| 1. |
- Bagdonaite, I., et al.
(författare)
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A Strategy for O-Glycoproteomics of Enveloped Viruses-the O-Glycoproteome of Herpes Simplex Virus Type 1
- 2015
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Ingår i: Plos Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Glycosylation of viral envelope proteins is important for infectivity and interaction with host immunity, however, our current knowledge of the functions of glycosylation is largely limited to N-glycosylation because it is difficult to predict and identify site-specific O-glycosylation. Here, we present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1) as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B were previously implicated in virus attachment to immune cells. We show that HSV-1 infection distorts the secretory pathway and that infected cells accumulate glycoproteins with truncated O-glycans, nonetheless retaining the ability to elongate most of the surface glycans. With the use of precise gene editing, we further demonstrate that elongated O-glycans are essential for HSV-1 in human HaCaT keratinocytes, where HSV-1 produced markedly lower viral titers in HaCaT with abrogated O-glycans compared to the isogenic counterpart with normal O-glycans. The roles of O-linked glycosylation for viral entry, formation, secretion, and immune recognition are poorly understood, and the O-glycoproteomics strategy presented here now opens for unbiased discovery on all enveloped viruses.
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| 2. |
- Nordén, Rickard, 1977, et al.
(författare)
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Activation of host antiviral RNA-sensing factors necessary for herpes simplex virus type 1-activated transcription of host cell fucosyltransferase genes FUT3, FUT5, and FUT6 and subsequent expression of sLex in virus-infected cells.
- 2009
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:7, s. 776-88
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV-1) induces expression of a selectin receptor, the carbohydrate epitope sialyl Lewis X (sLe(x)), at the surface of infected cells. The molecular background to this phenomenon is that a viral immediate early RNA interacts with as yet unidentified host factors, eventually resulting in transcription of three dormant host fucosyltransferase genes (FUT3, FUT5, and FUT6), whose gene products are rate-limiting for synthesis of sLe(x). The aim of the present study was to define the immediate targets for the viral RNA in this process. We found that the Protein Kinase R (PKR) inhibitors 2-aminopurine (2-AP) and C16 inhibited FUT3, FUT5, and FUT6 expression as well as HSV-1-induced expression of sLe(x), indicating a primary role of PKR as a viral RNA target. The PKR-dependent activation of the FUT genes seemed neither to involve PKR effects on translation nor to involve NF-kappaB- or JNK-dependent activation. IMD-0354, known as an inhibitor of the NF-kappaB-activating factor IKK-2, induced FUT transcription via a novel IKK-2-independent mechanism, irrespective of whether the cells were virus-infected or not. Altogether, the results suggested that PKR is the primary target for HSV-1 early RNA during induction of FUT3, FUT5, and FUT6, and that the subsequent steps in the transcriptional activation of these host genes involve a hitherto unknown IMD-0354, yet IKK-2-independent, pathway.
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| 3. |
- Nordén, Rickard, 1977, et al.
(författare)
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Involvement of viral glycoprotein gC-1 in expression of the selectin ligand sialyl-Lewis X induced after infection with herpes simplex virus type 1.
- 2013
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 1600-0463. ; 121:4, s. 280-289
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Tidskriftsartikel (refereegranskat)abstract
- Several herpesviruses induce expression of the selectin receptor sialyl-Lewis X (sLe(x) ) by activating transcription of one or more of silent host FUT genes, each one encoding a fucosyltransferase that catalyses the rate-limiting step of sLe(x) synthesis. The aim here was to identify the identity of the glycoconjugate associated with sLe(x) glycoepitope in herpes simplex virus type 1 (HSV-1) infected human diploid fibroblasts, using immunofluorescence confocal microscopy. Cells infected with all tested HSV-1 strains analysed demonstrated bright sLe(x) fluorescence, except for two mutant viruses that were unable to induce proper expression of viral glycoprotein gC-1: One gC-1 null mutant and another mutant expressing gC-1 devoid of its major O-glycan-containing region (aa 33-116). The sLe(x) reactivity of HSV-1 infected cells was abolished by mild alkali treatment. Altogether the results indicated that the detectable sLe(x) was associated with O-linked glycans, situated in the mucin region of gC-1. No evidence for sLe(x) (i) in other HSV-1 glycoproteins with mucin domains such as gI-1 or (ii) in host cell glycoproteins/glycolipids was found. Thus, the mucin domain of HSV-1 gC-1 may support expression of selectin ligands such as sLe(x) and other larger O-linked glycans in cell types lacking endogenous mucin domain-containing glycoproteins, optimized for O-glycan expression, provided that the adequate host glycosyltransferase genes are activated.
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| 4. |
- Nordén, Rickard, 1977, et al.
(författare)
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NF kappa B-mediated activation of the cellular FUT3, 5 and 6 gene cluster by herpes simplex virus type 1
- 2017
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 27:11, s. 999-1005
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 has the ability to induce expression of a human gene cluster located on chromosome 19 upon infection. This gene cluster contains three fucosyltransferases (encoded by FUT3, FUT5 and FUT6) with the ability to add a fucose to an N-acetylglucosamine residue. Little is known regarding the transcriptional activation of these three genes in human cells. Intriguingly, herpes simplex virus type 1 activates all three genes simultaneously during infection, a situation not observed in uninfected tissue, pointing towards a virus specific mechanism for transcriptional activation. The aim of this study was to define the underlying mechanism for the herpes simplex virus type 1 activation of FUT3, FUT5 and FUT6 transcription. The transcriptional activation of the FUT-gene cluster on chromosome 19 in fibroblasts was specific, not involving adjacent genes. Moreover, inhibition of NF kappa B signaling through panepoxydone treatment significantly decreased the induction of FUT3, FUT5 and FUT6 transcriptional activation, as did siRNA targeting of p65, in herpes simplex virus type 1 infected fibroblasts. NF kappa B and p65 signaling appears to play an important role in the regulation of FUT3, FUT5 and FUT6 transcriptional activation by herpes simplex virus type 1 although additional, unidentified, viral factors might account for part of the mechanism as direct interferon mediated stimulation of NF kappa B was not sufficient to induce the fucosyltransferase encoding gene cluster in uninfected cells.
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| 5. |
- Nordén, Rickard, 1977, et al.
(författare)
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O-linked glycosylation of the mucin domain of the herpes simplex virus type 1 specific glycoprotein gC-1 is temporally regulated in a seed-and-spread manner.
- 2015
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Ingår i: The Journal of biological chemistry. - 1083-351X. ; 290:8, s. 5078-5091
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Tidskriftsartikel (refereegranskat)abstract
- The herpes simplex virus type 1 (HSV-1) glycoprotein gC-1, participating in viral receptor interactions and immunity interference, harbors a mucin-like domain with multiple clustered O-linked glycans. Using HSV-1 infected diploid human fibroblasts, an authentic target for HSV-1 infection, and a protein immunoaffinity procedure, we enriched fully glycosylated gC-1 and a series of its biosynthetic intermediates. This fraction was subjected to trypsin digestion and a LC-MS/MS glycoproteomics approach. In parallel, we characterized the expression patterns of the 20 isoforms of human GalNAc transferases responsible for initiation of O-linked glycosylation. The gC-1 O-glycosylation was regulated in an orderly manner initiated by synchronous addition of one GalNAc unit each to T87 and T91, and one GalNAc unit to either T99 or T101, forming a core glycopeptide for subsequent additions of in all 11 GalNAc residues to selected Ser and Thr residues of the T76-L107 stretch of the mucin domain. The expression patterns of GalNAc transferases in the infected cells suggested that initial additions of GalNAc were carried out by initiating GalNAc transferases, in particular GalNAc-T2, whereas subsequent GalNAc additions were carried out by follow up transferases, in particular GalNAc-T10. Essentially all of the susceptible Ser or Thr residues had to acquire their GalNAc units before any elongation to longer O-linked glycans of the gC-1-associated GalNAc units was permitted. Since the GalNAc occupancy pattern is of relevance for receptor binding of gC-1, the data provides a model to delineate biosynthetic steps of O-linked glycosylation of the gC-1 mucin domain in HSV-1 infected target cells.
