| 1. |
- Olsson, Emma, 1977-, et al.
(författare)
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Coagulase-negative staphylococci isolated from sternal wound infections after cardiac surgery : attachment to and accumulation on sternal fixation stainless steel wires
- 2007
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - Oxford : Blackwell Publishing. - 0903-4641 .- 1600-0463. ; 115:2, s. 142-151
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Tidskriftsartikel (refereegranskat)abstract
- Sternal wound infection (SWI) is a serious complication after cardiac surgery. Coagulase-negative staphylococci (CoNS) have been found to be the most common pathogen involved in this postoperative infection related to implanted foreign materials, i.e. sternal fixation wires made from stainless steel. In this study a rapid and simple assay was developed for studying attachment and accumulation of CoNS on stainless steel wires in vitro using [(3)H] thymidine. The method showed a potential to detect differences in the dynamics of the adherence patterns among various CoNS isolates. However, no differences in attachment and accumulation were found between isolates causing deep SWI after cardiac surgery and contaminant isolates. In addition, there were no differences in the distribution of the ica operon between the two groups, as determined by polymerase chain reaction (PCR). Nevertheless, the ability to produce biofilm was found to be present significantly more frequently among SWI isolates than among contaminants.
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| 2. |
- Unemo, Magnus, 1970-, et al.
(författare)
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Genetic homogeneity/heterogeneity of Propionibacterium acnes isolated from patients during cardiothoracic reoperation
- 2007
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Ingår i: Anaerobe. - London : Academic Press. - 1075-9964 .- 1095-8274. ; 13:3-4, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- Following cardiothoracic surgery, deep sternal wound infection (SWI) remains one of the most severe complications. Recently, Propionibacterium acnes has been suspected as an etiological agent of deep SWI. However, this bacterium constitutes part of the resident micro-flora of the human skin. Consequently, findings of P. acnes in invasive samples are difficult to value. The aims of this study were to develop and optimize a pulsed-field gel electrophoresis (PFGE) protocol for P. acnes, in order to investigate the genetic homogeneity/heterogeneity of P. acnes isolates from multiple tissue samples (predominantly biopsies), collected at different locations, from 12 patients during cardiothoracic reoperation. There were 24 distinguishable PFGE fingerprints identified among the P. acnes isolates (n=54). Five (42%) of the patients carried only isolates that were interpreted as presumably clonally related. From the remaining seven patients, two or three different P. acnes clones were cultured, however, from six of them, the clones were identified in multiple samples. P. acnes may be a relatively frequent etiological agent of postoperative cardiothoracic infections. Existence of several clonally related P. acnes isolates derived from multiple samples from patients suffering from deep SWI after cardiothoracic surgery has not previously been shown.
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| 3. |
- Koskela, Anita, 1979-, et al.
(författare)
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Prevalence of the ica operon and insertion sequence IS256 among Staphylococcus epidermidis prosthetic joint infection isolates
- 2009
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - Berlin : Springer. - 0934-9723 .- 1435-4373. ; 28:6, s. 655-660
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Tidskriftsartikel (refereegranskat)abstract
- Joint replacement surgery has improved the quality of life for hundreds of thousands of patients. However, the infection of a joint implant is an important and serious complication, though the prevalence is low. Staphylococcus epidermidis is the most important pathogen involved in foreign-body infections. S. epidermidis is also a commensal that comprises a substantial part of the normal skin flora of humans. The possibility to demonstrate potential specific virulence markers may facilitate the interpretation of the bacteriological findings, as well as the clinical decision. The prevalence of the ica locus and insertion sequence IS256 by using polymerase chain reaction (PCR) among 32 clinical S. epidermidis isolates from prosthetic joint infections (PJIs) and 24 commensal isolates from nares and skin was investigated. Sixteen (50%) of the 32 PJI isolates harbored the ica operon compared with one-third of the commensal isolates obtained from the samples of the skin and nares of healthy individuals. The IS256 was demonstrated in 26 (81%) out of 32 PJI isolates. By contrast, IS256 was found in one of 24 commensal isolates. In conclusion, IS256 may be superior to the ica operon as a marker of the invasive capacity of S. epidermidis, since it was found in most of the PJI isolates, but rarely among commensals.
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| 4. |
- Månsson, Emeli, 1978-, et al.
