| 1. |
- Säll, Olof, 1980-, et al.
(författare)
-
Atypical presentation of Neisseria meningitidis serogroup W disease is associated with the introduction of the 2013 strain
- 2021
-
Ingår i: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 149
-
Tidskriftsartikel (refereegranskat)abstract
- Since 2015, the incidence of invasive meningococcal disease (IMD) caused by serogroup W (MenW) has increased in Sweden, due to the introduction of the 2013 strain belonging to clonal complex 11. The aim of this study was to describe the clinical presentation of MenW infections, in particular the 2013 strain, including genetic associations. Medical records of confirmed MenW IMD cases in Sweden during the years 1995-2019 (n = 113) were retrospectively reviewed and the clinical data analysed according to strain. Of all MenW patients, bacteraemia without the focus of infection was seen in 44%, bacteraemic pneumonia in 26%, meningitis in 13% and epiglottitis in 8%, gastrointestinal symptoms in 48% and 4% presented with petechiae. Phylogenetic analysis was used for possible links between genetic relationship and clinical picture. The 2013 strain infections, particularly in one cluster, were associated with more severe disease compared with other MenW infections. The patients with 2013 strain infections (n = 68) were older (52 years vs. 25 years for other strains), presented more often with diarrhoea as an atypical presentation (P = 0.045) and were more frequently admitted for intensive care (P = 0.032). There is a risk that the atypical clinical presentation of MenW infections, with predominantly gastrointestinal or respiratory symptoms rather than neck stiffness or petechiae, may lead to delay in life-saving treatment.
|
|
| 2. |
- Säll, Olof, 1980-, et al.
(författare)
-
Clinical presentation of invasive disease caused by Neisseria meningitidis serogroup Y in Sweden, 1995 to 2012
- 2017
-
Ingår i: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 145:10, s. 2137-2143
-
Tidskriftsartikel (refereegranskat)abstract
- Over the period 1995-2012, the incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y (NmY) increased significantly in Sweden. This is mainly due to the emergence of a predominant cluster named strain type YI subtype 1, belonging to the ST-23 clonal complex (cc). The aim of this study was to examine the clinical picture of patients with invasive disease caused by NmY and to analyse whether the predominant cluster exhibits certain clinical characteristics that might explain the increased incidence. In this retrospective observational study, the medical records available from patients with IMD caused by Nm serogroup Y in Sweden between 1995 and 2012 were systematically reviewed. Patient characteristics, in-hospital findings and outcome were studied and differences between the dominating cluster and other isolates were analysed. Medical records from 175 of 191 patients were retrieved. The median age was 62 years. The all-cause mortality within 30 days of admission was 9% (15/175) in the whole material; 4% (2/54) in the cohort with strain type YI subtype 1 and 11% (12/121) among patients with other isolates. Thirty-three per cent of the patients were diagnosed with meningitis, 19% with pneumonia, 10% with arthritis and 35% were found to have bacteraemia but no apparent organ manifestation. This survey included cases with an aggressive clinical course as well as cases with a relatively mild clinical presentation. There was a trend towards lower mortality and less-severe disease in the cohort with strain type YI subtype 1 compared with the group with other isolates.
|
|
| 3. |
|
|
| 4. |
- Säll, Olof, 1980-
(författare)
-
Infections in the central nervous system with focus on meningococcal disease : clinical and epidemiological aspects
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Infections in the central nervous system (CNS) include meningitis and encephalitis and are associated with high mortality and morbidity. A large number of different pathogens can cause these infections, including Neisseria meningitidis. It’s crucial to find the causative pathogen in order to provide the best treatment to the patient and for disease surveillance. In Paper I, molecular methods were used to investigate the microbial etiology in patients presenting with CNS infections at United Mission Hospital in Tansen, Nepal. Although the cerebrospinal fluid samples were analyzed for a large number of microbes using two commercial multiplex PCR panels and additional in-house real-time PCR, the etiology of the infections was still unknown in a large number of patients. This calls for further development of diagnostic methods for CNS infections.Neisseria meningitidis, the meningococcus, is a strictly human commensal but also capable to cause severe disease, typically in the form of sepsis and meningitis. The aim of Paper II and III was to study the clinical presentation of N. meningitidis serogroup Y and W infections, which increased unexpectedlyin Sweden from 2007 and 2014, respectively. By reviewing medical records of these infection episodes, the conclusion was drawn that atypical presentations with respiratory and gastrointestinal symptoms were common, rather than meningitis and petechiae.In Paper IV, meningococcal carriage was studied among students at Örebro University. Age ≤22 years, smoking, previous tonsillectomy, frequent partying and male gender were associated with higher carrier rates. The so far longest observation of carriage of the same meningococcal strain was presented, with a duration of at least one year.In conclusion, the results from these studies highlight the importance of early detection of meningococcal infections with atypical presentations and the need of improved diagnostics for CNS infections
|
|
| 5. |
|
|
| 6. |
- Eriksson, Lorraine, 1990-, et al.