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| 6. |
- Nordén, Rickard, 1977, et al.
(författare)
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Virus-induced appearance of the selectin ligand sLeX in herpes simplex virus type 1-infected T cells: Involvement of host and viral factors.
- 2013
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 23:3, s. 310-321
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Tidskriftsartikel (refereegranskat)abstract
- Circulating leukocytes that express selectin ligands such as the carbohydrate epitope sialyl Lewis X (sLeX) may interact with endothelial selectins, resulting in transmigration of the leukocyte across the endothelial wall to adjacent tissue. Due to the potential of selectin-ligand interactions as targets in viral pathogenesis, we aimed at determining whether herpes simplex virus type 1 (HSV1) is able to induce appearance of sLeX at the surface of infected leukocytes. We found that HSV1 infection of a T cell line resulted in transcriptional activation of human fucosyltransferase genes FUT3, FUT6 and FUT7, the two latter genes encoding fucosyltransferases rate limiting for sLeX synthesis. Flow cytometry and confocal microscopy demonstrated that HSV1 infection resulted in a two-fold rise in the proportion of sLeX-positive cells. Increased levels of FUT3, FUT6 and FUT7 RNA were detected already at 3 h post infection, and treatment with cycloheximide, a translation inhibitor, blocked HSV1-induced increase in expression of FUT3, FUT6 and FUT7 RNA, suggesting involvement of viral or cellular proteins. Studies with infectious viral mutants indicated that the viral immediate early (α) protein ICP0 is essential for initiation of FUT7 though not for FUT3 or FUT6 transcription. In CD3+ cells, derived from peripheral blood mononuclear cells, HSV1 infection induced expression of FUT3, FUT5 and FUT6, whereas FUT7 was not altered. The mean sLeX fluorescence intensity of CD3+ cells was significantly higher in HSV1-infected CD3+ cells. This suggests that infected leukocytes during HSV1 viremia may express selectin ligands with possible but as yet unproven roles in viral pathogenesis.
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| 7. |
- Nyström, Kristina, 1977, et al.
(författare)
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Induction of sialyl-Lex expression by herpes simplex virus type 1 is dependent on viral immediate early RNA-activated transcription of host fucosyltransferase genes. : Induction of sialyl-Lewis x expression by HSV-1
- 2009
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:8, s. 847-59
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that varicella-zoster virus (VZV) and cytomegalovirus (CMV) infection of diploid human fibroblasts (HEL) results in neo-expression of Lewis antigens sialyl Lewis x (sLe(x)) and Lewis y (Le(y)), respectively, after transcriptional activation of different combinations of dormant human fucosyltransferase genes (FUT1, FUT3, FUT5, and FUT6), whose gene products are responsible for the synthesis of Le antigens. Here, we show that herpes simplex virus type 1 (HSV-1) also induces sLe(x) expression dependent on induction of FUT3, FUT5, and FUT6 transcription in infected cells. HSV-1 induction of FUT5 was subsequently used as a model system for analyzing the mechanism of viral activation of dormant fucosyltransferase genes. We show that this is a rapid process, which gives rise to elevated FUT5 RNA levels already at 90 min postinfection. Augmented FUT5 transcription was found to be dependent on transcription of viral genes, but not dependent on the immediate early proteins ICP0 and ICP4, as demonstrated by experiments with HSV-1 mutants defective in expression of these genes. Augmented FUT5 transcription takes place in cycloheximide-treated HSV-1-infected cells, suggesting a more direct role for IE viral RNA during activation of cellular FUT5.
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| 8. |
- Samuelsson, Ebba, 1991, et al.
(författare)
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Sialic Acid and Fucose Residues on the SARS-CoV-2 Receptor-Binding Domain Modulate IgG Antibody Reactivity
- 2022
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Ingår i: Acs Infectious Diseases. - : American Chemical Society (ACS). - 2373-8227. ; 8:9, s. 1883-1893
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Tidskriftsartikel (refereegranskat)abstract
- The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is a conserved domain and a target for neutralizing antibodies. We defined the carbohydrate content of the recombinant RBD produced in different mammalian cells. We found a higher degree of complex-type N-linked glycans, with less sialylation and more fucosylation, when the RBD was produced in human embryonic kidney cells compared to the same protein produced in Chinese hamster ovary cells. The carbohydrates on the RBD proteins were enzymatically modulated, and the effect on antibody reactivity was evaluated with serum samples from SARS-CoV-2 positive patients. Removal of all carbohydrates diminished antibody reactivity, while removal of only sialic acids or terminal fucoses improved the reactivity. The RBD produced in Lec3.2.8.1-cells, which generate carbohydrate structures devoid of sialic acids and with reduced fucose content, exhibited enhanced antibody reactivity, verifying the importance of these specific monosaccharides. The results can be of importance for the design of future vaccine candidates, indicating that it is possible to enhance the immunogenicity of recombinant viral proteins.
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| 9. |
- Bagdonaite, I., et al.
(författare)
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Global Mapping of O-Glycosylation of Varicella Zoster Virus, Human Cytomegalovirus, and Epstein-Barr Virus
- 2016
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 291:23, s. 12014-12028
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Tidskriftsartikel (refereegranskat)abstract
- Herpesviruses are among the most complex and widespread viruses, infection and propagation of which depend on envelope proteins. These proteins serve as mediators of cell entry as well as modulators of the immune response and are attractive vaccine targets. Although envelope proteins are known to carry glycans, little is known about the distribution, nature, and functions of these modifications. This is particularly true for O-glycans; thus we have recently developed a "bottom up" mass spectrometry-based technique for mapping O-glycosylation sites on herpes simplex virus type 1. We found wide distribution of O-glycans on herpes simplex virus type 1 glycoproteins and demonstrated that elongated O-glycans were essential for the propagation of the virus. Here, we applied our proteome-wide discovery platform for mapping O-glycosites on representative and clinically significant members of the herpesvirus family: varicella zoster virus, human cytomegalovirus, and Epstein-Barr virus. We identified a large number of O-glycosites distributed on most envelope proteins in all viruses and further demonstrated conserved patterns of O-glycans on distinct homologous proteins. Because glycosylation is highly dependent on the host cell, we tested varicella zoster virus-infected cell lysates and clinically isolated virus and found evidence of consistent O-glycosites. These results present a comprehensive view of herpesvirus O-glycosylation and point to the widespread occurrence of O-glycans in regions of envelope proteins important for virus entry, formation, and recognition by the host immune system. This knowledge enables dissection of specific functional roles of individual glycosites and, moreover, provides a framework for design of glycoprotein vaccines with representative glycosylation.
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| 10. |
- Bagdonaite, Ieva, et al.
(författare)
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Glycoengineered keratinocyte library reveals essential functions of specific glycans for all stages of HSV-1 infection
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Viral and host glycans represent an understudied aspect of host-pathogen interactions, despite potential implications for treatment of viral infections. This is due to lack of easily accessible tools for analyzing glycan function in a meaningful context. Here we generate a glycoengineered keratinocyte library delineating human glycosylation pathways to uncover roles of specific glycans at different stages of herpes simplex virus type 1 (HSV-1) infectious cycle. We show the importance of cellular glycosaminoglycans and glycosphingolipids for HSV-1 attachment, N-glycans for entry and spread, and O-glycans for propagation. While altered virion surface structures have minimal effects on the early interactions with wild type cells, mutation of specific O-glycosylation sites affects glycoprotein surface expression and function. In conclusion, the data demonstrates the importance of specific glycans in a clinically relevant human model of HSV-1 infection and highlights the utility of genetic engineering to elucidate the roles of specific viral and cellular carbohydrate structures.
