Bo Söderquist

Örebro universitet, Örebro, Örebro, Sweden

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Publications (95)298.99 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The anterior nares have been regarded as the major carriage site of Staphylococcus aureus. From here, the organism can spread to other parts of the body where it might act as harmless commensal or cause mild to severe infections. Nasal sinuses are normally sterile, but in patients with chronic rhinosinusitis (CRS), the finding of S. aureus in maxillary sinus cultures is common. Isolates were obtained from the nares and maxillary sinus of patients with CRS and the nares of healthy controls. A significantly higher frequency of S. aureus was found in nares samples from patients (24/42) compared to controls (16/57) (p = 0.004). There is no consensus regarding whether S. aureus is a relevant pathogen in CRS. A DNA microarray was used to investigate the prevalence of S. aureus virulence genes with focus on staphylococcal enterotoxins, toxic shock syndrome toxin-1, agr types, and cell wall-associated proteins. The genotyping of S. aureus isolates revealed only small and non-significant differences in gene prevalence between isolates collected from patients with CRS and those collected from healthy nasal carriers. This study provides an increased knowledge of the genetic pattern of virulence genes among S. aureus collected in CRS.
    Apmis 08/2014; · 2.07 Impact Factor
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    ABSTRACT: The aim of the present study was to compare microbial skin sealant versus bare skin on the leg regarding intraoperative bacterial presence in the surgical wound and time to recolonization of the adjacent skin at the saphenous vein harvesting site. A second aim was to evaluate the incidence of leg wound infection 2 months after surgery. In this randomized controlled trial, 140 patients undergoing coronary artery bypass grafting (CABG) between May 2010 and October 2011 were enrolled. Bacterial samples were taken preoperatively and intraoperatively at multiple time points and locations. OF the patients, 125 (92.6 %) were followed up 2 months postoperatively regarding wound infection. Intraoperative bacterial growth did not differ between the bare skin (n = 68) and the microbial skin sealant group (n = 67) at any time point. At 2 months postoperatively, 7/61 patients (11.5 %) in the skin sealant versus 14/64 (21.9 %) in the bare skin group (p = 0.120) had been treated with antibiotics for a verified or suspected surgical site infection (SSI) at the harvest site. We found almost no intraoperative bacterial presence on the skin or in the subcutaneous tissue, irrespective of microbial skin sealant use. In contrast, we observed a relatively high incidence of late wound infection, indicating that wound contamination occurred postoperatively. Further research is necessary to determine whether the use of microbial skin sealant reduces the incidence of leg wound infection at the saphenous vein harvest site.
    European Journal of Clinical Microbiology 06/2014; · 3.02 Impact Factor
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    ABSTRACT: The emergence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a major global concern. CTX-M is the dominating ESBL type worldwide, and CTX-M-15 is the most widespread CTX-M type. The dissemination of CTX-M appears to be in part due to global spread of the Escherichia coli clone O25b-ST131. However, the gene-encoding CTX-M is mainly located on mobile genetic elements, such as plasmids, that also promote the horizontal dissemination of the CTX-M genes. In this study, 152 CTX-M-producing E. coli isolated in 1999–2008 in Örebro County, Sweden, were typed using a commercial repetitive sequence-based PCR (the DiversiLab system), and the prevalence of ST131 was investigated by pabB PCR. Real-time PCR-based plasmid replicon typing was performed on 82 CTX-M-15-producing E. coli isolates. In general, the CTX-M-producing E. coli population was genetically diverse; however, ST131 was highly prevalent (27%), and the dominating clone in our area. The blaCTX-M-15 gene was mainly located on IncF plasmids (69%), but a relatively high proportion of IncI1 plasmids (29%) were also detected among E. coli with diverse rep-PCR patterns, indicating that horizontal transmission of IncI1 plasmids carrying blaCTX-M-15 may have occurred between different E. coli strains.
