Peter Gaustad

• Tipu, Jahid Hasan; Tabassum, Anika; Klotz, Christian; Sivertsen, Audun; Afset, Jan Egil & Gaustad, Peter [Vis alle 13 forfattere av denne artikkelen] (2025). Diversity of domestic and imported assemblages of Giardia in Norway and multi-locus sequence typing of domestic assemblage A isolates. International Journal for Parasitology. ISSN 0020-7519. doi: 10.1016/j.ijpara.2025.08.018. Fulltekst i vitenarkiv Vis sammendrag

  Giardia duodenalis is a gastrointestinal parasite and one of the most frequently reported parasitic infections associated with contaminated water. This study investigated the diversity of domestic and imported Giardia assemblages in Norway, with a focus on the genetic characterization of domestic assemblage A isolates using multi-locus sequence typing (MLST) targeting six genome markers. We analysed 340 human, and 40 animal faecal samples collected between February 2022 and January 2024 from six medical microbiology laboratories and one veterinary diagnostic center across four Norwegian health regions. All the samples were analysed using nested PCR targeting part of the triose-phosphate isomerase (tpi) gene, and MLST was performed on 33 assemblage A isolates, targeting six polymorphic markers. The results revealed that assemblage B was most prevalent in humans (59 %), followed by assemblage A (41 %). Among the sub-assemblages, AII was the most frequently identified (37 %), followed by BIII (32 %), and BIV (27 %). Regarding the origin of infection, 30 % were of domestic origin, while 33 % were reported as imported–primarily originating from Africa (48 %) and South-East Asia (22 %). Sub-assemblage AII (46 %) was more common in domestic cases, whereas BIV (42 %) predominated in imported cases. We found a regional clustering of sub-assemblages, with AII frequently identified in Western Norway, BIII in South-Eastern Norway, and BIV in Mid Norway. The MLST analysis of domestic assemblage A isolates demonstrated high genetic variation, identifying 20 distinct MLST types among 21 isolates, including five novel variants. In animals, assemblage E was most common (62 %). This study provides a comprehensive overview of Giardia assemblages in human infections in Norway, offering insights into their genetic diversity. It also underscores the feasibility of employing MLST as a tool to evaluate potential epidemiological links of Giardia assemblage A isolates.

• Andersen, Thea A; Bjerner, Lars Johan; Tjade, Trygve; Ranheim, Trond Egil; Axelsen, Eyvind Wærsted & Sovershaev, Michael [Vis alle 8 forfattere av denne artikkelen] (2025). The COVID-19 pandemic and critical laboratory functions. Can fast-track molecular testing reduce work absence in the laboratory? Journal of Infection Prevention. ISSN 1757-1774. doi: 10.1177/17571774251330455. Fulltekst i vitenarkiv
• Tipu, Jahid Hasan; Sivertsen, Audun; Afset, Jan Egil; Sandven, Lars; Brekke, Hanne & Lund, Hilde Marie [Vis alle 13 forfattere av denne artikkelen] (2024). Cryptosporidium species and subtypes in Norway: predominance of C. parvum and emergence of C. mortiferum. Emerging microbes & infections. 13(1), s. 1–11. doi: 10.1080/22221751.2024.2412624. Fulltekst i vitenarkiv Vis sammendrag

  PCR-based diagnostics has revealed the previously largely unknown Cryptosporidium transmission and infections in high-income countries. This study aimed to determine domestic and imported subtypes of Cryptosporidium species in Norway, evaluate their demographic distribution, and identify potential small outbreaks. Cryptosporidium-positive human faecal samples were obtained from six medical microbiology laboratories between February 2022 and January 2024, together with 22 Cryptosporidium-positive animal samples. Species and subtypes were identified by sequencing PCR products from gp60 and SSU rRNA genes. Most cryptosporidiosis cases occurred during late summer/early autumn, primarily in children and young adults. Of 550 human samples, 359 were successfully characterized molecularly (65%), revealing infection with 10 different Cryptosporidium species. C. parvum occurred in 245 (68%) human isolates with IIa and IId being major allele families, with distinct regional distribution patterns of common subtypes. A kindergarten outbreak with 5 cases was due to C. parvum IIaA14G1R1. C. mortiferum was identified in 33 (9.2%) human cases of which 24 were known to be of domestic origin, making it the second most common species in human autochthonous cases in Norway. All C. mortiferum isolates were of the same genotype; XIVaA20G2T1, including 13 cases from a suspected small outbreak in Trøndelag. C. hominis occurred in 68 typed cases (19%), but mostly in infections acquired abroad, with allele families Ib and If occurring most often. In conclusion, this study of recent Cryptosporidium spp. and subtypes in Norway, highlights the predominance of C. parvum and the emergence of C. mortiferum among autochthonous cases.

• Ganan, Monica; Lorentzen, Silje Benedicte; Gaustad, Peter & Sørlie, Morten (2021). Synergistic antifungal activity of chito-oligosaccharides and commercial antifungals on biofilms of clinical Candida isolates. Journal of fungi (JoF). 7:718(9), s. 1–11. doi: 10.3390/jof7090718. Fulltekst i vitenarkiv Vis sammendrag

  The development of yeast biofilms is a major problem due to their increased antifungal resistance, which leads to persistent infections with severe clinical implications. The high antifungal activity of well-characterized chitosan polymers makes them potential alternatives for treating yeast biofilms. The activity of a chito-oligosaccharide with a depolymerization degree (DPn) of 32 (C32) and a fraction of acetylation (FA) of 0.15 on Candida sp. biofilms was studied. The results showed a concentration-dependent reduction in the number of viable cells present in C. albicans, C. glabrata, and C. guillermondii preformed biofilms in the presence of C32, especially on intermediate and mature biofilms. A significant decrease in the metabolic activity of yeast biofilms treated with C32 was also observed. The antifungals fluconazole (Flu) and miconazole (Mcz) decreased the number of viable cells in preformed early biofilms, but not in the intermediate or mature biofilms. Contrary to Flu or Mcz, C32 also reduced the formation of new biofilms. Interestingly, a synergistic effect on yeast biofilm was observed when C32 and Flu/Mcz were used in combination. C32 has the potential to become an alternative therapeutic agent against Candida biofilms alone or in combination with antifungal drugs and this will reduce the use of antifungals and decrease antifungal resistance.