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| 11. |
- Birindwa, Archippe M., et al.
(författare)
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Bacteria and viruses in the upper respiratory tract of Congolese children with radiologically confirmed pneumonia
- 2021
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Ingår i: Bmc Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Acute pneumonia remains a leading cause of death among children below 5 years of age in the Democratic Republic of the Congo (DR Congo), despite introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in 2013. Potential pathogens in the nasopharynx of hospitalised children with pneumonia have not been studied previously in DR Congo. Here we compare clinical characteristics, risk factors and nasopharyngeal occurrence of bacteria and viruses between children with severe and non-severe pneumonia. Methods Between June 2015 and June 2017, 116 children aged from 2 to 59 months hospitalised due to radiologically confirmed pneumonia at Panzi referral university hospital, Bukavu, Eastern DR Congo were included in the study and sampled from nasopharynx. A multiplex real-time PCR assay for detection of 15 different viruses and 5 bacterial species was performed and another multiplex PCR assay was used for pneumococcal serotype/serogroup determination. Results During the study period 85 (73%) of the children with radiologically confirmed pneumonia met the WHO classification criteria of severe pneumonia and 31 (27%) had non-severe pneumonia. The fatality rate was 9.5%. Almost all (87%) children were treated with antibiotics before they were hospitalised, in most cases with amoxicillin (58%) or trimethoprim-sulfamethoxazole (20%). The frequency of potential pathogens in the nasopharynx of the children was high, and any viral or bacterial nucleic acids present at high levels, irrespective of species or type, were significantly associated with severe pneumonia as compared with non-severe cases (52% versus 29%, p = 0.032). White blood cell count > 20,000/mu L and C-Reactive Protein > 75 mg/dL were associated with severe pneumonia at admission. Fatal outcome was in the multivariable analysis associated with having a congenital disease as an underlying condition. One or more pneumococcal serotypes/serogroups could be identified in 61 patients, and out of all identified serotypes 31/83 (37%) were non-PCV13 serotypes. Conclusions The occurrence of any bacteria or any viruses at high levels was associated with severe pneumonia at admission. Children with congenital disorders might need a higher attention when having symptoms of acute respiratory infection, as developed pneumonia could lead to fatal outcome.
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| 12. |
- Birindwa, Archippe M., et al.
(författare)
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Decreased number of hospitalized children with severe acute lower respiratory infection after introduction of the pneumococcal conjugate vaccine in the Eastern Democratic Republic of the Congo.
- 2020
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Ingår i: Pan African Medical Journal. - : Pan African Medical Journal. - 1937-8688. ; 37
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: acute lower respiratory infections (ALRI) are a leading killer of children under five worldwide including the Democratic Republic of the Congo (DR Congo). We aimed to determine the morbidity and case fatality rate due to ALRI before and after introduction of the 13-valent pneumococcal conjugate vaccine (PVC13) in DR Congo 2013. Methods: data were collected from medical records of children with a diagnosis of ALRI, aged from 2 to 59 months, treated at four hospitals in the eastern DR Congo. Two study periods were defined; from 2010 to 2012 (before introduction of PCV13) and from 2014 to 2015 (after PCV13 introduction). Results: out of 21,478 children admitted to the hospitals during 2010-2015, 2,007 were treated for ALRI. The case fatality rate among these children was 4.9%. Death was significantly and independently associated with malnutrition, severe ALRI, congenital disease and symptoms of fatigue. Among the ALRI hospitalised children severe ALRI decreased from 31% per year to 18% per year after vaccine introduction (p = 0.0002) while the fatality rate remained unchanged between the two study periods. Following introduction of PCV13, 63% of the children diagnosed with ALRI were treated with ampicillin combined with gentamicin while 33% received ceftriaxone and gentamicin. Conclusion: three years after PCV13 introduction in the Eastern part of the DR Congo, we found a reduced risk of severe ALRI among children below five years. Broad-spectrum antibiotics were frequently used for the treatment of ALRI in the absence of any microbiological diagnostic support.
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| 13. |
- Birindwa, Archippe M., et al.
(författare)
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High bacterial and viral load in the upper respiratory tract of children in the Democratic Republic of the Congo
- 2020
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 Muhandule Birindwa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background Respiratory pathogens including Streptococcus pneumoniae and Haemophilus influenzae, are implicated in the pathogenicity of acute lower respiratory infection (ALRI). These are also commonly found in both healthy and sick children. In this study, we describe the first data on the most frequent bacteria and viruses detected in the nasopharynx of children from the general population in the Eastern DR Congo. Methods From January 2014 to June 2015, nasopharyngeal samples from 375 children aged from 2 to 60 months attending health centres for immunisation or growth monitoring were included in the study. Multiplex real-time PCR assays were used for detection of 15 different viruses and 5 bacterial species and for determination of pneumococcal serotypes/serogroups in the nasopharyngeal secretions. Results High levels of S. pneumoniae were detected in 77% of cases, and H. influenzae in 51%. Rhinovirus and enterovirus were the most commonly found viruses, while respiratory syncytial virus (RSV) was rare (1%). Co-occurrence of both bacteria and viruses at high levels was detected in 33% of the children. The pneumococcal load was higher in those children who lived in a dwelling with an indoor kitchen area with an open fire, i.e. a kitchen with an open fire for cooking located inside the dwelling with the resultant smoke passing to the living room and/or bedrooms; this was also higher in children from rural areas as compared to children from urban areas or children not living in a dwelling with an indoor kitchen area with an open fire/not living in this type of dwelling. Immunization with 2–3 doses of PCV13 was associated with lower rates of pneumococcal detection. Half of the identified serotypes were non-PCV13 serotypes. The most common non-PCV13 serotypes/serogroups were 15BC, 10A, and 12F, while 5, 6, and 19F were the most prevalent PCV13 serotypes/serogroups. Conclusions The burden of respiratory pathogens including S. pneumoniae in Congolese children was high but relatively few children had RSV. Non-PCV13 serotypes/serogroups became predominant soon after PCV13 was introduced in DR Congo.
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| 14. |
- Birindwa, Archippe M., et al.
(författare)
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High rate of antibiotic resistance among pneumococci carried by healthy children in the eastern part of the Democratic Republic of the Congo
- 2018
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Ingår i: Bmc Pediatrics. - : Springer Science and Business Media LLC. - 1471-2431. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPneumococcal conjugate vaccines have been introduced in the infant immunisation programmes in many countries to reduce the rate of fatal pneumococcal infections. In the Democratic Republic of the Congo (DR Congo) a 13-valent vaccine (PCV13) was introduced in 2013. Data on the burden of circulating pneumococci among children after this introduction are lacking. In this study, we aimed to determine the risk factors related to pneumococcal carriage in healthy Congolese children after the vaccine introduction and to assess the antibiotic resistance rates and serotype distribution among the isolated pneumococci.MethodsIn 2014 and 2015, 794 healthy children aged one to 60months attending health centres in the eastern part of DR Congo for immunisation or growth monitoring were included in the study. Data on socio-demographic and medical factors were collected by interviews with the children's caregivers. Nasopharyngeal swabs were obtained from all the children for bacterial culture, and isolated pneumococci were further tested for antimicrobial resistance using disc diffusion tests and, when indicated, minimal inhibitory concentration (MIC) determination, and for serotype/serogroup by molecular testing.ResultsThe pneumococcal detection rate was 21%, being higher among children who had not received PCV13 vaccination, lived in rural areas, had an enclosed kitchen, were malnourished or presented with fever (p value <0.05). The predominant serotypes were 19F, 11, 6A/B/C/D and 10A. More than 50% of the pneumococcal isolates belonged to a serotype/serogroup not included in PCV13.Eighty per cent of the isolates were not susceptible to benzylpenicillin and non-susceptibility to ampicillin and ceftriaxone was also high (42 and 37% respectively). Almost all the isolates (94%) were resistant to trimethoprim-sulphamethoxazole, while 43% of the strains were resistant to 3 antibiotics.ConclusionsOur study shows alarmingly high levels of reduced susceptibility to commonly used antibiotics in pneumococci carried by healthy Congolese children. This highlights the importance of local antibiotic resistance surveillance and indicates the needs for the more appropriate use of antibiotics in the area. The results further indicate that improved living conditions are needed to reduce the pneumococcal burden, in addition to PCV13 vaccination.