    Apmis 04/2014; · 2.07 Impact Factor
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    ABSTRACT: Nitric oxide (NO) is produced as part of the host immune response to bacterial infections, including urinary tract infections. The enzyme flavohemoglobin, coded by the hmp gene, is involved in protecting bacterial cells from the toxic effects of NO and represents a potentially interesting target for development of novel treatment concepts against resistant uropathogenic bacteria. The aim of the present study was to investigate if the in vitro antibacterial effects of NO can be enhanced by pharmacological modulation of the enzyme flavohemoglobin. Four clinical isolates of multidrug-resistant extended-spectrum beta-lactamase (ESBL)-producing uropathogenic E. coli were included in the study. It was shown that the NO-donor substance DETA/NO, but not inactivated DETA/NO, caused an initial growth inhibition with regrowth noted after 8 h of exposure. An hmp-deficient strain showed a prolonged growth inhibition in response to DETA/NO compared to the wild type. The imidazole antibiotic miconazole, that has been shown to inhibit bacterial flavohemoglobin activity, prolonged the DETA/NO-evoked growth inhibition. When miconazole was combined with polymyxin B nonapeptide (PMBN), in order to increase the bacterial wall permeability, DETA/NO caused a prolonged bacteriostatic response that lasted for up to 24 h. An NO-donor in combination with miconazole and PMBN showed enhanced antimicrobial effects and proved effective against multidrug-resistant ESBL-producing uropathogenic E. coli.
    BMC Microbiology 03/2014; 14(1):65. · 2.98 Impact Factor
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    ABSTRACT: Staphylococcus epidermidis is a versatile agent, being both a commensal and a nosocomial pathogen usually with an opportunistic role in association with implanted foreign body materials. Pre-operative antiseptic preparation is an important strategy for reducing the risk of complications such as surgical site infection (SSI). Currently, the most widely used antiseptics are alcohols, quaternary ammonium compounds (QACs), and the bisbiguanide chlorhexidine. Occurrence of resistance to the latter agent has drawn increasing attention. The aim of this study was to investigate if decreased susceptibility to chlorhexidine among S. epidermidis was present in our setting, a Swedish university hospital. Staphylococcus epidermidis (n = 143), retrospectively collected, were obtained from prosthetic joint infections (PJI) (n = 61), post-operative infections after cardiac surgery (n = 31), and the skin of the chest after routine disinfection prior to cardiac surgery (n = 27). In addition, 24 commensal isolates were included. Minimum inhibitory concentration (MIC) of chlorhexidine was determined on Mueller Hinton agar plates supplemented with serial dilutions of chlorhexidine. Five QAC resistance genes, qacA/B, smr, qacH, qacJ, and qacG, were detected using PCR. Decreased susceptibility to chlorhexidine was found in 54% of PJI isolates, 68% of cardiac isolates, 21% of commensal isolates, and 7% of skin isolates from cardiac patients, respectively. The qacA/B gene was present in 62/143 isolates (43%), smr in 8/143 (6%), and qacH in one isolate (0.7%). The qacA/B gene was found in 52% of PJI isolates, 61% of cardiac isolates, 25% of commensal isolates, and 19% of the skin isolates. In conclusion, decreased susceptibility to chlorhexidine, as well as QAC resistance genes, were prevalent among S. epidermidis isolates associated with deep SSIs.
    Apmis 03/2014; · 2.07 Impact Factor
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    ABSTRACT: Staphylococcus epidermidis is an important cause of bloodstream infections in patients with hematological malignancies. Knowledge of the long-term epidemiology of these infections is limited. We surveyed all S. epidermidis blood culture isolates from patients treated for hematological malignancies at the University Hospital of Örebro, Sweden from 1980 to 2009. A total of 373 S. epidermidis isolates were identified and multilocus sequence typing, staphylococcal chromosome cassette mec (SCCmec) typing and standard antibiotic susceptibility testing were employed to characterize these isolates. The majority of the isolates 361/373 (97%) belonged to clonal complex 2, and the 373 isolates were divided into 45 sequence types (STs); Simpson's Diversity Index was 0.56. The most prevalent STs were ST2 (243/373, 65%) and ST215 (28/373, 8%). Ninety three percent (226/243) of the ST2 isolates displayed either SCCmec type III or IV. ST2 and 215 were isolated during the entire study period, and together these STs caused temporal peaks in the number of positive blood cultures of S. epidermidis. Methicillin resistance was detected in 213/273 (78%) of all isolates. In the two predominating STs, ST2 and ST215, methicillin resistance was detected in 256/271 isolates (95%), compared with 34/100 (34%) in other STs (p<0.001). In conclusion, in this long-term study of patients with hematological malignancies, we demonstrate a predominance of methicillin-resistant ST2 among S. epidermidis blood culture isolates.
