| 1. |
- Melki, Vilyam, et al.
(författare)
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Effect of Glyceryl Trinitrate on Staphylococcus aureus Growth and Leukocyte Activation during Simulated Extracorporeal Circulation
- 2014
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Ingår i: The thoracic and cardiovascular surgeon. - : Georg Thieme Verlag KG. - 0171-6425 .- 1439-1902. ; 62:5, s. 402-408
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Tidskriftsartikel (refereegranskat)abstract
- Background Previously, nitric oxide has been shown to possess antimicrobial effects. In this study, we aim to test the effect of glyceryl trinitrate (GTN) on Staphylococcus aureus growth during simulated extracorporeal circulation (SECC) and also to examine the effect of S. aureus, alone and in combination with GTN, on activation markers of the innate immune system during SECC. Methods In an in vitro system of SECC, we measured GTN-induced changes in markers of leukocyte activation in whole blood caused by S. aureus infestation, as well as the effect of GTN on S. aureus growth. Results GTN had no effect on S. aureus growth after 240 minutes SECC. Staphylococcus aureus reduced the expression of granulocyte Fc gamma-receptor CD32 but stimulated the expression of monocyte CD32. Staphylococcus aureus stimulated expression of some leukocyte adhesion key proteins, activation marker CD66b, lipopolysaccharide-receptor CD14, and C3b-receptor CD35. Staphylococcus aureus and GTN addition induced significant increases in monocyte CD63 (lysosomal granule protein) levels. Conclusion GTN does not affect S. aureus growth during SECC and has no effect on SECC-induced leukocyte activation.
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| 2. |
- Melki, Vilyam, 1972-, et al.
(författare)
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Enhanced growth of Staphylococcus aureus after nitric oxide supplementation during simulated extracorporeal circulation
- 2010
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Ingår i: The thoracic and cardiovascular surgeon. - : Georg Thieme Verlag KG. - 0171-6425 .- 1439-1902. ; 58:2, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- Background: Several factors contribute to postoperative bacterial infections in cardiac surgery. Long operation times and the use of extracorporeal circulation increase the risk of infection. Nitric oxide has been shown to possess a broad spectrum antimicrobial effect. Methods: In this study, we investigated the effect of nitric oxide on S. aureus growth in whole blood during simulated extracorporeal circulation. Results: S. aureus growth increased 6.2-fold after 180 min SECC in the presence of nitric oxide. Leukocyte counts remained unchanged without any differences between the groups. We observed a steady increase in markers of oxidative stress and activity of the innate immune system. Myeloperoxidase levels increased 8-fold, and C3a and terminal complement complex by 2-fold after 180 min. Conclusion: S. aureus growth is not due to the effect of nitric oxide on the innate immune system but from its effect on the bacteria itself. It has been shown that nitric oxide stimulates the expression of inducible lactate dehydrogenase, specific to S. aureus, which improves its resistance to oxidative stress, and may give S. aureus a survival advantage resulting in increased growth.
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| 3. |
- Sütterlin, Susanne, et al.
(författare)
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Effects of Silver-based Wound Dressings on the Bacterial Flora in Chronic Leg Ulcers and Its Susceptibility In vitro to Silver
- 2012
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 0001-5555 .- 1651-2057. ; 92:1, s. 34-39
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Tidskriftsartikel (refereegranskat)abstract
- Silver-based dressings have been used extensively in wound management in recent years, but data on their antimicrobial activity in the clinical setting are limited. In order to explore their effects on chronic leg ulcer flora, 14 ulcers were cultured after at least 3 weeks treatment with Aquacel Ag (R) or Acticoat (R). Phenotypic and genetic silver resistance were investigated in a total of 56 isolates. Silver-based dressings had a limited effect on primary wound pathogens, which were present in 79% of the cultures before, and 71% after, treatment. One silver-resistant Enterobacter cloacae strain was identified (silver nitrate minimal inhibitory concentration (MIC)>512 mg/l, positive for silE, silS and silP). Further studies in vitro showed that inducible silver-resistance was more frequent in Enterobacteriaceae with cephalosporin-resistance and that silver nitrate had mainly a bacteriostatic effect on Staphylococcus aureus. Monitoring of silver resistance should be considered in areas where silver is used extensively.
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| 4. |
- Tano, Eva, et al.
(författare)
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Evaluation of three swab transport systems for the maintenance of clinically important bacteria in simulated mono- and polymicrobial samples
- 2011
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 119:3, s. 198-203
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Tidskriftsartikel (refereegranskat)abstract
- In this study, three swab transport systems were evaluated: M40 Transystem, Amies broth with a relatively new type of swab (both Copan Diagnostics, Corona, CA, USA), and SSI transportmedium (Statens Serum Institut, Copenhagen Denmark). The CLSI M40-A standard procedures and 11 culture collection strains were used. The transport systems were tested at room temperature for holding times of 0, 24, and 48 h, and both mono- and polymicrobial samples were included. After 24 h of simulated transportation, all systems were able to maintain the viability of all organisms tested. SSI transportmedium exhibited the lowest maintaining ability, whereas the two Copan systems were the most growth-promoting system. In polymicrobial samples, this latter feature was a problem. At 48 h, no transport system could maintain the viability of all strains, and the recovery rates differed depending on organism and device. The species most difficult to recover in all the three systems was Neisseria gonorrhoeae. When selecting a swab transport system, consideration must be given to the sample type, the conditions that prevail locally, and the performance in the clinical setting.
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| 5. |
- Tano, Eva, et al.
(författare)
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Level of decontamination after washing textiles at 60°C or 70°C followed by tumble drying
- 2014
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Several major outbreaks in healthcare facilities have occurred with the emergence of multi-resistant bacteria. A possible route for dissemination is the hospital textiles and inadequate laundering of them. The aim of this study was to develop an easy-to-use method for simulating the laundering process of hospital textiles, and thereafter apply the method when evaluating the decontaminating efficacy of two different washing temperatures.METHODS: The laundering process, including tumble drying, took place at two professional laundries. Enterococcus faecium was used as bioindicator.RESULTS: The results showed that a lowering of the washing temperature from 70°C to 60°C did not affect the decontamination efficacy; the washing cycle alone reduced the number of bacteria with 3-5 log10 CFU, whereas the following tumble drying reduced the bacterial numbers with another 3-4 log10 CFU, yielding the same final result independent of washing temperature. Without tumble drying, there was an obvious risk of adding non-fermenting gram-negative bacteria to the fabric. These bacteria originated from the washing cycle.CONCLUSION: A simple method to simulate hospital laundering was developed. To save energy, it is possible to use a washing temperature of 60°C, but the washing cycle should be followed by tumble drying, and the whole laundering process needs to be monitored to maintain sufficient textile hygiene.
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