(författare)
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Staphylococcus epidermidis from prosthetic joint infections induces lower IL-1 release from human neutrophils than isolates from normal flora
- 2018
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Ingår i: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley-Blackwell Publishing Inc.. - 0903-4641 .- 1600-0463. ; 126:8, s. 678-684
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to test the hypothesis that Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) differs from S.epidermidis isolated from normal flora in terms of its capacity to induce activation of caspase-1 and release of IL-1 in human neutrophils. The amount of active caspase-1 was determined over 6h by detecting Ac-YVAD-AMC fluorescence in human neutrophils incubated with S.epidermidis isolates from PJIs (ST2) or normal flora. The amount of IL-1 was detected by ELISA in neutrophil supernatants after 6h of incubation. Mean IL-1 release was lower after incubation with S.epidermidis from PJIs compared to isolates from normal flora, but no statistically significant difference was found in active caspase-1. Substantial inter-individual differences in both active caspase-1 and IL-1 were noted. These results suggest that evasion of innate immune response, measured as reduced capacity to induce release of IL-1 from human neutrophils, might be involved in the predominance of ST2 in S.epidermidis PJIs, but that other microbe-related factors are probably also important.
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| 5. |
- Asfaw Idosa, Berhane, 1977-, et al.
(författare)
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C10X polymorphism in the CARD8 gene is associated with bacteraemia
- 2014
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Ingår i: Immunity, inflammation and disease. - West Sussex, UK : John Wiley & Sons. - 2050-4527. ; 2:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- The NLRP3 inflammasome is an intracellular multi-protein complex that triggers caspase-1 mediated maturation of interleukin-1β (IL-1β); one of the most potent mediators of inflammation and a major cytokine produced during severe infections, like sepsis. However, the excessive cytokine levels seem to stage for tissue injury and organ failure, and high levels of IL-1β correlates with severity and mortality of sepsis. Instead, recent data suggest caspase-1 to function as a guardian against severe infections. CARD8 has been implied to regulate the synthesis of IL-1β via interaction to caspase-1. In recent years, polymorphism of CARD8 (C10X) per se or in combination with NLRP3 (Q705K) has been implicated with increased risk of inflammation. The aim was to investigate the correlation of these polymorphisms with severe blood stream infection. Human DNA was extracted from blood culture bottles that were found to be positive for microbial growth (i.e. patients with bacteraemia). Polymorphisms Q705K in the NLRP3 gene and C10X in the CARD8 gene were genotyped using TaqMan genotyping assay. The results were compared to healthy controls and to samples from patients with negative cultures. The polymorphism C10X was significantly over-represented among patients with bacteraemia as compared to healthy controls, whereas patients with negative blood culture were not associated with a higher prevalence. No association was observed with polymorphism Q705K of NLRP3 in either group of patients. Patients carrying polymorphism C10X in the CARD8 gene are at increased risk of developing bacteraemia and severe inflammation.
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| 6. |
- Davidsson, Sabina, 1972-, et al.
(författare)
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Multilocus sequence typing and repetitive-sequence-based PCR (DiversiLab) for molecular epidemiological characterization of Propionibacterium acnes isolates of heterogeneous origin
- 2012
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Ingår i: Anaerobe. - : Elsevier. - 1075-9964 .- 1095-8274. ; 18:4, s. 392-399
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Tidskriftsartikel (refereegranskat)abstract
- Propionibacterium acnes is a gram-positive bacillus predominantly found on the skin. Although it is considered an opportunistic pathogen it is also been associated with severe infections. Some specific P. acnes subtypes are hypothesized to be more prone to cause infection than others. Thus, the aim of the present study was to investigate the ability to discriminate between P. acnes isolates of a refined multilocus sequence typing (MLST) method and a genotyping method, DiversiLab, based on repetitive-sequence-PCR technology.The MLST and DiversiLab analysis were performed on 29 P. acnes isolates of diverse origins; orthopedic implant infections, deep infections following cardiothoracic surgery, skin, and isolates from perioperative tissue samples from prostate cancer. Subtyping was based on recA, tly, and Tc12S sequences.The MLST analysis identified 23 sequence types and displayed a superior ability to discriminate P. acnes isolates compared to DiversiLab and the subtyping. The highest discriminatory index was found when using seven genes. DiversiLab was better able to differentiate the isolates compared to the MLST clonal complexes of sequence types.Our results suggest that DiversiLab can be useful as a rapid typing tool for initial discrimination of P. acnes isolates. When better discrimination is required, such as for investigations of the heterogeneity of P. acnes isolates and its involvement in different pathogenic processes, the present MLST protocol is valuable.
