Nilson B, Gilje P, Rasmussen M. ‘Time to blood culture positivity in Staphylococcus aureus bacteraemia to determine risk of infective endocarditis' – Author’s reply. Clin Microbiol Infect 2022; 28:747-748. [DOI: 10.1016/j.cmi.2022.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 01/16/2022] [Indexed: 11/29/2022]
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Öberg J, Rasmussen M, Buchwald P, Nilson B, Inghammar M. Streptococcus bovis-bacteremia: subspecies distribution and association with colorectal cancer: a retrospective cohort study. Epidemiol Infect 2021; 150:e8. [PMID: 38751047 PMCID: PMC8753481 DOI: 10.1017/s0950268821002533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/06/2021] [Accepted: 11/16/2021] [Indexed: 12/03/2022] Open
Abstract
This study aimed to describe the incidence of Streptococcus bovis/Streptococcus equinus complex (SBSEC) bacteremia, distribution of the SBSEC subspecies, and their respective association with colorectal cancer (CRC). A population-based retrospective cohort study of all episodes of SBSEC-bacteremia from 2003 to 2018 in Skåne Region, Sweden. Subspecies was determined by whole-genome sequencing. Medical charts were reviewed. The association between subspecies and CRC were analysed using logistic regression. In total 266 episodes of SBSEC-bacteremia were identified and the average annual incidence was 2.0 per 100 000 inhabitants. Of the 236 isolates available for typing, the most common subspecies was S. gallolyticus subsp. pasteurianus 88/236 (37%) followed by S. gallolyticus subsp. gallolyticus 58/236 (25%). In order to determine the risk of cancer following bacteremia, an incidence cohort of 174 episodes without a prior diagnosis of CRC or metastasised cancer was followed for 560 person-years. CRC was found in 13/174 (7%), of which 9 (69%) had S. gallolyticus subsp. gallolyticus-bacteremia. In contrast to other European studies, S. gallolyticus subsp. pasteurianus was the most common cause of SBSEC-bacteremia. CRC diagnosis after bacteremia was strongly associated with S. gallolyticus subsp. gallolyticus-bacteremia. Identification of SBSEC subspecies can guide clinical decision-making regarding CRC work-up following bacteremia.
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Affiliation(s)
- Jonas Öberg
- Department of Clinical Sciences Lund, Section for Infection Medicine, Lund University, Lund,Sweden
- Department of Infectious Diseases, Helsingborg Hospital, Helsingborg, Sweden
| | - Magnus Rasmussen
- Department of Clinical Sciences Lund, Section for Infection Medicine, Lund University, Lund,Sweden
| | - Pamela Buchwald
- Department of Surgery, Skåne University Hospital Malmö, Malmö, Sweden
- Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
- Department of Clinical Microbiology, Infection Control and Prevention, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Malin Inghammar
- Department of Clinical Sciences Lund, Section for Infection Medicine, Lund University, Lund,Sweden
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13
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Krus D, Kahn F, Nilson B, Sunnerhagen T, Rasmussen M. Blood culture time to positivity in non-β-hemolytic streptococcal bacteremia as a predictor of infective endocarditis-a retrospective cohort study. Eur J Clin Microbiol Infect Dis 2021; 41:325-329. [PMID: 34654986 PMCID: PMC8770443 DOI: 10.1007/s10096-021-04339-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/23/2021] [Indexed: 11/24/2022]
Abstract
Non-β-hemolytic streptococci (NBHS) cause infective endocarditis (IE) and a short blood culture time to positivity (TTP) is associated with risk of IE in bacteremia with other pathogens. In this retrospective population-based cohort study, we investigate if TTP is associated to IE or mortality. Of 263 episodes with NBHS bacteremia, 28 represented IE and the median TTP did not differ significantly between episodes with IE (15 h) and non-IE (15 h) (p=0.51). TTP was similar among those who survived and those who died within 30 days. However, TTP significantly differed when comparing the different streptococcal groups (p<0.001).
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Affiliation(s)
- David Krus
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University, BMC B14, Tornavägen 10, 221 84, Lund, Sweden
| | - Fredrik Kahn
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University, BMC B14, Tornavägen 10, 221 84, Lund, Sweden.,Division for Infectious Diseases, Skåne University Hospital, Lund, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Division of Medical Microbiology, Medical Faculty, Lund University, Lund, Sweden.,Department of Clinical Microbiology, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Torgny Sunnerhagen
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University, BMC B14, Tornavägen 10, 221 84, Lund, Sweden.,Department of Clinical Microbiology, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Magnus Rasmussen
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University, BMC B14, Tornavägen 10, 221 84, Lund, Sweden. .,Division for Infectious Diseases, Skåne University Hospital, Lund, Sweden.
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14
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Vilén A, Nilson B, Petersson AC, Cigut M, Nielsen C, Ström H. Detection of bacterial DNA in synovial fluid in dogs with arthritis: a comparison between bacterial culture and 16S rRNA polymerase chain reaction. Acta Vet Scand 2021; 63:34. [PMID: 34461947 PMCID: PMC8404341 DOI: 10.1186/s13028-021-00599-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/22/2021] [Indexed: 12/03/2022] Open
Abstract
Background Septic arthritis (SA) is a serious condition in dogs that requires a prompt diagnosis and treatment to minimize long-term joint pathology. Although bacterial detection in synovial fluid (SF) through culture or cytology is often performed to confirm diagnosis, the sensitivity of these tests is low. The need for a reliable diagnostic tool to confirm the presence of bacteria in SF in humans has led to the increased use of 16S rRNA (i.e., ribosomal RNA) gene sequencing by polymerase chain reaction (16S rRNA PCR). The aim of this prospective clinical study was to compare the sensitivity and specificity of 16S rRNA PCR with bacterial culture on blood agar plates after pre-incubation of SF in paediatric blood bacterial culture bottles to identify bacteria in dogs with clinical signs of SA and to investigate the usefulness of these methods as diagnostic tools. Results Ten dogs with clinical signs of SA, nine with osteoarthritis (OA, control group) and nine with clinical signs of immune-mediated polyarthritis (IMPA, second control group) were examined. Bacterial culture was positive in seven of 10 dogs with clinical SA, of which only two were positive by 16S rRNA PCR. The sensitivity of 16S rRNA PCR and bacterial culture analysis for dogs with clinical SA were 20% and 70%, respectively. All SF samples collected from control group (n = 9) and second control group (n = 14) animals were negative on culture, and 16S rRNA PCR rendered a specificity of 100%. Conclusions Our study showed a lower sensitivity of 16S rRNA PCR than bacterial culture for dogs with clinical SA. Our findings suggest that there is currently no advantage in using 16S rRNA PCR as a diagnostic tool for dogs with clinical SA. Furthermore, our study indicates that pre-incubation in paediatric blood bacterial culture bottles before bacterial cultivation on blood agar plates might enhance bacterial culture sensitivity compared to other culture methods.
