| 1. |
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| 2. |
- Kihlström, Erik, 1948-, et al.
(författare)
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Mykoplasma och Ureaplasma
- 2021. - 2
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Ingår i: Medicinsk mikrobiologi & immunologi. - Lund : Studentlitteratur AB. - 9789144123578 ; , s. 325-328
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Ordet mykoplasma används ofta som trivialnamn när man avser arter inom klassen Mollicutes, vilka karakteriseras av att de till skillnad från andra bakterier saknar cellvägg. Namnen Mollicutes och Mykoplasma syftar på denna egenskap och betyder mjukt skinn respektive svampliknande och formbar. I dag finns över 200 Mollicutes beskrivna, de flesta patogenerna hittar man inom släktena Mycoplasma och Ureoplasma. Man har isolerat ett flertal mykoplasmaarter från människa och uppfyllt Kochs postulat för M. pneumoniae, M. hominis, M. genitalium och vissa Ureoplasma-arter. I detta kapitel kommer vi använda mykoplasma i en bredare bemärkelse när vi beskriver olika arter inom Mollicutes.
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| 3. |
- Coble, Britt-Inger, 1946-, et al.
(författare)
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Urine-based testing for Chlamydia trachomatis using polymerase chain reaction, leucocyte esterase and urethral and cervical smears
- 2006
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 66:4, s. 269-278
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Tidskriftsartikel (refereegranskat)abstract
- The performance of Roche polymerase chain reaction (PCR) Amplicor to detect Chlamydia trachomatis in first-voided urine specimens from 422 males and 456 females attending two clinics for sexually transmitted infections was evaluated in comparison with cultures of urethral and cervical specimens. At the same time, the ability of leucocyte esterase (LE) in first-voided urine and the presence of leucocytes in urethral and cervical smears to identify C. trachomatis -infected individuals based on PCR and culture was determined. The prevalence of C. trachomatis infection was 10.9 % in men and 7.7 % in women. Sensitivity, specificity, positive predictive value and negative predictive value of Amplicor was 93.5 %, 99.7 %, 97.7 % and 99.2 % in males and 91.4 %, 99.5 %, 94.1 % and 99.3 % in females. All Chlamydia-infected men were identified by means of a combination of urethritis (≥4 leucocytes in the urethral smear) and/or a positive LE test in urine, although the specificity was only 42.2 %. In women, the combination of urethritis and/or cervicitis and/or a positive LE test identified 85.7 % of Chlamydia-infected patients with a specificity of 38.2 %. It is concluded that a combination of urethral and/or cervical smears and LE testing of urine can be used as a screening test to select patients, especially males, for specific C. trachomatis testing.
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| 4. |
- Fornander, Louise, et al.
(författare)
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Innate immunity proteins and a new truncated form of SPLUNC1 in nasopharyngeal aspirates from infants with respiratory syncytial virus infection
- 2011
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Ingår i: PROTEOMICS CLINICAL APPLICATIONS. - : Wiley-VCH Verlag Berlin. - 1862-8346. ; 5:9-10, s. 513-522
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Respiratory syncytial virus (RSV) is the most common cause of severe respiratory tract infection in infants. The aim was to identify host defence components in nasopharyngeal aspirate (NPA) from infants with RSV infection and to study the expression of the novel 25 kDa innate immunity protein SPLUNC1. less thanbrgreater than less thanbrgreater thanExperimental design: NPAs from infants were analyzed with 2-DE and MS in a pilot study. The levels of SPLUNC1 were analyzed with immunoblotting in 47 NPAs, admitted for RSV diagnosis. less thanbrgreater than less thanbrgreater thanResults: Totally, 35 proteins were identified in NPA, including several innate immunity proteins such as group X phospholipase A(2), different S100 proteins and SPLUNC1. In addition, a new truncated 15 kDa form of SPLUNC1 was identified that was detected in about 50% of the aspirates admitted for RSV diagnosis. RSV-positive boys had significantly less 25 kDa SPLUNC1 than RSV-negative boys while there were no significant differences among girls. less thanbrgreater than less thanbrgreater thanConclusions and clinical relevance: Several important innate immunity proteins were identified in NPA. Notably, a new truncated form of the newly suggested anti-bacterial protein SPLUNC1 was found. It is possible that a decrease in SPLUNC1 in the upper airways may increase the risk for severe pneumonia in boys.
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| 5. |
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| 6. |
- Friberg, Örjan, et al.