    PLoS ONE 01/2014; 9(6):e99045. · 3.53 Impact Factor
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    ABSTRACT: Carbon monoxide (CO) releasing molecules (CO-RMs) have been shown to inhibit growth of commensal Escherichia coli (E. coli). In the present study we examined the effect of CORM-2 on uropathogenic E. coli (UPEC) that produces extended-spectrum β-lactamase (ESBL). Viability experiments showed that CORM-2 inhibited the growth of several different ESBL-producing UPEC isolates and that 500 μM CORM-2 had a bactericidal effect within 4 hours. The bactericidal effect of CORM-2 was significantly more pronounced than the effect of the antibiotic nitrofurantoin. CORM-2 demonstrated a low level of cytotoxicity in eukaryotic cells (human bladder epithelial cell line 5637) at the concentrations and time-points where the antibacterial effect was obtained. Real-time RT-PCR studies of different virulence genes showed that the expression of capsule group II kpsMT II and serum resistance traT was reduced and that some genes encoding iron acquisition systems were altered by CORM-2. Our results demonstrate that CORM-2 has a fast bactericidal effect against multiresistant ESBL-producing UPEC isolates, and also identify some putative UPEC virulence factors as targets for CORM-2. CO-RMs may be candidate drugs for further studies in the field of finding new therapeutic approaches for treatment of uropathogenic ESBLproducing E. coli.
    Microbial Pathogenesis 12/2013; · 1.97 Impact Factor
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    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 ≤2 mg/L (56.4 %). Thus, the presence of hGISE cannot be ruled out by teicoplanin MIC ≤2 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.
    European Journal of Clinical Microbiology 12/2013; · 3.02 Impact Factor
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    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.
    Immunity, Inflammation and Disease. 11/2013;
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    ABSTRACT: Reduced monocyte human leukocyte antigen (mHLA)-DR surface expression in the late phase of sepsis is postulated as a general biomarker of sepsis-induced immunosuppression and an independent predictor of nosocomial infections.However, traditional monitoring of mHLA-DR by flow cytometry has disadvantages due to specific laboratory requirements. An mRNA-based HLA-DR monitoring by PCR would improve the clinical usage and facilitate conduction of large multicenter studies. In this study we evaluated an mRNA based HLA-DR monitoring by quantitative real-time PCR (qRT-PCR) as an alternative method to traditional flow cytometry. 59 patients with sepsis and blood culture growing pathogenic bacteria were studied. Blood samples were collected at day 1-2 after admission, for measurement of mHLA-DR by flow cytometry and mRNA expression of HLA-DRA and class II transactivator (CIITA) by qRT-PCR. Blood samples from blood donors were used as controls (n = 30). A significant reduced expression of mHLA-DR, HLA-DRA and CIITA was seen in septic patients compared to controls. HLA-DRA mRNA level in whole blood was highly correlated with surface expression of mHLA-DR. Septic patients display a diminished expression of HLA-DR at the monocyte surface as well as in the gene expression at the mRNA level. The mRNA expression level of HLA-DRA monitored by qRT-PCR, correlates highly with surface expression of HLA-DR and appears to be a possible future biomarker for evaluation of immunosuppression in sepsis.
    Critical care (London, England) 10/2013; 17(5):R223. · 4.72 Impact Factor
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    ABSTRACT: The aim was to investigate whether the detection and quantification of Staphylococcus epidermidis DNA in blood could distinguish S. epidermidis blood stream infections (BSIs) from blood culture contaminations in patients with hematological malignancies. The hld gene was chosen to identify S. epidermidis DNA and DNA in blood samples was detected by real-time PCR. Blood samples were obtained simultaneously with blood cultures positive for S. epidermidis (n = 30), during blood culture-negative episodes (n = 10) and episodes of bacteremia with other bacteria than S. epidermidis (n = 4) and from healthy blood donors (n = 10). In addition, DNA from S. epidermidis and a selection of other bacterial species were analyzed. Three different sets of criteria were used to classify episodes with positive blood cultures with S. epidermidis as BSIs or contaminations. All DNA preparations from S. epidermidis (n = 48) were hld-positive, but other bacterial species (n = 13) were negative. Sixteen (53%) of 30 blood samples from patients with blood cultures positive for S. epidermidis were hld-positive, but none of the controls. There was no clear association between a positive hld PCR and episodes interpreted as BSIs. In conclusion, hld PCR failed to distinguish S. epidermidis BSIs from blood culture contaminations in patients with hematological malignancies.