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15
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Forsvall A, Fisher J, Cardoso JFP, Wagenius M, Tverring J, Nilson B, Dahlin A, Bratt O, Linder A, Mohanty T. Evaluation of the Forsvall biopsy needle in an ex vivo model of transrectal prostate biopsy - a novel needle design with the objective to reduce the risk of post-biopsy infection. Scand J Urol 2021; 55:227-234. [PMID: 33999753 DOI: 10.1080/21681805.2021.1921023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Transrectal prostate biopsy (TRbx) transfers colonic bacteria into prostatic tissue, potentially causing infectious complications, including sepsis. Our objective was to determine whether biopsy needle shape, surface properties and sampling mechanism affect the number of bacteria transferred through the colon wall, and evaluate a novel needle with improved properties. METHODS The standard Tru-Cut biopsy needle used today was evaluated for mechanisms of bacterial transfer in a pilot study. A novel Tru-Cut needle (Forsvall needle prototype) was developed. TRbx was simulated using human colons ex-vivo. Four subtypes of the prototype needle were compared with a standard Tru-Cut needle (BARD 18 G). Prototype and standard needles were used to puncture 4 different colon specimens in 10 randomized sites per colon. Needles were submerged into culture media to capture translocated bacteria. The media was cultured on blood agar and then the total amount of transferred bacteria was calculated for each needle. The primary outcome measure was the percent reduction of bacteria translocated by the prototype needles relative to the standard needle. Secondary outcome measures were the effects of tip design and coating on the percent reduction of translocated bacteria. RESULTS Prototype needles reduced the number of translocated bacteria by, on average, 96.0% (95% confidence interval 93.0-97.7%; p < 0.001) relative to the standard needle. This percent reduction was not significantly affected by prototype needle tip style or surface coating. CONCLUSIONS The Forsvall needle significantly reduces colonic bacterial translocation, suggesting that it could reduce infectious complications in prostate biopsy. A clinical trial has been initiated.
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Affiliation(s)
- Andreas Forsvall
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden.,Department of Urology, Helsingborg Hospital, Helsingborg, Sweden
| | - Jane Fisher
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden
| | | | - Magnus Wagenius
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden.,Department of Urology, Helsingborg Hospital, Helsingborg, Sweden
| | - Jonas Tverring
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden.,Department of Infectious Diseases, Helsingborg Hospital, Helsingborg, Sweden
| | - Bo Nilson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden.,Clinical Microbiology, Lund, Sweden
| | - Andreas Dahlin
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ola Bratt
- Department of Urology, Institute of Clinical Science, Sahlgrenska Academy, Gothenburg University, Sweden.,Department of Urology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Adam Linder
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden
| | - Tirthankar Mohanty
- Faculty of Medicine, Department of Clinical Sciences, Infection Medicine, Lund University, Lund, Sweden
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16
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Kahn F, Resman F, Bergmark S, Filiptsev P, Nilson B, Gilje P, Rasmussen M. Time to blood culture positivity in Staphylococcus aureus bacteraemia to determine risk of infective endocarditis. Clin Microbiol Infect 2020; 27:1345.e7-1345.e12. [PMID: 33197608 DOI: 10.1016/j.cmi.2020.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/30/2020] [Accepted: 11/08/2020] [Indexed: 01/04/2023]
Abstract
OBJECTIVES Patients with Staphylococcus aureus bacteraemia (SAB) at risk for infective endocarditis (IE) need to be identified because they should undergo echocardiography. We validated previous scoring systems for IE risk determination and evaluated whether time to blood culture positivity (TTP) could improve scoring systems. METHODS This retrospective population-based study included adults with SAB in 2016 in a derivation cohort and those from 2017 in a validation cohort. TTP was compared between patients with and without IE. A new score including TTP was constructed using a least absolute shrinkage selection operator. The new POSITIVE score was compared to the previously described PREDICT and VIRSTA scores. RESULTS A total of 465 episodes with SAB were included in the derivation cohort, of which 38 (8.2%) represented IE. Median (interquartile range) TTP was significantly shorter in episodes with IE, at 8.7 (7.7-10.6) hours compared to those without, at 13.3 (10.5-16.5) hours. When using a cutoff at 13 hours, TTP had a sensitivity of 100% (95% confidence interval (CI), 91-100) and specificity of 52% (95% CI, 47-57) for IE. The POSITIVE score included TTP, intravenous drug use, embolizations and presence of preexisting heart conditions. It had a sensitivity of 93% (95% CI, 76-99) and a specificity of 70% (95% CI, 66-74) in the validation cohort. The performance of POSITIVE was superior to PREDICT, and the specificity was higher than that of VIRSTA. CONCLUSIONS TTP, either by itself or as part of the POSITIVE score, can be used to identify patients with SAB at low risk for IE. Further validation is needed because TTP is sensitive to several external factors.
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Affiliation(s)
- Fredrik Kahn
- Skåne University Hospital, Sweden; Division of Infection Medicine, Department of Clinical Sciences Lund, Sweden
| | - Fredrik Resman
- Skåne University Hospital, Sweden; Division of Infectious Diseases, Department of Translational Medicine, Lund University, Malmö, Sweden
| | | | | | - Bo Nilson
- Clinical Microbiology, Labmedicine, Region Skåne, Lund, Sweden; Division of Medical Microbiology, Department of Laboratory Medicine, Sweden
| | - Patrik Gilje
- Skåne University Hospital, Sweden; Division of Cardiology, Department of Clinical Sciences, Lund University, Sweden
| | - Magnus Rasmussen
- Skåne University Hospital, Sweden; Division of Infection Medicine, Department of Clinical Sciences Lund, Sweden.
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17
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Fisher J, Pavan C, Ohlmeier LS, Nilson B, Lundgaard I, Linder A, Bentzer P. A functional observational battery for evaluation of neurological outcomes in a rat model of acute bacterial meningitis. Intensive Care Med Exp 2020; 8:40. [PMID: 32770475 PMCID: PMC7415049 DOI: 10.1186/s40635-020-00331-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/21/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Acute bacterial meningitis is a disease with a high mortality and a high incidence of neurological sequelae in survivors. There is an acute need to develop new adjuvant therapies. To ensure that new therapies evaluated in animal models are translatable to humans, studies must evaluate clinically relevant and patient-important outcomes, including neurological symptoms and sequelae. METHODS We developed and tested a functional observational battery to quantify the severity of a variety of relevant neurological and clinical symptoms in a rat model of bacterial meningitis. The functional observational battery included symptoms relating to general clinical signs, gait and posture abnormalities, involuntary motor movements, focal neurological signs, and neuromotor abnormalities which were scored according to severity and summed to obtain a combined clinical and neurological score. To test the functional observational battery, adult Sprague-Dawley rats were infected by intracisternal injection of a clinical isolate of Streptococcus pneumoniae. Rats were evaluated for 6 days following the infection. RESULTS Pneumococcal meningitis was not lethal in this model; however, it induced severe neurological symptoms. Most common symptoms were hearing loss (75% of infected vs 0% of control rats; p = 0.0003), involuntary motor movements (75% of infected vs 0% of control rats; p = 0.0003), and gait and posture abnormality (67% of infected vs 0% of control rats; p = 0.0013). Infected rats had a higher combined score when determined by the functional observational battery than control rats at all time points (24 h 12.7 ± 4.0 vs 4.0 ± 2.0; 48 h 17.3 ± 7.1 vs 3.4 ± 1.8; 6 days 17.8 ± 7.4 vs 1.7 ± 2.4; p < 0.0001 for all). CONCLUSIONS The functional observational battery described here detects clinically relevant neurological sequelae of bacterial meningitis and could be a useful tool when testing new therapeutics in rat models of meningitis.