• Gilboe, Hanne Margrethe; Reiakvam, Olaug Marie; Aasen, Linda; Tjade, Trygve; Bjerner, Johan & Ranheim, Trond Egil [Vis alle 7 forfattere av denne artikkelen] (2021). Rapid diagnosis and reduced workload for urinary tract infection using flowcytometry combined with direct antibiotic susceptibility testing. PLOS ONE. 16(7). doi: 10.1371/journal.pone.0254064. Fulltekst i vitenarkiv
• Lanternier, Fanny; Seidel, Danila; Pagano, Livio; Styczynski, Jan; Mikulska, Malgorzata & Pulcini, Celine [Vis alle 25 forfattere av denne artikkelen] (2020). Invasive pulmonary aspergillosis treatment duration in haematology patients in Europe: An EFISG, IDWP-EBMT, EORTC-IDG and SEIFEM survey. Mycoses (Berlin). ISSN 0933-7407. 63(5), s. 420–429. doi: 10.1111/myc.13056. Fulltekst i vitenarkiv
• Hesstvedt, Liv; Gaustad, Peter; Müller, Fredrik; Andersen, Cecilie Torp; Brunborg, Cathrine & Mylvaganam, Haima [Vis alle 19 forfattere av denne artikkelen] (2019). The impact of age on risk assessment, therapeutic practice and outcome in candidemia. Infectious Diseases. ISSN 2374-4235. 51(6), s. 425–434. doi: 10.1080/23744235.2019.1595709. Fulltekst i vitenarkiv
• Ganan, Monica; Lorentzen, Silje Benedicte; Agger, Jane Wittrup; Heyward, Catherine Anne; Bakke, Oddmund & Knutsen, Svein Halvor [Vis alle 10 forfattere av denne artikkelen] (2019). Antifungal activity of well-defined chitooligosaccharide preparations against medically relevant yeasts. PLOS ONE. 14(1). doi: 10.1371/journal.pone.0210208. Fulltekst i vitenarkiv Vis sammendrag

  Due to their antifungal activity, chitosan and its derivatives have potential to be used for treating yeast infections in humans. However, to be considered for use in human medicine, it is necessary to control and know the chemical composition of the compound, which is not always the case for polymeric chitosans. Here, we analyze the antifungal activity of a soluble and well-defined chito-oligosaccharide (CHOS) with an average polymerization degree (DPn) of 32 and fraction of acetylation (FA) of 0.15 (C32) on 52 medically relevant yeast strains. Minimal inhibitory concentrations (MIC) varied widely among yeast species, strains and isolates (from > 5000 to < 9.77 μg mL-1) and inhibition patterns showed a time- and dose-dependencies. The antifungal activity was predominantly fungicidal and was inversely proportional to the pH, being maximal at pH 4.5, the lowest tested pH. Furthermore, antifungal effects of CHOS fractions with varying average molecular weight indicated that those fractions with an intermediate degree of polymerization, i.e. DP 31 and 54, had the strongest inhibitory effects. Confocal imaging showed that C32 adsorbs to the cell surface, with subsequent cell disruption and accumulation of C32 in the cytoplasm. Thus, C32 has potential to be used as a therapy for fungal infections.

• Ganan, Monica; Lorentzen, Silje Benedicte; Aam, Berit Bjugan; Eijsink, Vincent; Gaustad, Peter & Sørlie, Morten (2019). Antibiotic saving effect of combination therapy through synergistic interactions between well-characterized chito-oligosaccharides and commercial antifungals against medically relevant yeasts. PLOS ONE. 14(12), s. 1–13. doi: 10.1371/journal.pone.0227098. Fulltekst i vitenarkiv Vis sammendrag

  Combination therapies can be a help to overcome resistance to current antifungals in humans. The combined activity of commercial antifungals and soluble and well-defined low molecular weight chitosan with average degrees of polymerization (DPn) of 17–62 (abbreviated C17 –C62) and fraction of acetylation (FA) of 0.15 against medically relevant yeast strains was studied. The minimal inhibitory concentration (MIC) of C32 varied greatly among strains, ranging from > 5000 μg mL-1 (Candida albicans and C. glabrata) to < 4.9 (C. tropicalis). A synergistic effect was observed between C32 and the different antifungals tested for most of the strains. Testing of several CHOS preparations indicated that the highest synergistic effects are obtained for fractions with a DPn in the 30–50 range. Pre-exposure to C32 enhanced the antifungal effect of fluconazole and amphotericin B. A concentration-dependent post-antifungal effect conserved even 24 h after C32 removal was observed. The combination of C32 and commercial antifungals together or as part of a sequential therapy opens new therapeutic perspectives for treating yeast infections in humans.

