liu.seSearch for publications in DiVA
Change search
Refine search result
1 - 26 of 26
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Berglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Hoang, Ngoc Thi Bich
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Le, Ngai Kien
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Khu, Dung Thi Khanh
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Nilsson, Lennart E.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Olson, Linus
    The Karolinska Institute, Stockholm, Sweden.
    Le, Hai Thanh
    National Hospital of Pediatrics, Hanoi, Vietnam.
    Larsson, Mattias
    The Karolinska Institute, Stockholm, Sweden.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Colistin- and carbapenem-resistant Klebsiella pneumoniae carrying mcr-1 and bla(OXA-48) isolated at a paediatric hospital in Vietnam2018In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 73, no 4, p. 1100-1102Article in journal (Other academic)
    Abstract [en]

    n/a

  • 2.
    Bonnedahl, Jonas
    et al.
    Department of Medical Sciences/Section of Infectious Diseases, Uppsala University, Uppsala, Sweden; Clinical Microbiology, Kalmar County Hospital, Kalmar, Sweden.
    Drobni, P.
    Clinical Microbiology, Central Hospital, Växjö, Sweden.
    Johansson, A.
    Department of Clinical Microbiology/Section of Infectious Diseases, Umeå University, Umeå, Sweden.
    Hernandez, Jorge
    Department of Medical Sciences/Section of Infectious Diseases, Uppsala University, Uppsala, Sweden; Department of Natural Sciences/Section of Zoonotic Ecology and Epidemiology, Linnaeus University, Kalmar, Sweden.
    Melhus, Åsa
    Department of Medical Sciences/Section of Clinical Bacteriology, Uppsala University, Uppsala, Sweden.
    Stedt, J.
    Department of Natural Sciences/Section of Zoonotic Ecology and Epidemiology, Linnaeus University, SE-39182 Kalmar, Sweden.
    Olsen, Björn
    Department of Medical Sciences/Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
    Drobni, Mirva
    Department of Medical Sciences/Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
    Characterization, and comparison, of human clinical and black-headed gull (Larus ridibundus) extended-spectrum β-lactamase-producing bacterial isolates from Kalmar, on the southeast coast of Sweden2010In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 65, no 9, p. 1939-1944Article in journal (Refereed)
    Abstract [en]

    Antibiotic resistance is one of the great challenges for modern healthcare. In Gram-negative bacteria, CTX-M-type extended-spectrum beta-lactamases (ESBLs) have been rapidly spreading through Europe since the early 2000s. In Sweden, ESBL-producing Escherichia coli are still rare, but a 3-fold increase has been seen from 2004 to 2007. Enterobacteria and normal flora of wild animals, with or without antibiotic resistance traits, constitute a potential source of human infection and colonization. We studied wild birds with the aim to understand the environmental dissemination of antibiotic resistance and, focusing on clinically relevant resistance types, we made comparisons with human clinical samples. In this study, ESBL-producing human clinical isolates and isolates from juvenile black-headed gulls from Kalmar County hospital and the city of Kalmar, respectively, on the southeast coast of Sweden, were characterized and compared. Despite a low frequency of antibiotic resistance among the isolates from gulls, ESBL-producing E. coli isolates were found, two with bla(CTX-M-14) and one with bla(CTX-M-15). The same CTX-M types were dominant among human ESBL isolates. In addition, gull isolates were dispersed among the human samples in the PhenePlate (TM) clustering system, indicating that they neither differ from the human isolates nor form any separate clonal clustering. The finding of CTX-M-type ESBLs in E. coli isolated from black-headed gulls in Sweden, where 'background resistance' is low, is consistent with an ongoing environmental spread of these plasmid-borne resistance genes. The results indicate that a potential for transfer between the human population and environment exists even in countries with a low level of antibiotic resistance.

  • 3.
    Ekelund, Oskar
    et al.
    Vaxjo Cent Hosp, Sweden; Blekinge Cty Hosp, Sweden.
    Hetland, Marit Andrea Klokkhammer
    Stavanger Univ Hosp, Norway; Univ Bergen, Norway.
    Löhr, Iren Hoyland
    Stavanger Univ Hosp, Norway.
    Schön, Thomas
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Medicine Center, Department of Infectious Diseases. Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden.
    Somajo, Sofia
    Blekinge Cty Hosp, Sweden.
    Rapid high-resolution detection of colistin resistance in Gram-negative bacteria using flow cytometry: a comparison with broth microdilution, a commercial screening test and WGS2021In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 76, no 12, p. 3183-3191Article in journal (Refereed)
    Abstract [en]

    Background: Even though both EUCAST and CLSI consider broth microdilution (BMD) as the reference method for antimicrobial susceptibility testing (AST) of colistin, the method exhibits potential flaws related to properties of the colistin molecule. Objectives: To develop a flow cytometry method (FCM) for colistin AST and to validate it against BMD, a commercial screening test and WGS. Methods: Colistin-mediated loss of membrane integrity in Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter spp. was detected with the fluorescent probe YoPro-1 by FCM. An international collection of 65 resistant and 109 susceptible isolates were analysed and the colistin concentration required to reach the EC50 was compared with the BMD MIC and the presence of genotypic resistance markers. Results: The overall FCM sensitivity and specificity for colistin resistance was 89% and 94%, with E. coli>K. pneumoniae>P. aeruginosa, whereas the performance for Acinetobacter spp. was poor. All tested E. coli were correctly categorized. Three K. pneumoniae isolates with genotypic findings consistent with colistin resistance were detected by FCM but not BMD. Compared with BMD, FCM delivered AST results with a 75% reduction of time. Conclusions: Here, we present a rapid FCM-based AST assay for qualitative and quantitative testing of colistin resistance in E. coli and K. pneumoniae. The assay revealed probable chromosomal colistin resistance in K. pneumoniae that was not detected by BMD. If confirmed, these results question the reliability of BMD for colistin testing.