(författare)
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Collagen-gentamicin implant for prevention of sternal wound infection : long-term follow-up of effectiveness
- 2009
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Ingår i: Interactive Cardiovascular and Thoracic Surgery. - Amsterdam : Elsevier. - 1569-9293 .- 1569-9285. ; 9:3, s. 454-458
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Tidskriftsartikel (refereegranskat)abstract
- In a previous randomized controlled trial (LOGIP trial) the addition of local collagen-gentamicin reduced the incidence of postoperative sternal wound infections (SWI) compared with intravenous prophylaxis only. Consequently, the technique with local gentamicin was introduced in clinical routine at the two participating centers. The aim of the present study was to re-evaluate the technique regarding the prophylactic effect against SWI and to detect potential shifts in causative microbiological agents over time. All patients in this prospective two-center study received prophylaxis with application of two collagen-gentamicin sponges between the sternal halves in addition to routine intravenous antibiotics. All patients were followed for 60 days postoperatively. From January 2007 to May 2008, 1359 patients were included. The 60-day incidences of any SWI was 3.7% and of deep SWI 1.5% (1.0% mediastinitis). Both superficial and deep SWI were significantly reduced compared with the previous control group (OR=0.34 for deep SWI, P<0.001). There was no increase in the absolute incidence of aminoglycoside resistant agents. The majority of SWI were caused by coagulase-negative staphylococci (CoNS). The incidence of deep SWI caused by Staphylococcus aureus was 0.07%. The results indicate a maintained effect of the prophylaxis over time without absolute increase in aminoglycoside resistance. (ClinicalTrials.gov NCT00484055).
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| 7. |
- Ghafouri, Bijar, 1972-, et al.
(författare)
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PLUNC in human nasal lavage fluid : multiple isoforms that bind to lipopolysaccharide
- 2004
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Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics. - 1570-9639 .- 1878-1454. ; 1699:1-2, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Here, we demonstrate the presence of multiple isoforms of palate lung nasal epithelial clone (PLUNC) in human nasal lavage fluid (NLF). Eight isoforms were separated by two-dimensional gel electrophoresis (2-DE), and peptide mapping of the proteins was performed using MALDI-TOF MS (matrix assisted laser desorption/ionization time of flight mass spectrometry) of tryptic and asparginase cleavages. The identification was verified by amino acid sequencing after analysis of collision-induced dissociation (CID) fragmentation spectra with nanoelectrospray MS/MS. One isoform showed an electrophoretic mobility shift after N-glycosidase treatment, indicating that at least one of the PLUNC isoforms is glycosylated. We also demonstrate that PLUNC in NLF binds to lipopolysaccharide (LPS) in vitro; indeed, out of all proteins present in NLF only the PLUNC isoforms were found to adsorb to an LPS-coated surface. These results show that PLUNC is expressed as multiple LPS-binding isoforms in human NLF. The possibility that PLUNC may play a role in the innate immune response of the upper airways is inferred.
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| 8. |
- Ghafouri, Bijar, 1972-, et al.
(författare)
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PLUNC (palate, lung and nasal epithelial clone) proteins in human nasal lavage fluid
- 2003
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Ingår i: Biochemical Society Transactions. - 0300-5127 .- 1470-8752. ; 31:4, s. 810-814
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Tidskriftsartikel (refereegranskat)abstract
- PLUNC (palate, lung and nasal epithelial clone) is a newly discovered gene that is expressed in the upper respiratory tract and is suggested to be of importance in host defence against bacteria. We have identified two forms of the PLUNC protein in human nasal lavage fluid (NLF) using two-dimensional gel electrophoresis (2-DE) and MS. The apparent molecular masses and isoelectric points of these forms are 24.8 kDa/pI 5.4 and 25.1 kDa/pI 5.5. Notably, the 24.8 kDa/pI 5.4 form of PLUNC is an abundant protein in the 2-DE protein patterns of NLF from healthy subjects. Decreased levels of PLUNC were found in NLF from smokers and workers exposed to reactive epoxy chemicals, indicating that long-term exposure to airway irritants impairs the production of PLUNC in the upper respiratory tract. We have also investigated the presence of lipopolysaccharide (LPS)-binding proteins in NLF. Five proteins were found to adsorb to a LPS-coated surface; two of these proteins correspond to the two PLUNC forms, as judged by 2-DE pattern matching. For comparison, human saliva was found to contain a set of LPS-binding proteins with similar 2-DE spot positions (the same pIs but somewhat lower apparent molecular masses of 20 kDa). These results indicate that PLUNC may be a new marker of airway inflammation and may play a part in the innate immune response, and that human saliva contains yet other members of the family of LPS-binding proteins.
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| 9. |
- Högdahl, Marie, et al.