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Affiliation(s)
- Jane Fisher
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden.
| | - Chiara Pavan
- Center for Translational Neuromedicine, Faculties of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Luisa S Ohlmeier
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Bo Nilson
- Faculty of Medicine, Department of Laboratory Medicine, Division of Medical Microbiology Lund, Lund University, Lund, Sweden
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden
| | - Iben Lundgaard
- Department of Experimental Medical Science, University of Lund, Lund, Sweden
- Wallenberg Center for Molecular Medicine, University of Lund, Lund, Sweden
| | - Adam Linder
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Peter Bentzer
- Department of Anesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden
- Division of Anesthesia and Intensive Care, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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18
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Lamei S, Stephan JG, Nilson B, Sieuwerts S, Riesbeck K, de Miranda JR, Forsgren E. Feeding Honeybee Colonies with Honeybee-Specific Lactic Acid Bacteria (Hbs-LAB) Does Not Affect Colony-Level Hbs-LAB Composition or Paenibacillus larvae Spore Levels, Although American Foulbrood Affected Colonies Harbor a More Diverse Hbs-LAB Community. Microb Ecol 2020; 79:743-755. [PMID: 31506760 PMCID: PMC7176604 DOI: 10.1007/s00248-019-01434-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Abstract
The main current methods for controlling American Foulbrood (AFB) in honeybees, caused by the bacterial pathogen Paenibacillus larvae, are enforced incineration or prophylactic antibiotic treatment, neither of which is fully satisfactory. This has led to an increased interest in the natural relationships between the pathogenic and mutualistic microorganisms of the honeybee microbiome, in particular, the antagonistic effects of Honeybee-Specific Lactic Acid Bacteria (hbs-LAB) against P. larvae. We investigated whether supplemental administration of these bacteria affected P. larvae infection at colony level over an entire flowering season. Over the season, the supplements affected neither colony-level hbs-LAB composition nor naturally subclinical or clinical P. larvae spore levels. The composition of hbs-LAB in colonies was, however, more diverse in apiaries with a history of clinical AFB, although this was also unrelated to P. larvae spore levels. During the experiments, we also showed that qPCR could detect a wider range of hbs-LAB, with higher specificity and sensitivity than mass spectrometry. Honeybee colonies are complex super-organisms where social immune defenses, natural homeostatic mechanisms, and microbiome diversity and function play a major role in disease resistance. This means that observations made at the individual bee level cannot be simply extrapolated to infer similar effects at colony level. Although individual laboratory larval assays have clearly demonstrated the antagonistic effects of hbs-LAB on P. larvae infection, the results from the experiments presented here indicate that direct conversion of such practice to colony-level administration of live hbs-LAB is not effective.
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Affiliation(s)
- Sepideh Lamei
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Jörg G Stephan
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
- Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Bo Nilson
- Clinical Microbiology, Labmedicine, Region Skåne, Lund, Sweden
- Department of Laboratory Medicine Lund, Lund University, Lund, Sweden
| | | | - Kristian Riesbeck
- Clinical Microbiology, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Joachim R de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Eva Forsgren
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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19
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Axelsson C, Rehnstam-Holm AS, Nilson B. Rapid detection of antibiotic resistance in positive blood cultures by MALDI-TOF MS and an automated and optimized MBT-ASTRA protocol for Escherichia coli and Klebsiella pneumoniae. Infect Dis (Lond) 2019; 52:45-53. [PMID: 31661349 DOI: 10.1080/23744235.2019.1682658] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Introduction: For fast and effective antibiotic therapy of serious infections like sepsis, it is crucial with rapid information about antibiotic susceptibility, especially in a time when the number of infections caused by multi resistant bacteria has escalated in the world.Methods: Here, we have used a semi-quantitative MALDI-TOF-MS based method for antibiotic resistance detection, MBT-ASTRA™, which is based on the comparison of growth rate of the bacteria cultivated with and without antibiotics. We demonstrate a new protocol where several parameters have been optimized and automated leading to reduced hands-on time and improved capacity to simultaneously analyse multiple clinical samples and antibiotics.Results: Ninety minutes of incubation at 37 °C with agitation was sufficient to differentiate the susceptible and resistant strains of E. coli and K. pneumoniae, for the antibiotics cefotaxime, meropenem and ciprofloxacin. In total, 841 positive blood culture analyses of 14 reference strains were performed. The overall sensitivity was 99%, specificity 99% and the accuracy 97%. The assay gave no errors for cefotaxime (n = 263) or meropenem (n = 289) for sensitive and resistant strains, whilst ciprofloxacin (n = 289) gave six (0.7%) major errors (false resistance) and four (0.5%) very major errors (false susceptibility). The intermediate strains showed a larger variety compared to the E-test MIC values.Conclusions: The hands-on time and the analysis time to detect antibiotic resistance of clinical blood samples can be substantially reduced and the sample capacity can be increased by using automation and this improved protocol.