(författare)
-
Difference in virulence between Neisseria meningitidis serogroups W and Y in transgenic mice
- 2020
-
Ingår i: BMC Microbiology. - : BioMed Central. - 1471-2180. ; 20:1
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neisseria meningitidis serogroups W and Y are the most common serogroups causing invasive meningococcal disease in Sweden. The majority of cases are caused by the serogroup W UK 2013 strain of clonal complex (cc) 11, and subtype 1 of the serogroup Y, YI strain of cc23. In this study, virulence factors of several lineages within cc11 and cc23 were investigated in transgenic BALB/c mice expressing human transferrin. Transgenic mice were infected intraperitoneally with serogroup W and Y isolates. Levels of bacteria and the proinflammatory cytokine CXCL1 were determined in blood collected 3 h and 24 h post-infection. Apoptosis was investigated in immune cells from peritoneal washes of infected mice. Adhesion and induction of apoptosis in human epithelial cells were also scored.RESULTS: The levels of bacteraemia, CXCL1, and apoptosis were higher in serogroup W infected mice than in serogroup Y infected mice. Serogroup W isolates also induced higher levels of apoptosis and adhesion in human epithelial cells. No significant differences were observed between different lineages within cc11 and cc23.CONCLUSIONS: N. meningitidis Serogroup W displayed a higher virulence in vivo in transgenic mice, compared to serogroup Y. This was reflected by higher bacteremia, proinflammatory activity, and ability to induce apoptosis in mouse immune cells and human epithelial cells.
|
|
| 7. |
- Eriksson, Lorraine, 1990-, et al.
(författare)
-
Genetic variants linked to the phenotypic outcome of invasive disease and carriage of Neisseria meningitidis
- 2023
-
Ingår i: Microbial Genomics. - : Microbiology Society. - 2057-5858. ; 9:10
-
Tidskriftsartikel (refereegranskat)abstract
- Neisseria meningitidis can be a human commensal in the upper respiratory tract but is also capable of causing invasive diseases such as meningococcal meningitis and septicaemia. No specific genetic markers have been detected to distinguish carriage from disease isolates. The aim here was to find genetic traits that could be linked to phenotypic outcomes associated with carriage versus invasive N. meningitidis disease through a bacterial genome-wide association study (GWAS). In this study, invasive N. meningitidis isolates collected in Sweden (n=103) and carriage isolates collected at Örebro University, Sweden (n=213) 2018-2019 were analysed. The GWAS analysis, treeWAS, was applied to single-nucleotide polymorphisms (SNPs), genes and k-mers. One gene and one non-synonymous SNP were associated with invasive disease and seven genes and one non-synonymous SNP were associated with carriage isolates. The gene associated with invasive disease encodes a phage transposase (NEIS1048), and the associated invasive SNP glmU S373C encodes the enzyme N-acetylglucosamine 1-phosphate (GlcNAC 1-P) uridyltransferase. Of the genes associated with carriage isolates, a gene variant of porB encoding PorB class 3, the genes pilE/pilS and tspB have known functions. The SNP associated with carriage was fkbp D33N, encoding a FK506-binding protein (FKBP). K-mers from PilS, tbpB and tspB were found to be associated with carriage, while k-mers from mtrD and tbpA were associated with invasiveness. In the genes fkbp, glmU, PilC and pilE, k-mers were found that were associated with both carriage and invasive isolates, indicating that specific variations within these genes could play a role in invasiveness. The data presented here highlight genetic traits that are significantly associated with invasive or carriage N. meningitidis across the species population. These traits could prove essential to our understanding of the pathogenicity of N. meningitidis and could help to identify future vaccine targets.
|
|
| 8. |
- Säll, Olof, 1980-, et al.