    Apmis 09/2013; · 2.07 Impact Factor
  • The Journal of hospital infection 09/2013; · 3.01 Impact Factor
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    ABSTRACT: BACKGROUND: Sternal wound infection after cardiac surgery is a serious complication. Various perioperative strategies, including plastic adhesive drapes, are used to reduce bacterial contamination of surgical wounds. AIM: To compare plastic adhesive drape to bare skin regarding bacterial growth in wound and time to recolonization of the adjacent skin intraoperatively, in cardiac surgery patients. METHODS: This single-blinded randomized controlled trial (May 2010 to May 2011) included 140 patients scheduled for cardiac surgery via median sternotomy. The patients were randomly allocated to the adhesive drape (chest covered with plastic adhesive drape) or bare skin group. Bacterial samples were taken preoperatively and intraoperatively every hour during surgery until skin closure. RESULTS: Disinfection with 0.5% chlorhexidine solution in 70% alcohol decreased coagulase-negative staphylococci (CoNS), while the proportion colonized with Propionibacterium acnes was not significantly reduced and was still present in more than 50% of skin samples. P. acnes was significantly more common in men than in women. Progressive bacterial recolonization of the skin occurred within 2-3 h. At 120 min there were significantly more positive cultures in the adhesive drape group versus bare skin group for P. acnes (63% vs 44%; P = 0.034) and for CoNS (45% vs 24%; P = 0.013). The only statistically significant difference in bacterial growth in the surgical wound was higher proportion of CoNS at the end of surgery in the adhesive drape group (14.7% vs 4.4%; P = 0.044). CONCLUSION: Plastic adhesive drape does not reduce bacterial recolonization. P. acnes colonized men more frequently, and was not decreased by disinfection with chlorhexidine solution in alcohol.
    The Journal of hospital infection 04/2013; · 3.01 Impact Factor
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    ABSTRACT: The aim of the present study was to characterise the staphylococcal cassette chromosome mec (SCCmec) in Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) and, if possible, assign them to any of the presently known SCCmec types. In addition, the isolates were examined for the presence of the arginine catabolic mobile element (ACME). Sixty-one S. epidermidis isolates obtained from PJIs and 24 commensal S. epidermidis isolates were analysed. The mecA gene was detected in 49 of the 61 (80 %) PJI isolates and in four of the 24 (17 %) commensal isolates, and the composition of the SCCmec was further analysed. SCCmec types I and IV were the most common types among the PJI isolates. However, for over half (57 %) of the isolates, it was not possible to assign an SCCmec type. ACME was detected in eight (13 %) of the PJI isolates and in 14 (58 %) of the commensal isolates. The characterisation of the SCCmec elements revealed a large heterogeneity, with a high frequency of isolates carrying more than one type of the ccr gene complex. ACME was more common among the commensal isolates and may represent a survival benefit for S. epidermidis colonising healthy individuals in the community.
    European Journal of Clinical Microbiology 01/2013; · 3.02 Impact Factor
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    ABSTRACT: Infections caused by extended spectrum beta-lactamases (ESBL)-producing bacteria have been emerging worldwide and the majority of ESBL-producing E. coli strains are isolated from patients with urinary tracts infections. The purpose of this study was to compare the host-response mechanisms in human polymorphonucleated leukocytes (PMN) and renal epithelial cells when stimulated by ESBL- or non-ESBL-producing uropathogenic E. coli (UPEC) isolates. The host-pathogen interaction of these ESBL-producing strains in the urinary tract is not well studied. The ability of ESBL strains to evoke ROS-production from PMN cells was significantly higher than that of the non-ESBL strains. The growth of ESBL strains was slightly suppressed in the presence of PMN compared to non-ESBL strains after 30 min and 2h, but the opposite was observed after 5 and 6h. The number of migrating PMN was significantly higher in response to ESBL strains compared to non-ESBL strains. Stimulation of A498 cells with ESBL strains elicited lower production of IL-6 and IL-8 compared to non-ESBL strains. Significant differences in host-response mechanisms were identified when host cells were stimulated by ESBL- or non-ESBL producing strains. The obtained results on the early interactions of ESBL-producing strains with the host immune system may provide valuable information for management of these infections.