(författare)
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Expression of chemokines and adhesion molecules in human coronary artery endothelial cells infected with Chlamydia (Chlamydophila) pneumoniae
- 2008
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Ingår i: APMIS. - : Wiley. - 0903-4641 .- 1600-0463. ; 116:12, s. 1082-1088
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Tidskriftsartikel (refereegranskat)abstract
- Chlamydia pneumoniae has during recent years been associated with cardiovascular disease and atherosclerosis. Chemokines, leukocyte adhesion proteins and metalloproteinases are significant for chemotaxis and attachment of leukocytes to vessel walls, and for stability of atherosclerotic plaques. To determine the ability of C. pneumoniae to elicit inflammation in a relevant target host cell, we infected human coronary artery endothelial cells (HCAEC) with a clinical isolate of C. pneumoniae. Extracellular release of five chemokines, two adhesion proteins and a metalloproteinase was measured at different time points after infection using a cytometric bead assay and ELISA. Secretion of IL-8, MCP-1, MIG, IP-10 and ICAM-1 was significantly increased 48 h after C. pneumoniae infection of HCAEC in comparison with uninfected controls. Release of RANTES occurred already 6 h after infection. C. pneumoniae did not elicit release of E-selectin or MMP-1. We conclude that C. pneumoniae induces expression of proinflammatory components in HCAEC, which would promote migration of leukocytes towards endothelial cells. This suggests that C. pneumoniae initiates and propagates vascular inflammation in ways that contribute to coronary artery disease.
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| 10. |
- Högdahl, Marie, et al.
(författare)
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Leucocyte esterase testing of first-voided urine and urethral and cervical smears to identify Mycoplasma genitalium-infected men and women.
- 2007
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Ingår i: International Journal of STD and AIDS (London). - : SAGE Publications. - 0956-4624 .- 1758-1052. ; 18:12, s. 835-838
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Tidskriftsartikel (refereegranskat)abstract
- Leucocyte esterase (LE) in first-voided urine (FVU) and presence of leucocytes in urethral and cervical smears were evaluated to identify Mycoplasma genitalium infection in 416 men and 417 women attending Department of Genitourinary Medicine. M. genitalium was diagnosed in FVU specimens by realtime polymerase chain reaction. The prevalence of M. genitalium was 6.5% in women and 6.7% in men. In total, 88.5% (23/26) of M. genitalium-infected men were identified by a combination of urethral smear and the LE test. In women, the combination of urethral and/or cervical smears and/or a positive LE test identified 91.3% (21/23) of M. genitalium-infected patients. Organism load in FVU correlated significantly with presence of urethritis (> or =4 leucocytes per high-power field) in men. A combination of LE testing of urine and urethral and/or cervical smears can be used as screening tests to select patients for specific M. genitalium testing. By this strategy, about 10% of infected individuals will remain undetected.
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| 11. |
- Jurstrand, Margaretha, 1947-
(författare)
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Detection of Chlamydia trachomatis and Mycoplasma genitalium by genetic and serological methods
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chlamydia trachomatis infections are associated with a spectrum of clinical diseases including urethritis, prostatitis and epididymitis among men and cervicitis and pelvic inflammatory disease (PID), with an increased risk of infertility and ectopic pregnancy (EP), among women. In the search for other pathogens causing urethritis, Mycoplasma genitalium was isolated from urethral specimens from two men with acute urethritis (1980). Mycoplasma bacteria are extremely difficult to isolate by culture, and clinical studies have been possible only after the advent of the first PCR-based detection method. M. genitalium has been found to be associated with lower genital tract infections in both men and women. Finding evidence for a connection between M. genitalium and upper genital tract infections in women is still of major importance. The aim in papers I and II was to develop a PCR method for genetic characterization of clinical C. trachomatis isolates by sequence analysis of the omp1 gene, and to study the distribution of genotypes within sexual networks and determine if genotyping would improve partner notification. The method was used to determine the genotypes of C. trachomatis in 237 positive urogenital and/or urine specimens from men and women attending the STDClinic in Örebro during one year. Sequence analysis of the omp1 gene revealed that the most prevalent genotypes corresponded to C. trachomatis serovar E (47%), followed by F (17%), and K (9%). There were 161 networks found and specimens were sequenced from at least two patients in 47 networks. In seven of these 47 networks there were discrepant genotypes. In the largest network comprising 26 individuals two different C. trachomatis genotypes were found, and one partner had urethritis due to a Mycoplasma genitalium infection but was C. trachomatis negative. The need for a new method for M. genitalium DNA detection was one reason for study III. An existing conventional PCR protocol for detection of M. genitalium DNA was further developed into a real-time PCR (RT-PCR) with hybridisation probes. In order to evaluate the RT-PCR assay with clinical material, specimens from 398 men and 301 women attending the STD Clinic in Örebro were analysed, using the RT-PCR assay, and also by the well established conventional PCR in Copenhagen. Using the conventional PCR method as “gold standard”, the sensitivity for the RT-PCR assay was 72.2% and 68.2% and the specificity was 99.7% and 98.6%, respectively, in urogenital specimens from men and women. The aim in paper IV was to adapt a Triton X-114 extracted Lipid-Associated Membrane Protein (LAMP) Enzyme Immuno Assays (EIA) method to detect antibodies against M. genitalium and to evaluate the association between M. genitalium and PID and EP, using sera sampled in Örebro during the 1980s, and also to compare the number of sera having M. genitalium antibodies against those having C. trachomatis antibodies, using a commercial anti- Chlamydia trachomatis EIA assay. No statistical significant association could be demonstrated between M. genitalium antibodies and PID or EP in our serum material. However, a slight trend toward association was found when focusing on younger individuals. Antibodies against C. trachomatis were found to be significantly associated with PID and EP.
