| 1. |
- Artin, Ingrid, et al.
(författare)
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Effects of carbon dioxide on neurotoxin gene expression in nonproteolytic Clostridium botulinum type E
- 2008
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 74:8, s. 2391-2397
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Tidskriftsartikel (refereegranskat)abstract
- Carbon dioxide is an antimicrobial gas commonly used in modified atmosphere packaging. In the present study, the effects of carbon dioxide on the growth of and neurotoxin production by nonproteolytic Clostridium botulinum type E were studied during the growth cycle. Quantitative reverse transcription-PCR and an enzyme-linked immunosorbent assay were used to quantify expression of the type E botulinum neurotoxin gene (cntE) and the formation of type E neurotoxin. The expression levels of cntE were similar in two strains, with relative expression peaking in the transition between exponential phase and stationary phase. In stationary phase, cntE mRNA expression declined rapidly. The cntE mRNA half-life was calculated to be approximately 9 minutes. Neurotoxin formation occurred in late exponential phase and stationary phase. High carbon dioxide concentrations delayed growth by increasing the lag time and decreasing the maximum growth rate. The effects of carbon dioxide concentration on relative neurotoxin gene expression and neurotoxin formation were significant. Expression of cntE mRNA and the formation of extracellular neurotoxin were twofold higher with a headspace carbon dioxide concentration of 70% (vol/vol) compared to 10% (vol/vol). This finding sheds a new, cautionary light on the potential risks of botulism associated with the use of modified atmosphere packaging. Copyright © 2008, American Society for Microbiology. All Rights Reserved.
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| 2. |
- Lövenklev, Maria, et al.
(författare)
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Quantitative interaction effects of carbon dioxide, sodium chloride, and sodium nitrite on neurotoxin gene expression in nonproteolytic Clostridium botulinum type B
- 2004
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 70:5, s. 2928-2934
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Tidskriftsartikel (refereegranskat)abstract
- The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a tryptone-peptone-yeast extract (TPY) medium. Various concentrations of these selected food preservatives were studied by using a complete factorial design in order to quantitatively study interaction effects, as well as main effects, on the following responses: lag phase duration (LPD), growth rate, relative cntB expression, and extracellular BoNT/B production. Multiple linear regression was used to set up six statistical models to quantify and predict these responses. All combinations of NaCl and NaNO2 in the growth medium resulted in a prolonged lag phase duration and in a reduction in the specific growth rate. In contrast, the relative BoNT/B gene expression was unchanged, as determined by the cntB-specific quantitative reverse transcription-PCR method. This was confirmed when we measured the extracellular BoNT/B concentration by an enzyme-linked immunosorbent assay. CO2 was found to have a major effect on gene expression when the cntB mRNA levels were monitored in the mid-exponential, late exponential, and late stationary growth phases. The expression of cntB relative to the expression of the 16S rRNA gene was stimulated by an elevated CO2 concentration; the cntB mRNA level was fivefold greater in a 70% CO2 atmosphere than in a 10% CO2 atmosphere. These findings were also confirmed when we analyzed the extracellular BoNT/B concentration; we found that the concentrations were 27 ng·ml -1·unit of optical density-1 in the 10% CO 2 atmosphere and 126 ng·ml-1·unit of optical density-1 in the 70% CO2 atmosphere.
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| 3. |
- Artin, Ingrid, et al.
(författare)
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Effects of Carbon Dioxide on Growth of Proteolytic Clostridium botulinum, Its Ability To Produce Neurotoxin, and Its Transcriptome
- 2010
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 76:4, s. 1168-1172
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Tidskriftsartikel (refereegranskat)abstract
- The antimicrobial gas carbon dioxide is frequently used in modified atmosphere packaging. In the present study, the effects of CO2 (10 to 70%, vol/vol) on gene expression (measured using quantitative reverse transcription-PCR and a whole-genome DNA microarray) and neurotoxin formation (measured using an enzyme-linked immunosorbent assay [ELISA]) by proteolytic Clostridium botulinum type A1 strain ATCC 3502 were studied during the growth cycle. Interestingly, in marked contrast to the situation with nonproteolytic C. botulinum types B and E, CO2 had little effect on any of these parameters. At all CO2 concentrations, relative expression of neurotoxin cluster genes peaked in the transition between exponential and stationary phases, with evidence of a second rise in expression in late stationary phase. Microarray analysis enabled identification of coding sequences whose expression profiles matched those of the neurotoxin cluster. Further research is needed to determine whether these are connected to neurotoxin formation or are merely growth phase associated.
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| 4. |
- Artin, Ingrid, et al.
(författare)
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First case of type E wound botulism diagnosed using real-time PCR.