    BMC Microbiology 01/2013; 13(1):181. · 2.98 Impact Factor
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    ABSTRACT: The NLRP3 inflammasome has been recognized as one of the key components of the innate immunity by sensing a diversity of insults. Inflammasome activation results in the maturation of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Increased production of IL-1β is found in patients with gain-of-function polymorphisms in genes encoding the NLRP3 inflammasome. Since approximately 5% of the Swedish population are heterozygote carriers of these combined gene variants, their impact on inflammasome status and a relationship on disease development is therefore highly relevant to study. The present study investigates levels of inflammasome-produced cytokines as a measure of inflammasome activation in healthy individuals carrying Q705K polymorphism in the NLRP3 gene combined with C10X in the CARD8 gene. Genotyping of 1006 healthy blood donors was performed for the polymorphisms Q705K in the NLRP3 and C10X in the CARD8 genes. IL-1β, IL-18, IL-33, as well as a number of other pro-inflammatory cytokines, were analyzed by Luminex or ELISA in plasma from individuals carrying the polymorphisms and in age and gender matched non-carrier controls. The prevalence of the polymorphisms was in line with previous studies. Plasma levels of IL-1β and IL-33 were elevated among carriers of combined Q705K+C10X polymorphisms compared to controls, whereas no difference was found for IL-18 and the other cytokines measured. Moreover, carriers of C10X or Q705K per se had similar plasma levels of IL-1β as non-carriers. These data suggest that the combined polymorphisms create inflammasomes with increased basal activation state, which might provide a more favourable innate immune response. In spite of this, it could also represent the mechanisms by which the inflammatory loop is triggered into a long-term inflammatory phenotype.
    PLoS ONE 01/2013; 8(10):e75457. · 3.53 Impact Factor
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    ABSTRACT: Staphylococcus aureus encodes a remarkable number of virulence factors which may contribute to its pathogenicity and ability to cause invasive disease. The main objective of this study was to evaluate the association between S. aureus invasiveness and bacterial genotype, in terms of the presence of virulence genes and affiliation to clonal complexes. Also, the significance of different virulence genes, mainly adhesins, for the development of infective endocarditis was investigated. DNA microarray technology was used to analyze 134 S. aureus isolates, all methicillin-susceptible, derived from three groups of clinically well-characterized patients: nasal carriers (n=46), bacteremia (n=55), and bacteremia with infective endocarditis (n=33). INVASIVE ISOLATES WERE DOMINANT IN FOUR OF THE MAJOR CLONAL COMPLEXES: 5, 8, 15, and 25. Of the 170 virulence genes examined, those encoding accessory gene regulator group II (agr II), capsule polysaccharide serotype 5 (cap5), and adhesins such as S. aureus surface protein G (sasG) and fibronectin-binding protein B (fnbB) were found to be associated with invasive disease. The same was shown for the leukocidin genes lukD/lukE, as well as the genes encoding serine protease A and B (splA/splB), staphylococcal complement inhibitor (scn) and the staphylococcal exotoxin-like protein (setC or selX). In addition, there was a trend of higher prevalence of certain genes or gene clusters (sasG, agr II, cap5) among isolates causing infective endocarditis compared to other invasive isolates. In most cases, the presence of virulence genes was linked to clonal complex affiliation. In conclusion, certain S. aureus clonal lineages harboring specific sets of virulence genes seem to be more successful in causing invasive disease.