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Affiliation(s)
- Carolina Axelsson
- Faculty of Natural Science, Kristianstad University, Kristianstad, Sweden.,Faculty of Medicine, Lund University, Lund, Sweden
| | - Ann-Sofi Rehnstam-Holm
- Faculty of Natural Science, Kristianstad University, Kristianstad, Sweden.,Faculty of Medicine, Lund University, Lund, Sweden
| | - Bo Nilson
- Department of Clinical Microbiology, Labmedicin, Lund, Sweden.,Department of Laboratory Medicine Lund, Faculty of Medicine, Division of Medical Microbiology, Lund University, Lund, Sweden
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20
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Sunnerhagen T, Törnell A, Vikbrant M, Nilson B, Rasmussen M. HANDOC: A Handy Score to Determine the Need for Echocardiography in Non-β-Hemolytic Streptococcal Bacteremia. Clin Infect Dis 2019; 66:693-698. [PMID: 29040411 DOI: 10.1093/cid/cix880] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/09/2017] [Indexed: 11/14/2022] Open
Abstract
Background Non-β-hemolytic streptococci (NBHS) can cause infective endocarditis (IE). Echocardiography is used to diagnose IE, but it is not known which patients with NBHS bacteremia should undergo echocardiography. Method Medical records of patients with NBHS bacteremia in southern Sweden from 2012 to 2014 were studied retrospectively. The patients were divided into 2 cohorts. In the first, correlations between the reported data and IE were studied. These variables were used to construct the HANDOC score, which was then validated in the second cohort. Results Three hundred thirty-nine patients with NBHS bacteremia were included in the first cohort, of whom 26 fulfilled the criteria for IE. Several factors differed significantly between the patients with IE and those without. Among these variables, the presence of Heart murmur or valve disease; Aetiology with the groups of Streptococcus mutans, Streptococcus bovis, Streptococcus sanguinis, or Streptococcus anginosus; Number of positive blood cultures ≥2; Duration of symptoms of 7 days or more; Only 1 species growing in blood cultures; and Community-acquired infection were chosen to form the HANDOC score. With a cutoff between 2 and 3 points, HANDOC had a sensitivity of 100% and specificity of 73% in the first cohort. When tested in the validation cohort (n = 399), the sensitivity was 100% and the specificity 76%. Conclusions HANDOC can be used in to identify patients with NBHS bacteremia who have a risk of IE so low that echocardiography can be omitted; therefore, its implementation might reduce the use of echocardiography.
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Affiliation(s)
- Torgny Sunnerhagen
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University
| | - Amanda Törnell
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University
| | - Maria Vikbrant
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, Lund.,Department of Laboratory Medicine Lund, Division of Medical Microbiology, Medical Faculty, Lund University
| | - Magnus Rasmussen
- Department for Clinical Sciences Lund, Division of Infection Medicine, Medical Faculty, Lund University.,Division for Infectious Diseases, Skåne University Hospital, Lund, Sweden
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21
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Trell K, Rignér S, Wierzbicka M, Nilson B, Rasmussen M. Colonization of β-hemolytic streptococci in patients with erysipelas-a prospective study. Eur J Clin Microbiol Infect Dis 2019; 38:1901-1906. [PMID: 31292789 PMCID: PMC6778588 DOI: 10.1007/s10096-019-03625-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 06/28/2019] [Indexed: 11/28/2022]
Abstract
Erysipelas is a common skin infection causing significant morbidity. At present there are no established procedures for bacteriological sampling. Here we investigate the possibility of using cultures for diagnostic purposes by determining the perianal colonization with beta-hemolytic streptococci (BHS) in patients with erysipelas. Patients with erysipelas and a control group of patients with fever without signs of skin infection were prospectively included and cultures for BHS were taken from the tonsils, the perianal area, and wounds. BHS were grouped according to Lancefield antigen, species-determined, and emm-typed. Renewed cultures were taken after four weeks from patients with erysipelas and a positive culture for BHS. 25 patients with erysipelas and 25 with fever were included. In the group with erysipelas, 11 patients (44%) were colonized with BHS, ten patients were colonized in the perianal area, and one patient in the throat. In contrast, only one patient in the control group was colonized (p = 0.005 for difference). All of the patients with erysipelas colonized with BHS had an erythema located to the lower limb. The BHS were then subjected to MALDI-TOF MS and most commonly found to be Streptococcus dysgalactiae. Renewed cultures were taken from nine of the 11 patients with BHS and three of these were still colonized. Streptococcus dysgalactiae colonizes the perianal area in a substantial proportion of patients with erysipelas. The possibility of using cultures from this area as a diagnostic method in patients with erysipelas seems promising.
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Affiliation(s)
- Kristina Trell
- Division of Infection Medicine, Lund University, BMC, B14, Tornavägen 10, 22184, Lund, Sweden.
| | - Sofia Rignér
- Division of Infection Medicine, Lund University, BMC, B14, Tornavägen 10, 22184, Lund, Sweden
| | - Marcelina Wierzbicka
- Department of Internal Medicine and Emergency Medicine, Skåne University Hospital, Malmö, Sweden
| | - Bo Nilson
- Clinical Microbiology, Lund, Region Skåne, Sweden.,Department of Laboratory Medicine, Division of Medical Microbiology, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Lund University, BMC, B14, Tornavägen 10, 22184, Lund, Sweden
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22
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Badri M, Nilson B, Ragnarsson S, Senneby E, Rasmussen M. Clinical and microbiological features of bacteraemia with Gram-positive anaerobic cocci: a population-based retrospective study. Clin Microbiol Infect 2018; 25:760.e1-760.e6. [PMID: 30217761 DOI: 10.1016/j.cmi.2018.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/28/2018] [Accepted: 09/04/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Gram-positive, anaerobic cocci (GPAC) can cause infections in humans. Only a few cases of bacteraemia with GPAC have been reported. We describe the clinical and microbiological characteristics of GPAC bacteraemia. METHODS A retrospective population-based study of GPAC bacteraemia 2012-2016 in southern Sweden was performed. GPAC were identified using matrix-associated laser desorption ionization time-of-flight mass spectrometry or 16S rRNA gene sequencing. Etests were used to determine antibiotic susceptibilities. Data on patient and infection characteristics, treatment, and outcome were collected from the medical records. RESULTS A total of 226 episodes of GPAC bacteraemia in adults were studied; this corresponds to an annual incidence of 3.4 cases per 100,000 persons per year. The bacteria identified were Anaerococcus spp. (n = 43), Atopobium spp. (n = 7), Blautia spp. (n = 1), Finegoldia spp. (n = 15), Parvimonas spp. (n = 100), Peptoniphilus spp. (n = 52), Peptostreptococcus spp. (n = 2), and Ruminococcus spp. (n = 9) of which 200 isolates were identified to the species level. Resistance to imipenem and piperacillin was not identified, whereas resistance among the 229 isolates to penicillin was detected in four, to metronidazole in six, and clindamycin in 16 isolates. The median age of patients was 73 years (55-83, IQR), 57% were male and comorbidities were common. Fifty-one per cent of infections were polymicrobial. In 60% of cases a focus of infection was identified. Forty per cent of patients had either organ dysfunction or shock. The 30-day mortality was 11%, and nosocomial infections were over-represented among the deceased. CONCLUSIONS GPAC bacteraemia is much more common than previously reported. GPAC-bacteraemia is a condition with significant mortality mainly affecting elderly persons with comorbidities.