• Rehbinder, Eva Maria; Carlsen, Karin C. Lødrup; Staff, Anne Cathrine; Angell, Inga Leena; Landrø, Linn Aina Ysland & Hilde, Katarina [Vis alle 8 forfattere av denne artikkelen] (2018). Is amniotic fluid of women with uncomplicated term pregnancies free of bacteria? American Journal of Obstetrics and Gynecology. ISSN 0002-9378. 219(3), s. 289.e1–289.e12. doi: 10.1016/j.ajog.2018.05.028. Fulltekst i vitenarkiv Vis sammendrag

  Background: The “sterile womb” paradigm is debated. Recent evidence suggests that the offspring’s first microbial encounter is before birth in term uncomplicated pregnancies. The establishment of a healthy microbiota early in life might be crucial for reducing the burden of diseases later in life. Objective We aimed to investigate the presence of a microbiota in sterilely collected amniotic fluid in uncomplicated pregnancies at term in the Preventing Atopic Dermatitis and Allergies in children (PreventADALL) study cohort. Study Design Amniotic fluid was randomly sampled at cesarean deliveries in pregnant women in 1 out of 3 study sites included in the PreventADALL study. From 65 pregnancies at term, where amniotic fluid was successfully sampled, we selected 10 from elective (planned, without ongoing labor) cesarean deliveries with intact amniotic membranes and all 14 with prior rupture of membranes were included as positive controls. Amniotic fluid was analyzed by culture-independent and culture-dependent techniques. Results The median (min-max) concentration of prokaryotic DNA (16S rRNA gene copies/mL; digital droplet polymerase chain reaction) was low for the group with intact membranes [664 (544–748)]–corresponding to the negative controls [596 (461–679)], while the rupture of amniotic membranes group had >10-fold higher levels [7700 (1066–251,430)] (P = .0001, by Mann-Whitney U test). Furthermore, bacteria were detected in 50% of the rupture of amniotic membranes samples by anaerobic culturing, while none of the intact membranes samples showed bacterial growth. Sanger sequencing of the rupture of amniotic membrane samples identified bacterial strains that are commonly part of the vaginal flora and/or associated with intrauterine infections. Conclusion We conclude that fetal development in uncomplicated pregnancies occurs in the absence of an amniotic fluid microbiota and that the offspring microbial colonization starts after uterine contractions and rupture of amniotic membrane.

• Johnsen, Bjørn Odd; Handal, Nina; Meisal, Roger; Bjørnholt, Jørgen; Gaustad, Peter & Leegaard, Truls Michael (2017). erm gene distribution among Norwegian Bacteroides isolates and evaluation of phenotypic tests to detect inducible clindamycin resistance in Bacteroides species. Anaerobe. ISSN 1075-9964. 47, s. 226–232. doi: 10.1016/j.anaerobe.2017.06.004. Fulltekst i vitenarkiv
• Håvelsrud, Othilde Else & Gaustad, Peter (2017). Draft genome sequences of Candida glabrata isolates 1A, 1B, 2A, 2B, 3A, and 3B. Microbiology Resource Announcements (MRA). 5(10). doi: 10.1128/genomeA.00328-16. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Kristoffersen, Anne Karin; Ingebretsen, André; Vikholt, Katharina Johnsen; Ørtengren, Ulf Thore & Olsen, Ingar [Vis alle 8 forfattere av denne artikkelen] (2016). Diversity and anti-fungal susceptibility of Norwegian Candida glabrata clinical isolates. Journal of Oral Microbiology. 8(1). doi: 10.3402/jom.v8.29849. Fulltekst i vitenarkiv Vis sammendrag

  BACKGROUND: Increasing numbers of immunocompromised patients have resulted in greater incidence of invasive fungal infections with high mortality. Candida albicans infections dominate, but during the last decade, Candida glabrata has become the second highest cause of candidemia in the United States and Northern Europe. Reliable and early diagnosis, together with appropriate choice of antifungal treatment, is needed to combat these challenging infections. OBJECTIVES: To confirm the identity of 183 Candida glabrata isolates from different human body sites using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and VITEK®2, and to analyze isolate protein profiles and antifungal susceptibility. The minimum inhibitory concentration (MIC) of seven antifungal drugs was determined for the isolates to elucidate susceptibility. DESIGN: A total of 183 C. glabrata isolates obtained between 2002 and 2012 from Norwegian health-care units were analyzed. For species verification and differentiation, biochemical characterization (VITEK®2) and mass spectrometry (MALDI–TOF) were used. MIC determination for seven antifungal drugs was undertaken using E-tests®. RESULTS: Using VITEK®2, 92.9% of isolates were identified as C. glabrata, while all isolates (100%) were identified as C. glabrata using MALDI-TOF. Variation in protein spectra occurred for all identified C. glabrata isolates. The majority of isolates had low MICs to amphotericin B (≤1 mg/L for 99.5%) and anidulafungin (≤0.06 mg/L for 98.9%). For fluconazole, 18% of isolates had MICs >32 mg/L and 82% had MICs in the range ≥0.016 mg/L to ≤32 mg/L. CONCLUSIONS: Protein profiles and antifungal susceptibility characteristics of the C. glabrata isolates were diverse. Clustering of protein profiles indicated that many azole resistant isolates were closely related. In most cases, isolates had highest susceptibility to amphotericin B and anidulafungin. The results confirmed previous observations of high MICs to fluconazole and flucytosine. MALDI-TOF was more definitive than VITEK®2 for C. glabrata identification.

