| 1. |
- Eberhard, Thomas, et al.
(författare)
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Interaction of vitronectin with Haemophilus influenzae
- 2002
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 34:3, s. 215-219
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Tidskriftsartikel (refereegranskat)abstract
- Eight strains of Haemophilus influenzae were tested for binding to human vitronectin. All strains adhered to vitronectin-coated glass slides but no binding was detected using soluble vitronectin, suggesting that surface association of vitronectin is a prerequisite. Vitronectin binding was not likely to be mediated by fimbriae as non-fimbriated and fimbriated isogenic strains adhered equally. Adhesion could be blocked by heparin, which is also known to block vitronectin binding to Staphylococcus aureus. However, no blocking was achieved with sialic acid-rich glycoproteins such as fetuin and mucin contrasting with Helicobacter pylori for which sialic acid seems to play an important role. With Streptococcus pneumoniae binding was detected both with soluble and surface-associated vitronectin and could not be blocked by heparin. Our results suggest that H. influenzae, Streptococcus pneumoniae and Helicobacter pylori all use distinct modes to interact with vitronectin.
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| 2. |
- Eriksson, Ronnie, et al.
(författare)
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Multiplex and quantifiable detection of nucleic acid from pathogenic fungi using padlock probes, generic real time PCR and specific suspension array readout
- 2009
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Ingår i: Journal of Microbiological Methods. - : Elsevier BV. - 0167-7012 .- 1872-8359. ; 78:2, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- A new concept for multiplex detection and quantification of microbes is here demonstrated on a range of infectious fungal species. Padlock probe methodology in conjunction with qPCR and Luminex technology was used for simultaneous detection of ten fungal species in one single experiment. By combining the multiplexing properties of padlock probes and Luminex detection with the well established quantitative characteristics of qPCR, quantitative microbe detection was done in 10-plex mode. A padlock probe is an oligonucleotide that via a ligation reaction forms circular DNA when hybridizing to specific target DNA. The region of the padlock probe that does not participate in target DNA hybridization contains generic primer sequences for amplification and a tag sequence for Luminex detection. This was the fundament for well performing multiplexing. Circularized padlock probes were initially amplified by rolling circle amplification (RCA), followed by a SybrGreen real time PCR which allowed an additive quantitative assessment of target DNA in the sample. Detection and quantification of amplified padlock probes were then done on color coded Luminex microspheres carrying anti-tag sequences. A novel technique, using labeled oligonucleotides to prevent reannealing of amplimers by covering the flanks of the address sequence, improved the signal to noise ratio in the detection step considerably. The method correctly detected fungi in a variety of clinical samples and offered quantitative information on fungal nucleic acid.
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| 3. |
- Fraenkel, Carl-Johan, et al.
(författare)
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In vitro activities of three carbapenems against recent bacterial isolates from severely ill patients at Swedish hospitals
- 2006
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 38:10, s. 853-859
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Tidskriftsartikel (refereegranskat)abstract
- To study the in vitro activity of imipenem, meropenem and ertapenem against common pathogens isolated from patients in intensive care, haematology and dialysis/nephrology units at 7 Swedish university hospitals, a total of 788 isolates were collected during 2002-2003. The distribution of the isolates was as follows: Escherichia coli (n = 140), Klebsiella spp. (n = 132), Proteus spp. (n = 97), Enterobacter spp. (n = 113), Pseudomonas aeruginosa (n = 126), Acinetobacter spp. (n = 53) and Enterococcus faecalis (n = 127). The susceptibility to the 3 carbapenems was determined by E-test, and the MICs were interpreted according to SRGA criteria. All 3 carbapenems were highly active against Enterobacteriaceae. The overall susceptibility to imipenem, meropenem and ertapenem was 90%, 98% and 93%, respectively. Against Enterobacteriaceae, Enterobacter spp. excluded, ertapenem had an equal or lower MIC(90) than meropenem. Apart from being the most active carbapenem against Enterobacteriaceae, meropenem was also the most active carbapenem against P. aeruginosa, whereas imipenem was the most active drug against Acinetobacter spp. The carbapenems are still potent antibiotics. With the introduction of ertapenem, and an expected increase in the carbapenem consumption due to an increased prevalence of strains with extended-spectrum beta-lactamases, continuous surveillance of carbapenem resistance appears to be warranted, with special attention to P. aeruginosa, Enterobacter and Proteus spp.
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| 4. |
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| 5. |
- Innings, Åsa, et al.
(författare)
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Multiplex real-time PCR targeting the RNase P RNA gene for detection and identification of Candida species in blood
- 2007
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 45:3, s. 874-880
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a single-tube multiplex real-time PCR method for the detection of the eight most common Candida species causing septicemia: Candida albicans, C. dubliniensis, C. famata, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis. The method developed targets the RNase P RNA gene RPR1. Sequences of this geiie were determined for seven of the Candida species and showed surprisiRgly large sequence variation. C. glabrata was found to have a gene that was five times longer gene than those of the other species, and the nucleotide sequence similarity between C. krusei and C. albicans was as low as 55%. The multiplex PCR contained three probes that enabled the specific detection of C. albicans, C. glabrata, and C. krusei and a fourth probe that allowed the general detection of the remaining species. The method was able to detect 1 to 10 genome copies when the detection limit was tested repeatedly for the four species C. albicans, C. glabrata, C. krusei, and C. guilliermondii. No significant difference in the detection limit was seen when the multiplex format was compared with single-species PCR, i.e., two primers and one probe. The method detected eight clinically relevant Candida species and did not react with other tested non-Candida species or human DNA. The assay was applied to 20 blood samples from nine patients and showed a sensitivity similar to that of culture.