- 2007
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 45:11, s. 3589-3594
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Tidskriftsartikel (refereegranskat)abstract
- Wound botulism is a growing problem among injecting drug users. The condition is often difficult to diagnose, with laboratory confirmation in only 50% of the cases. Here we present a real-time PCR-based method for the diagnosis of wound botulism caused by Clostridium botulinum. The assay includes an internal amplification control which is amplified simultaneously with the genes encoding neurotoxin types A, B, and E. This method was used to detect the first case of wound botulism in an injecting drug user in Sweden. In addition, to the best of our knowledge, this is the first reported case of wound botulism caused by C. botulinum type E.
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| 5. |
- Cederholm, Tommy, et al.
(författare)
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ESPEN guidelines on definitions and terminology of clinical nutrition
- 2017
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Ingår i: Clinical Nutrition. - 0261-5614 .- 1532-1983. ; 36:1, s. 49-64
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundA lack of agreement on definitions and terminology used for nutrition-related concepts and procedures limits the development of clinical nutrition practice and research.ObjectiveThis initiative aimed to reach a consensus for terminology for core nutritional concepts and procedures.MethodsThe European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a consensus group of clinical scientists to perform a modified Delphi process that encompassed e-mail communication, face-to-face meetings, in-group ballots and an electronic ESPEN membership Delphi round.ResultsFive key areas related to clinical nutrition were identified: concepts; procedures; organisation; delivery; and products. One core concept of clinical nutrition is malnutrition/undernutrition, which includes disease-related malnutrition (DRM) with (eq. cachexia) and without inflammation, and malnutrition/undernutrition without disease, e.g. hunger-related malnutrition. Over-nutrition (overweight and obesity) is another core concept. Sarcopenia and frailty were agreed to be separate conditions often associated with malnutrition. Examples of nutritional procedures identified include screening for subjects at nutritional risk followed by a complete nutritional assessment. Hospital and care facility catering are the basic organizational forms for providing nutrition. Oral nutritional supplementation is the preferred way of nutrition therapy but if inadequate then other forms of medical nutrition therapy, i.e. enteral tube feeding and parenteral (intravenous) nutrition, becomes the major way of nutrient delivery.ConclusionAn agreement of basic nutritional terminology to be used in clinical practice, research, and the ESPEN guideline developments has been established. This terminology consensus may help to support future global consensus efforts and updates of classification systems such as the International Classification of Disease (ICD). The continuous growth of knowledge in all areas addressed in this statement will provide the foundation for future revisions.
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| 6. |
- Fischer, Hans, et al.
(författare)
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Altered microbiota in microscopic colitis
- 2015
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Ingår i: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 64:7, s. 1185-1186
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Forsum, Urban, 1946-, et al.
(författare)
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Bacterial vaginosis--a microbiological and immunological enigma.
- 2005
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 0903-4641 .- 1600-0463. ; 113:2, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.
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| 8. |
- Frick, Inga-Maria, et al.
(författare)
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Identification of a novel protein promoting the colonization and survival of Finegoldia magna, a bacterial commensal and opportunistic pathogen.
- 2008
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 70, s. 695-708
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Tidskriftsartikel (refereegranskat)abstract
- Anaerobic bacteria dominate the human normal microbiota but strikingly little is known about these commensals. Finegoldia magna is a Gram-positive anaerobe found in the skin and at other non-sterile body surfaces, but it is also an opportunistic pathogen. This study describes a novel protein designated FAF (F. magnaAdhesion Factor) and expressed by more than ninety percent of F. magna isolates. The protein is present in substantial quantities at the F.magna surface but is also released from the surface. FAF forms large protein aggregates in solution and surface-associated FAF causes bacterial clumping. In skin F. magna bacteria were localized to the epidermis, where they adhere to basement membranes. FAF was found to mediate this adhesion via interactions with BM-40, a basement membrane protein. The biological significance of FAF is further underlined by the observation that it blocks the activity of LL-37, a major human antibacterial peptide. Altogether, the data demonstrate that FAF plays an important role in colonization and survival of F. magna in the human host.
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| 9. |
- Holst, Elisabet, et al.
(författare)
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In vitro activities of cefcanel and some other cephalosporins against Pasteurella multocida
- 1989
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Ingår i: Antimicrobial Agents and Chemotherapy. - 1098-6596. ; 33:12, s. 2142-2143
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Tidskriftsartikel (refereegranskat)abstract
- Thirty-five strains of Pasteurella multocida from humans and animals were tested for susceptibility to five cephalosporins by a broth dilution method. Cefcanel showed high activity against all isolates (MIC and MBC, less than or equal to 0.64 micrograms/ml). The corresponding figure for cefaclor and cefuroxime was 2.56 micrograms/ml. Cefadroxil and cephalexin were the least active compounds tested.
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| 10. |
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