• Gurung, Ishwori; Spielman, Ingrid; Davies, Mark R.; Lala, Rajan; Gaustad, Peter & Biais, Nicolas [Vis alle 7 forfattere av denne artikkelen] (2016). Functional analysis of an unusual type IV pilus in the Gram-positive Streptococcus sanguinis. Molecular Microbiology. ISSN 0950-382X. 99(2), s. 380–392. doi: 10.1111/mmi.13237. Fulltekst i vitenarkiv
• Hesstvedt, Liv; Gaustad, Peter; Andersen, Cecilie Torp; Haarr, Elisebet; Hannula, Raisa & Haukland, Hanne Husom [Vis alle 12 forfattere av denne artikkelen] (2015). Twenty-two years of candidaemia surveillance: Results from a Norwegian national study. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 21(10), s. 938–945. doi: 10.1016/j.cmi.2015.06.008. Fulltekst i vitenarkiv
• Heggelund, Lars; Gaustad, Peter; Håvelsrud, Othilde Else; Blom, Jochen; Borgen, Lars & Sundset, Arve [Vis alle 8 forfattere av denne artikkelen] (2015). Corynebacterium pseudotuberculosis Pneumonia in a veterinary stuent infected during lobaratory work. Open Forum Infectious Diseases. 2:0fv053(2), s. 1–6. doi: 10.1093/ofid/ofv053. Fulltekst i vitenarkiv Vis sammendrag

  We present a case of Corynebacterium pseudotuberculosis pneumonia in a veterinary student, with molecular genetic evidence of acquisition during laboratory work, an observation relevant for laboratory personnel working with C pseudotuberculosis isolates. The patient was clinically cured with 14 months trimethoprim/sulfamethoxazole and rifampicin combination treatment.

• Berents, Teresa Løvold; Rønnevig, Jørgen Rikard; Søyland, Elisabeth; Gaustad, Peter; Nylander, Gro & Løland, Beate Fossum (2015). Topical treatment with fresh human milk versus emollient on atopic eczema spots in young children: A small, randomized, split body, controlled, blinded pilot study. BMC Dermatology. 15. doi: 10.1186/s12895-015-0027-9. Fulltekst i vitenarkiv Vis sammendrag

  Background Public health nurses report on effects of fresh human milk as treatment for conjunctivitis, rhinitis and atopic eczema (AE), the latter being highly prevalent in early childhood. Emollients and topical corticosteroids are first line treatment of AE. As many caregivers have steroid phobia, alternative treatment options for mild AE are of interest. The aim of this small pilot study was to assess the potential effects and risks of applying fresh human milk locally on eczema spots in children with AE. Methods This was a split body, controlled, randomized and physician blinded pilot study, of children with AE with two similar contralateral eczema spots having a mother breastfeeding the child or a sibling. Fresh expressed milk and emollient was applied on the intervention spot and emollient alone on the control area, three times a day for four weeks. The severity and area of the eczema spots was evaluated weekly, and samples from milk and the spots were analysed weekly with respect to bacterial colonisation. Results Of nine patients included, six completed the study. Mean age at inclusion was 18.5 months. The spots examined were localized on the arms, legs or cheeks. The spots were similar in severity, but differed in area. In one patient the eczema ceased after inclusion. In four patients both control and intervention areas increased during the intervention. The relative change in eczema area compared to baseline showed less increase in the intervention spots in two patients, whereas the opposite was observed in three. In four children Staphylococcus aureus was found in their eczema once or more. In three of the 28 human milk samples, Staphylococcus aureus, alfa haemolytic streptococci or coagulase negative staphylococci were detected. Staphylococcus aureus was found once both in human milk and in the eczema spots, no clinical signs of infection were however observed. No secondary infection due to milk application was detected. Conclusion In this small pilot study, no effect was found on eczema spots treated with topical application of fresh human milk. (ClinicalTrials.gov Identifier, NCT02381028 ).

• Linden, Jan W.M. van der; Arendrup, Maiken Cavling; Warris, Adilia; Lagrou, Katrien; Pelloux, Hervé & Hauser, Philippe M. [Vis alle 27 forfattere av denne artikkelen] (2015). Prospective multicenter international surveillance of azole resistance in Aspergillus fumigatus. Emerging Infectious Diseases. ISSN 1080-6040. 21(6), s. 1041–1044. doi: 10.3201/eid2106.140717. Fulltekst i vitenarkiv
• Berents, Teresa Løvold; Carlsen, Karin C. Lødrup; Mowinckel, Petter; Skjerven, Håvard Ove; Kvenshagen, Bente & Rolfsjord, Leif Bjarte [Vis alle 11 forfattere av denne artikkelen] (2015). Skin barrier function and Staphylococcus aureus colonization in vestibulum nasi and fauces in healthy infants and infants with eczema: A population-based cohort study. PLOS ONE. 10(6). doi: 10.1371/journal.pone.0130145. Fulltekst i vitenarkiv Vis sammendrag

  Atopic eczema (AE) is associated with Staphylococcus aureus (S. aureus) colonization and skin barrier dysfunction, often measured by increased transepidermal water loss (TEWL). In the present study, the primary aim was to see whether S. aureus colonization in the vestibulum nasi and/or fauces was associated with increased TEWL in infants with healthy skin and infants with eczema. Secondarily, we aimed to investigate whether TEWL measurements on non-lesional skin on the lateral upper arm is equivalent to volar forearm in infants. In 167 of 240 infants, recruited from the general population, TEWL measurements on the lateral upper arm and volar forearm, using a DermaLab USB, fulfilled our environmental requirements. The mean of three TEWL measurements from each site was used for analysis. The infants were diagnosed with no eczema (n = 110), possible AE (n = 28) or AE (n = 29). DNA samples were analysed for mutations in the filaggrin gene (FLG). Bacterial cultures were reported positive with the identification of at least one culture with S. aureus from vestibulum nasi and/or fauces. S. aureus colonization, found in 89 infants (53%), was not associated with increased TEWL (i.e. TEWL in the upper quartile), neither on the lateral upper arm or volar forearm (p = 0.08 and p = 0.98, respectively), nor with AE (p = 0.10) or FLG mutation (p = 0.17). TEWL was significantly higher on both measuring sites in infants with AE compared to infants with possible AE and no eczema. FLG mutation was significantly associated with increased TEWL, with a 47% difference in TEWL. We conclude that S. aureus in vestibulum nasi and/or fauces was not associated with TEWL, whereas TEWL measurements on the lateral upper arm and volar forearm appear equally appropriate in infants.