    Download full text (pdf)
    fulltext
  • 4.
    Falk, Lars
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care. Linköping University, Faculty of Medicine and Health Sciences.
    Enger, Martin
    Vastervik Hosp, Vastervik, Sweden.
    Jensen, Jorgen Skov
    Statens Serum Institut Köpenhamn.
    Time to eradication of Mycoplasma genitalium after antibiotic treatment in men and women.2015In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 70, no 11, p. 3134-3140Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES:

    The objectives of this study were to evaluate the time to a Mycoplasma genitalium-negative test after start of treatment and to monitor if and when antibiotic resistance developed.

    METHODS:

    Sexually transmitted disease (STD) clinic attendees with suspected or verified M. genitalium infection were treated with azithromycin (5 days, 1.5 g; n = 85) or moxifloxacin (n = 5). Subjects with symptomatic urethritis or cervicitis of unknown aetiology were randomized to either doxycycline (n = 49) or 1 g of azithromycin as a single dose (n = 51). Women collected vaginal specimens and men collected first-catch urine 12 times during 4 weeks. Specimens were tested for M. genitalium with a quantitative MgPa PCR and for macrolide resistance-mediating mutations with a PCR targeting 23S rRNA.

    CLINICAL TRIALS REGISTRATION:

    NCT01661985.

    RESULTS:

    Ninety M. genitalium cases were enrolled. Of 56 patients with macrolide-susceptible strains before treatment with azithromycin (1.5 g, n = 46; 1 g single oral dose, n = 10), 54 (96%) had a negative PCR test within 8 days. In four patients, M. genitalium converted from macrolide susceptible to resistant after a 10 day lag time with negative tests (azithromycin 1.5 g, n = 3; 1 g single oral dose, n = 1). Moxifloxacin-treated subjects (n = 4) were PCR negative within 1 week. Six of eight (75%) remained positive despite doxycycline treatment.

    CONCLUSIONS:

    PCR for M. genitalium rapidly became negative after azithromycin treatment. Macrolide-resistant strains were detected after initially negative tests. Test of cure should be recommended no earlier than 3-4 weeks.

  • 5.
    Falk, Lars
    et al.
    Region Östergötland, Heart and Medicine Center, Department of Dermatology and Venerology. Region Östergötland, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care. Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Skov Jensen, Jorgen
    Microbiology and Infection Control, Sexually Transmitted Infections, Research and Development, Statens Serum Institut, Copenhagen, Denmark.
    Successful outcome of macrolide-resistant Mycoplasma genitalium urethritis after spectinomycin treatment: a case report2017In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 72, no 2, p. 624-625Article in journal (Refereed)
  • 6.
    Hanberger, Håkan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Östergötlands Läns Landsting, Centre for Medicine, Department of Infectious Diseases in Östergötland.
    Nilsson, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment.
    Claesson, B
    Kärnell, A
    Larsson, P
    Rylander, M
    Svensson, E
    Linköping University, Faculty of Health Sciences. Linköping University, Department of health and environment. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Microbiology.
    Sörberg, M
    Sörén, L
    New species-related MIC breakpoints for early detection of development of resistance among Gram-negative bacteria in Swedish intensive care units. 1999In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 44, p. 611-619Article in journal (Refereed)
  • 7.
    Hällgren, Anita
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Abednazari, Hossein
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Ekdahl, Christer
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Samuelsson, Annika
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Antimicrobial susceptibility patterns of enterococci in intensive care units in Sweden evaluated by different MIC breakpoint systems2001In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 48, no 1, p. 53-62Article in journal (Refereed)
    Abstract [en]

    Three hundred and twenty-two (322) clinical isolates were collected from patients admitted to intensive care units (ICUs) at eight Swedish hospitals between December 1996 and December 1998. Of the isolates, 244 (76%) were Enterococcus faecalis, 74 (23%) were Enterococcus faecium and four (1%) were other Enterococcus spp. MICs of ampicillin, imipenem, meropenem, piperacillin/tazobactam, ciprofloxacin, trovafloxacin, clinafloxacin, gentamicin, streptomycin, vancomycin, teicoplanin, quinupristin/dalfopristin, linezolid and evernimicin were determined by Etest. Susceptible and resistant isolates were defined according to the species-related MIC breakpoints of the British Society for Antimicrobial Chemotherapy (BSAC), the National Committee for Clinical Laboratory Standards (NCCLS) and the Swedish Reference Group for Antibiotics (SRGA). Tentative breakpoints were applied for new/experimental antibiotics. Multidrug resistance among enterococci in ICUs is not uncommon in Sweden, particularly among E. faecium, and includes ampicillin resistance and concomitant resistance to fluoroquinolones. Almost 20% of E. faecalis isolates showed high-level resistance to gentamicin and concomitant resistance to fluoroquinolones. Vancomycin-resistant enterococci were only found sporadically. Among the new antimicrobial agents, linezolid and evernimicin showed the best activity against all enterococcal isolates. There was good concordance between the BSAC, NCCLS and SRGA breakpoints in detecting resistance. When applying the SRGA breakpoints for susceptibility, isolates were more frequently interpreted as intermediate. This might indicate earlier detection of emerging resistance using the SRGA breakpoint when the native population is considered susceptible, but with the risk that isolates belonging to the native susceptible population will be incorrectly interpreted as intermediate.