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| 7. |
- Lindell, Fredrik, et al.
(författare)
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Prosthetic valve endocarditis caused by Propionibacterium species: a national registry-based study of 51 Swedish cases
- 2018
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Ingår i: European Journal of Clinical Microbiology & Infectious Diseases. - : Springer Science and Business Media LLC. - 0934-9723 .- 1435-4373. ; 37:4, s. 765-771
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Tidskriftsartikel (refereegranskat)abstract
- Propionibacterium spp. are a rare cause of infective endocarditis (IE). The diagnosis is difficult because the bacteria are slow-growing and growth in blood cultures is often misinterpreted as contamination from the skin flora. The aim of this study was to describe all cases of Propionibacterium spp. endocarditis in the Swedish national registry of IE. The registry was searched for all cases of IE from 1995 to 2016 caused by Propionibacterium spp. Data concerning clinical characteristics, treatment, and outcome were registered. A total of 51 episodes of definitive prosthetic valve endocarditis (PVE) caused by Propionibacterium spp. were identified, comprising 8% of cases of PVE during the study period. Almost all cases (n = 50) were male. The median time from surgery to diagnosis of IE was 3 years. Most patients were treated mainly with beta-lactams, partly in combination with aminoglycosides. Benzyl-penicillin was the most frequently used beta-lactam. A total of 32 patients (63%) underwent surgery. Overall, 47 patients (92.1%) were cured, 3 (5.9%) suffered relapse, and 1 (2.0%) died during treatment. IE caused by Propionibacterium spp. almost exclusively affects men with a prosthetic valve and findings of Propionibacterium spp. in blood cultures in such patients favors suspicion of a possible diagnosis of IE. In patients with prosthetic valves, prolonged incubation of blood cultures up to 14 days is recommended. The prognosis was favorable, although a majority of patients required cardiac surgery during treatment. Benzyl-penicillin should be the first-line antibiotic treatment option for IE caused by Propionibacterium spp.
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| 8. |
- Littorin, C., et al.
(författare)
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In vitro activity of tedizolid and linezolid against Staphylococcus epidermidis isolated from prosthetic joint infections
- 2017
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer. - 0934-9723 .- 1435-4373. ; 36:9, s. 1549-1552
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Tidskriftsartikel (refereegranskat)abstract
- Prosthetic joint infections (PJIs) are rare but long-lasting and are serious complications without any spontaneous resolution, requiring additional surgery and long-term treatment with antibiotics. Staphylococci are the most important aetiological agents of PJIs, and among the coagulase-negative staphylococci Staphylococcus epidermidis is the most common. However, S. epidermidis often displays multidrug resistance (MDR), demanding additional treatment options. The objective was to examine the effectiveness of tedizolid and linezolid against S. epidermidis isolated from PJIs. The standard antibiotic susceptibility pattern of S. epidermidis (n = 183) obtained from PJIs was determined by disc diffusion test, and MIC was determined by Etest for tedizolid, linezolid, and vancomycin. Tedizolid displayed MIC values ranging from 0.094 to 0.5 mg/L (MIC50: 0.19 mg/L, MIC90: 0.38 mg/L), linezolid MIC values ranging from 0.25 to 2 mg/L (MIC50: 0.75 mg/L, MIC90: 1 mg/L), and vancomycin MIC values ranging from 0.5 to 3 mg/L (MIC50 and MIC90 both 2 mg/L). According to the disc diffusion test, 153/183 (84%) isolates were resistant to ≥3 antibiotic groups, indicating MDR. In conclusion, S. epidermidis isolates from PJIs were fully susceptible, and the MIC50 and MIC90 values for tedizolid were two- to four-fold dilution steps lower compared with linezolid. Tedizolid is not approved, and there are no reports of long-term treatment, but it may display better tolerability and fewer adverse effects than linezolid; it thus could be a possible treatment option for PJIs, alone or in combination with rifampicin.