• Høyvoll, Liv Ragnhild; Fløisand, Yngvar; Lang, Hilde Elisabeth; Gunnarsson, Ragnar; Landro, Linn Herland & Brevig, Trine [Vis alle 8 forfattere av denne artikkelen] (2015). Hemophagocytic lymphohistiocytosis in leprosy. Leprosy Review. ISSN 0305-7518. 86(4), s. 403–406. Fulltekst i vitenarkiv
• Kommedal, Øyvind; Wilhelmsen, Marianne; Skrede, Steinar; Meisal, Roger; Jakovljev, Aleksandra & Gaustad, Peter [Vis alle 13 forfattere av denne artikkelen] (2014). Massive parallel sequencing provides new perspectives on bacterial brain abscesses. Journal of Clinical Microbiology. ISSN 0095-1137. 52(6), s. 1990–1997. doi: 10.1128/JCM.00346-14. Fulltekst i vitenarkiv
• Husøy, Magnus Andreas Rognlien; Brinch, Lorentz; Tjønnfjord, Geir Erland; Gedde-Dahl, Tobias Jr.; Heldal, Dag & Holme, Pål Andre [Vis alle 16 forfattere av denne artikkelen] (2014). Allogen stamcelletransplantasjon hos voksne 1985-2012. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 134(16), s. 1569–1575. doi: 10.4045/tidsskr.13.1415. Fulltekst i vitenarkiv
• Pascual, Ana Lobato; Sæther, Per Christian; Dahle, Maria Krudtaa; Gaustad, Peter; Dissen, Erik & Fossum, Sigbjørn [Vis alle 7 forfattere av denne artikkelen] (2013). Rat Macrophage C-type Lectin is an Activating Receptor Expressed by Phagocytic Cells. PLOS ONE. 8(2). doi: 10.1371/journal.pone.0057406. Fulltekst i vitenarkiv
• Espinel-Ingroff, Ana; Arendrup, M.C.; Pfaller, M.A.; Bonfietti, L.X.; Bustamante, B. & Canton, E. [Vis alle 24 forfattere av denne artikkelen] (2013). Interlaboratory variability of Caspofungin MICs for Candida spp. Using CLSI and EUCAST methods: should the clinical laboratory be testing this agent? Antimicrobial Agents and Chemotherapy. ISSN 0066-4804. 57(12), s. 5836–5842. doi: 10.1128/AAC.01519-13. Fulltekst i vitenarkiv
• Reikvam, Dag Henrik; Derrien, Muriel; Islam, Rejoanoul; Erofeev, Alexander; Grcic, Vedrana & Sandvik, Anders [Vis alle 11 forfattere av denne artikkelen] (2012). Epithelial-microbial crosstalk in polymeric Ig receptor deficient mice. European Journal of Immunology. ISSN 0014-2980. 42(11), s. 2959–2970. doi: 10.1002/eji.201242543. Fulltekst i vitenarkiv
• Gammelsrud, Karianne Wiger; Langnes, Belinda; Gaustad, Peter; Ingebretsen, André; Høiby, Ernst Arne & Brandtzaeg, Petter [Vis alle 7 forfattere av denne artikkelen] (2012). Multilocus sequence typing of serial Candida albicans isolates from children with cancer, children with cystic fibrosis and healthy controls. Medical Mycology. ISSN 1369-3786. 50(6), s. 619–626. doi: 10.3109/13693786.2012.675088. Fulltekst i vitenarkiv
• Skiada, A.; Pagano, L.; Groll, A.; Zimmerli, S.; Dupont, B. & Lagrou, K. [Vis alle 18 forfattere av denne artikkelen] (2011). Zygomycosis in Europe: analysis of 230 cases accrued by the registry of the European Confederation of Medical Mycology (ECMM) Working Group on Zygomycosis between 2005 and 2007. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 17(12), s. 1859–1867. doi: 10.1111/j.1469-0691.2010.03456.x. Fulltekst i vitenarkiv
• Gammelsrud, Karianne Wiger; Sandven, Per; Høiby, Ernst Arne; Sandvik, Leiv; Brandtzæg, Petter & Gaustad, Peter (2011). Colonization by Candida in children with cancer, children with cystic fibrosis, and healthy controls. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 17(12), s. 1875–1881. doi: 10.1111/j.1469-0691.2011.03528.x. Fulltekst i vitenarkiv
• Zinöcker, Severin; Wang, Mengyu; Gaustad, Peter; Kvalheim, Gunnar; Rolstad, Bent & Vaage, John Torgils (2011). Mycoplasma Contamination Revisited: Mesenchymal Stromal Cells Harboring Mycoplasma hyorhinis Potently Inhibit Lymphocyte Proliferation In Vitro. PLOS ONE. 6(1). doi: 10.1371/journal.pone.0016005. Fulltekst i vitenarkiv Vis sammendrag