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| 12. |
- Kälvegren, Hanna, et al.
(författare)
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Correlation between rises in Chlamydia pneumoniae-specific antibodies, platelet activation and lipid peroxidation after percutaneous coronary intervention.
- 2008
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer Science and Business Media LLC. - 0934-9723 .- 1435-4373. ; 27:7, s. 503-511
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Tidskriftsartikel (refereegranskat)abstract
- We recently showed that Chlamydia pneumoniae activates platelets in vitro, with an associated oxidation of low-density lipoproteins. The aim of this study was to investigate whether C. pneumoniae is released during percutaneous coronary intervention (PCI) and, thereby, causes platelet activation and lipid peroxidation. Seventy-three patients undergoing coronary angiography and following PCI or coronary artery bypass graft (CABG) and 57 controls were included in the study. C. pneumoniae antibodies, serotonin and lipid peroxidation were measured before and 24 h, 1 month and 6 months after angiography. The results show that serum C. pneumoniae IgA concentrations were significantly higher in patients than in the controls. Furthermore, in 38% of the C. pneumoniae IgG positive patients, the C. pneumoniae IgG concentration increased 1 month after PCI. The levels of C. pneumoniae IgG antibodies 1 month after PCI correlated with plasma-lipid peroxidation (r = 0.91, P < 0.0001) and platelet-derived serotonin (r = 0.62, P = 0.02). There was no elevation in the total serum IgG 1 month after PCI. In conclusion, the present results suggest that PCI treatment of coronary stenosis releases C. pneumoniae from the atherosclerotic lesions, which leads to platelet activation and lipid peroxidation.
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| 13. |
- Kälvegren, Hanna, 1978-
(författare)
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The Role of Chlamydia pneumoniae-induced Platelet Activation in Cardiovascular Disease : In vitro and In vivo studies
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The common risk factors for atherosclerosis, such as obesity, high cholesterol levels, sedentary lifestyle, diabetes and high alcohol intake, only explain approximately 50% of cardiovascular disease events. It is thereby important to identify new mechanisms that can stimulate the process of atherosclerosis. During the past decades, a wide range of investigations have demonstrated connections between infections by the respiratory bacterium Chlamydia pneumoniae and atherosclerosis. Earlier studies have focused on the interaction between C. pneumoniae and monocytes/macrophages, T-lymphocytes, smooth muscle cells and endothelial cells, which are present in the atherosclerotic plaque. However, another important player in atherosclerosis and which is also present in the plaques is the platelet. Activation of platelets can stimulate both initiation and progression of atherosclerosis and thrombosis, which is the ultimate endpoint of the disease. The aim of the present thesis was to investigate the capacity of C. pneumoniae to activate platelets and its role in atherosclerosis.The results show that C. pneumoniae at low concentrations binds to platelets and stimulates platelet aggregation, secretion, reactive oxygen species (ROS) production and oxidation of low-density lipoproteins (LDL), and that these effects are mediated by lipopolysaccharide (LPS). Activation of protein kinase C, nitric oxide synthase and 12-lipoxygenase (12-LOX) was required for platelet ROS production, whereas platelet aggregation was dependent on activation of GpIIb/IIIa. Pharmacological studies showed that the C. pneumoniae-induced platelet activation is prevented by inhibitors against 12-LOX, platelet activating factor (PAF) and the purinergic P2Y1 and P2Y12 receptors, but not against cyclooxygenase (COX). These findings were completely opposite to the effects of these inhibitors on collagen-stimulated platelets. We also present data from a clinical study indicating that percutaneous coronary intervention (PCI or balloon dilatation) leads to release of C. pneumoniae into the circulation, which causes platelet activation and LDL oxidation.In conclusion, these data support a role for C. pneumoniae-induced platelet activation in the process of atherosclerosis. Stimulation of platelets by C. pneumoniae leads to release of growth factors and cytokines, oxidation of LDL and platelet aggregation, which are processes that can stimulate both atherosclerosis and thrombosis. Development of novel drugs that prevent C. pneumoniae-platelet interaction by inhibiting 12-LOX and/or PAF, may be important in the future treatment of cardiovascular disease.