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| 15. |
- Elfving, Kristina, et al.
(författare)
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Pneumococcal concentration and serotype distribution in preschool children with radiologically confirmed pneumonia compared to healthy controls prior to introduction of pneumococcal vaccination in Zanzibar : an observational study
- 2022
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Ingår i: BMC Infectious Diseases. - : BioMed Central (BMC). - 1471-2334. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The World Health Organization recommends pneumococcal vaccination (PCV) in the first year of life. We investigated pneumococcal serotypes in children with clinical or radiologically confirmed pneumonia and healthy controls prior to PCV13 vaccine introduction in Zanzibar. Methods: Children (n = 677) with non-severe acute febrile illness aged 2-59 months presenting to a health centre in Zanzibar, Tanzania April-July 2011 were included. Nasopharyngeal swabs collected at enrolment were analysed by real-time PCR to detect and quantify pneumococcal serotypes in patients (n = 648) and in healthy asymptomatic community controls (n = 161). Children with clinical signs of pneumonia according to the Integrated Management of Childhood illness guidelines ( "IMCI pneumonia ") were subjected to a chest-X-ray. Consolidation on chest X-ray was considered "radiological pneumonia ". Results: Pneumococcal DNA was detected in the nasopharynx of 562/809 (69%) children (70% in patients and 64% in healthy controls), with no significant difference in proportions between patients with or without presence of fever, malnutrition, IMCI pneumonia or radiological pneumonia. The mean pneumococcal concentration was similar in children with and without radiological pneumonia (Ct value 26.3 versus 27.0, respectively, p = 0.3115). At least one serotype could be determined in 423 (75%) participants positive for pneumococci of which 33% had multiple serotypes detected. A total of 23 different serotypes were identified. One serotype (19F) was more common in children with fever (86/648, 13%) than in healthy controls (12/161, 7%), (p = 0.043). Logistic regression adjusting for age and gender showed that serotype 9A/V [aOR = 10.9 (CI 2.0-60.0, p = 0.006)] and 14 [aOR = 3.9 (CI 1.4-11.0, p = 0.012)] were associated with radiological pneumonia. The serotypes included in the PCV13 vaccine were found in 376 (89%) of the 423 serotype positive participants. Conclusion: The PCV13 vaccine introduced in 2012 targets a great majority of the identified serotypes. Infections with multiple serotypes are common. PCR-determined concentrations of pneumococci in nasopharynx were not associated with radiologically confirmed pneumonia.
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| 16. |
- Emgård, Matilda, et al.
(författare)
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Carriage of penicillin-non-susceptible pneumococci among children in northern Tanzania in the 13-valent pneumococcal vaccine era.
- 2019
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Ingår i: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases. - : Elsevier BV. - 1878-3511. ; 81, s. 156-166
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Tidskriftsartikel (refereegranskat)abstract
- To determine the antibiotic susceptibility and serotype distribution of colonizing Streptococcus pneumoniae in Tanzanian children. Serial cross-sectional surveys were performed following the national introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in December 2012.A total of 775 children less than 2 years of age were recruited at primary health centres in Moshi, Tanzania between 2013 and 2015, and samples were obtained from the nasopharynx. S. pneumoniae were isolated by culture and tested for antibiotic susceptibility by disc diffusion and E-test methods; molecular testing was used to determine serotype/group.Penicillin non-susceptibility in the isolated pneumococci increased significantly from 31% (36/116) in 2013, to 47% (30/64) in 2014 and 53% (32/60) in 2015. Non-susceptibility to amoxicillin/ampicillin and ceftriaxone was low (n=8 and n=9, respectively), while 97% (236/244) of the isolates were non-susceptible to trimethoprim-sulfamethoxazole. The majority of the children (54%, n=418) had been treated with antibiotics in the past 3 months, and amoxicillin/ampicillin were overall the most commonly used antibiotics. Carriage of penicillin-non-susceptible pneumococci was more common in children with many siblings. The prevalence of PCV13 serotypes among the detected serotypes/groups decreased from 56% (40/71) in 2013 to 23% (13/56) in 2015.Penicillin non-susceptibility in S. pneumoniae colonizing Tanzanian children increased during an observation period shortly after the introduction of PCV13. Measures to ensure rational use of antibiotics and more effective systems for surveillance of antibiotic resistance and serotype distribution are needed to assure continued effective treatment of pneumococcal disease.
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| 17. |
- Emgård, Matilda, 1984, et al.
(författare)
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Co-occurrence of bacteria and viruses and serotype distribution of Streptococcus pneumoniae in the nasopharynx of Tanzanian children below 2 years of age following introduction of the PCV13
- 2024
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Ingår i: FRONTIERS IN PUBLIC HEALTH. - 2296-2565. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Pneumococcal conjugate vaccines have reduced severe disease attributed to vaccine-type pneumococci in children. However, the effect is dependent on serotype distribution in the population and disease development may be influenced by co-occurrence of viral and bacterial pathogens in the nasopharynx. Methods: Following introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in Tanzania we performed repeated cross-sectional surveys, including 775 children below 2 years of age attending primary healthcare centers. All children were sampled from nasopharynx and pneumococci were detected by single-target PCR. Pneumococcal serotypes/groups and presence of viruses and other bacteria were determined by two multiplex PCR assays. Results: The prevalence of PCV13 vaccine-type pneumococci decreased by 50%, but residual vaccine-types were still detected in 21% of the children 2 years after PCV13 introduction. An increase in the non-vaccine-type 15 BC was observed. Pneumococci were often co-occurring with Haemophilus influenzae, and detection of rhino/enterovirus was associated with higher pneumococcal load. Discussion: We conclude that presence of residual vaccine-type and emerging non-vaccine-type pneumococci in Tanzanian children demand continued pneumococcal surveillance. High co-occurrence of viral and bacterial pathogens may contribute to the disease burden and indicate the need of multiple public health interventions to improve child health in Tanzania.
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| 18. |
- Gonzales-Siles, Lucia, et al.