  Background Mesenchymal stromal cells (MSC) have important immunomodulatory effects that can be exploited in the clinical setting, e.g. in patients suffering from graft-versus-host disease after allogeneic stem cell transplantation. In an experimental animal model, cultures of rat T lymphocytes were stimulated in vitro either with the mitogen Concanavalin A or with irradiated allogeneic cells in mixed lymphocyte reactions, the latter to simulate allo-immunogenic activation of transplanted T cells in vivo. This study investigated the inhibitory effects of rat bone marrow-derived MSC subsequently found to be infected with a common mycoplasma species (Mycoplasma hyorhinis) on T cell activation in vitro and experimental graft-versus-host disease in vivo. Principal Findings We found that M. hyorhinis infection increased the anti-proliferative effect of MSC dramatically, as measured by both radiometric and fluorimetric methods. Inhibition could not be explained solely by the well-known ability of mycoplasmas to degrade tritiated thymidine, but likely was the result of rapid dissemination of M. hyorhinis in the lymphocyte culture. Conclusions This study demonstrates the potent inhibitory effect exerted by M. hyorhinis in standard lymphocyte proliferation assays in vitro. MSC are efficient vectors of mycoplasma infection, emphasizing the importance of monitoring cell cultures for contamination.

• Reikvam, Dag Henrik; Erofeev, Alexander; Sandvik, Anders; Grcic, Vedrana; Jahnsen, Frode Lars & Gaustad, Peter [Vis alle 10 forfattere av denne artikkelen] (2011). Depletion of Murine Intestinal Microbiota: Effects on Gut Mucosa and Epithelial Gene Expression. PLOS ONE. 6(3). doi: 10.1371/journal.pone.0017996. Fulltekst i vitenarkiv
• Vestrheim, Didrik Frimann; Gaustad, Peter; Aaberge, Ingeborg Sundsvalen & Caugant, Dominique A (2011). Pherotypes of pneumococcal strains co-existing in healthy children. Infection, Genetics and Evolution. ISSN 1567-1348. 11(7), s. 1703–1708. doi: 10.1016/j.meegid.2011.07.003. Fulltekst i vitenarkiv
• Warris, A.; Onken, Annette; Gaustad, Peter; Janssen, W; Lee, H van der & Verweij, P. E. [Vis alle 7 forfattere av denne artikkelen] (2010). Point-of-use filtration method for the prevention of fungal contamination of hospital water. Journal of Hospital Infection. ISSN 0195-6701. 76(1), s. 56–59. doi: 10.1016/j.jhin.2010.03.014. Fulltekst i vitenarkiv
• Leegaard, Truls M; Bootsma, Hester J; Caugant, Dominique A; Eleveld, Marc J; Mannsåker, Turid & Frøholm, Leif Oddvar [Vis alle 9 forfattere av denne artikkelen] (2010). Phenotypic and genomic characterization of pneumococcus-like streptococci isolated from HIV-seropositive patients. Microbiology (Reading). ISSN 1350-0872. 156(Pt 3), s. 838–848. doi: 10.1099/mic.0.035345-0. Fulltekst i vitenarkiv
• Dannaoui, Eric; Schwarz, Patrick; Slany, Michael; Loeffler, Juergen; Jorde, Anne Tomine & Cuenca-Estrella, Manuel [Vis alle 16 forfattere av denne artikkelen] (2010). Molecular Detection and Identification of Zygomycetes Species from Paraffin-Embedded Tissues in a Murine Model of Disseminated Zygomycosis: a Collaborative European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Fungal Infection Study Group (EFISG) Evaluation. Journal of Clinical Microbiology. ISSN 0095-1137. 48(6), s. 2043–2046. doi: 10.1128/JCM.02319-09. Fulltekst i vitenarkiv
• Aarag, Elizabeth; Klingenberg, Claus; Rohde, Holger; Frankenberger, S; Gaustad, Petter & Flaegstad, T [Vis alle 8 forfattere av denne artikkelen] (2009). Biofilm Formation by Staphylococcus haemolyticus. Journal of Clinical Microbiology. ISSN 0095-1137. 47(4), s. 1172–1180. doi: 10.1128/JCM.01891-08. Fulltekst i vitenarkiv
• Lobmaier, Ingvild Victoria Koren; Vege, Åshild; Gaustad, Peter & Rognum, Torleiv Ole (2009). Bacteriological investigation-significance of time lapse after death. European Journal of Clinical Microbiology and Infectious Diseases. ISSN 0934-9723. 28(10), s. 1191–1198. doi: 10.1007/s10096-009-0762-0. Fulltekst i vitenarkiv
• Thorgersen, Ebbe Billmann; Pharo, Anne Margrethe; Haverson, K; Axelsen, Anne Kilsund; Gaustad, Peter & Kotwal, GJ [Vis alle 8 forfattere av denne artikkelen] (2009). Inhibition of Complement and CD14 Attenuates the Escherichia coli-Induced Inflammatory Response in Porcine Whole Blood. Infection and Immunity. ISSN 0019-9567. 77(2), s. 725–732. doi: 10.1128/IAI.01305-08. Fulltekst i vitenarkiv
• Riise, OR; Lee, A; Cvancarova, M; Handeland, KS; Wathne, KO & Nakstad, Britt [Vis alle 8 forfattere av denne artikkelen] (2008). Recent-onset childhood arthritis - association with Streptococcus pyogenes in a population-based study. Rheumatology. ISSN 1462-0324. 47, s. 1006–1011. doi: 10.1093/rheumatology/ken122. Fulltekst i vitenarkiv
• Castellheim, A; Thorgersen, EB; Hellerud, BC; Pharo, A; Johansen, HT & Brosstad, F [Vis alle 13 forfattere av denne artikkelen] (2008). New biomarkers in an acute model of live Escherichia coli-induced sepsis in pigs. Scandinavian Journal of Immunology. ISSN 0300-9475. 68, s. 75–84. doi: 10.1111/j.1365-3083.2008.02122.x. Fulltekst i vitenarkiv
• Arendrup, MC; Chryssanthou, E; Gaustad, Peter; Koskela, Merja; Sandven, Per & Fernandez, V (2007). Diagnostics of fungal infections in the Nordic countries: we still need to improve! Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 39, s. 337–343. Fulltekst i vitenarkiv
• Winn, R.M.; Warris, A; Gaustad, Peter & Abrahamsen, Tore G (2007). The effect of antifungal agents and human monocytes on in vitro galactomannan release by Aspergillus spp. in liquid culture medium. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. 115, s. 1364–1369. Fulltekst i vitenarkiv
• Bajanowski, Thomas; Vege, Åshild; Byard, Roger W; Krous, Henry F; Arnestad, Marianne & Bachs, Liliana Casulleras [Vis alle 30 forfattere av denne artikkelen] (2007). Sudden infant death syndrome (SIDS)- Standardised investigations and classification: Recommendations. Forensic Science International. ISSN 0379-0738. 165(2-3), s. 129–143. doi: 10.1016/j.forsciint.2006.05.028. Fulltekst i vitenarkiv
• Stray-Pedersen, Arne; Gaustad, Peter; Stray-Pedersen, Babill & Rognum, Torleiv Ole (2007). Detection rate of Helicobacter pylori stool antigen in newborn infants and small children. Journal of Perinatal Medicine. ISSN 0300-5577. 35, s. 155–158. doi: 10.1515/JPM.2007.040. Fulltekst i vitenarkiv
• Arendrup, Maiken Cavling; Chryssanthou, Erja; Gaustad, Petter; Koskela, Markku; Sandven, Per & Fernandez, Victor (2007). Diagnostics of fungal infections in the nordic countries: we still need to improve! Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 39(4), s. 337–343. doi: 10.1080/00365540601071859. Fulltekst i vitenarkiv
• Hageskal, Gunhild; Gaustad, Peter; Heier, B.T. & Skaar, Ida (2007). Occurrence of moulds in drinking water. Journal of Applied Microbiology. ISSN 1364-5072. 102, s. 774–780. Fulltekst i vitenarkiv
• Lehne, Gustav; Haneberg, Bjørn; Gaustad, Peter; Johansen, Per Wiik; Preus, Hans Ragnar & Abrahamsen, Tore G (2006). Oral administration of a new soluble branched β-1,3-D-glucan is well tolerated and can lead to increased salivary concentrations of immunoglobulin A in healthy volunteers. Clinical and Experimental Immunology. ISSN 0009-9104. 143(1), s. 65–69. doi: 10.1111/j.1365-2249.2005.02962. Fulltekst i vitenarkiv Vis sammendrag