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| 14. |
- Lai, Xin-He, 1963-
(författare)
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Francisella tularensis infection induces macrophage cell death
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Francisella tularensis, the causative agent of tularemia, is a potent human and animal pathogen. Its principal survival mechanism is rapid intracellular multiplication. The mechanisms that enables it to multiply intracellularly have been ill-defined and the thesis focused on characterizing the outcome of the macrophage-Francisella interaction and also if the interactions differ between the various subspecies of F tularensis. The nature of host cell death was examined and the correlation of macrophage killing with intramacrophage Francisella growth was investigated by in vitro infection of J774A.1 macrophages with either the live vaccine (LVS) strain of F. tularensis, belonging to subspecies holarctica, or the subspecies novicida strain U112 Macrophage entry was in both cases cytochalasin D-sensitive but the intramacrophage growth of the two Francisella strains led to distinct types of host cell death, i.e., apoptosis vs. necrosis. The macrophage apoptosis induced by infection with the LVS strain was mediated via the intrinsic pathway with critical involvement of caspase-3 and the mitochondria. The infected and apoptotic macrophages were shrunken, their chromatin was specifically degraded and revealed a typical DNA ladder pattern upon electrophoresis. Moreover, they were TUNEL positive, indicating the occurrence of apoptosis-dependent DNA fragmentation. The necessity of intracellular growth for the apoptosis was shown by the use of an isogenic mutant, denoted iglC, which lacked the ability to multiply intracellularly and this infection did not result in apoptosis. The F. novicida strain U112, on the other hand, inhibited NF- B activity and ultimately induced macrophage necrosis. The infected and necrotic macrophages were enlarged, their chromatin was randomly degraded which gave a diffuse DNA pattern typical of necrosis. There was no apoptosis-specific caspase activation. By the use of an isogenic mutant, denoted mglA, it was shown that intracellular replication was necessary for the induction of necrosis. A hemolytic protein, novilysin A, was found in the F. novicida strain U112 but lacking in other subspecies of F. tularensis. The protein is a putative virulence factor but most likely not involved in the induction of necrosis. Its significance for the pathogenesis of F. novicida remains to be determined. The findings of the thesis provide a detailed picture of the interaction between the host cells and various subspecies of F. tularensis. It also shows that the outcome of the interaction is critically dependent on the type of F. tularensis subspecies. The findings also question the use of F. novicida as a model organism for understanding pathogenicity mechanisms of the species in general. The induction of the host cell death is presumably an important mechanism for the survival of F. tularensis since it allows the bacterium to escape from cells deplete of nutrients and subsequently to invade cells with an intact supply of nutrients necessary for its continuous multiplication.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Majeed, Meytham, et al.
(författare)
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Roles of Ca2+ and F-actin in intracellular aggregation of Chlamydia trachomatis in eucaryotic cells
- 1993
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 61:4, s. 1406-1414
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Tidskriftsartikel (refereegranskat)abstract
- The effect of intracellular free Ca2+ ([Ca2+]i) on the intracellular aggregation of Chlamydia trachomatis serovars L2 and E in McCoy and HeLa cells is investigated. Loading the cells with the Ca2+ chelator MAPT/AM (1,2-bis-5-methyl-amino-phenoxylethane-N,N-n'-tetra-acetoxymethyl acetate), thereby decreasing the [Ca2+]i from 67 to 19 nM, decreased the number of cells with a local aggregation of chlamydiae in a dose-dependent manner. Neither the attachment nor the uptake of elementary bodies (EBs) was, however, affected after depletion of Ca2+ from the cells. There was no significant difference in the level of measured [Ca2+]i between infected and uninfected cells. Reducing the [Ca2+]i also significantly inhibited chlamydial inclusion formation. Differences in the organization of the actin filament network were observed in response to [Ca2+]i depletion. In Ca(2+)-depleted cells, where few EB aggregates were formed, few local accumulations of F-actin were observed in the cytosol. These results suggest that the aggregation of EBs in eucaryotic cells requires a normal homeostasis of intracellular Ca2+. By affecting F-actin reorganization and putatively certain Ca(2+)-binding proteins, [Ca2+]i plays a vital role in the infectious process of chlamydiae.
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| 19. |
- Matussek, A, et al.
(författare)
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Infection of human endothelial cells with Staphylococcus aureus induces transcription of genes encoding an innate immunity response
- 2005
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 61:6, s. 536-544
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is a gram-positive bacterium frequently isolated from patients with bloodstream infections. Endothelial cells (EC) play an important role in host defence against bacteria, and recent reports have shown that infection of EC with S. aureus induces expression of cytokines and cell surface receptors involved in activating the innate immune response. The ability of S. aureus to invade nonphagocytic cells, including EC, has been documented. However, the knowledge of the role of EC in pathogenesis of S. aureus infection is still limited. In this study, we investigate the gene-expression program in human EC initiated by internalized 5. aureus, using microarray analysis. We found 156 genes that were differentially regulated at least threefold, using arrays representing 14,239 genes. Many of the up regulated genes code for proteins involved in innate immunity, such as cytokines, chemokines and cell adhesion proteins. Other upregulated genes encode proteins involved in antigen presentation, cell signalling and metabolism. Furthermore, intracellular bacteria survived for days without inducing EC death. © 2005 Blackwell Publishing Ltd.
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| 20. |
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| 21. |
- Monstein, Hans-Jürg, et al.