  • 8.
    Hällgren, Anita
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Saeedi, Baharak
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Monstein, Hans-Jürg
    Linköping University, Department of Biomedicine and Surgery. Linköping University, Faculty of Health Sciences.
    Isaksson, Barbro
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart
    Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Genetic relatedness among Enterococcus faecalis with transposon-mediated high-level gentamicin resistance in Swedish intensive care units2003In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 52, no 2, p. 162-167Article in journal (Refereed)
    Abstract [en]

    We studied 45 isolates of Enterococcus faecalis with high-level gentamicin resistance (HLGR), all but one concomitantly resistant to ciprofloxacin, and 25 ciprofloxacin-resistant isolates without HLGR for genetic relatedness using pulsed-field gel electrophoresis (PFGE). E. faecalis were isolated from patients admitted to intensive care units at eight hospitals in southern Sweden from December 1996 through December 1998. Genomic analysis by PFGE resulted in three clusters of genetically related isolates (designated clusters I, II and III) and 23 unique clones. Cluster I was found predominantly in the eastern and central parts of southern Sweden and clusters II and III in south-western Sweden. Among the 45 isolates with HLGR, 69% belonged to cluster I, 20% to cluster II, and 11% had unique PFGE patterns, which suggests that the majority of isolates with HLGR are closely related. Among the 25 ciprofloxacin-resistant isolates without HLGR, 68% had unique PFGE patterns, 12% belonged to cluster I and 20% to cluster III, which suggests the ciprofloxacin-resistant isolates are not related. All isolates with HLGR contained the aac(6)Ie-aph(2)Ia gene, which was carried on a Tn5281-like transposon in all isolates except one. We conclude that HLGR in E. faecalis was mainly due to dissemination of genetically related clones during the time studied, and that HLGR in these isolates was due to the presence of the aac(6)Ie-aph(2)Ia gene.

  • 9.
    Isaksson, Barbro
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Maller, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Synergic post-antibiotic effect of amikacin in combination with beta-lactam antibiotics on gram-negative bacteria.1991In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 28, no 1, p. 25-34Article in journal (Refereed)
    Abstract [en]

    The post-antibiotic effect (PAE) of amikacin alone and in combination with ceftazidime, ceftriaxone and piperacillin was studied for two strains each of Pseudomonas aeruginosa and Serratia marcescens using a bioluminescent assay of bacterial ATP. Two models were used for combining beta-lactam antibiotics and amikacin: in one model the cultures were incubated with 32 mg/L of ceftazidime, 128 mg/L of ceftriaxone or 32 mg/L of piperacillin for 1 h. Different concentrations of amikacin (0.5-64 mg/L) were then added. Incubation of the combinations continued for one more hour. The antibiotics were eliminated by dilution. In the second model tested, one strain of S. marcescens was simultaneously exposed to amikacin and a beta-lactam antibiotic for 2 h. The PAEs produced by the drugs in combination were longer than the sum of the individual effects of the drugs when they were used alone. Results were equally good with both models. A synergic PAE was also found with amikacin concentrations close to the MIC in combination with low concentrations of ceftazidime, ceftriaxone and piperacillin.

  • 10.
    Isaksson, Barbro
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Maller, Rolf
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Synergistic post-antibiotic effect of amikacin and beta-lactam antibiotics on Enterococcus faecalis.1991In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 27, p. 9-14Article in journal (Refereed)
    Abstract [en]

    The in-vitro post-antibiotic effect (PAE) of amikacin alone and in combination with ceftazidime, ceftriaxone and piperacillin was studied for two strains of Enterococcus faecalis using a bioluminescent assay of bacterial ATP. The two strains of E. faecalis were resistant to amikacin, ceftazidime and ceftriaxone but sensitive to piperacillin. The bacterial cultures were incubated with the beta-lactam antibiotics for 1 h and concentrations of amikacin between 2-64 mg/l were then added. Thereafter, incubation continued with the combinations for one more hour. After dilution, regrowth was monitored by measuring bacterial ATP every hour. Increasing concentrations of amikacin (2-64 mg/l), ceftazidime (8-32 mg/l) and ceftriaxone (32-128 mg/l) resulted in little or no PAE (0-0.3 h) on these strains. PAEs of 0.5 to 1.6 h resulted from exposure to piperacillin (4-32 mg/l). In combination amikacin and piperacillin increased the PAE to 5.5 h. A synergistic PAE was also seen when the enterococci were exposed to amikacin combined with ceftazidime or ceftriaxone in concentrations close to the MICs of the latter antibiotics.

  • 11.
    Isaksson, Barbro
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Maller, Rolf
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Postantibiotic effect of aminoglycosides on staphylococci.1993In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 32, no 2, p. 215-222Article in journal (Refereed)
    Abstract [en]

    The postantibiotic effects (PAEs) of amikacin, gentamicin, netilmicin and tobramycin on Staphylococcus aureus and S. epidermidis were determined in vitro by a bioluminescence assay of bacterial ATP. Five strains of S. aureus and two strains of S. epidermidis were exposed for 1 h to varying concentrations of these aminoglycosides. Following removal of the antibiotics by dilution, bacterial regrowth was monitored at hourly intervals. The duration of the PAE increased with increasing aminoglycoside concentration. The mean PAEs for the five S. aureus strains ranged from 5-10 h at clinically achievable aminoglycoside concentrations (16-32 mg/L of amikacin and 4-8 mg/L of gentamicin, netilmicin and tobramycin). The results for one of the strains of S. epidermidis were similar to those observed for the S. aureus strains, while the PAEs on the other less susceptible S. epidermidis strain were shorter (0.5-2.5 h). For comparison, two of the S. aureus strains were exposed for 1 and 2 h to a range of concentrations of dicloxacillin (0.25-32 mg/L); this agent induced a much shorter PAE (0-2.3 h). It may be important to take account of the PAE when designing dosing regimens.