  The soluble branched yeast β-1,3-D-glucan (SBG) belongs to a group of carbohydrate polymers known to exert potent immunomodulatory effects when administered to animals and humans. A new oral solution of SBG has been developed for local application to the oropharyngeal and oesophageal mucosa in order to strengthen the defence mechanisms against microbial and toxic influences. In the present study oral administration of SBG has been investigated primarily for assessment of safety and tolerability in an early phase human pharmacological study (phase I). Eighteen healthy volunteers were included among non-smoking individuals. The study was an open 1 : 1 : 1 dose-escalation safety study consisting of a screening visit, an administration period of 4 days and a follow-up period. Groups of six individuals received SBG 100 mg/day, 200 mg/day or 400 mg/day, respectively, for 4 consecutive days. The dose increase was allowed after a careful review of the safety data of the lower dose group. No drug-related adverse event, including abnormalities in vital signs, was observed. By inspection of the oral cavity only minor mucosal lesions not related to the study medication were seen in seven subjects. Repeated measurements of β-glucan in serum revealed no systemic absorption of the agent following the oral doses of SBG. In saliva, the immunoglobulin A concentration increased significantly for the highest SBG dose employed. SBG was thus safe and well tolerated by healthy volunteers, when given orally

• Sandven, Per; Bevanger, Lars; Digranes, Asbjørn; Haukland, hanne; Mannsåker, Turid & Gaustad, Peter (2006). Candidemia in Norway (1991 to 2003): Results from a nationwide study. Journal of Clinical Microbiology. ISSN 0095-1137. 44(6), s. 1977–1981. doi: 10.1128/JCM.00029-06. Fulltekst i vitenarkiv Vis sammendrag

  A long-term, nationwide prospective candidemia study has been ongoing in Norway since 1991. All medical microbiological laboratories in the country have participated. During the period 1991 to 2003 a total of 1,393 episodes of candidemia occurred in 1,348 patients. The incidence of candidemia episodes per 100,000 inhabitants increased from approximately 2 episodes in the early 1990s to 3 episodes in 2001 to 2003. The average annual incidences varied markedly between the age groups. The incidence was high in patients aged < 1 year and in patients aged > or = 70 years. In patients > or = 80 years of age, the incidence has increased during the last 3 years from an annual average of 6.5 to 15.6 cases/100,000 inhabitants in 2003. Four Candida species (C. albicans [70%], C. glabrata [13%], C. tropicalis [7%], and C. parapsilosis [6%]) accounted for 95.5% of the isolates. The species distribution has been constant during the 13-year study period. The distribution of the most important species varied with the age of the patient. In patients < 1 year of age, the majority of episodes were caused by C. albicans (91%). The occurrence of C. glabrata increased with age. In patients > or = 80 years of age, approximately 1/3 of all episodes were due to this species. All C. albicans strains were susceptible to fluconazole. The percentage of yeast isolates with decreased susceptibility to fluconazole (MICs > or = 16 microg/ml) was 10.7% during the first period of this study (1991 to 1996) and 11.7% during the second period (1997 to 2003).

