V Fridriksdottir

University of Iceland, Reykjavík, Capital Region, Iceland

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Publications (14)30.27 Total impact

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    ABSTRACT: Rannsóknir og þróun eru undirstaða allra atvinnugreina. Atvinnugrein sem heldur ekki í við framfarir og þróun þrífst ekki eða dafnar til lengdar. Á Tilraunastöð Háskóla Íslands í meinafraeði að Keldum eru stundaðar rannsóknir sem tengjast dýraheilbrigði og sjúkdómum í dýrum og mönnum. Þar er veitt ráðgjöf og þjónusta í þágu heilbrigðiseftirlits, sjúkdómagreininga og sjúkdóma­ varna fyrir búfé, eldisfiska og önnur dýr. Nemar í líffraeði, lífefnafraeði, lífeindafraeði og dýralaekningum vinna rannsóknarverkefni á fraeða­ sviðum stofnunarinnar sem hluta af grunn­ eða framhaldsnámi sínu. Með vaxandi innflutningi, hnatt­ vaeðingu og hlýnandi loftslagi má gera ráð fyrir að nýir smitsjúkdómar berist til landsins í auknum maeli. Fyrir utan haettulega smitsjúkdóma sem herja á búpening og geta valdið fjárhagslegu tjóni eru margir af varasömustu smit­ sjúkdómum í mönnum svokallaðar súnur (zoonosis), en það eru sýklar sem smitast úr dýrum í fólk (s.s. fuglaflensa, svínaflensa, ebólaveira og fleiri). Þörfin fyrir öflugar rannsóknir á sviði dýrasjúkdóma og dýraheilbrigðis er því vaxandi og rannsóknirnar eru þar að auki nauðsynlegur liður í öruggri faeðuframleiðslu og liður í að viðhalda nauðsynlegu viðbúnaðarstigi. Líkt og tíðkast á öðrum rannsóknar stofnunum hafa vísinda­ menn á Keldum sótt stóran hluta af sínu styrkfé í Rannsóknasjóð Rannís og aðra sjóði. Velflestir meistara­ og doktorsnemar sem ljúka námi frá stofnuninni hafa þegið styrkfé að hluta eða öllu leyti. Nýliðun starfs­ krafta og viðhald þekkingar verður aðeins tryggt með menntun og þjálfun nema. Nú eru blikur á lofti varðandi fjárveitingar í Rannsóknasjóð, en hlutverk hans er að styrkja vísinda­ rannsóknir og rannsóknartengt framhaldsnám á Íslandi. Samkvaemt fjárlagafrumvarpi 2014 er gert ráð fyrir verulegum niðurskurði. Verði styrkfé minnkað til muna er alveg ljóst að það kippir fótunum undan fjölmörgum rannsóknarverkefnum við háskóla og rannsóknarstofnanir landsins og setur framtíð þess unga fólks sem í verkefnunum vinnur í uppnám. Framleiðnisjóður land­ búnaðarins var skorinn að mestu leyti niður fyrir nokkrum árum og endur­ fjármögnun gengur haegt. Líkja má þessum niðurskurði við óheppilegar skammtímaákvarðanir líkt og byrjað vaeri á því að slátra bestu mjólkur­ kúnni þegar herðir að, eða gaeða sér á kartöfluútsaeðinu. Slík öfugþróun er óheillavaenleg. Samfella, sem mjög erfitt er að ná upp að nýju, mun rofna og valda óbaetanlegu tjóni og skapa gríðar­ lega erfiðleika fyrir stofnanir eins og Keldur að viðhalda hlutverki sínu við rannsóknir og greiningar á dýrasjúkdómum. Allmargar alþjóðlegar greinar­ gerðir benda á að þekkingarsköpun er dýrmaet auðlind sem stuðlar að hagvexti. Samkeppnissjóðir eru viðurkennd leið til að fjármagna rannsóknir og nýsköpun. Almennt er þessi hugmyndafraeði viðurkennd á Íslandi en samt hefur verið tregða hjá stjórnvöldum að skilgreina fjármögnun vegna þekkingar sköpunar og vísindarannsóknir eru fjár sveltar. Daemi eru um að í nágranna löndum hafi verið brugðist við efnahagskreppu með því að efla samkeppnissjóði. Slíkt hefur opnað leiðir fyrir hagnýtingu nýsköpunar, sem leiðir til aukinnar verðmaeta sköpunar og styrkir stoðir samfélagsins. Ljóst er að samkeppnissjóðir eru mikil vaeg undirstaða þekkingar­ samfélagsins. Mikilvaegt er fyrir íslenskt samfélag að snúa ekki af þeirri braut að treysta rannsóknir
    Bændablaðið. 10/2013; 19(20):33.
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    ABSTRACT: To investigate feed as a source for fluoroquinolone-resistant Escherichia coli in broiler chickens, we compared antimicrobial drug-resistant E. coli from broiler feed and broilers with ciprofloxacin-resistant human clinical isolates by using pulsed-field gel electrophoresis. Feed was implicated as a source for ciprofloxacin-resistant broiler-derived E. coli and broilers as a source for ciprofloxacin-resistant human-derived E. coli.
    Emerging Infectious Diseases 01/2010; 16(1):133-5. · 6.79 Impact Factor