  • 12.
    Isaksson, Barbro
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Maller, Rolf
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Sörén, Lars
    Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Postantibiotic effect of aminoglycosides on gram-negative bacteria evaluated by a new method.1988In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 22, no 1, p. 23-33Article in journal (Refereed)
    Abstract [en]

    The in-vitro postantibiotic effect (PAE) of amikacin, gentamicin, netilmicin and tobramycin was investigated by a bioluminescent assay of bacterial ATP. Two strains each of Escherichia coli and Pseudomonas aeruginosa were exposed for 1 h to different concentrations of the aminoglycosides. The aminoglycoside was removed by a 10(-3) dilution, and regrowth of bacteria was followed at hourly intervals by monitoring bacterial ATP. This method simplified the PAE studies and made such studies possible at high aminoglycoside concentrations. The length of the PAE was dose-dependent for all the aminoglycosides studied. The PAEs ranged between three and seven hours for all four strains at the aminoglycoside concentrations normally reached in serum during standard dosing. The long PAE of aminoglycosides, especially after exposure to high drug concentrations, constitutes an argument in favour of administering aminoglycosides in higher-than-usual doses with longer intervals between doses. This proposal is also supported by recent pharmacokinetic, bacteriological and toxicity data.

  • 13. Kronvall, Göran
    et al.
    Karlsson, Inga
    Walder, Mats
    Sörberg, Mikael
    Nilsson, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Clinical Microbiology.
    Epidemiological MIC cut-off values for tigecycline calculated from Etest MIC values using normalized resistance interpretation2006In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 57, no 3, p. 498-505Article in journal (Refereed)
    Abstract [en]

    Objectives: To apply the normalized resistance interpretation (NRI) method to Etest MIC results which have higher precision than conventional log2 dilution MIC tests due to the inclusion of intermediate values. If successful, NRI might provide an objective tool for the definition of epidemiological MIC cut-off values. Methods: MICs of tigecycline and other antimicrobial agents were determined for 4771 clinical isolates comprising five Gram-positive and 13 Gram-negative species or species groups using the Etest. Histograms of MIC values were constructed for each species and NRI calculations were applied to them. An upper MIC limit of 2.5 SD above the theoretical mean of the normalized distribution was used for setting the epidemiological cut-off values. Results: Calculated cut-off values for wild-type strains were between 0.11 and 0.96 mg/L for Gram-positive species, and between 0.44 and 8.3 mg/L for Gram-negative species, except for Pseudomonas aeruginosa, which had a cut-off value of 450 mg/L, consistent with earlier reports on the lack of activity of tigecycline against this species. Conclusions: NRI offers an objective method for the analysis of MICs produced using Etests and the determination of epidemiological MIC cut-off values. © The Author 2006. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

  • 14.
    Li, Jiyun
    et al.
    China Agr Univ, Peoples R China.
    Hulth, Anette
    Publ Hlth Agcy Sweden, Sweden.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Borjesson, Stefan
    Natl Vet Inst SVA, Sweden.
    Chen, Baoli
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Bi, Zhenwang
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Wang, Yang
    China Agr Univ, Peoples R China.
    Schwarz, Stefan
    China Agr Univ, Peoples R China; Free Univ Berlin, Germany.
    Wu, Congming
    China Agr Univ, Peoples R China.
    Letter: Occurrence of the mobile colistin resistance gene mcr-3 in Escherichia coli from household pigs in rural areas in JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY, vol 73, issue 6, pp 1721-17232018In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 73, no 6, p. 1721-1723Article in journal (Other academic)
    Abstract [en]

    n/a

  • 15.
    Liakopoulos, Apostolos
    et al.
    Department of Bacteriology and Epidemiology, CVI of Wageningen University, Lelystad, The Netherlands.
    Mevius, Dik J.
    Department of Bacteriology and Epidemiology, CVI of Wageningen University, Lelystad, The Netherlands; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
    Olsen, Björn
    Section of Clinical Microbiology and Infectious Diseases, Department of Medical Sciences, Uppsala University, Uppsala, Sweden; Zoonosis Science Center, IMBIM, Uppsala University, Uppsala, Sweden.
    Bonnedahl, Jonas
    Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden.
    The colistin resistance mcr-1 gene is going wild2016In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 71, no 8, p. 2335-2336Article in journal (Other academic)
  • 16.
    Lindstrom, Johan
    et al.
    Sahlgrens Univ Hosp, Sweden.
    Helldén, Anders
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Lycke, Jan
    Univ Gothenburg, Sweden.
    Grahn, Anna
    Sahlgrens Univ Hosp, Sweden.
    Studahl, Marie
    Univ Gothenburg, Sweden.
    An unexpectedly high occurrence of aciclovir-induced neuropsychiatric symptoms in patients treated for herpesvirus CNS infection: a prospective observational study2019In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 74, no 12, p. 3565-3572Article in journal (Refereed)
    Abstract [en]