(författare)
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Detection and identification of bacteria using in-house broad range 16S rDNA PCR amplification and genus-specific DNA hybridization probes, located within variable regions of 16S rRNA genes
- 1996
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 104:1-6, s. 451-458
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Tidskriftsartikel (refereegranskat)abstract
- Broad range PCR amplification and genus-specific 16S ribosomal DNA hybridization was used to demonstrate that Chlamydia, Helicobacter and Mobiluncus hybridization probes, located within variable regions V3, V4, and V9 of the 16S rDNA, specifically bound to the corresponding PCR product obtained from pure cultures of the three genera. The sensitivity of the assay was determined by analysis of C. trachomatis serially diluted in urine. The detection limit was 1–10 elementary bodies using a hybridization probe derived from the variable region V3 of the 16S rRNA gene. A PCR product was furthermore formed in urine specimens not containing C. trachomatis, showing amplification of chlamydia also in the presence of DNA from the resident urethral flora that competes for annealing sites. Analysis of a restricted number of male urine specimens using the C. trachomatis-specific probe showed complete agreement with culture and a commercially available PCR kit. Our method not only has the capacity to detect C. trachomatis in microbiologically mixed urine samples but also the potential advantage of identifying other bacterial pathogens from the same PCR product by varying the hybridization probes.
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| 22. |
- Nilsson, Anders, et al.
(författare)
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Microorganisms and volatile organic compounds in airborne dust from damp residences
- 2004
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Ingår i: Indoor Air. International Journal of Indoor Environment and Health. - : Hindawi Limited. - 0905-6947 .- 1600-0668. ; 14:2, s. 74-82
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Tidskriftsartikel (refereegranskat)abstract
- Airborne dust samples from damp (n = 9) and control (n = 9) residences were analyzed for microorganisms (molds and bacteria), bacterial markers (3-hydroxy fatty acids and muramic acid), and adsorbed volatile organic compounds (VOCs). The number of mold species was greater in the damp residences than in the controls (23 vs.18) and nine mold species were found only in damp residences. The levels of 3-hydroxy fatty acids and muramic acid correlated better in damp residences than in controls, indicating that damp conditions affect the bacterial flora of airborne dust. Identifications made by culture and microscopy of the major molds found, i.e. Aspergillus, Cladosporium, and Penicillum, coincided with the identification of VOCs known to be produced by these species. A number of additional VOCs irritating to the skin, eyes, or respiratory tract were also found. The results from this pilot study illustrate the diversity of microorganisms and VOCs present in the indoor environment and suggest that analysis of airborne dust may help to assess human exposure to microorganisms and chemical compounds.
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| 23. |
- Schöier, Johan, et al.
(författare)
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Chlamydia (Chlamydophila) pneumoniae-induced cell death in human coronary artery endothelial cells is caspase-independent and accompanied by subcellular translocations of Bax and apoptosis-inducing factor.
- 2006
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 47:2, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- Atherosclerosis and coronary heart disease are causing high morbidity and mortality worldwide. Different risk factors have been demonstrated, but the exact mechanisms behind these diseases are still not fully understood. Recent studies have suggested Chlamydia pneumoniae to be involved in the pathogenesis, and increased apoptotic indexes in atherosclerotic plaques have been documented. In this study, we show that C. pneumoniae induces apoptosis and necrosis in populations of human coronary artery endothelial cells. Apoptosis was determined by TUNEL and flow cytometry after staining of cells with annexin V and propidium iodide, and defined as TUNEL-reactive or annexin V-positive, propidium iodide-negative cells. The apoptosis was induced within 2 h postinfection and increased with inoculation dose. The general caspase inhibitor z-VAD-fmk did not affect apoptotic frequencies. By immunochemistry and immunoblot, we demonstrated activation and subcellular translocation of the proapoptotic protein Bax, and translocation of apoptosis-inducing factor from the cytosol to the nucleus. These results indicate that C. pneumoniae-induced apoptosis in human coronary artery endothelial cells is caspase-independent and regulated by Bax and apoptosis-inducing factor.
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| 24. |
- Schöier, Johan, et al.
(författare)
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Chlamydia trachomatis -induced apoptosis occurs in uninfected McCoy cells late in the developmental cycle and is regulated by the intracellular redox state
- 2001
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Ingår i: Microbial Pathogenesis. - : Elsevier BV. - 0882-4010 .- 1096-1208. ; 31:4, s. 173-184
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Tidskriftsartikel (refereegranskat)abstract
- Infections with the obligate intracellular bacterium Chlamydia trachomatis are characterized by avoidance of fusion between chlamydia-containing endosomes and lysosomes, bacterial persistence and development of post-infectious sequelae. In this report we show that C. trachomatis induces apoptosis in McCoy and HeLa cells. Apoptosis was monitored by three different techniques; enzyme-linked immunoassay (EIA) of fragmented nucleosomes, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) and flow cytometry of propidium iodide-stained cells. Apoptosis occurred in uninfected cells, was induced late in the chlamydial developmental cycle, beyond 24 h post-infection and was dependent on bacterial protein synthesis. Apoptosis was not significantly increased in infected, inclusion-containing cells. Treatment of cells with the antioxidants ascorbic acid (10 μM) and α-tocopherol (10 μM) reduced the degree of apoptosis. These results suggest that host cells infected with C. trachomatis generate proapoptotic stimuli that induce apoptosis in uninfected, neighbouring cells and that the redox state of the cell is a regulator in chlamydia-induced apoptosis.