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Affiliation(s)
- M Badri
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund, Sweden
| | - B Nilson
- Clinical Microbiology, Laboratory Medicine, Region Skåne, Lund, Sweden; Lund University, Faculty of Medicine, Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund, Sweden
| | - S Ragnarsson
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Division of Cardiothoracic Surgery, Lund, Sweden
| | - E Senneby
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund, Sweden; Clinical Microbiology, Laboratory Medicine, Region Skåne, Lund, Sweden; Lund University, Faculty of Medicine, Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund, Sweden
| | - M Rasmussen
- Lund University, Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund, Sweden; Skåne University Hospital, Division of Infection Medicine, Lund, Sweden.
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Bläckberg A, Nilson B, Özenci V, Olaison L, Rasmussen M. Infective endocarditis due to Streptococcus dysgalactiae: clinical presentation and microbiological features. Eur J Clin Microbiol Infect Dis 2018; 37:2261-2272. [PMID: 30196469 DOI: 10.1007/s10096-018-3367-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 08/27/2018] [Indexed: 01/17/2023]
Abstract
Knowledge of infective endocarditis (IE) caused by Streptococcus dysgalactiae (SD) is limited. This study aimed to identify the clinical and microbiological features of SD-caused IE and to investigate any possible synergy between penicillin and gentamicin on SD isolates. Cases of IE 2008-2016 due to SD reported to the Swedish Registry of Infective Endocarditis (SRIE) were identified. Isolates were emm typed and synergy between antibiotics was determined in time-kill experiments. Medical records were reviewed and SD-cases were compared to cases of IE due to other pathogens reported to the SRIE. Fifty cases of SD-caused IE were confirmed. emm types stC74a, stG62647, and stG643 were most commonly encountered. The patients had a median age of 74 years (range 38-93) and were significantly older compared to patients with Staphylococcus aureus-caused IE, (65 years (p = 0.003)). The median time to diagnosis from symptom onset was 1 day for patients with SD-caused IE which was less compared to patients with IE due to the other pathogens (2-15 days). Embolization was seen in 46% and the in-hospital mortality was 8%. Etest-based methods did not indicate any synergy between penicillin and gentamicin whereas synergy was noted for four out of nine isolates applying time-kill assays. This is the largest study of SD-caused IE, a condition with an acute onset predominantly affecting elderly people. Synergy between penicillin and gentamicin against some SD isolates was distinguished but the potential benefit of this must be weighed against the risk of aminoglycoside side effects.
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Affiliation(s)
- Anna Bläckberg
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, BMC B14 Baravägen 27, 223 63, Lund, Sweden.
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden.,Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
| | - Volkan Özenci
- Department of Clinical Microbiology, Karolinska University Hospital, Huddinge, Stockholm, Sweden.,Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Lars Olaison
- Department of Infectious Diseases, Sahlgrenska University Hospital, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Swedish Society of Infectious Diseases, Swedish Registry of Infective Endocarditis, Gothenburg, Sweden
| | - Magnus Rasmussen
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, BMC B14 Baravägen 27, 223 63, Lund, Sweden
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24
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Trell K, Nilson B, Petersson AC, Rasmussen M. Clinical and microbiological features of bacteremia with Streptococcus equi. Diagn Microbiol Infect Dis 2016; 87:196-198. [PMID: 27829495 DOI: 10.1016/j.diagmicrobio.2016.10.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/13/2016] [Accepted: 10/16/2016] [Indexed: 01/26/2023]
Abstract
Streptococcus equi (SE) rarely causes human infections. We identified 18 SE isolates from blood cultures. The focus of infection was unknown (n = 5), arthritis (n = 3), catheter-related (n = 2), pneumonia (n = 2), or other (n = 6). There were no fatalities. Several patients had animal contacts but there were no indications of clonal outbreaks.
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Affiliation(s)
- Kristina Trell
- Division of Infection Medicine, Lund University, Lund, Sweden
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden; Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
| | - Ann-Cathrine Petersson
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden; Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
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25
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Olofsson TC, Butler É, Lindholm C, Nilson B, Michanek P, Vásquez A. Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria. Curr Microbiol 2016; 73:463-73. [PMID: 27324340 PMCID: PMC4999459 DOI: 10.1007/s00284-016-1080-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022]
Abstract
In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.
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Affiliation(s)
| | - Éile Butler
- Laboratory Medicine, Lunds Universitet, Lund, Sweden
| | | | - Bo Nilson
- Laboratory Medicine, Clinical Microbiology, Region Skåne, Lund, Sweden
- Department of Laboratory Medicine Lund, Medical Microbiology, Lund University, Sölvegatan 23, 22362, Lund, Sweden
| | - Per Michanek
- Animal Farm Veterinary Consultants, Degebergavägen, 27568, Vollsjö, Sweden
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26
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Sunnerhagen T, Nilson B, Olaison L, Rasmussen M. Clinical and microbiological features of infective endocarditis caused by aerococci. Infection 2015; 44:167-73. [PMID: 26119199 DOI: 10.1007/s15010-015-0812-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 06/13/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To define the clinical presentation of aerococcal infective endocarditis (IE) and the prevalence of synergy between penicillin and gentamicin on aerococcal isolates. METHODS Cases of aerococcal IE between 2002 and 2014 were identified in the Swedish Registry of Infective Endocarditis (SRIE). MALDI-TOF MS was used to confirm species determination. The medical records were analysed and compared to cases reported to the SRIE caused by other pathogens. RESULTS Sixteen cases of aerococcal IE, fourteen with Aerococcus urinae and two with Aerococcus sanguinicola, were confirmed. Etest-based methods and time-kill experiments suggested synergy between penicillin and gentamicin towards seven of fifteen isolates. The patients with aerococcal IE were significantly older than those with streptococci or Staphylococcus aureus IE. Most of the patients had underlying urinary tract diseases or symptoms suggesting a urinary tract focus of the infection. Seven patients with aerococcal IE presented with severe sepsis but ICU treatment was needed only in one patient and there was no fatality. Valve exchange surgery was needed in four patients and embolization was seen in three patients. CONCLUSIONS This report is the largest on aerococcal IE and suggests that the prognosis is relatively favourable despite the fact that the patients are old and have significant comorbidities.
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Affiliation(s)
- Torgny Sunnerhagen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Tornavägen 10, BMC B14, 221 84, Lund, Sweden
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden.,Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
| | - Lars Olaison
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Swedish Registry of Infective Endocarditis, Swedish Society of Infectious Diseases, Gothenburg, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Tornavägen 10, BMC B14, 221 84, Lund, Sweden.