(författare)
-
Diagnostic challenges in a patient with myocardial tuberculoma : A case report
- 2016
-
Ingår i: International Journal of Surgery Case Reports. - : Elsevier. - 2210-2612. ; 29, s. 201-203
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Tuberculosis can affect any organ of the body, including the heart.PRESENTATION OF CASE: An 18-year old woman presented with a multifocal tuberculosis infection involving abdominal lymph nodes, a sternotomy wound, an abscess of the abdominal wall and most notably a myocardial tuberculoma. Establishing the diagnosis of the myocardial tuberculoma was challenging mainly due to the location within the heart. Initially a diagnostic percutaneous femoral vascular catheter guided biopsy of the right atrial mass was performed, but later open surgery involving median sternotomy was needed. The patient recovered fully after surgery and nine months treatment with anti-tuberculosis drugs.DISCUSSION: The optimal length of treatment for myocardial tuberculoma is unknown. Medical treatment for six months might be enough regardless whether surgery is performed or not.CONCLUSION: Myocardial tuberculoma requires culture from the infected tissue for confirmed diagnosis and might be successfully treated with anti-tuberculosis drugs only. Indications for surgery include uncertain diagnosis, poor response to medical treatment or cardiac complications. (C) 2016 The Authors. Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.
|
|
| 9. |
- Säll, Olof, 1980-, et al.
(författare)
-
Etiology of Central Nervous System Infections in a Rural Area of Nepal Using Molecular Approaches
- 2019
-
Ingår i: American Journal of Tropical Medicine and Hygiene. - : HighWire Press. - 0002-9637 .- 1476-1645. ; 101:1, s. 253-259
-
Tidskriftsartikel (refereegranskat)abstract
- The etiology of infections of the central nervous system (CNS) in Nepal often remains unrecognized because of underdeveloped laboratory facilities. The aim of this study was to investigate the etiology of CNS infections in a rural area of Nepal using molecular methods. From November 2014 to February 2016, cerebrospinal fluid (CSF) was collected from 176 consecutive patients presenting at United Mission Hospital in Tansen, Nepal, with symptoms of possible CNS infection. After the CSF samples were stored and transported frozen, polymerase chain reaction (PCR) was performed in Sweden, targeting a total of 26 pathogens using the FilmArray® ME panel (BioFire, bioMerieux, Salt Lake City, UT), the MeningoFinder® 2SMART (PathoFinder, Maastricht, The Netherlands), and an in-house PCR test for dengue virus (DENV), Japanese encephalitis virus (JEV), and Nipah virus (NiV). The etiology could be determined in 23%. The bacteria detected were Haemophilus influenzae (n = 5), Streptococcus pneumoniae (n = 4), and Neisseria meningitidis (n = 1). The most common virus was enterovirus detected in eight samples, all during the monsoon season. Other viruses detected were cytomegalovirus (n = 6), varicella zoster virus (n = 5), Epstein-Barr virus (n = 3), herpes simplex virus (HSV) type 1 (HSV-1) (n = 3), HSV-2 (n = 3), human herpes virus (HHV) type 6 (HHV-6) (n = 3), and HHV-7 (n = 2). Cryptococcus neoformans/gatti was found in four samples. None of the samples were positive for DENV, JEV, or NiV. Of the patients, 67% had been exposed to antibiotics before lumbar puncture. In conclusion, the etiology could not be found in 77% of the samples, indicating that the commercial PCR panels used are not suitable in this setting. Future studies on the etiology of CNS infections in Nepal could include metagenomic techniques.
|
|
| 10. |
- Säll, Olof, 1980-, et al.
(författare)
-
High genomic-based predicted strain coverage among invasive meningococcal isolates when combining Bexsero and Trumenba vaccines
- 2020
-
Ingår i: Vaccine. - : Elsevier. - 0264-410X .- 1873-2518. ; 38:28, s. 4374-4378
-
Tidskriftsartikel (refereegranskat)abstract
- Two protein-based vaccines (Bexsero® and Trumenba®) are licensed for invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup B (MenB). The aim of this study was to evaluate the possible protection of these vaccines, based on the genomic profiles of IMD isolates. All invasive meningococcal isolates in Sweden during 2014–2018 (n = 242) were analyzed with the vaccine coverage scheme available at the PubMLST database. The overall estimated genomic strain coverage among the Swedish invasive meningococcal isolates was 55% for Bexsero and 57% for Trumenba (p = 0.714). The estimated serogroup-specific coverage for Bexsero respectively Trumenba was: MenB; 67% and 90% (p < 0.05), MenW; 93% and 4% (p < 0.05), MenC; 87% and 30% (p < 0.05) and MenY; 1% and 96% (p < 0.05). With the combination of the two vaccines, the potential genomic-based strain coverage was 95%, indicating a possible additive effect of combining Bexsero and Trumenba, which, however, needs to be confirmed by analysis of phenotypic antigen expression.
|
|