    PLoS ONE 01/2013; 8(10):e77477. · 3.53 Impact Factor
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    ABSTRACT: Propionibacterium acnes is a Gram-positive, slow-growing, anaerobic bacillus, predominantly found as a commensal on the skin and mucous membranes of adults. It is, however, also considered an opportunistic pathogen; mostly associated with acne vulgaris, but rarely also with severe infections such as infective endocarditis, prosthetic joint infections, and deep sternal wound infections following cardiothoracic surgery. In addition, P. acnes has recently been found in high frequency in prostate tissue from patients with prostatitis and prostate cancer. The NOD-like receptors (NLR) act as intracellular sensors of microbial components, and a number of various bacteria have been found to induce assembling and activation of NLR-inflammasomes; leading to a pro-inflammatory response. The inflammasome-mediated formation of the pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18 involves the auto-proteolytic maturation of caspase-1. This study investigated if P. acnes activates inflammasomes. Propionibacterium acnes isolates (n = 29) with diverse origin were used as stimuli for peripheral leukocytes obtained from blood donors (BDs). The activity of inflammasomes was determined by measuring caspase-1 by flow cytometry and cytokine production by ELISA. A significant amount of caspase-1 was found in neutrophils upon P. acnes stimulation, whereas only a modest activation was seen in monocytes. The activation was mainly produced by components of the bacterial cell and no exo-products, because heat-killed and live bacteria caused high activation of caspase-1 as well as cytokine production, whereas the bacterial supernatant elicited minor effect. The response among different BDs varied significantly, almost fivefold. In addition, P. acnes of various origins showed considerable variation, however, the commensal isolates showed a stronger response compared with the invasive. In conclusion, although regarded as a harmless commensal of the skin, P. acnes strongly activates the inflammasome of human peripheral neutrophils.
    Apmis 12/2012; · 2.07 Impact Factor
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    ABSTRACT: Staphylococcus epidermidis is the predominant bacterial species in the normal flora of the human skin and superficial mucosal membranes. However, it has also emerged as the most important pathogen in infections related to foreign-body materials, such as prosthetic joints and heart valves. The aims of this study were to characterise S. epidermidis isolated from prosthetic joint infections (PJI; n=61) and commensal isolates from healthy individuals (n=24) in regard to antimicrobial sensitivity, agr type, hld gene presence, biofilm production including presence of ica and aap genes involved in the biofilm formation process and epidemiology using both phenotypic (the PhenePlate-system) and genotypic [multilocus sequence typing (MLST)] methods. Among the PJI isolates, the majority (67%) were multidrug-resistant. Two major clusters of PJI isolates could be identified; 44% belonged to MLST sequence type (ST) 2, all but one were of agr type 1, and 31% were assigned ST215 and were of agr type 3. Of the commensal isolates, only one isolate was multidrug-resistant, and they were more molecular epidemiologically diverse with mainly MLST singletons and a maximum of 3 isolates assigned to the identical ST. Biofilm production was detected in 41% of the PJI isolates and 58% of the commensal isolates, with the aap gene (95%) more frequently detected than the ica genes (62%) in the biofilm-positive isolates. In conclusion, S. epidermidis isolated from PJIs and commensal isolates differed regarding antimicrobial sensitivity and molecular epidemiological typing using MLST, but not substantially in the distribution of agr types, biofilm production, or the presence of ica and aap genes.
    International journal of medical microbiology: IJMM 12/2012; · 4.54 Impact Factor

Publication Stats

1k Citations
298.99 Total Impact Points

Institutions

  • 2011–2014
    • Örebro universitet
      • School of Medicine
      Örebro, Örebro, Sweden
    • Universitetet i Tromsø
      • Department of Medical Biology(IMB)
      Tromsø, Troms Fylke, Norway
  • 1992–2014
    • Örebro University Hospital
      • • Department of Laboratory Medicine
      • • Department of Cardiothoracic Surgery
      • • Department of Internal Medicine
      • • Department of Infectious Diseases
      Örebro, Örebro, Sweden
  • 2008
    • Juntendo University
      • Department of Infection Control Science
      Edo, Tōkyō, Japan
    • Aleris
      Tukholma, Stockholm, Sweden
  • 2007
    • Linköping University
      Linköping, Östergötland, Sweden
  • 2004–2005
    • Mid Sweden University
      Härnösand, Västernorrland, Sweden
  • 1996–2000
    • Karolinska Institutet
      Solna, Stockholm, Sweden