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27
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Sunnerhagen T, Nilson B, Rasmussen M. Antibiotic synergy against viridans streptococci isolated in infective endocarditis. Int J Antimicrob Agents 2015; 45:550-1. [PMID: 25697413 DOI: 10.1016/j.ijantimicag.2015.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 10/24/2022]
Affiliation(s)
- Torgny Sunnerhagen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Bo Nilson
- Clinical Microbiology, Region Skåne, Lund, Sweden; Division of Medical Microbiology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Magnus Rasmussen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
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28
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Isaksson J, Rasmussen M, Nilson B, Stadler LS, Kurland S, Olaison L, Ek E, Herrmann B. Comparison of species identification of endocarditis associated viridans streptococci using rnpB genotyping and 2 MALDI-TOF systems. Diagn Microbiol Infect Dis 2014; 81:240-5. [PMID: 25616316 DOI: 10.1016/j.diagmicrobio.2014.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/28/2014] [Accepted: 12/20/2014] [Indexed: 11/17/2022]
Abstract
Streptococcus spp. are important causes of infective endocarditis but challenging in species identification. This study compared identification based on sequence determination of the rnpB gene with 2 systems of matrix-assisted laser desorption ionization-time of flight mass spectrometry, MALDI Biotyper (Bruker) and VITEK MS IVD (bioMérieux). Blood culture isolates of viridans streptococci from 63 patients with infective endocarditis were tested. The 3 methods showed full agreement for all 36 isolates identified in the Anginosus, Bovis, and Mutans groups or identified as Streptococcus cristatus, Streptococcus gordonii, or Streptococcus sanguinis. None of the methods could reliably identify the 23 isolates to the species level when designated as Streptococcus mitis, Streptococcus oralis, or Streptococcus tigurinus. In 7 isolates classified to the Mitis group, the rnpB sequences deviated strikingly from all reference sequences, and additional analysis of sodA and groEL genes indicated the occurrence of yet unidentified Streptococcus spp.
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Affiliation(s)
- Jenny Isaksson
- Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Magnus Rasmussen
- Division for Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, SE-22184 Lund, Sweden
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, SE-221 85 Lund, Sweden; Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, SE-22362 Lund, Sweden
| | - Liselott Svensson Stadler
- Department of Infectious Diseases, Sahlgrenska Academy, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Siri Kurland
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Lars Olaison
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, SE-416 85 Gothenburg, Sweden
| | - Elisabeth Ek
- Section of Infectious Diseases, Department of Medical Sciences, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Björn Herrmann
- Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
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29
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Hammarström B, Nilson B, Laurell T, Nilsson J, Ekström S. Acoustic Trapping for Bacteria Identification in Positive Blood Cultures with MALDI-TOF MS. Anal Chem 2014; 86:10560-7. [DOI: 10.1021/ac502020f] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Björn Hammarström
- Department
of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
| | - Bo Nilson
- Clinical
Microbiology, Labmedicin, Region Skåne, 221 85 Lund, Sweden
- Department
of Laboratory Medicine, Division of Medicinal Microbiology, Lund University, SE-223 62 Lund, Sweden
| | - Thomas Laurell
- Department
of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
- Department
of Biomedical Engineering, Dongguk University, Jung-gu, Seoul 100-715, Korea
| | - Johan Nilsson
- Department
of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
| | - Simon Ekström
- Department
of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
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30
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Butler É, Oien RF, Lindholm C, Olofsson TC, Nilson B, Vásquez A. A pilot study investigating lactic acid bacterial symbionts from the honeybee in inhibiting human chronic wound pathogens. Int Wound J 2014; 13:729-37. [PMID: 25196349 DOI: 10.1111/iwj.12360] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/29/2014] [Accepted: 08/03/2014] [Indexed: 12/17/2022] Open
Abstract
Treatment and management of chronic wounds is a large burden on the health sector and causes substantial suffering for the patients. We believe that 13 lactic acid bacteria (LAB) symbionts isolated from the honey crop of the honeybee are important players in the antimicrobial action of honey, by producing antimicrobial substances and can be used in combination with heather honey as an effective treatment in wound management. A total of 22 patients with chronic ulcers were included; culture-dependent and molecular-based (MALDI-MS and 16S rRNA gene sequencing) techniques were used to identify bacteria from chronic wounds. These clinical isolates were used for in vitro antimicrobial testing with standardised viable LAB and sterilised heather honey mixture. Twenty of the patients' wounds were polymicrobial and 42 different species were isolated. Patient isolates that were tested in vitro were inhibited by the LAB and honey combination with inhibitory zones comparable with different antibiotics. LAB and heather honey in combination presents a new topical option in chronic wound management because of the healing properties of honey, antimicrobial metabolite production from the LAB and their bactericidal effect on common chronic wound pathogens. This new treatment may be a stepping stone towards an alternative solution to antibiotics.
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Affiliation(s)
- Éile Butler
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden.
| | - Rut F Oien
- Blekinge Wound Healing Centre, Blekinge Hospital, Karlshamn, Sweden
| | | | - Tobias C Olofsson
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
| | - Bo Nilson
- Labmedicin, Region Skåne, Clinical Microbiology, Lund, Sweden
| | - Alejandra Vásquez
- Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, Lund, Sweden
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Olofsson TC, Alsterfjord M, Nilson B, Butler È, Vásquez A. Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov., isolated from the honey stomach of the honeybee Apis mellifera. Int J Syst Evol Microbiol 2014; 64:3109-3119. [PMID: 24944337 PMCID: PMC4156108 DOI: 10.1099/ijs.0.059600-0] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We previously discovered a symbiotic lactic acid bacterial (LAB) microbiota in the honey stomach of the honeybee Apis mellifera. The microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. 16S rRNA gene sequence analyses and phenotypic and genetic characteristics revealed that the phylotypes isolated represent seven novel species. One grouped with Lactobacillus kunkeei and the others belong to the Lactobacillus buchneri and Lactobacillus delbrueckii subgroups of Lactobacillus. We propose the names Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov. for these novel species, with the respective type strains being Fhon13N(T) ( = DSM 26257(T) = CCUG 63287(T)), Bin4N(T) ( = DSM 26254(T) = CCUG 63291(T)), Hon2N(T) ( = DSM 26255(T) = CCUG 63289(T)), Hma8N(T) ( = DSM 26256(T) = CCUG 63629(T)), Hma2N(T) ( = DSM 26263(T) = CCUG 63633(T)), Bma5N(T) ( = DSM 26265(T) = CCUG 63301(T)) and Biut2N(T) ( = DSM 26262(T) = CCUG 63631(T)).