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| 6. |
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| 7. |
- Krifors, Anders, et al.
(författare)
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Combining T2Bacteria and T2Candida Panels for Diagnosing Intra-Abdominal Infections : A Prospective Multicenter Study
- 2022
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Ingår i: JOURNAL OF FUNGI. - : MDPI. - 2309-608X. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- The T2Bacteria panel is a direct-from-blood assay that delivers rapid results, targeting E. coli, S. aureus, K. pneumoniae, A. baumanii, P. aeruginosa, and E. faecium (ESKAPE pathogens). In this study, T2Bacteria and T2Candida (targeting C. albicans/C. tropicalis, C. glabrata/C. krusei, and C. parapsilosis) were evaluated in parallel with blood cultures in 101 consecutive surgical patients with suspected intra-abdominal infection admitted to the intensive care unit or high dependency unit. Fifteen patients had bacteremia, with T2Bacteria correctly identifying all on-panel (n = 8) pathogens. T2Bacteria was positive in 19 additional patients, 11 of whom had supportive cultures from other normally sterile sites (newly inserted drains, perioperative cultures or blood cultures) within seven days. Six of these eleven patients (55%) received broad-spectrum antibiotics at the sampling time. T2Candida identified the two cases of blood-culture-positive candidemia and was positive in seven additional patients, three of whom were confirmed to have intra-abdominal candidiasis. Of four patients with concurrent T2Bacteria and T2Candida positivity, only one patient had positive blood cultures (candidemia), while three out of four patients had supporting microbiological evidence of a mixed infection. T2Bacteria and T2Candida were fast and accurate in diagnosing on-panel bloodstream infections, and T2Bacteria was able to detect culture-negative intra-abdominal infections.
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| 8. |
- Strålin, Kristoffer, et al.
(författare)
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Performance of PCR/electrospray ionization-mass spectrometry on whole blood for detection of bloodstream microorganisms in patients with suspected sepsis
- 2020
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Ingår i: Journal of Clinical Microbiology. - : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 58:9, s. e01860-19
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Tidskriftsartikel (refereegranskat)abstract
- Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the USA (n=13) and Europe (n=3). First, on 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true positive and 97.2% true negative results. Secondly, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC+/PCR/ESI-MS-, 4.3%; BC+/PCR/ESI-MS+, 10.3%; BC-/PCR/ESI-MS+, 15.3%; and BC-/PCR/ESI-MS-, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were > 94% for all individual species. Patients treated with prior antimicrobial medications (n=603) had significantly increased PCR/ESI-MS positivity rates compared with patients without prior antimicrobial treatment, 31% vs 22% (p<0.0001), with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics on whole blood for detection of bloodstream microorganisms in sepsis.
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| 9. |
- Tängdén, Thomas, et al.
(författare)
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Neurosurgical Gram-Negative Bacillary Ventriculitis and Meningitis : A Retrospective Study Evaluating the Efficacy of Intraventricular Gentamicin Therapy in 31 Consecutive Cases
- 2011
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 52:11, s. 1310-1316
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Tidskriftsartikel (refereegranskat)abstract
- Background. Gram-negative bacillary (GNB) ventriculitis and meningitis are rare but serious complications after neurosurgery. Prospective studies on antibiotic treatment for these infections are lacking, and retrospective reports are sparse. At our hospital in Uppsala, Sweden, meropenem has been recommended as empirical therapy since 1996, with the addition of intraventricular gentamicin in cases that do not respond satisfactorily to treatment. In this study, we retrospectively compare the efficacy of combination treatment with intraventricular gentamicin to that of systemic antibiotics alone. In addition, we report our experience of meropenem for the treatment of GNB ventriculomeningitis. Methods. Adult consecutive patients with gram-negative bacteria isolated from cerebrospinal fluid during a 10-year period and with postneurosurgical GNB ventriculitis or meningitis were included retrospectively. Data were abstracted from the medical records. Results. Thirty-one patients with neurosurgical GNB ventriculitis or meningitis and follow-up for 3 months were identified. The main intravenous therapies were meropenem (n = 24), cefotaxime (n = 3), ceftazidime (n = 2), imipenem (n = 1), and trimethoprim-sulfamethoxazole (n = 1). Thirteen patients were given combination treatment with appropriate intraventricular gentamicin. These patients had a higher cure rate and a lower relapse rate than did those treated with intravenous antibiotics alone (P = .03). Relapse occurred in 0 of 13 patients treated intraventricularly and in 6 of 18 patients treated with systemic antibiotics alone. The mortality rate was 19%; 3 patients in each group died, but in no case was death considered to be attributable to meningitis. Conclusions. Our results support combination treatment with intraventricular gentamicin for postneurosurgical GNB ventriculomeningitis. Meropenem seems to be an effective and safe alternative for the systemic antibiotic treatment of these neurointensive care infections.
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