    Background: Aciclovir is effective in herpesvirus infections of the CNS. Aciclovir-induced neuropsychiatric symptoms (AINS) have been reported and are associated with high CSF concentrations of aciclovir metabolite 9-carboxymethoxymethylguanine (CMMG). Risk factors except for renal failure have not been explored, and disruption of the blood-brain barrier (BBB) in acute CNS infection may be of interest. Objectives: To investigate the impact of risk factors on aciclovir and CMMG concentrations, and to relate the results to AINS. Methods: We investigated 21 consecutively included, consenting patients treated with aciclovir or valaciclovir for herpesvirus CNS infection. Regression models were constructed to study the impact of risk factors including BBB disruption, as measured with CSF:serum albumin ratio, on CSF aciclovir and CMMG concentrations. Medical records were assessed retrospectively to identify patients with AINS. Results: Increased CSF:serum albumin ratio, as well as decreased renal function and high aciclovir doses, was associated with increased aciclovir and CMMG concentrations in the CSF. We identified five patients with new neuropsychiatric symptoms; four of those were considered to have AINS and had increased CSF CMMG concentrations. Only one patient without suspicion of AINS had an increased CSF CMMG concentration. Conclusions: In patients with herpesvirus CNS infections, BBB disruption is associated with increasing aciclovir and CMMG CSF concentrations. We also found an unexpectedly high number of patients with AINS. Evaluation of CSF:serum albumin ratios, renal function and CSF concentrations of aciclovir and CMMG may all contribute to the optimization of aciclovir dosing and avoidance of AINS.

    Download full text (pdf)
    fulltext
  • 17.
    Ma, Shizhen
    et al.
    China Agr Univ, Peoples R China.
    Sun, Chengtao
    China Agr Univ, Peoples R China.
    Hulth, Anette
    Publ Hlth Agcy Sweden, Sweden; Karolinska Inst, Sweden.
    Li, Jiyun
    China Agr Univ, Peoples R China.
    Nilsson, Lennart E
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Zhou, Yuqing
    China Agr Univ, Peoples R China.
    Borjesson, Stefan
    Natl Vet Inst SVA, Sweden.
    Bi, Zhenwang
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Bi, Zhenqiang
    Shandong Ctr Dis Control and Prevent, Peoples R China.
    Sun, Qiang
    Shandong Univ, Peoples R China; Shandong Univ, Peoples R China.
    Wang, Yang
    China Agr Univ, Peoples R China.
    Mobile colistin resistance gene mcr-5 in porcine Aeromonas hydrophila2018In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 73, no 7, p. 1777-1780Article in journal (Refereed)
    Abstract [en]

    Objectives: To characterize the mobile colistin resistance gene mcr-5 in Aeromonas hydrophila from backyard pigs in rural areas of China. Methods: Pig faecal samples from 194 households were directly tested for the presence of mcr-5 by PCR assay and the phenotypic antimicrobial susceptibility profiles of the mcr-5-positive isolates were determined using the broth dilution method. The genomic location and transferability of mcr-5 were analysed by S1-PFGE with Southern blotting and DNA hybridization, and natural transformation, respectively. One strain isolated from an mcr-5-positive sample was subjected to WGS and the stability of the mcr-5-harbouring plasmid over successive generations was examined by subculturing. Results: One mcr-5-positive A. hydrophila isolate showing resistance, with a colistin MIC of 4 mg/L, was isolated from a backyard pig faecal sample. mcr-5 was located on a 7915 bp plasmid designated pI064-2, which could naturally transform into a colistin-susceptible A. hydrophila strain of porcine origin and mediated colistin resistance in both the original isolate and its transformants. The plasmid backbone (3790 bp) of pI064-2 showed 81% nucleotide sequence identity to the corresponding region of the ColE2-type plasmid pAsa1 from Aeromonas salmonicida, while similar replication primases are widely distributed among aeromonads, Enterobacteriaceae and Pseudomonas species. Conclusions: To the best of our knowledge, this is the first identification of the novel colistin resistance gene mcr-5 in an A. hydrophila isolate from the faeces of a backyard pig. mcr-5 is expected to be able to disseminate among different bacterial species and genera.

  • 18.
    Maller, Rolf
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Isaksson, Barbro
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Nilsson, L
    Sörén, L
    A study of amikacin given once versus twice daily in serious infections.1988In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 22, no 1, p. 75-79Article in journal (Refereed)
    Abstract [en]

    Forty-five mostly elderly patients with serious infections were treated in a prospective, comparative and randomized pharmacokinetic study with amikacin 11.0 or 15.0 mg/kg administered in a single daily dose as an intravenous, short-term infusion or with amikacin 7.5 mg/kg administered twice daily in the same way. The results indicate that administration of amikacin 15 mg/kg in a single daily dose should be a practical and safe principle of administration. However elderly patients often have reduced creatinine clearance and should preferably be given a lower dose of 11 mg/kg bw. The risk of nephrotoxicity did not increase, but conclusions on ototoxicity and clinical efficacy cannot be drawn from this limited study. This should be considered as an initial part of a future multicentre trial.

  • 19.
    Monnet, Dominique L
    et al.
    Köpenhamn.
    Mölstad, Sigvard
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, General Practice.
    Cars, Otto
    Uppsala sjukhus.
    Defined daily doses of antimicrobials reflect antimicrobial prescriptions in ambulatory care2004In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 53, p. 1109-1111Article in journal (Refereed)
  • 20.
    Montelin, Hanna
    et al.
    Uppsala Univ, Sweden.
    Camporeale, Angela
    Karolinska Inst, Sweden.
    Hallgren, Anna
    Uppsala Univ, Sweden.
    Angelin, Martin
    Umea Univ, Sweden; Danderyd Hosp, Sweden.
    Hogvall, Jonas
    Karlstad Cent Hosp, Sweden.
    Östholm, Åse
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Medicine Center, Department of Infectious Diseases.
    Vading, Malin
    Karolinska Inst, Sweden.
    Giske, Christian G.
    Karolinska Inst, Sweden; Karolinska Univ Hosp, Sweden.
    Tangden, Thomas
    Uppsala Univ, Sweden.
    Treatment, outcomes and characterization of pathogens in urinary tract infections caused by ESBL-producing Enterobacterales: a prospective multicentre study2024In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091Article in journal (Refereed)
    Abstract [en]