(författare)
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Identification and capsular serotype sequetyping of Streptococcus pneumoniae strains
- 2019
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Ingår i: Journal of Medical Microbiology. - : Microbiology Society. - 0022-2615 .- 1473-5644. ; 68:8, s. 1173-1188
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. Correct serotype identification of Streptococcus pneumoniae (pneumococcus) is important for monitoring disease epidemiology and assessing the impacts of pneumococcal vaccines. Furthermore, correct identification and differentiation of the pathogenic S. pneumoniae from closely related commensal species of the mitis group of the genus Streptococcus are essential for correct serotype identification. Methodology. A new protocol for determining the existing 98 serotypes of pneumococcus was developed, applying two PCR amplifications and amplicon sequencing, using newly designed internal primers. The new protocol was validated using S. pneumoniae genome sequences, reference strains with confirmed serotypes and clinical isolates, and comparing the results with those from the traditional Quellung reaction or antiserum panel gel precipitation, in addition to real-time PCR analysis. The taxonomic identifications of 422 publicly available (GenBank) genome sequences of S. pneumoniae, Streptococcus pseudopneumoniae and Streptococcus mitis were assessed by whole-genome sequence average nucleotide identity based on blast (ANIb) analysis. Results. The proposed sequetyping protocol generates a 1017 bp whole cpsB region sequence, increasing resolution for serotype identification in pneumococcus isolates. The identifications of all GenBank genome sequences of S. pneumoniae were confirmed, whereas most of the S. pseudopneumoniae and almost all of the S. mitis genome sequences did not fulfil the ANIb thresholds for species-level identification. The housekeeping biomarker gene, groEL, correctly identified S. pneumoniae but often misclassified S. pseudopneumoniae and S. mitis as S. pneumoniae. Conclusions. These studies affirm the importance of applying reliable identification protocols for S. pneumoniae before serotyping; our protocols provide reliable diagnostic tools, as well as an improved workflow, for serotype identification of pneumococcus and differentiation of serogroup 6 types.
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| 19. |
- Gustavsson, Lars, et al.
(författare)
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Slow Clearance of Norovirus following Infection with Emerging Variants of Genotype GII.4 Strains.
- 2017
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Ingår i: Journal of clinical microbiology. - 1098-660X. ; 55:5, s. 1533-1539
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of new norovirus genotype GII.4 strains is associated with widespread norovirus epidemics. Extended periods of viral shedding can contribute to the epidemic potential of norovirus. To describe the duration of viral shedding in infections with novel emerging GII.4 strains versus infections with previously circulating strains, we performed a prospective cohort study of patients hospitalized with norovirus gastroenteritis during separate winter seasons. Rectal swab samples were obtained at the time of inclusion and weekly during follow-ups. The subgenotype strain was determined from capsid sequences. The outcome was defined by the detection of virus for >14 days (slow clearance) or by the detection of negative samples within 14 days (rapid clearance). Two major epidemic GII.4 strains emerged during the study period, GII.4 New Orleans 2009, in 2010, and GII.4 Sydney 2012, in 2012. From these two seasons, sequences were available from 24 cases where the duration of shedding could be determined. The median age of the patients was 83 years and 50% were women. The majority of patients were infected with virus that clustered with the respective season's epidemic strain (n = 19), whereas 5 patients had previously circulating strains (3 were Den Haag 2006b, in 2010, and 2 were New Orleans 2009, in 2012). Among the patients infected with an epidemic strain, the proportion who shed virus for >14 days was significantly higher (16/19 [84%] versus 1/5 [20%], P = 0.01). In summary, a slow clearance of norovirus from stool was more common in infections with novel epidemic GII.4 strains. This suggests that the average duration of shedding may be longer during seasons when new GII.4 strains have emerged.
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| 20. |
- Larsson, Simon B., et al.
(författare)
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Self-reported symptom severity, general health, and impairment in post-acute phases of COVID-19: retrospective cohort study of Swedish public employees
- 2022
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- This study aimed to examine current symptom severity and general health in a sample of primarily non-hospitalized persons with polymerase chain reaction (PCR) confirmed COVID-19 in comparison to PCR negative controls. During the first quarter of 2021, we conducted an online survey among public employees in West Sweden, with a valid COVID-19 test result. The survey assessed past-month severity of 28 symptoms and signs, self-rated health, the WHO Disability Assessment Schedule (WHODAS) 2.0 and illness severity at the time of test. We linked participants' responses to their SARS-CoV-2 PCR tests results. We compared COVID-19 positive and negative participants using univariable and multivariable regression analyses. Out of 56,221 invited, 14,222 (25.3%) responded, with a response rate of 50% among SARS-CoV-2 positive individuals. Analysis included 10,194 participants (86.4% women, mean age 45 years) who tested positive 4-12 weeks (N = 1425; subacute) and > 12 weeks (N = 1584; postcovid) prior to the survey, and 7185 PCR negative participants who did not believe that they had had COVID-19. Symptoms were highly prevalent in all groups, with worst symptoms in subacute phase participants, followed by postcovid phase and PCR negative participants. The most specific symptom for COVID-19 was loss of smell or taste. Both WHODAS 2.0 score and self-rated health were worst in subacute participants, and modestly worse in postcovid participants than in negative controls. Female gender, older age and acute illness severity had larger effects on self-rated health and WHODAS 2.0 score in PCR positive participants than in PCR negative. Studies with longer follow-up are needed to determine the long-term improvement after COVID-19.
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| 21. |
- Magnusson, Jesper, et al.
(författare)
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Cell-free DNA as a biomarker after lung transplantation: A proof-of-concept study
- 2022
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Ingår i: Immunity Inflammation and Disease. - : Wiley. - 2050-4527. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lung transplantation (LTx) is a lifesaving procedure burdened with limited long-term survival. The most common cause of death after LTx is chronic lung allograft dysfunction (CLAD). Today, useful biomarkers for the detection of CLAD are lacking. Circulating cell-free DNA (cfDNA) is released during cellular decay and can be detected using polymerase chain reaction (PCR). Thus, donor-derived cfDNA in recipient serum indicates cellular decay in the transplanted organ. In the current study, we explore the possibility of using a novel PCR method to detect cfDNA as a biomarker for clinical events, especially CLAD. Methods: Four patients were retrospectively tested for levels of both donor and recipient-derived cfDNA using digital droplet PCR after targeted preamplification. The results were correlated to recorded clinical events. Results: All available samples rendered results. Both patients that later developed CLAD showed a persistently elevated ratio between donor-and recipient-derived cfDNA. Also, the mean level of cfDNA was higher in the two patients who later developed CLAD than in patients who did not (p = .0015). Conclusions: This proof-of-concept study suggests that cfDNA quantified with PCR may be used as a biomarker of significant clinical events such as CLAD.
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| 22. |
- Magnusson, Jesper, et al.
(författare)
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Viral Respiratory Tract Infection During the First Postoperative Year Is a Risk Factor for Chronic Rejection After Lung Transplantation
- 2018
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Ingår i: Transplantation Direct. - : Ovid Technologies (Wolters Kluwer Health). - 2373-8731. ; 4:8
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Tidskriftsartikel (refereegranskat)abstract
- Background. Chronic lung allograft dysfunction (CLAD) is the major limiting factor for long-term survival in lung transplant recipients. Viral respiratory tract infection (VRTI) has been previously associated with CLAD development. The main purpose of this study was to evaluate the long-term effects of VRTI during the first year after lung transplantation in relation to CLAD development. Method. Ninety-eight patients undergoing lung transplantation were prospectively enrolled between 2009 and 2012. They were monitored for infections with predefined intervals and on extra visits during the first year, the total follow-up period ranged between 5 and 8 years. Nasopharyngeal swab and bronchoalveolar lavage samples were analyzed using a multiplex polymerase chain reaction panel for respiratory pathogens. Data regarding clinical characteristics and infectious events were recorded. Results. Viral respiratory tract infection during the first year was identified as a risk factor for long-term CLAD development (P = 0.041, hazard ratio 1.94 [1.03-3.66]) in a time-dependent multivariate Cox regression analysis. We also found that coronavirus in particular was associated with increased risk for CLAD development. Other identified risk factors were acute rejection and cyclosporine treatment. Conclusions. This study suggests that VRTI during the first year after lung transplantation is associated with long-term CLAD development and that coronavirus infections in particular might be a risk factor.