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Banke E, Rödström K, Ekelund M, Dalla-Riva J, Lagerstedt JO, Nilsson S, Degerman E, Lindkvist-Petersson K, Nilson B. Superantigen activates the gp130 receptor on adipocytes resulting in altered adipocyte metabolism. Metabolism 2014; 63:831-40. [PMID: 24684823 DOI: 10.1016/j.metabol.2014.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 02/25/2014] [Accepted: 03/04/2014] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The bacteria Staphylococcus aureus is part of the normal bacterial flora and produces a repertoire of enterotoxins which can cause food poisoning and toxic shock and might contribute to the pathogenesis of inflammatory diseases. These enterotoxins directly cross-link the T cell receptor with MHC class II, activating large amounts of T cells and are therefore called superantigens. It was recently discovered that the superantigen SEA binds to the cytokine receptor gp130. As obesity and type 2 diabetes are highly associated with inflammation of the adipose tissue and gp130 has been shown to play an important role in adipocytes, we wanted to investigate the effect of SEA on adipocyte signaling and function. MATERIALS/METHODS Binding of SEA to gp130 was examined using surface plasmon resonance in a cell free system. Effects of SEA on adipocyte signaling, insulin sensitivity and function were studied using western blotting and biological assays for lipolysis, lipogenesis and glucose uptake. RESULTS We demonstrate that SEA binds to gp130 with a medium affinity. Furthermore, SEA induces phosphorylation of a key downstream target, STAT3, in adipocytes. SEA also inhibits insulin-induced activation of PKB and PKB downstream signaling which was associated with reduced basal and insulin induced glucose uptake, reduced lipogenesis as well as reduced ability of insulin to inhibit lipolysis. CONCLUSIONS SEA inhibits insulin signaling as well as insulin biological responses in adipocytes supporting that bacterial infection might contribute to the development of insulin resistance and type 2 diabetes.
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Affiliation(s)
- Elin Banke
- Department of Experimental Medical Science, Lund University, BMC, 221 84 Lund, Sweden.
| | - Karin Rödström
- Department of Experimental Medical Science, Lund University, BMC, 221 84 Lund, Sweden
| | - Mikael Ekelund
- Department of Surgery, Skåne University Hospital & Lund University, 221 85 Lund, Sweden
| | - Jonathan Dalla-Riva
- Department of Experimental Medical Science, Lund University, BMC, 221 84 Lund, Sweden
| | - Jens O Lagerstedt
- Department of Experimental Medical Science, Lund University, BMC, 221 84 Lund, Sweden
| | - Staffan Nilsson
- Pure and Applied Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, 221 00 Lund, Sweden
| | - Eva Degerman
- Department of Experimental Medical Science, Lund University, BMC, 221 84 Lund, Sweden
| | | | - Bo Nilson
- Department of Laboratory Medicine, Division of Medicinal Microbiology, Lund University, 223 62 Lund, Sweden; Department of Clinical Microbiology, University and Regional Laboratories in Region Skåne, 221 85 Lund, Sweden
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Rasmussen M, Nilson B, Olaison L. P47 FEATURES OF INFECTIVE ENDOCARDITIS CAUSED BY AEROCOCCI. Int J Antimicrob Agents 2013. [DOI: 10.1016/s0924-8579(13)70071-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Senneby E, Nilson B, Petersson AC, Rasmussen M. Matrix-assisted laser desorption ionization-time of flight mass spectrometry is a sensitive and specific method for identification of aerococci. J Clin Microbiol 2013; 51:1303-4. [PMID: 23390276 PMCID: PMC3666765 DOI: 10.1128/jcm.02637-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 01/30/2013] [Indexed: 11/20/2022] Open
Abstract
Conventional methods for the identification of human-pathogenic aerococci to the species level are not reliable. We show that matrix-assisted laser desorption ionization-time of flight mass spectrometry correctly identifies aerococci to the species level and that it can be used to identify aerococci with high specificity in the diagnostic clinical microbiology laboratory.
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Affiliation(s)
- Erik Senneby
- Clinical Microbiology, University and Regional Laboratories, Region Skåne, Lund, Sweden.
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35
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Pizzolla A, Hultqvist M, Nilson B, Grimm MJ, Eneljung T, Jonsson IM, Verdrengh M, Kelkka T, Gjertsson I, Segal BH, Holmdahl R. Reactive oxygen species produced by the NADPH oxidase 2 complex in monocytes protect mice from bacterial infections. J Immunol 2012; 188:5003-11. [PMID: 22491245 DOI: 10.4049/jimmunol.1103430] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chronic granulomatous disease (CGD) is an inherited disorder characterized by recurrent life-threatening bacterial and fungal infections. CGD results from defective production of reactive oxygen species by phagocytes caused by mutations in genes encoding the NADPH oxidase 2 (NOX2) complex subunits. Mice with a spontaneous mutation in Ncf1, which encodes the NCF1 (p47(phox)) subunit of NOX2, have defective phagocyte NOX2 activity. These mice occasionally develop local spontaneous infections by Staphylococcus xylosus or by the common CGD pathogen Staphylococcus aureus. Ncf1 mutant mice were more susceptible to systemic challenge with these bacteria than were wild-type mice. Transgenic Ncf1 mutant mice harboring the wild-type Ncf1 gene under the human CD68 promoter (MN(+) mice) gained the expression of NCF1 and functional NOX2 activity specifically in monocytes/macrophages, although minimal NOX2 activity was also detected in some CD11b(+)Ly6G(+) cells defined as neutrophils. MN(+) mice did not develop spontaneous infection and were more resistant to administered staphylococcal infections compared with MN(-) mice. Most strikingly, MN(+) mice survived after being administered Burkholderia cepacia, an opportunistic pathogen in CGD patients, whereas MN(-) mice died. Thus, monocyte/macrophage expression of functional NCF1 protected against spontaneous and administered bacterial infections.
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Affiliation(s)
- Angela Pizzolla
- Medical Inflammation Research, Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
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Singh B, Blom AM, Unal C, Nilson B, Mörgelin M, Riesbeck K. Vitronectin binds to the head region ofMoraxella catarrhalisubiquitous surface protein A2 and confers complement-inhibitory activity. Mol Microbiol 2010; 75:1426-44. [DOI: 10.1111/j.1365-2958.2010.07066.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wells RD, Dahl B, Nilson B. Comparison of the levels of quality of inpatient care delivered by pediatrics residents and by private, community pediatricians at one hospital. Acad Med 1998; 73:192-197. [PMID: 9484193 DOI: 10.1097/00001888-199802000-00019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE To compare the quality and cost of inpatient care provided by pediatrics residents with the quality and cost of that provided by private, practicing pediatricians. METHOD Valley Children's Hospital--a 175-bed, private, nonprofit, university-affiliated pediatric hospital located in Fresno, California--has both a resident service and a community physician service. From May 1994 to March 1995 a total of 154 pediatric patients (64 from the resident service, 90 from the community service) were selected for the study using incidental sampling. In order to be included in the study, patients had discharge diagnoses of uncomplicated gastroenteritis or asthma. The parent or guardian of each patient completed a satisfaction questionnaire at discharge and agreed to a home visit one month later, when the same questionnaire and another were completed. Patients' charts were studied for treatment procedures, and follow-up data for a year were compiled. Statistical analyses were conducted with analysis of variance for continuous measures and chi-squares for dichotomous variables. RESULTS The findings indicated no difference between the two services in terms of the parents' and guardians' satisfaction with patient care, hospital charges, and degrees of adherence to follow-up care after discharge. The community physicians were more likely than were the residents to employ non-standard laboratory and management procedures with both the asthma and gastroenteritis patients. The asthma patients cared for by community physicians had significantly more frequent asthma attacks after discharge, with a higher frequency of patients being subsequently treated in the emergency room and readmitted to the hospital, than did the asthma patients cared for by the residents. CONCLUSION Common perceptions that physicians-in-training (1) overuse medical services and (2) fail, due to their inexperience, to provide high-quality services were not supported in this study.