    Objectives: Treatment options for urinary tract infections (UTIs) caused by ESBL-producing Enterobacterales are limited. Moreover, evidence to support therapeutic decisions is lacking. This study assessed current treatment strategies and patient and pathogen characteristics in relation to clinical and microbiological outcomes.Methods: Patients with UTI caused by ESBL-producing Enterobacterales were prospectively recruited by investigators at 15 infectious disease hospital departments. Data were collected on patient characteristics, treatments, clinical and microbiological cure 10-14 days after the end of treatment, and relapse within 3 months. Bacterial isolates were subjected to MIC determination and WGS.Results: In total, 235 patients (107 febrile UTI, 128 lower UTI) caused by Escherichia coli (n = 223) and Klebsiella spp. (n = 12) were included. Clinical and microbiological cure rates were 83% and 64% in febrile UTI, and 79% and 65% in lower UTI. Great variability in treatments was observed, especially in oral therapy for febrile UTI. No difference was seen in clinical outcomes with piperacillin/tazobactam (n = 28) compared with carbapenems (n = 41). Pivmecillinam was frequently used in lower UTI (n = 62), and was also associated with high clinical cure rates when used as initial therapy (10/10) or follow-up (7/8) for febrile UTI. Recurrent infection, diabetes mellitus and urogenital disease were associated (P < 0.05) with clinical failure and relapse. In E. coli, ST131 was significantly associated with relapse, and haemolysin with microbiological failure or relapse.Conclusions: Antibiotic treatments were highly variable. Patient and pathogen factors were identified as potential determinants of disease presentation and outcomes and may prove useful to guide individualized treatment and follow-up.

  • 21.
    Niward, Katarina
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Davies Forsman, Lina
    Karolinska Inst, Sweden; Karolinska Univ Hosp Solna, Sweden.
    Bruchfeld, Judith
    Karolinska Inst, Sweden; Karolinska Univ Hosp Solna, Sweden.
    Chryssanthou, Erja
    Karolinska Univ Hosp Solna, Sweden; Karolinska Inst, Sweden.
    Carlström, Oskar
    Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Alomari, Teba
    Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Carlsson, Björn
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pharmacology.
    Pohanka, Anton
    Karolinska Univ Hosp Huddinge, Sweden.
    Mansjö, Mikael
    Publ Hlth Agcy Sweden, Sweden.
    Jonsson Nordvall, Michaela
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Johansson, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Eliasson, Erik
    Karolinska Univ Hosp Huddinge, Sweden.
    Werngren, Jim
    Publ Hlth Agcy Sweden, Sweden.
    Paues, Jakob
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Simonsson, Ulrika S. H.
    Uppsala Univ, Sweden.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Kalmar Cty Hosp, Sweden.
    Distribution of plasma concentrations of first-line anti-TB drugs and individual MICs: a prospective cohort study in a low endemic setting2018In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 73, no 10, p. 2838-2845Article in journal (Refereed)
    Abstract [en]

    Background: Therapeutic drug monitoring (TDM) could improve current TB treatment, but few studies have reported pharmacokinetic data together with MICs. Objectives: To investigate plasma concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol along with MICs. Methods: Drug concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol were analysed pre-dose and 2, 4 and 6 h after drug intake at week 2 in 31 TB patients and MICs in BACTEC 960 MGIT were determined at baseline. The highest plasma concentrations at 2, 4 and 6 h post-dose (C-high) were determined, as well as estimates of C-high/MIC and area under the concentration-time curve (AUC(0-6))/MIC including the corresponding ratios based on calculated free-drug concentrations. This trial was registered at www.clinicaltrials.gov (NCT02042261). Results: After 2 weeks of treatment, the median C-high values for rifampicin, isoniazid, pyrazinamide and ethambutol were 10.0, 5.3, 41.1 and 3.3 mg/L respectively. Lower than recommended drug concentrations were detected in 42% of the patients for rifampicin (amp;lt;8 mg/L), 19% for isoniazid (amp;lt;3 mg/L), 27% for pyrazinamide (amp;lt;35 mg/L) and 16% for ethambutol (amp;lt;2 mg/L). The median Chigh/MIC values for rifampicin, isoniazid, pyrazinamide and ethambutol were 164, 128, 1.3 and 2.5, respectively, whereas the AUC(0-6)/MIC was 636 (range 156-2759) for rifampicin and 351 (range 72-895) for isoniazid. Conclusions: We report low levels of first-line TB drugs in 16%-42% of patients, in particular for rifampicin. There was a wide distribution of the ratios between drug exposures and MICs. The future use of MIC determinations in TDM is dependent on the development of a reference method and clinically validated pharmacokinetic/pharmacodynamic targets.