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| 25. |
- Stark, Lisa
(författare)
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Staphylococcus aureus : aspects of pathogenesis and molecular epidemiology
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Staphylococcus aureus is a human commensal colonizing about 30 per cent of the population. Besides, it is a frequent cause of infections such as skin, wound and deep tissue infections and also more life-threatening conditions such as pneumonia, endocarditis and septicaemia. S. aureus may also cause different toxicoses. Moreover, this bacterium is one of the most common causes of nosocomial infections worldwide and an increase in antibiotic resistance, especially against methicillin, is seen. This underlines the importance to prevent and control outbreaks of S. aureus. The aims of this thesis were to increase the knowledge of S. aureus virulence and pathogenesis as well as to understand pattern of colonization and transmission.Various virulence factors operate together in the pathogenic process of S. aureus. The virulence of S. aureus was studied by the interaction with human umbilical vein endothelial cells (HUVEC) as a model. In paper I, we found that one bacterial isolate survived intracellularly and that 156 genes were differentially regulated in microarray analysis of HUVEC. The major part of these genes coded for proteins involved in innate immunity. In paper II, we wanted to explore possible differences in global gene expression patterns in HUVEC induced by invasive compared to colonizing isolates of S. aureus. We also used microarray to investigate possible differences in the presence of virulence genes between the two groups. The main finding was that virulent and commensal S. aureus did not differ in interaction with HUVEC and in the presence of virulence genes. All isolates survived intracellularly for days.Since no obvious differences in virulence between the two groups of isolates were found, we focused on epidemiology and transmission patterns. Colonization with S. aureus is an important risk factor for subsequent S. aureus infection. In paper III, we investigated S. aureus colonization and transmission among nursing home residents in three regions in the south of Sweden and used staphylococcal protein A (spa) typing as an epidemiological tool. A diverse distribution of different spa types was found and a majority of types were unique to one individual. Interestingly, we found a local accumulation of one spa type in one nursing home. Also common spa types were equally distributed in the different regions. We also noted that some individuals were colonized with two different spa types of S. aureus and in five of these cases there was one resistant and one non-resistant strain.The issue of multiclonal colonization and infection is highly important and clinical diagnostic laboratories do not routinely address this problem. Therefore, in paper IV a novel method to assess multiclonality of S. aureus was developed. It was based on denaturing gradient gel electrophoresis with the amplification of the spa gene. The method simultaneously separated eight different spa types. It also detected two spa types in an outbreak.In conclusion, we found no differences in virulence genes and in the interaction with HUVEC between commensal and invasive isolates. This indicates that any isolate of S. aureus might have a pathogenic potential. We also confirmed that some spa types are more successful colonizers with a potential to nosocomial spread. The method for detection of multiclonality of S. aureus is of importance in future epidemiological and clinical studies.
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| 26. |
- Stark, Lisa, et al.
(författare)
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Staphylococcus aureus isolates from blood and anterior nares induce similar innate immune responses in endothelial cells
- 2009
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Ingår i: APMIS. - : Wiley. - 0903-4641 .- 1600-0463 .- 0903-465X .- 1600-5503. ; 117:11, s. 814-824
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the possibility to distinguish virulent from non-virulent isolates, gene expression in human umbilical vein endothelial cells (HUVEC) induced by invasive and colonizing isolates of Staphylococcus aureus was compared. Gene expression in HUVEC was analyzed by microarray analysis after 4 h of infection with Staphylococcus aureus, isolated from healthy nasal carriers (n = 5) and from blood of septic patients (n = 5), to explore possible differences between the groups of bacteria in interaction with HUVEC. All isolates were spa-typed to disclose strain relatedness. Moreover, the isolates were characterized with DNA microarray to determine the presence of virulence genes and to investigate the potential genes of importance in HUVEC interaction. The expression of 41 genes was up-regulated, and four were down-regulated in HUVEC by all isolates. Most of the up-regulated genes encode cytokines, chemokines, interferon-induced proteins, proteins regulating apoptosis and cell proliferation. There was no difference in the gene expression pattern between HUVEC infected with invasive or colonizing isolates. Furthermore, there was no difference in the presence of bacterial virulence genes between the two groups. In conclusion, our data indicate that S. aureus isolates induce comparable expression patterns in HUVEC, irrespective of invasiveness or presence of virulence genes.
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| 27. |
- Strindhall, J, et al.