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| 9. |
- Tevell, Staffan, 1975-, et al.
(författare)
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Heterogeneous glycopeptide intermediate Staphylococcus epidermidis isolated from prosthetic joint infections
- 2014
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - New York : Springer. - 0934-9723 .- 1435-4373. ; 33:6, s. 911-917
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Tidskriftsartikel (refereegranskat)abstract
- Methicillin-resistant Staphylococcus epidermidis (MRSE) poses a major problem in prosthetic joint infections (PJIs). Vancomycin is often considered the drug of choice in the empirical treatment of staphylococcal PJIs. As recent decades have seen reports of heterogeneous glycopeptide intermediate S. aureus (hGISA), our aim was to examine the prevalence of heterogeneous glycopeptide intermediate S. epidermidis (hGISE) in PJIs. S. epidermidis isolates (n = 122) from 119 patients in three Swedish counties between 1993 and 2012 were included. All were isolated from perioperative tissue samples from revision surgery in clinically verified PJIs. Antimicrobial susceptibility testing against staphylococcal antibiotics was performed. The macromethod Etest (MME) and glycopeptide resistance detection (GRD) Etest were used to detect hGISE. Standard minimal inhibitory concentration (MIC) determination revealed no vancomycin-resistant isolates, while teicoplanin resistance was detected in 14 out of 122 isolates (11.5 %). hGISE was found in 95 out of 122 isolates (77.9 %), 64 out of 67 of isolates with teicoplanin MIC > 2 mg/L (95.5 %) and 31 out of 55 of isolates with teicoplanin MIC a parts per thousand currency sign2 mg/L (56.4 %). Thus, the presence of hGISE cannot be ruled out by teicoplanin MIC a parts per thousand currency sign2 mg/L alone. Multidrug resistance was detected in 86 out of 95 hGISE isolates (90.5 %) and in 16 out of 27 isolates (59.3 %), where hGISE could not be detected. In conclusion, hGISE detected by MME or GRD was common in this material. However, hGISE is difficult to detect with standard laboratory diagnostic routines. Glycopeptide treatment may not be sufficient in many of these PJIs, even if standard MIC classifies the isolated S. epidermidis as susceptible.
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| 10. |
- Rendboe, Amalie Katrine, et al.
(författare)
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The Epidome : a species-specific approach to assess the population structure and heterogeneity of Staphylococcus epidermidis colonization and infection
- 2020
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Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAlthough generally known as a human commensal, Staphylococcus epidermidis is also an opportunistic pathogen that can cause nosocomial infections related to foreign body materials and immunocompromized patients. Infections are often caused by multidrug-resistant (MDR) lineages that are difficult and costly to treat, and can have a major adverse impact on patients’ quality of life. Heterogeneity is a common phenomenon in both carriage and infection, but present methodology for detection of this is laborious or expensive.In this study, we present a culture-independent method, labelled Epidome, based on an amplicon sequencing-approach to deliver information beyond species level on primary samples and to elucidate clonality, population structure and temporal stability or niche selection of S. epidermidis communities.ResultsBased on an assessment of > 800 genes from the S. epidermidis core genome, we identified genes with variable regions, which in combination facilitated the differentiation of phylogenetic clusters observed in silico, and allowed classification down to lineage level. A duplex PCR, combined with an amplicon sequencing protocol, and a downstream analysis pipeline were designed to provide subspecies information from primary samples. Additionally, a probe-based qPCR was designed to provide valuable absolute abundance quantification of S. epidermidis. The approach was validated on isolates representing skin commensals and on genomic mock communities with a sensitivity of < 10 copies/μL. The method was furthermore applied to a sample set of primary skin and nasal samples, revealing a high degree of heterogeneity in the S. epidermidis populations. Additionally, the qPCR showed a high degree of variation in absolute abundance of S. epidermidis.ConclusionsThe Epidome method is designed for use on primary samples to obtain important information on S. epidermidis abundance and diversity beyond species-level to answer questions regarding the emergence and dissemination of nosocomial lineages, investigating clonality of S. epidermidis communities, population dynamics, and niche selection. Our targeted-sequencing method allows rapid differentiation and identification of clinically important nosocomial lineages in low-biomass samples such as skin samples.
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