  • 22.
    Niward, Katarina
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Ängeby, Kristian
    Karolinska University Hospital, Stockholm, Sweden. The University of the West Indies, Kingston, Jamaica.
    Chryssanthou, Erja
    Karolinska University Hospital, Stockholm, Karolinska Institute, Stockholm, Sweden..
    Paues, Jakob
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Infectious Diseases.
    Bruchfeld, Judith
    Karolinska University Hospital, Stockholm, Sweden Department of Medicine, Karolinska Institute, Solna, Sweden.
    Jureen, Pontus
    The Public Health Agency of Sweden, Stockholm, Sweden.
    Giske, Christian G
    Karolinska University Hospital, Stockholm, Karolinska Institute, Stockholm, Sweden.
    Kahlmeter, Gunnar
    Uppsala University, Uppsala, Sweden. Växjö Hospital, Växjö, Sweden.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Kalmar County Hospital, Kalmar.
    Susceptibility testing breakpoints for Mycobacterium tuberculosis categorize isolates with resistance mutations in gyrA as susceptible to fluoroquinolones: implications for MDR-TB treatment and the definition of XDR-TB.2016In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 71, no 2, p. 333-338Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: Fluoroquinolones (FQs) are important in the treatment of MDR-TB and in the definition of XDR-TB. Our objective was to investigate how discrepancies in the phenotypic and genotypic methods for antimicrobial susceptibility testing could affect the interpretation of antimicrobial susceptibility test results.

    METHODS: We analysed MICs of ofloxacin and levofloxacin in Middlebrook 7H10 broth (7H10) as well as sequencing of the quinolone resistance-determining region of the gyrA gene and the MTBDRsl assay in 75 resistant isolates, including MDR and XDR strains of Mycobacterium tuberculosis.

    RESULTS: Among 75 resistant isolates, 27 had mutations associated with FQ resistance. Among isolates with resistance mutations in gyrA, 26% (seven of 27) were susceptible to levofloxacin and ofloxacin by phenotypic testing at 1 mg/L and 2 mg/L. The most common mutation was in codon 94 and these isolates had significantly increased MICs of levofloxacin (2-8 mg/L) compared with isolates with mutations in codon 90 (0.25-2 mg/L, P < 0.05). The sensitivity and specificity for the MTBDRsl assay compared with gyrA sequencing were 96% and 98%, respectively.

    CONCLUSION: Current critical concentrations may classify up to 26% of isolates with gyrA mutations as susceptible to FQs due to a close relationship between susceptible and resistant populations. These results should be considered while improving clinical breakpoints for M. tuberculosis and may have an impact on the definition of XDR-TB.

  • 23.
    Schon, Thomas
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences. Kalmar County Hospital, Sweden .
    Jureen, P
    Swedish Institute Communicable Disease Control SMI, Sweden .
    Chryssanthou, E
    Karolinska University Hospital, Sweden .
    Giske, C G.
    Karolinska University Hospital, Sweden .
    Kahlmeter, G
    Vaxjo Hospital, Sweden .
    Hoffner, S
    Swedish Institute Communicable Disease Control SMI, Sweden .
    Angeby, K
    Karolinska University Hospital, Sweden .
    Rifampicin-resistant and rifabutin-susceptible Mycobacterium tuberculosis strains: a breakpoint artefact?2013In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 68, no 9, p. 2074-2077Article in journal (Refereed)
    Abstract [en]

    It has long been assumed that some rifampicin-resistant Mycobacterium tuberculosis strains are susceptible to, and thus treatable with, rifabutin. However, clinical breakpoints for susceptibility testing of rifabutin as well as the evidence for a clinical effect of rifabutin in rifampicin-resistant strains remains poorly defined. The objective of this study was to re-evaluate the breakpoint for rifabutin in relation to its MIC wild-type distribution and the presence of mutations in rpoB. less thanbrgreater than less thanbrgreater thanThe MIC in 7H10 Middlebrook medium was determined for clinical isolates of M. tuberculosis (n95), where a majority were multidrug resistant. Additionally, all strains were screened for rpoB mutations by sequencing and the GenoType MTBDRplus assay. less thanbrgreater than less thanbrgreater thanRifampicin resistance was confirmed by genotypical and/or phenotypical tests in 73 isolates (76.8). Nineteen isolates, defined as rifampicin resistant and rifabutin susceptible according to the present breakpoint, exhibited significantly higher MICs of rifabutin (0.0640.5 mg/L) than rifabutin-susceptible isolates without any detectable mutations in rpoB (P0.001). These 19 isolates were clearly resistant to rifampicin (MIC 2256 mg/L) and all but one had mutations in rpoB, with 9 (47.4) specifically in Asp516Val. less thanbrgreater than less thanbrgreater thanOur results indicate that rifampicin-resistant but rifabutin-susceptible isolates according to the present breakpoints harbour rpoB mutations and have a rifabutin MIC significantly higher than strains without any detectable mutations in rpoB. So far there are no clinical, pharmacological or microbiological data to confirm that such isolates can be treated with rifabutin and we suggest a revision of the current breakpoints.

  • 24.
    Åkerlund, Anna
    et al.
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology. Cty Hosp Ryhov, Sweden.
    Jonasson, Emma
    Cent Hosp Vaxjo, Sweden; EUCAST Dev Lab, Sweden.
    Matuschek, Erika
    EUCAST Dev Lab, Sweden.
    Serrander, Lena
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Sundqvist, Martin
    Orebro Univ, Sweden.
    Kahlmeter, Gunnar
    Cent Hosp Vaxjo, Sweden; EUCAST Dev Lab, Sweden.
    EUCAST rapid antimicrobial susceptibility testing (RAST) in blood cultures: validation in 55 European laboratories2020In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 75, no 11, p. 3230-3238Article in journal (Refereed)
    Abstract [en]