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| 23. |
- Nordén, Rickard, 1977
(författare)
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Herpesvirus-induced glycans: Selectin ligands and related structures on the surface of the infected cell
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human herpesviruses are usually acquired early in life and are widely distributed in the population. A common feature of all human herpesviruses is that they persist in the host after the primary infection. Thus, the host immune system resolves the acute stage of the infection but these viruses have evolved means to remain in a state of latency in some cells from which they occasionally reactivate into a state of replication. A functional immune system will clear these episodes and the clinical manifestations are therefore usually mild or absent. On the other hand, when the immune system is dysfunctional the herpesviruses pose a serious threat. Especially cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are associated with severe infections in transplant patients and other immunosuppressed patients, where infiltration of virus-infected leukocytes into organ tissue can give rise to pneumonia, hepatitis and renal failure. The mechanism behind organ colonization of herpesvirus-infected leukocytes is not clear. However, the normal pathway for leukocyte transmigration over the endothelial wall is well characterized and involves interaction between carbohydrate binding proteins, selectins, and selectin ligands, including the Lewis antigen sialyl Lewis X (sLeX). The selectin ligands are therefore potential targets in viral pathogenesis and we have previously demonstrated that several herpesviruses can in fact activate the cellular pathway for synthesis of sLeX and related structures. In this work we aimed at defining the mechanism behind herpesvirus-induced selectin-ligand expression using herpes simplex virus type 1 (HSV-1) as a model virus. Moreover, we aimed at establish a model system for studying the effects of CMV and EBV infections on selectin ligand synthesis in leukocytes. We determined that sLeX expression in HSV-1 infected fibroblasts depends on viral RNA transcription and the cellular protein kinase R, an antiviral protein complex that detects small double stranded RNA fragments generated by transcription of HSV-1 genes. We also found that the mechanism for HSV-1-induced expression of sLeX in T-lymphocytes was dependent on viral early protein synthesis, contrary to the situation in fibroblasts. Selectin ligands are expressed on glycoproteins in the cell and we found that sLeX can also be displayed on virus-encoded glycoproteins in fibroblasts. Preliminary data suggests that CMV and EBV also can manipulate the cellular machinery for selectin-ligand synthesis in leukocytes. Patients with supressed immune system are always at risk of developing severe CMV or EBV disease and are therefore carefully monitored for viral DNA in the blood. Unfortunately the viral load does not always correlate to disease progression and the patients risk severe complications. It is possible that selectin-ligands comprise a new set of diagnostic tools that can be used in parallel with traditional PCR based methods for better prediction of CMV/EBV disease progression. It is also possible that selectin-ligands are new targets for antiviral treatment and several substances, which block interaction with selectins, are already in clinical trials for evaluation of their anti-metastatic potential.
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| 24. |
- Nordén, Rickard, 1977, et al.
(författare)
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Inhibition of protein deacetylation augments herpes simplex virus type 1-activated transcription of host fucosyltransferase genes associated with virus-induced sLex expression.
- 2010
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Ingår i: Archives of virology. - : Springer Science and Business Media LLC. - 1432-8798 .- 0304-8608. ; 155:3, s. 305-13
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 induces expression of the selectin ligand sialyl Lewis X in infected cells by activating transcription of three normally silent host glycosyltransferase genes, FUT3, FUT5, and FUT6, a process that is initiated by binding of viral RNA to cellular protein kinase R. We investigated the involvement of protein deacetylation and promoter methylation in viral activation of host FUT genes by analysing the effects of appropriate inhibitors on the transcription rates of the FUT genes in virus-infected cells. The histone deacetylase inhibitor trichostatin A augmented the viral activation of FUT transcription, whereas inhibition of DNA methylation did not affect transcription of these genes. The trichostatin A enhancement did not involve interference with expression of viral late genes or viral DNA replication. Thus, the virus-activated FUT genes are at least partially suppressed by deacetylation of histones or other regulatory proteins in uninfected HEL cells, whereas promoter methylation is a less important factor.
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| 25. |
- Nordén, Rickard, 1977, et al.
(författare)
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Quantification of torque teno virus and Epstein-Barr virus is of limited value for predicting the net state of immunosuppression after lung transplantation
- 2018
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Ingår i: Open Forum Infectious Diseases. - : Oxford University Press (OUP). - 2328-8957. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Background. Major hurdles for survival after lung transplantation are rejections and infectious complications. Adequate methods for monitoring immune suppression status are lacking. Here, we evaluated quantification of torque teno virus (TTV) and Epstein-Barr virus (EBV) as biomarkers for defining the net state of immunosuppression in lung-transplanted patients. Methods. This prospective single-center study included 98 patients followed for 2 years after transplantation. Bacterial infections, fungal infections, viral respiratory infections (VRTI), cytomegalovirus (CMV) viremia, and acute rejections, as well as TTV and EBV levels, were monitored. Results. The levels of torque teno virus DNA increased rapidly after transplantation, likely due to immunosuppressive treatment. A modest increase in levels of Epstein-Barr virus DNA was also observed after transplantation. There were no associations between either TTV or EBV and infectious events or acute rejection, respectively, during follow-up. When Tacrolimus was the main immunosuppressive treatment, TTV DNA levels were significantly elevated 6-24 months after transplantation as compared with Cyclosporine treatment. Conclusions. Although replication of TTV, but not EBV, appears to reflect the functionality of the immune system, depending on the type of immunosuppressive treatment, quantification of TTV or EBV as biomarkers has limited potential for defining the net state of immune suppression.
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| 26. |
- Nordén, Rickard, 1977, et al.
(författare)
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Recombinant Glycoprotein E of Varicella Zoster Virus Contains Glycan-Peptide Motifs That Modulate B Cell Epitopes into Discrete Immunological Signatures
- 2019
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 20:4
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Tidskriftsartikel (refereegranskat)abstract
- A recombinant subunit vaccine (Shingrix((R))) was recently licensed for use against herpes zoster. This vaccine is based on glycoprotein E (gE) of varicella zoster virus (VZV), the most abundantly expressed protein of VZV, harboring sites for N- and O-linked glycosylation. The subunit vaccine elicits stronger virus-specific CD4+ T cell response as well as antibody B cell response to gE, compared to the currently used live attenuated vaccine (Zostavax((R))). This situation is at variance with the current notion since a live vaccine, causing an active virus infection, should be far more efficient than a subunit vaccine based on only one single viral glycoprotein. We previously found gE to be heavily glycosylated, not least by numerous clustered O-linked glycans, when it was produced in human fibroblasts. However, in contrast to Zostavax((R)), which is produced in fibroblasts, the recombinant gE of Shingrix((R)) is expressed in Chinese hamster ovary (CHO) cells. Hence, the glycan occupancy and glycan structures of gE may differ considerably between the two vaccine types. Here, we aimed at (i) defining the glycan structures and positions of recombinant gE and (ii) identifying possible features of the recombinant gE O-glycosylation pattern contributing to the vaccine efficacy of Shingrix((R)). Firstly, recombinant gE produced in CHO cells (Shingrix situation) is more scarcely decorated by O-linked glycans than gE from human fibroblasts (Zostavax situation), with respect to glycan site occupancy. Secondly, screening of immunodominant B cell epitopes of gE, using a synthetic peptide library against serum samples from VZV-seropositive individuals, revealed that the O-linked glycan signature promoted binding of IgG antibodies via a decreased number of interfering O-linked glycans, but also via specific O-linked glycans enhancing antibody binding. These findings may, in part, explain the higher protective efficacy of Shingrix((R)), and can also be of relevance for development of subunit vaccines to other enveloped viruses.
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| 27. |
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| 28. |
- Novo, Mirza, et al.