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    ABSTRACT: The prevalence of resistant bacteria in food products in Iceland is unknown, and little is known of the prevalence in production animals. The aim of this study was to investigate the prevalence and genetic relatedness of antimicrobial-resistant Escherichia coli from healthy pigs and broiler chicken, pork, broiler meat, slaughterhouse personnel and outpatients in Iceland. A total of 419 E. coli isolates were tested for antimicrobial susceptibility using a microbroth dilution method (VetMIC), and resistant strains were compared using pulsed-field gel electrophoresis (PFGE). All samples were screened for enrofloxacin-resistant strains with selective agar plates. The resistance rates among E. coli isolates were moderate to high from caecal and meat samples of pigs (54.1% and 28%), broilers (33.6% and 52%) and slaughterhouse personnel (39.1%), whereas isolates from outpatients showed moderate resistance rates (23.1%). Of notice was resistance to quinolones (minimum inhibitory concentrations: nalidixic acid > or = 32, ciprofloxacin > or = 0.12 and enrofloxacin > or = 0.5), particularly among broiler and broiler meat isolates (18.2% and 36%), as there is no known antimicrobial selection pressure in the broiler production in Iceland. The majority (78.6%) of the resistant E. coli isolates was genotypically different, based on PFGE fingerprint analyses and clustering was limited. However, the same resistance pattern and pulsotype were found among isolates from broiler meat and a slaughterhouse worker, indicating spread of antimicrobial-resistant E. coli from animals to humans. Diverse resistance patterns and pulsotypes suggest the presence of a large population of resistant E. coli in production animals in Iceland. This study gives baseline information on the prevalence of antimicrobial-resistant E. coli from production animals, and their food products in Iceland and the moderate to high resistance rates emphasize the need for continuing surveillance. Further studies on the origin of the resistant strains and the genetic relatedness of strains of different origin are needed.
    Zoonoses and Public Health 11/2009; 57(3):189-96. · 2.09 Impact Factor
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    ABSTRACT: Our objective was to identify temperature-related risk factors associated with the colonization of broiler-chicken flocks with Campylobacter spp. in Iceland, with an underlying assumption that at minimum ambient temperatures, flies (Musca domestica) play a role in the epidemiology and seasonality of Campylobacter. At slaughter, pooled caecal samples were obtained from 792 flocks that hatched between March 15 and September 15 each year from 2001 to 2004, and cultured for Campylobacter. Daily temperature data (average, maximum and minimum temperatures) were obtained from the Icelandic Meteorological Office. We determined the closest weather station to each farm using ArcGIS 9. We then used logistic-regression models (with a random-effects term for farm) to examine associations between flock positivity and temperature-related predictors. The overall prevalence of Campylobacter was 27.4%, and the month with the highest prevalence (54.4%) was August. The final model included cumulative degree-days (CDD) above an average temperature of 4.4 degrees C and the presence of 1 or more days below a maximum temperature of 8.9 degrees C (threshold below which fly activity was expected to be substantially reduced and egg laying was not expected to occur) during the period 2-4 weeks (i.e. days 8-28) before slaughter. Below 79 CDD, the risk of flock Campylobacter colonization was generally low. Between 79 and 139 CDD, the risk increased gradually, but was lower for flocks raised during periods with 1 or more days <8.9 degrees C than flocks raised without days <8.9 degrees C. The risk increased sharply under conditions of high CDD (>139) and when the maximum temperature remained >8.9 degrees C during the period 2-4 weeks before slaughter.
    Preventive Veterinary Medicine 09/2008; 86(1-2):14-29. · 2.39 Impact Factor
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    ABSTRACT: Minimum inhibitory concentrations of six antimicrobial agents were determined for one Campylobacter sp. isolate from each of the 362 Campylobacter-positive commercial chicken flocks in Iceland in the years 2001-2005. Of all isolates tested, 6.9% were resistant, although none were multiresistant. Resistance to ampicillin was most commonly observed (3.6%) followed by resistance to enrofloxacin (3%), nalidixic acid (1.9%), and oxytetracyclin (0.3%), with cross-resistance between enrofloxacin and nalidixic acid. All isolates were susceptible to erythromycin and gentamicin. Resistance rates among Campylobacter coli isolates (7/13 or 53.8%) were much higher than among Campylobacter jejuni isolates (18/349 or 5.2%), and resistance patterns differed. Resistant strains were compared using pulsed field gel electrophoresis. Macrorestriction with SmaI and KpnI restriction enzymes yielded 13 different pulsotypes, none of which indicated a predominant genotype. Specific pulsotypes with uniform resistance patterns arising on geographically separated farms indicate clonal dissemination. Although resistance levels were low and similar to that seen in the other Nordic countries, further research on this matter is needed as there is no antimicrobial selective pressure in chicken farming in Iceland.
    Microbial Drug Resistance 04/2008; 14(1):49-53. · 2.36 Impact Factor
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    ABSTRACT: We sampled 1,091 Icelandic broiler flocks at slaughter from May 2001 to December 2003 to determine the prevalence of, and investigate risk factors for the presence of, Campylobacter spp. at the flock level. Approximately 15% of the flocks were positive for Campylobacter spp.; most (95%) of the infected flocks being raised during the months of April-September. Based on the data from the latter months, and using multivariable logistic regression with random effects for herd, we found that the odds of a flock being positive for Campylobacter spp. increased with age and flock size. Additionally, vertical ventilation systems were strongly associated with positive flocks (OR=5.3). After controlling for these variables, we found no evidence of an effect of: year; company; Campylobacter being carried over from one flock to the next; time interval between flocks; using (at the hatcheries) eggs laid on the floor; density of bird housing, or the number of catch lots a flock was divided into for slaughtering purposes on the risk of a Campylobacter-positive flock.
    Preventive Veterinary Medicine 07/2006; 74(4):264-78. · 2.39 Impact Factor
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    ABSTRACT: Campylobacter jejuni remains the most frequently reported bacterial cause of human gastroenteritis in Nordic countries. The primary source of transmission to humans is suggested as mishandled raw poultry or consuming improperly prepared chicken. The focus of this report was to characterize the prevalence and cell numbers of the organism within the commercial Icelandic poultry industry. Commercial broiler flocks were sampled from May 2001 through 2003 in a total population study. At the slaughter plant, 40 randomly selected ceca were obtained from each flock, pooled into four samples containing 10 ceca each, and analyzed. Cell numbers and prevalence of Campylobacter spp. were estimated by direct plating of dilutions onto Campy-Cefex agar and incubating the plates at 42 degrees C under microaerobic atmosphere; colonies were confirmed as Campylobacter spp. by microscopy and latex agglutination to provide quantification of cell numbers per gm of cecal material. A total of 15.4% of the flocks carried the organism at at a maximum cell number of 8.1 x 10(7) cfu/g, having a mean raw count of colonized birds at 1.3 x 10(7) cfu/g (geometric mean of 1.5 x 10(6)). During the 3 years of sampling, the prevalence ranged from 17.6% to 17.3% to 12.7% for slaughter years 2001, 2002, and 2003, respectively. Isolation rates varied with numbers of catch lots (groups of birds taken for slaughter)/flock; with one catch lot/flock, the prevalence was 13.7%, with two 17.5%, and with three 33.3%. With increased flock size, isolation rates also increased; flocks of greater than 5,000 birds had a prevalence of 12.0% positive, 14.0% of flocks with 5,000-10,000 birds were positive, and 25.5% of flocks with more than 10,000 birds were positive for Campylobacter spp. Isolation rates varied with the processing lines: M was positive at 17.3%, B was positive at 10.1%, and G at 17.2%. Flocks were more frequently colonized in the warmer months, and younger birds were less frequently colonized than were older slaughtered birds. This study provides descriptive microbiology pertaining to Iceland broilers in a total population study.
    Foodborne Pathogens and Disease 02/2005; 2(1):82-9. · 2.28 Impact Factor
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    ABSTRACT: To access publisher full text version of this article. Please click on the hyperlink in Additional Links field Isolates of Campylobacter jejuni shipped internationally often arrive in a noncultivable state. We describe a PCR-based methodology whereby phylogenetic information can be recovered from noncultivable C. jejuni stored in Wang's transport medium. The robustness of this methodology was initially tested using 5 previously characterized strains of C. jejuni isolated from various sources associated with poultry production. These isolates were stored in Wang's transport medium before being subjected to 1 of 5 treatments designed to render the stored cells noncultivable: prolonged storage at room temperature, prolonged incubation at 42 degrees C, multiple rounds of freezing and thawing, boiling, or contamination with Pseudomonas aeruginosa (ATCC 27853). This method resulted in DNA appropriate for PCR. An approximately 400-nucleotide amplicon from the flaA gene and an approximately 800-nucleotide amplicon from 16S rDNA were readily obtained, and a 1.5-kb section of the flaA locus was amplified from about half of the samples. These results indicate that this method may be useful for isolate typing schemes based on PCR amplification of Campylobacter DNA, including flaA short variable region (flaA SVR) sequencing, multilocus sequence typing (MLST), and flaA PCR-RFLP. By using this method, isolates unrecoverable from transport medium can still be used to provide phylogenetic information for epidemiological studies.