(författare)
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Clinical isolates of Staphylococcus aureus vary in ability to stimulate cytokine expression in human endothelial cells
- 2005
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 61:1, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- Human umbilical vein endothelial cells (HUVEC) were infected for 24 h with 18 well-characterized Staphylococcus aureus isolates, and the supernatants from infected HUVEC were analysed for interleukin (IL)-1β, tumour necrosis factor-alpha, IL-6, IL-8, IL-10, IL-12p70, growth-related oncogene (GRO)-α, granulocyte macrophage colony-stimulating factor (GM-CSF) and regulated upon activation, normal T cell expressed and secreted (RANTES) by immunoassay. All staphylococcal isolates induced the expression of IL-6, IL-8, GRO-α, GM-CSF and RANTES. The magnitude of cytokine expression varied between isolates. Staphylococcus aureus inducing high expression of one of these cytokines also showed simultaneous high expression of the other four, indicating a common mechanism for the ability of individual S. aureus to induce expression of these cytokines. No direct correlation between cytokine expression and adhesion of S. aureus to HUVEC was observed, indicating that bacterial properties besides adhesion contribute to the activation of HUVEC.
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| 28. |
- Strindhall, Jan, et al.
(författare)
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Cytokine expression in human endothelial cells stimulated with clinical isolates and culture filtrate of Staphylococcus aureus
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Human umbilical vein endothelial cells (HUVEC) were infected for 24 h with 18 well-characterized, noninvasive Staphylococcus aureus isolates and the supernatants were analyzed for IL-1ß, TNF-α, IL-6, IL-8, IL-10, IL-12p70, GRO-α, GM-CSF and RANTES by immuno assay. All isolates induced expression of IL-6, IL-8, GRO-α, GM-CSF, and RANTES. The highest concentrations were observed for IL-6, IL-8 and GRO-α, which reached levels close to that of HUVEC stimulated with LPS (0.1µg ml-1). The magnitude of cytokine expression varied between isolates. S. aureus inducing high expression of one of these cytokines also showed simultaneous high expression of the other four, indicating a common ability of individual S. aureus to induce high or low expression of these cytokines. IL-1ß, TNF-α, IL-10 and IL-12p70 were not upregulated by any of the S. aureus isolates. No correlation between cytokine profile and S. aureus production of enterotoxin A-D, TSST-1, cytotoxicity, PFGE and phage pattem or susceptibility to methicillin was observed. The ability of individual S. aureus to induce expression of cytokines correlated with their ability to upregulate ICAM-1, but not E-selectin, in HUVEC. Similarly, a heat-stable, high molecular weight component(s) from sterile culture filtrate of S. aureus upregulated expression of IL-8 and ICAM-1 in HUVEC.Our results show that individual clinical isolates of S. aureus vary in ability to directly stimulate human endothelial cells to upregulate cytoldnes that promote leukocyte recruitment and inflammation.
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| 29. |
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| 30. |
- Strindhall, Jan, et al.
(författare)
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Variations among clinical isolates of Staphylococcus aureus to induce expression of E-selectin and ICAM-1 in human endothelial cells
- 2002
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 32:3, s. 227-235
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Tidskriftsartikel (refereegranskat)abstract
- Eighteen clinical isolates of Staphylococcus aureus, nine methicillin-sensitive and nine methicillin-resistant, were investigated for their ability to induce expression of E-selectin and ICAM-1 in human endothelial cells. Upregulation of adhesion molecules varied between isolates; 17 isolates induced expression of E-selectin and 13 of ICAM-1. Some isolates induced a significant expression of E-selectin without stimulation of ICAM-1, whereas the opposite was not found. Bacterial viability was required for induction of the adhesion molecules. The kinetics of ICAM-1 expression in S. aureus-infected cells differed from those stimulated with interleukin-1β (IL-1β). On the other hand, expression of E-selectin was very similar in S. aureus-infected and IL-1β-stimulated cells. There was no correlation between ability of S. aureus to induce expression of cell adhesion molecules, methicillin susceptibility, pulse field gel electrophoresis patterns, biochemical characteristics, phage typing and toxin production.
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| 31. |
- Söderquist, Bo, et al.
(författare)
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The influence of adhesive and invasive properties of Staphylococcus aureus defective in fibronectin-binding proteins on secretion of interleukin-6 by human endothelial cells
- 2006
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 114:2, s. 112-116
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Tidskriftsartikel (refereegranskat)abstract
- Fibronectin-binding proteins (FnBP) are surface adhesins of Staphylococcus aureus documented to be virulence attributes in, for example, endovascular infections. By using mutants of S. aureus defective in the FnBPA and B genes we have investigated whether these adhesins affect cytokine expression in human umbilical vein endothelial cells (HUVEC). S. aureus expressing FnBPA and B adhered to and were internalized into HUVEC to a greater extent compared to mutants defective in expression of FnBP. Production and release of IL-6 was higher from endothelial cells infected with the parent FnBP-expressing strain compared to the FnBP-defective mutants. These results indicate that adhesion to and invasion of S. aureus into endothelial cells are important regulators of cytokine expression.
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