(författare)
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COMP: A Potential Early Biomarker of RAS After Lung Transplantation
- 2021
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Ingår i: Transplantation Direct. - : Ovid Technologies (Wolters Kluwer Health). - 2373-8731. ; 7:8
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Chronic rejection, defined as chronic lung allograft dysfunction (CLAD), is the major factor limiting longterm survival after lung transplantation (LTx). A specific subgroup of CLAD is restrictive allograft syndrome (RAS). CLAD's pathogenesis is largely unknown, but previous findings suggest that it is associated with increased fibrosis in the transplanted lung. Cartilage oligomeric matrix protein (COMP) has been associated with multiple fibrotic conditions. The current study aimed to explore the relation between COMP serum levels and development of CLAD, and RAS in particular, in a retrospective cohort of LTx patients. Methods. This study included retrospective data from patients who underwent LTx during 2009-2011. Blood samples and spirometry data were obtained at follow-up visits 1, 3, 6, 9, and 12 mo after transplantation. Serum samples were analyzed for COMP. CLAD and RAS were defined according to the 2019 International Society for Heart and Lung Transplantation consensus document. Results. Data from 38 patients (19 men and women, respectively) were collected. Twenty-three patients (60.5%) developed CLAD, of whom 6 (26.1 %) fulfilled the criteria for RAS. Patients who developed RAS had higher mean COMP levels between 1 and 3 mo after LTx than those who did not develop RAS (10.9 [3.9-17.5] U/L vs 7.4 [3.9-10.8] U/L, P=0.008). RAS was also associated with shorter survival. We found no association between COMP levels and CLAD of other types than RAS. Conclusions. Serum level of COMP early after LTx seems to be associated with RAS development and might serve as a biomarker suitable for clinical use in the LTx setting.
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| 29. |
- Sansone, Martina, et al.
(författare)
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Extensive Hospital In-Ward Clustering Revealed By Molecular Characterization of Influenza A Virus Infection.
- 2020
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 71:9
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Tidskriftsartikel (refereegranskat)abstract
- Nosocomial transmission of influenza A virus (InfA) infection is not fully recognized. The aim of this study was to describe the characteristics of hospitalized patients with InfA infections during an entire season and to investigate in-ward transmission at a large, acute-care hospital.During the 2016-17 season, all hospitalized patients≥18 years old with laboratory-verified (real-time polymerase chain reaction) InfA were identified. Cases were characterized according to age; sex; comorbidity; antiviral therapy; viral load, expressed as cycle threshold values; length of hospital stay; 30-day mortality; and whether the InfA infection met criteria for a health care-associated influenza A infection (HCAI). Respiratory samples positive for InfA that were collected at the same wards within 7 days were chosen for whole-genome sequencing (WGS) and a phylogenetic analysis was performed to detect clustering. For reference, concurrent InfA strains from patients with community-acquired infection were included.We identified a total of 435 InfA cases, of which 114 (26%) met the HCAI criteria. The overall 30-day mortality rate was higher among patients with HCAI (9.6% vs 4.6% among non-HCAI patients), although the difference was not statistically significant in a multivariable analysis, where age was the only independent risk factor for death (P<.05). We identified 8 closely related clusters (involving≥3 cases) and another 10 pairs of strains, supporting in-ward transmission.We found that the in-ward transmission of InfA occurs frequently and that HCAI may have severe outcomes. WGS may be used for outbreak investigations, as well as for evaluations of the effects of preventive measures.
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| 30. |
- Sansone, Martina, et al.
(författare)
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Molecular characterization of a nosocomial outbreak of influenza B virus in an acute care hospital setting
- 2019
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Ingår i: Journal of Hospital Infection. - : Elsevier BV. - 0195-6701. ; 101:1, s. 30-37
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To describe a hospital outbreak of influenza B virus (InfB) infection during season 2015/2016 by combining clinical and epidemiological data with molecular methods. Methods: Twenty patients diagnosed with InfB from a hospital outbreak over a four-week-period were included. Nasopharyngeal samples (NPS) positive for InfB by multiplex real-time polymerase chain reaction were sent for lineage typing and whole genome sequencing (WGS). Medical records were reviewed retrospectively for data regarding patient characteristics, localization, exposure and outcome, and assembled into a timeline. In order to find possible connections to the hospital outbreak, all patients with a positive NPS for influenza from the region over an extended time period were also reviewed. Findings: All 20 cases of InfB were of subtype B/Yamagata, and 17 of 20 patients could be linked to each other by either shared room or shared ward. WGS was successful or partially successful for 15 of the 17 viral isolates, and corroborated the epidemiological link supporting a close relationship. In the main affected ward, 19 of 75 inpatients were infected with InfB during the outbreak period, resulting in an attack rate of 25%. One probable case of influenza-related death was identified. Conclusion: InfB may spread within an acute care hospital, and advanced molecular methods may facilitate assessment of the source and extent of the outbreak. A multifaceted approach, including rapid diagnosis, early recognition of outbreak situations, simple rules for patient management and the use of regular infection control measures, may prevent nosocomial transmission of influenza virus. (C) 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
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| 31. |
- Sansone, Martina, et al.
(författare)
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System dynamic modelling of healthcare associated influenza -a tool for infection control
- 2022
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Ingår i: Bmc Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The transmission dynamics of influenza virus within healthcare settings are not fully understood. Capturing the interplay between host, viral and environmental factors is difficult using conventional research methods. Instead, system dynamic modelling may be used to illustrate the complex scenarios including non-linear relationships and multiple interactions which occur within hospitals during a seasonal influenza epidemic. We developed such a model intended as a support for health-care providers in identifying potentially effective control strategies to prevent influenza transmission. Methods By using computer simulation software, we constructed a system dynamic model to illustrate transmission dynamics within a large acute-care hospital. We used local real-world clinical and epidemiological data collected during the season 2016/17, as well as data from the national surveillance programs and relevant publications to form the basic structure of the model. Multiple stepwise simulations were performed to identify the relative effectiveness of various control strategies and to produce estimates of the accumulated number of healthcare-associated influenza cases per season. Results Scenarios regarding the number of patients exposed for influenza virus by shared room and the extent of antiviral prophylaxis and treatment were investigated in relation to estimations of influenza vaccine coverage, vaccine effectiveness and inflow of patients with influenza. In total, 680 simulations were performed, of which each one resulted in an estimated number per season. The most effective preventive measure identified by our model was administration of antiviral prophylaxis to exposed patients followed by reducing the number of patients receiving care in shared rooms. Conclusions This study presents an system dynamic model that can be used to capture the complex dynamics of in-hospital transmission of viral infections and identify potentially effective interventions to prevent healthcare-associated influenza infections. Our simulations identified antiviral prophylaxis as the most effective way to control in-hospital influenza transmission.
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| 32. |
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| 33. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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Intact Pneumococci Trigger Transcription of Interferon-Related Genes in Human Monocytes, while Fragmented, Autolyzed Bacteria Subvert This Response
- 2017
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Ingår i: Infection and Immunity. - 0019-9567. ; 85:5
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Tidskriftsartikel (refereegranskat)abstract
- A peculiar trait of pneumococci (Streptococcus pneumoniae) is their propensity to undergo spontaneous lysis during stationary growth due to activation of the enzyme autolysin (LytA), which fragments the peptidoglycan cell wall. The fragments that are generated upon autolysis impair phagocytosis and reduce production of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) by human leukocytes in response to intact pneumococci, thereby impeding crucial host defenses. The objective was to identify additional monocyte genes whose transcription is induced by intact pneumococci and subverted by autolyzed bacteria. Monocytes were isolated from healthy blood donors and stimulated for 3 h with UV-inactivated S. pneumoniae (Rx1PLY(-) LytA(+) strain), which is capable of autolyzing, its LytA(-) isogenic autolysin-deficient mutant, or a mixture of the two (containing twice the initial bacterial concentration). Gene expression was assessed by Illumina microarray, and selected findings were confirmed by reverse transcription-quantitative real-time PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and flow cytometry. In all, we identified 121 genes that were upregulated to a significantly higher degree by intact than autolyzed pneumococci. These included IFNB1 and a large set of interferon-induced genes, such as IFIT3, RSAD2, CFCL1, and CXCL10 genes, as well as IL12B and CD40 genes. RT-qPCR revealed that transcription of these genes in response to intact pneumococci diminished when autolyzed pneumococci were admixed and that this pattern was independent of pneumolysin. Thus, transcription of interferon-related genes is triggered by intact pneumococci and subverted by fragments generated by spontaneous bacterial autolysis. We suggest that interferon-related pathways are important for elimination of pneumococci and that autolysis contributes to virulence by extinguishing these pathways.