    01/2005;
  • Eggert Gunnarsson, Vala Fridriksdóttir, Sigurdur Sigurdarson
    Acta veterinaria Scandinavica 02/2003; 44(3-4):255. · 1.35 Impact Factor
  • Acta veterinaria Scandinavica 02/2003; 44(3-4):273. · 1.35 Impact Factor
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    ABSTRACT: Paratuberculosis as well as the slow virus infections maedi/visna and jaagsiekte came to Iceland in 1933 when 20 sheep of the Karakul breed were imported from Halle, Germany. At least five of these sheep were subclinical carriers of paratuberculosis. Within 16 years paratuberculosis together with the other Karakul diseases (maedi/visna and jaagsiekte) almost ruined sheep farming, the main agricultural industry in Iceland. The first clinical case of paratuberculosis in sheep was confirmed in 1938, and in cattle in 1944. The first cattle cases of paratuberculosis appeared on farms where the disease had been prevalent in sheep for years. The virulence in cattle appeared to be considerably lower than in sheep. Extensive measures were used to control the spread of paratuberculosis in sheep. Hundreds of kilometres of fences were put up and used together with natural geographic borders to restrict the movement of sheep from infected areas. Serological and other immunological tests were also used to detect and dispose of infected individuals. These measures proved inadequate and the disease could not be eradicated. Culling and restocking of uninfected sheep in endemic areas eradicated maedi/visna and jaagsiekte but not paratuberculosis. Experiments showed that vaccination against paratuberculosis could reduce mortality in sheep by 94%. Vaccination of sheep in endemic areas has been compulsory in Iceland since 1966 and as a result losses have been reduced considerably. Today, serology is used to detect and control infection in cattle herds. Furthermore, serology is used to control vaccination of sheep and screen for infection in non-endemic areas. The complement fixation (CF) test for paratuberculosis has been used until now, but recently we have started comparing the CF test with the CSL absorbed ELISA test.
    Veterinary Microbiology 01/2001; 77(3-4):263-7. · 3.13 Impact Factor
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    ABSTRACT: Recombinant beta-toxin has been expressed and secreted from Bacillus subtilis. Biological activity was tested in vivo and in vitro. The lethal dose in mice was determined. Hemolysis of rabbit and sheep erythrocytes was tested but no effect was observed. Seven mutant proteins were produced. Targets for mutagenesis were mostly selected on the basis of the similarity between beta-toxin and alpha-toxin from Staphylococcus aureus, a pore-forming toxin. Mutations of two amino acids affected the lethal dose in mice. Both residues have counterparts in the membrane binding region of alpha-toxin. Alteration of the single cysteine residue did not affect protein function, contrary to previous suggestions.
    FEMS Microbiology Letters 02/1998; 158(1):17-23. · 2.05 Impact Factor
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    FEMS Microbiology Letters 01/1996; 136(1):99-99. · 2.05 Impact Factor
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    ABSTRACT: The beta-toxin gene from Clostridium perfringens type C was cloned and expressed as a glutathione S-transferase fusion protein in Escherichia coli. The DNA sequence was determined and compared to the type B sequence. Two nucleotide differences were found in the protein coding sequence, resulting in one amino acid difference between the two proteins. The purified beta-toxin fusion protein is not toxic in mice, but rabbit antiserum raised against it neutralises the toxic effect of C. perfringens type C culture filtrate in mice.
    FEMS Microbiology Letters 09/1995; 130(2-3):273-8. · 2.05 Impact Factor

Publication Stats

115 Citations
30.27 Total Impact Points

Institutions

  • 2001
    • University of Iceland
      • Institute for Experimental Pathology
      Reykjavík, Capital Region, Iceland