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Affiliation(s)
- R D Wells
- Valley Children's Hospital, Fresno, CA 93703, USA.
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Sigurdardóytir V, Bolund C, Nilson B. Quality of life and ethics: Opinions about chemotherapy among patients with advanced melanoma, next of kin and care-providers. Psychooncology 1995. [DOI: 10.1002/pon.2960040406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Nilson B, Björck L, Akerström B. Enzyme linked immunosorbent assay using alkaline phosphatase conjugated with streptococcal protein G. J Immunoassay 1988; 9:207-25. [PMID: 3372703 DOI: 10.1080/15321818808057041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Protein G, an IgG-binding protein, purified from the surface of group G streptococci, was coupled to alkaline phosphatase. The conjugate was used for detection of polyclonal goat and rabbit antibodies and monoclonal mouse IgG1, IgG2a and IgG2b in an enzyme-linked immunosorbent assay. A two-step coupling procedure was used, in which glutaraldehyde was allowed to react with the enzyme, excess glutaraldehyde was then removed by dialysis, and finally protein G added to the glutaraldehyde-activated and polymerized alkaline phosphatase. The activity and yield of the conjugates were then tested in an enzyme-linked immunosorbent assay. Coupling of 25 micrograms protein G to 5 mg alkaline phosphatase gave a conjugate which could be used for more than 10,000 determinations with maximal antibody binding giving an absorbance of 2.0. Under these conditions, there was no need for separation of the reactants before using the protein G-alkaline phosphatase complex.
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Affiliation(s)
- B Nilson
- Department of Physiological Chemistry, University of Lund, Sweden
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Nilson B, Akerström B, Lögdberg L. Cross-reacting monoclonal anti-alpha 1-microglobulin antibodies produced by multi-species immunization and using protein G for the screening assay. J Immunol Methods 1987; 99:39-45. [PMID: 2437206 DOI: 10.1016/0022-1759(87)90029-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In order to generate monoclonal antibodies (MAb) directed against the low molecular weight glycoprotein alpha 1-microglobulin, a BALB/c mouse was immunized with a mixture of human, guinea pig, rat and rabbit alpha 1-microglobulin homologues (multi-species immunization) and boosted several times. On day 194, the mouse splenocytes were fused to SP2/0 myeloma cells. The resulting hybridomas were screened for anti-alpha 1-microglobulin activity against the alpha 1-microglobulin mixture or against the individual homologues. For this screening, protein G (the newly described IgG-binding streptococcal protein) was used in a solid-phase radioimmunoassay. The binding of protein G to immobilized antigen-antibody complexes was enhanced by pre-incubation with rabbit anti-mouse immunoglobulin G. The result was a panel of nine established hybridoma lines, all producing unique monoclonal antibodies, of IgG1 or IgG2a class, to alpha 1-microglobulin. The antibodies were not only reactive in solid-phase radioimmunoassay, but they could also immunoprecipitate 125I-labeled soluble alpha 1-microglobulin. Moreover, they reacted specifically with the alpha 1-microglobulin band in Western blots of urinary proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Such monoclonal antibodies are potentially valuable reagents for the further characterization of alpha 1-microglobulin.
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Abstract
An enzyme histochemical method and histomorphological examination were applied in the cases of 37 patients with cytological atypia. Good agreement was found between the presence of aberrant glucose-6-phosphate dehydrogenase (G-6-PD) activity (metabolic atypia) and histopathologically demonstrable dysplasia. Only three women with metabolic atypia showed a normal histopathological picture. The results suggest that enzyme histochemistry may also be a valuable supplement to histopathology in the diagnosis of cervical neoplastic changes.
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Nilson B, Björck L, Akerström B. Detection and purification of rat and goat immunoglobulin G antibodies using protein G-based solid-phase radioimmunoassays. J Immunol Methods 1986; 91:275-81. [PMID: 2426365 DOI: 10.1016/0022-1759(86)90490-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Using the newly described streptococcal surface protein, protein G, which has powerful immunoglobulin G binding properties, solid-phase radioimmunoassays were developed for the quantitation of goat and rat immunoglobulin G bound to the plastic surface of microtiter plates. The binding of goat immunoglobulin G to the surface via a specific antigen (guinea pig alpha 1-microglobulin) permitted the determination of antigen-specific antibodies with a detection limit of 50-100 ng. Optimum assay conditions were established and the whole assay procedure could be brought to completion at room temperature in less than a working day. The value of the assays was illustrated by monitoring rat and goat immunoglobulin G antibodies during their purification from whole sera by classical chromatographic procedures.
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Linde A, Jontell M, Lundgren T, Nilson B, Svanberg U. Noncollagenous proteins of rat compact bone. J Biol Chem 1983; 258:1698-705. [PMID: 6822529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
In order to obtain a comprehensive overview of the noncollagenous proteins (NCPs) of bone matrix, the NCPs were extracted from rat compact bone and fractionated using methods aiming to prevent artifactual degradation and losses of protein. The NCP content of rat bone was found to be similar to that of rat dentin in several respects but different in others. The soluble NCPs of bone fell into four categories: acidic glycoproteins, gamma-carboxyglutamate-containing proteins, phosphoproteins, and proteoglycans. With the exception of the gamma-carboxyglutamate-containing proteins, the majority of NCPs had apparent molecular weights exceeding 50,000. As in rat dentin, several gamma-carboxyglutamate-containing proteins could be demonstrated in rat bone. Earlier studies have only taken one molecular species into consideration. No highly phosphorylated phosphoprotein could be demonstrated in bone. However, at least two phosphoproteins with a low degree of phosphorylation were found to be present. No plasma proteins could be demonstrated in any of the chromatographic fractions from the EDTA extracted NCPs by means of double diffusion. The NCPs, remaining firmly associated with the collagenous matrix after thorough demineralization and extraction, were analyzed after CNBr and collagenase degradation of the matrix. Much smaller amounts of phosphoprotein were recovered after CNBr digestion than reported earlier. Collagenase digestion released small amounts of acidic glycoprotein, phosphoprotein, and proteoglycan. The results give additional evidence that this small remainder might be explained, not by any covalent linkage to collagen, but by an inefficient extraction.
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Nilson B. Problemsf the nutritionist in obtaining information. Proc Nutr Soc 1968; 27:117. [PMID: 5726988 DOI: 10.1079/pns19680032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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