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| 34. |
- Skovbjerg, Susann, 1973, et al.
(författare)
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Sequetyping Validation of Streptococcus pneumoniae Clinical Isolates
- 2016
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Ingår i: 10th International Symposium on Pneumococci and Pneumococcal Diseases. Glasgow, UK; 20160626-30.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Serotyping of Streptococcus pneumoniae (pneumococcus) is required to monitor epidemiological trends following introductions of pneumococcal conjugate vaccines. However, new techniques are needed to lower the costs and work-load for obtaining pneumococcal serotype information, especially in low-income settings. Here, we validated a modified protocol of sequetyping for S. pneumoniae serotype identification. Methods: Forty-six strains of S. pneumoniae, isolated from blood cultures at the Sahlgrenska University Hospital, Gothenburg, Sweden, were analyzed. Serotypes of the strains were identified by Sanger sequencing of the regulatory gene cpsB of the capsulation locus of S. pneumoniae, using a modification of an earlier protocol (Leung et. al. 2012). To increase the coverage of the 1,000 bp sequence length of the cpsB gene, two additional sequencing primers in the central region of the gene were designed. The sequences were compared to available reference sequences, using the NCBI BLAST function. The results were compared to those obtained by multiplex qPCR, modified from a protocol published by the U.S. Centres of Disease Control and Prevention, and with the results obtained by gel diffusion and/or Quellung reactions, performed by the Public Health Agency of Sweden. Results: In total, 22 different serotypes/serotype groups were acquired by sequetyping of the 46 isolates. Contrary to the 74% of isolates that were serotyped/serotype grouped by qPCR, sequetyping could identify the serotype/serotype group in 98% of the isolates. Of the serotypes correctly identified by sequetyping, 32% were identified to a single serotype, whereas in 68% of the isolates, a single serotype could not be assigned. The serotype groups that could not be differentiated further included 6A/6B/6C/6D and 9A/9V. Conclusion: Sequetyping is a sensitive technique for serotype identification. However, in many cases, the difference between serotypes is detected in only one or two base-pairs, or the sequences are identical, making a definitive serotype identification difficult. To obtain serotype results in these cases, additional PCRs for differentiating particular serotypes/groups are required.
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| 35. |
- Swartling, L., et al.
(författare)
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Hepatitis E virus is an infrequent but potentially serious infection in allogeneic hematopoietic stem cell transplant recipients
- 2020
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Ingår i: Bone Marrow Transplantation. - : Springer Science and Business Media LLC. - 0268-3369 .- 1476-5365. ; 55:7, s. 1255-63
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus (HEV) can cause chronic infection and liver cirrhosis in immunocompromised individuals. The frequency and clinical importance of HEV was studied retrospectively in a cohort of 236 Swedish allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In blood samples collected at 6 months after HSCT, HEV RNA was identified in 8/236 (3.4%) patients, and 11/236 (4.7%) patients had detectable anti-HEV IgG and/or IgM, eight of whom were HEV RNA negative. Two of the patients with positive HEV RNA died with ongoing signs of hepatitis: one of acute liver and multiple organ failure, the other of unrelated causes. The remaining six patients with HEV RNA had cleared the infection at 7-24 (median 8.5) months after HSCT. HEV infection was associated with elevated alanine aminotransferase at 6 months after HSCT (OR 15, 1.3-174, p = 0.03). Active graft-versus-host disease of the liver at 6 months after HSCT was present in 3/8 (38%) patients with HEV RNA, but was not significantly associated with HEV infection. In conclusion, HEV infection is an important differential diagnosis in patients with elevated liver enzymes after HSCT. Although spontaneous clearance was common, the clinical course may be severe.
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| 36. |
- Tamire, Mulugeta, et al.
(författare)
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Household fuel use and its association with potential respiratory pathogens among healthy mothers and children in Ethiopia
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Background Over 90% of Ethiopians still rely on solid fuels for cooking food. The pollution from the burning process causes adverse respiratory outcomes including respiratory infections. This study aimed to assess the association of the pollution with nasopharyngeal occurrence of potential pathogens. Methods We conducted a comparative cross-sectional study in urban and rural settings in Ethiopia in 2016. Questionnaire-based data were collected from 168 mothers and 175 children aged below two years. Multiplex real-time PCR assays were performed on nasopharyngeal secretions for detection of bacteria and viruses and for the identification of pneumococcal serotypes/groups. Results High rates of bacteria and viruses in the nasopharynx were detected by PCR among both the children and the mothers. Among the detected viruses, enterovirus was more commonly detected among rural children than among children from urban areas. Streptococcus pneumoniae and Haemophilus influenzae were both more prevalent among children and mothers from rural areas compared with urban groups and among those using solid fuels compared with cleaner fuel users. Children from rural households using solid fuels and children whose mothers had educational status below high school had four times higher odds for detection of S. pneumoniae compared with those households using cleaner energy or those children having mothers with a higher educational status, respectively. One or more serotype/serogroup was identified in about 40% of the samples that were positive for pneumococci. Out of all identified serotypes/serogroups, 43% in the children and 45% in the mothers belonged to PCV13, indicating the larger majority of detected pneumococci being non-PCV13 serotypes. Conclusion This study presented a high carriage rate of S. pneumoniae and H. influenzae among both children and their mothers, especially in rural areas and among solid fuel users. Thus, interventions should target cleaner energy sources to the public and promote maternal education.
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- Viklund, Emilia, et al.
(författare)
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Severe acute respiratory syndrome coronavirus 2 can be detected in exhaled aerosol sampled during a few minutes of breathing or coughing
- 2022
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Ingår i: Influenza and other Respiratory Viruses. - : Wiley. - 1750-2640 .- 1750-2659. ; 16:3, s. 402-10
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Tidskriftsartikel (refereegranskat)abstract
- Background: The knowledge on the concentration of viral particles in exhaled breath is limited. The aim of this study was to explore if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be detected in aerosol from subjects with the coronavirus disease 2019 (COVID-19) during various types of breathing and coughing and how infection with SARS-CoV-2 may influence the number and size of exhaled aerosol particles. Methods: We counted and collected endogenous particles in exhaled breath in subjects with COVID-19 disease by two different impaction-based methods, during 20 normal breaths, 10 airway opening breaths, and three coughs, respectively. Breath samples were analyzed with reverse transcription real-time polymerase chain reaction (RT-PCR). Results: Detection of RNA in aerosol was possible in 10 out of 25 subjects. Presence of virus RNA in aerosol was mainly found in cough samples (n = 8), but also in airway opening breaths (n = 3) and in normal breaths (n = 4), with no overlap between the methods. No association between viral load in aerosol and number exhaled particles <5μm was found. Subjects with COVID-19 exhaled less particles than healthy controls during normal breathing and airway opening breaths (all P < 0.05), but not during cough. Conclusion: SARS-CoV-2 RNA can be detected in exhaled aerosol, sampled during a limited number of breathing and coughing procedures. Detection in aerosol seemed independent of viral load in the upper airway swab as well as of the exhaled number of particles. The infectious potential of the amount of virus detected in aerosol needs to be further explored.
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