    Objectives: When bloodstream infections are caused by resistant bacteria, rapid antimicrobial susceptibility testing (RAST) is important for adjustment of therapy. The EUCAST RAST method, directly from positive blood cultures, was validated in a multi-Laboratory study in Europe. Methods: RAST was performed in 40 Laboratories in northern Europe (NE) and 15 in southern Europe (SE) from clinical blood cultures positive for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Categorical results at 4, 6 and 8 h of incubation were compared with results for EUCAST standard 16-20 h disc diffusion. The method, preliminary breakpoints and the performance of the Laboratories were evaluated. Results: The total number of isolates was 833/318 in NE/SE. The number of zone diameters that could be read (88%, 96% and 99%) and interpreted (70%, 81% and 85%) increased with incubation time (4, 6 and 8 h). The categorical agreement was acceptable, with total error rates in NE/SE of 2.4%/4.9% at 4 h, 1.1%/3.5% at 6 h and 1.1%/3.3% at 8 h. False susceptibility at 4, 6 and 8 h of incubation was below 0.3% and 1.1% in NE and SE, respectively, and the corresponding percentages for false resistance were below 1.9% and 2.8%. After fine-tuning breakpoints, more zones could be interpreted (73%, 89% and 93%), with only marginally affected error rates. Conclusions: The EUCAST RAST method can be implemented in routine Laboratories without major investments. It provides reliable antimicrobial susceptibility testing results for relevant bloodstream infection pathogens after 4-6 h of incubation.

    Download full text (pdf)
    fulltext
  • 25.
    Åkerlund, Anna
    et al.
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Serrander, Lena
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Microbiology.
    Sundqvist, Martin
    Orebro Univ, Sweden.
    Short incubation of disc diffusion for Streptococcus pneumoniae and Haemophilus influenzae to reduce time to susceptibility report2023In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 78, no 10, p. 2563-2571Article in journal (Refereed)
    Abstract [en]

    Background Rapidly instituted antimicrobial therapy is important in severe infections, and reduced time to the antimicrobial susceptibility testing (AST) report is thus of importance. Disc diffusion (DD) is a cheap, rapidly adaptable, flexible and comprehensive method for phenotypic AST. Previous studies have shown that early reading of inhibition zones for non-fastidious species is possible.Objectives To evaluate zone reading after short incubation of DD in Haemophilus influenzae (n = 73) and Streptococcus pneumoniae (n = 112).Methods The readability was evaluated and susceptibility interpretation (SIR) was performed, using the EUCAST 18 & PLUSMN; 2 h incubation breakpoint table (version 12.0), after 6 and 8 h of incubation. Categorical agreement (CA) and error rates were calculated using standard DD and broth microdilution as reference.Results The proportion of readable zones in H. influenzae was 19% (6 h) and 89% (8 h). The CA was 98% after 8 h. The corresponding readability in S. pneumoniae was 63%/98% and CA was 95%/97% after 6 and 8 h, respectively. Early reading of the screening discs (benzylpenicillin 1 unit in H. influenzae and oxacillin 1 & mu;g in S. pneumoniae) correctly identified 18/22 of the H. influenzae isolates and all the readable S. pneumoniae isolates with reduced & beta;-lactam susceptibility. For non-& beta;-lactam agents, very major errors were most common for quinolones in S. pneumoniae. Introduction of areas of technical uncertainty (ATUs) reduced the error rate to & LE;1.1%.Conclusions We conclude that shortened incubation is feasible for H. influenzae and S. pneumoniae. To reduce the risk of false categorization a buffer zone (i.e. ATU) near the breakpoints must be used.

    Download full text (pdf)
    fulltext
  • 26.
    Östholm Balkhed, Åse
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Tärnberg, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Maud
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Lennart E.
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Hanberger, Håkan
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Hällgren, Anita
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Infectious Diseases.
    Travel-associated faecal colonization with ESBL-producing Enterobacteriaceae: incidence and risk factors2013In: Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, E-ISSN 1460-2091, Vol. 68, no 9, p. 2144-2153Article in journal (Refereed)
    Abstract [en]

    Objectives To study the acquisition of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) among the faecal flora during travel, with a focus on risk factors, antibiotic susceptibility and ESBL-encoding genes.

    Methods An observational prospective multicentre cohort study of individuals attending vaccination clinics in south-east Sweden was performed, in which the submission of faecal samples and questionnaires before and after travelling outside Scandinavia was requested. Faecal samples were screened for ESBL-PE by culturing on ChromID ESBL and an in-house method. ESBL-PE was confirmed by phenotypic and genotypic methods. Susceptibility testing was performed with the Etest. Individuals who acquired ESBL-PE during travel (travel-associated carriers) were compared with non-carriers regarding risk factors, and unadjusted and adjusted ORs after manual stepwise elimination were calculated using logistic regression.

    Results Of 262 enrolled individuals, 2.4% were colonized before travel. Among 226 evaluable participants, ESBL-PE was detected in the post-travel samples from 68 (30%) travellers. The most important risk factor in the final model was the geographic area visited: Indian subcontinent (OR 24.8, P < 0.001), Asia (OR 8.63, P < 0.001) and Africa north of the equator (OR 4.94, P  = 0.002). Age and gastrointestinal symptoms also affected the risk significantly. Multiresistance was seen in 77 (66%) of the ESBL-PE isolates, predominantly a combination of reduced susceptibility to third-generation cephalosporins, trimethoprim/sulfamethoxazole and aminoglycosides. The most common species and ESBL-encoding gene were Escherichia coli (90%) and CTX-M (73%), respectively.

    Conclusion Acquisition of multiresistant ESBL-PE among the faecal flora during international travel is common. The geographical area visited has the highest impact on ESBL-PE acquisition.

    Download full text (pdf)
    fulltext
1 - 26 of 26
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf