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- Claesson, Carina, 1970-, et al.
(author)
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Susceptibility of staphylococci and enterococci to antimicrobial agents at different ward levels in four north European countries
- 2007
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In: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 39:11-12, s. 1002-1012
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Journal article (peer-reviewed)abstract
- A multicentre susceptibility study was performed on staphylococci and enterococci isolated from patients at 3 different ward levels: primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs), in Denmark, Finland, Norway and Sweden. There was a markedly higher incidence of resistance among CoNS in ICUs compared to GHWs and PCCs. Resistance rates were low among S. aureus isolates and no differences were found between the ward levels. Oxacillin resistance was found among 1.6% of S. aureus and 47% of CoNS isolates. 14% of CoNS and 0.9% of S. aureus isolates were glycopeptide intermediate. The prevalence of E. faecium isolates in this study differed significantly between the ward levels with the lowest prevalence found at PCCs. High level gentamicin resistant (HLGR) enterococci occurred in 11-25% of E. faecium and 6-20% of E. faecalis isolates. The HLGR rate was significantly higher among E. faecalis from hospitalized patients (GHWs and ICUs) compared to patients at PCCs. For enterococcal isolates, no other significant differences in antimicrobial resistance were found between the ward levels. All enterococci were teicoplanin susceptible, but decreased susceptibility to vancomycin was found among 2.0% and 0.6% of the E. faecium and E. faecalis isolates, respectively.
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| 2. |
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| 3. |
- Claesson, Carina, 1970-
(author)
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Staphylococci and Enterococci : Studies on activity of antimicrobial agents and detection of genes involved in biofilm formation
- 2010
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Doctoral thesis (other academic/artistic)abstract
- The Gram-positive cocci, Staphylococcus aureus, coagulase negative staphylococci (CoNS), Enterococcus faecalis and Enterococcus faecium, are the bacteria most often isolated from patients with hospital acquired infections. S. aureus is one of the most important pathogens and have a variety of virulence mechanisms which help it to infect the patient and cause tissue damage. CoNS and enterococci are low virulent bacteria and predominantly cause infections in individuals with underlying illness, individuals that have undergone surgery or with suppressed immune-system. The aims of this thesis were i) to investigate the susceptibility to different antimicrobial agents among S. aureus, CoNS, E. faecium and E. faecalis isolates from primary care centres, general hospital wards and intensive care units in Denmark, Finland, Norway and Sweden and ii) to study the prevalence of the cytolysin genes and genes involved in biofilm formation among CoNS, E. faecium and E. faecalis. The results in this thesis show that the resistance rates among S. aureus and E. faecalis is still rather low in the north European countries. Among CoNS and E. faecium resistance rates are higher and comparable with rates in other European countries and US. CoNS had statistically significant differences in susceptibility rates between the ward levels with the lower susceptibility rates found at ICUs. Continued surveillance of resistance rates to antimicrobial agents among both staphylococci and enterococci are important internationally, nationally and locally. The results in this thesis also show that all multidrug resistant and 96% of the susceptible CoNS isolates carried at least one of the atlE and aap genes or the ica operon. Among E. faecalis isolates with HLGR, belonging to a cluster of genetically related isolates, both the esp and asa1 genes were carried in a high degree while the cyl operon was less frequently found. In addition, about 30% of unique E. faecalis isolates carried two or more of the virulence genes. Among E. faecium isolates the esp gene was common but asa1 and the cyl operon was not found in any of the isolates. Both CoNS and E. faecalis isolates from hospitalised patients are well equipped with genes involved in biofilm formation. These genes, when expressed and even more in combination with resistance to antimicrobial agents, might give these isolates an advantage compared to other isolates when it comes to adhesion to artificial surfaces, persistence in the hospital environment, colonisation of hospitalised patients and to cause nosocomial infections. Further studies are needed to be able to determine which isolates that causes hospital acquired infections and to evaluate the importance of the genes involved in biofilm formation as virulence factors and about how to prevent biofilm related infections from emerging
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| 4. |
- Dellgren, Linus, et al.
(author)
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Phenotypic screening for quinolone resistance in Escherichia coli
- 2019
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In: European Journal of Clinical Microbiology and Infectious Diseases. - : SPRINGER. - 0934-9723 .- 1435-4373. ; 38:9, s. 1765-1771
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Journal article (peer-reviewed)abstract
- Recent studies show that rectal colonization with low-level ciprofloxacin-resistant Escherichia coli (ciprofloxacin minimal inhibitory concentration (MIC) above the epidemiological cutoff point, but below the clinical breakpoint for resistance), i.e., in the range amp;gt; 0.06-0.5 mg/L is an independent risk factor for febrile urinary tract infection after transrectal ultrasound-guided biopsy (TRUS-B) of the prostate, adding to the other risk posed by established ciprofloxacin resistance in E. coli (MIC amp;gt; 0.5 mg/L) as currently defined. We aimed to identify the quinolone that by disk diffusion best discriminates phenotypic wild-type isolates (ciprofloxacin MIC amp;lt;= 0.06 mg/L) of E. coli from isolates with acquired resistance, and to determine the resistance genotype of each isolate. The susceptibility of 108 E. coli isolates was evaluated by ciprofloxacin, levofloxacin, moxifloxacin, nalidixic acid, and pefloxacin disk diffusion and correlated to ciprofloxacin MIC (broth microdilution) using EUCAST methodology. Genotypic resistance was identified by PCR and DNA sequencing. The specificity was 100% for all quinolone disks. Sensitivity varied substantially, as follows: ciprofloxacin 59%, levofloxacin 46%, moxifloxacin 59%, nalidixic acid 97%, and pefloxacin 97%. We suggest that in situations where low-level quinolone resistance might be of importance, such as when screening for quinolone resistance in fecal samples pre-TRUS-B, a pefloxacin (S amp;gt;= 24 mm) or nalidixic acid (S amp;gt;= 19 mm) disk, or a combination of the two, should be used. In a setting where plasmid-mediated resistance is prevalent, pefloxacin might perform better than nalidixic acid.
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| 5. |
- Holmbom, Martin, et al.
(author)
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14-Year Survey in a Swedish County Reveals a Pronounced Increase in Bloodstream Infections (BSI). Comorbidity : An Independent Risk Factor for Both BSI and Mortality
- 2016
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 11:11
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Journal article (peer-reviewed)abstract
- Objectives: we assessed the incidence, risk factors and outcome of BSI over a 14-year period (2000-2013) in a Swedish county.Methods: retrospective cohort study on culture confirmed BSI among patients in the county of Östergötland, Sweden, with approximately 440,000 inhabitants. A BSI was defined as either community-onset BSI (CO-BSI) or hospital-acquired BSI (HA-BSI).Results: of a total of 11,480 BSIs, 67% were CO-BSI and 33% HA-BSI. The incidence of BSI increased by 64% from 945 to 1,546 per 100,000 hospital admissions per year during the study period. The most prominent increase, 83% was observed within the CO-BSI cohort whilst HA-BSI increased by 32%. Prescriptions of antibiotics in outpatient care decreased with 24% from 422 to 322 prescriptions dispensed/1,000 inhabitants/year, whereas antibiotics prescribed in hospital increased by 67% (from 424 to 709 DDD per 1,000 days of care). The overall 30-day mortality for HA-BSIs was 17.2%, compared to 10.6% for CO-BSIs, with an average yearly increase per 100,000 hospital admissions of 2 and 5% respectively. The proportion of patients with one or more comorbidities, increased from 20.8 to 55.3%. In multivariate analyses, risk factors for mortality within 30 days were: HA-BSI (2.22); two or more comorbidities (1.89); single comorbidity (1.56); CO-BSI (1.21); male (1.05); and high age (1.04).Conclusion: this survey revealed an alarming increase in the incidence of BSI over the 14-year study period. Interventions to decrease BSI in general should be considered together with robust antibiotic stewardship programmes to avoid both over- and underuse of antibiotics.
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| 6. |
- Hällgren, Anita, et al.
(author)
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Frequency of aggregation substance, cytolysin and enterococcal surface protein in vitro adhesion to urinary catheters of E. faecalis and E. faecium of clinical origin
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Other publication (other academic/artistic)abstract
- Enterococcal isolates, 21 E. faecium and 94 E. faecalis, isolated from blood cultures, rectal specimens and various other clinical samples were examined for the presence of the virulence factors hemolysin/cytolysin, aggregation substance (asa1) and enterococcal surface protein (esp). The isolates were previously characterized by pulsed-field gel electrophoresis (PFGE). Adhesion to siliconized latex urinary catheters was analysed in 14 clinical isolates and 3 control strains. Densities of adhering bacteria were determined by a bioluminescence assay of bacterial ATP. The only virulence factor found in E. faecium, esp, was found in 71% of the 21 E. faceium isolates. Cytolysin production, asa1 and esp were found in 13%, 79% and 73%, respectively, of the 94 E. faecalis isolates. Isolates belonging to a cluster of genetically related isolates differed significantly with respect to carriage of esp and asa1 compared to unique isolates, with the virulence factors more commonly found among clustered isolates (p<0.01). No difference was found with respect to cytolysio production (p = 0.76). E. faecalis isolates adhered with higher bacterial densities than E. faecium. E. faecalis isolates within the same PFGE cluster adhered with similar bacterial densities, but there was no association between adhesion and the presence of esp when isolates within the same cluster were compared (p = 0.38 and 0.64).
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| 7. |
- Hällgren, Anita, et al.
(author)
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Molecular detection of aggregation substance, enterococcal surface protein, and cytolysin genes and in vitro adhesion to urinary catheters of Enterococcus faecalis and E. faecium of clinical origin
- 2009
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In: International Journal of Medical Microbiology. - : Elsevier BV. - 1438-4221 .- 1618-0607. ; 299:5, s. 323-332
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Journal article (peer-reviewed)abstract
- It has been hypothesized that nosocomial enterococci might have virulence factors that enhance their ability to colonise hospitalised patients. The objectives of this study were to investigate the prevalence of genes encoding 3 virulence factors: aggregation substance (asa1), enterococcal surface protein (esp), and 5 genes within the cytolysin operon (cylA, cylB, cylM, cylL(L), cylL(S)) and cytolysin production in 115 enterococcal clinical isolates (21 Enterococcus faecium and 94 E. faecalis). Adhesion to siliconized latex urinary catheters in relation to presence of esp was analysed in a subset of isolates. The isolates were previously characterised by pulsed-field gel electrophoresis (PFGE). esp was the only virulence gene found in E. faecium. It was found in 71% of the 21 E. faecium isolates. asa1, esp, and the cyl operon were found in 79%, 73% and 13% respectively, of the 94 E. faecalis isolates. There was a complete agreement between presence of the cyl operon and phenotypic cytolysin production. Isolates belonging to a cluster of genetically related isolates carried esp and asa1 more often when compared to unique isolates. No difference was found with respect to cyl genes. E. faecalis isolates adhered with higher bacterial densities than E. faecium. E. faecalis isolates within the same PFGE cluster adhered with similar bacterial densities, but there was no association between adhesion and the presence of esp when isolates within the same cluster were compared. In conclusion, E. faecalis isolates with high-level gentamicin resistance (HLGR) belonging to clusters of genetically related isolates widely distributed in Swedish hospitals, were likely to carry both esp and asa1. Adhesion was not affected by esp.
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