• Hageskal, Gunhild; Knutsen, AK; Gaustad, Peter; Hoog, G. S. de & Skaar, Ida (2006). Diversity and significance of mold species in Norwegian drinking water. Applied and Environmental Microbiology. ISSN 0099-2240. 72(12), s. 7586–7593. Fulltekst i vitenarkiv
• Walberg, Mette; Mørk, Cato; Sandven, Per; Jorde, Anne Tomine; Bjørås, Magnar & Gaustad, Peter (2006). 18S rDNA polymerase chain reaction and sequencing in onychomycosis diagnostics. Acta Dermato-Venereologica. ISSN 0001-5555. 86(3), s. 223–226. Fulltekst i vitenarkiv
• Næss-Andresen, Carl Fredrik; Walberg, Mette & Gaustad, Peter (2006). In vitro activity of a cytotoxic factor isolated from human leukocytes. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. 114(6), s. 428–435. Fulltekst i vitenarkiv Vis sammendrag

  The aim of the present study was to test the in vitro antimicrobial properties of a cytotoxic factor isolated from human leukocytes and for an effect on DNA synthesis. A microdilution broth method was used to determine MIC values for fungi and bacteria. Flow cytometry was used to examine the effect on DNA synthesis. The MIC values for fungi were in the range 1-128 mu g CF/mL and concentrations 2-4 times the MIC were fungicidal. CF had no effect on bacteria (MIC and MBC values > 1024 mu g CF/mL). Growth experiments performed with increasing concentration of CF showed a dose-dependent effect on growth of the yeasts tested. We confirmed that zinc ions could abrogate the antiproliferative effect of CF. Flow cytometric experiments showed that CF had no effect on the cell cyclus. The present study shows that this endogenous substance isolated from human leukocytes has growth inhibitory properties towards fungi. Because of the origin from human leukocytes, CF may have a role in the non-specific defense against fungal infections. The use of CF may potentially have a role in the treatment of infections caused by fungi. Further investigations to characterize CF chemically and to study the antifungal mechanism are necessary.

• Naess-Andresen, CF; Walberg, Mette & Gaustad, Peter (2006). In vitro activity of a cytotoxic factor isolated from human leukocytes. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. 114. Fulltekst i vitenarkiv
• Leegaard, Truls Michael; Sandven, Per & Gaustad, Peter (2005). Clostridium tertium: 3 case reports. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 37(3), s. 230–232. Fulltekst i vitenarkiv
• Warris, Adilia; Netea, M.G.; Verweij, Paul E.; Gaustad, Peter; Kullberg, Bart Jan & Weemaes, Corry M.R. [Vis alle 7 forfattere av denne artikkelen] (2005). Cytokine responses and regulation of interferon-gamma release by human mononuclear cells to Aspergillus fumigatus and other filamentous fungi. Medical Mycology. ISSN 1369-3786. 43(7), s. 613–621. doi: 10.1080/13693780500088333. Fulltekst i vitenarkiv Vis sammendrag

  There is substantial evidence that the production of proinflammatory cytokines is important in host resistance to invasive aspergillosis. Knowledge of the host response towards other filamentous fungi is scarce, as most studies have focused on Aspergillus fumigatus. In addition, interferon-gamma (IFNγ) plays a crucial role in the control of invasive aspergillosis, but little is known about the regulation of IFNγ after stimulation of mononuclear cells by A. fumigatus. Cytokine responses to four different Aspergillus spp., Scedosporium prolificans, and a Rhizopusoryzae strain were compared for their ability to induce the release of tumour necrosis factor-alpha (TNFα) and interleukin(IL)-6 by human monocytes. S. prolificans induced significantly more TNFα and IL-6 release compared to A. fumigatus, while the various Aspergillus spp. induce comparable levels of these cytokines. By using specific cytokine inhibitors we were able to show that endogenous IL-1, but not IL-18 and TNFα, was required for IFNγ and IL-10 release upon stimulation with A. fumigatus hyphae, whereas conidia induced IFNγ stimulation is independent of these cytokines.

• Simonsen, Gunnar S; Bergh, Kåre; Bevanger, Lars Solbu; Digranes, Asbjørn; Gaustad, Peter & Melby, Kjetil K [Vis alle 7 forfattere av denne artikkelen] (2004). Susceptibility to Quinopristin-Dalfopristin and Linezolid in 839 Clinical Isolates of Gram-Positive Cocci from Norway. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 36, s. 254–258. Fulltekst i vitenarkiv
• Simonsen, GS; Bergh, K; Bevanger, L; Digranes, A; Gaustad, Peter & Melby, Kjetil K. [Vis alle 7 forfattere av denne artikkelen] (2004). Susceptibility to quinupristin-dalfopristin and linezolid in 839 clinical isolates of gram-positive cocci from Norway. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 36, s. 254–258. Fulltekst i vitenarkiv Vis sammendrag

  A total of 839 clinical isolates of Gram-positive cocci from Norway including Staphylococcus aureus (n = 214), coagulase negative Staphylococcus spp. (n = 100), Streptococcus pyogenes (n = 99), Streptococcus agalactiae (n = 80), Streptococcus pneumoniae (n = 127), Streptococcus spp. viridans group (n = 70), Enterococcus faecalis (n = 75), and Enterococcus faecium (n = 74), were tested by E-test for susceptibility to a range of antimicrobials including the novel antibiotics quinupristin-dalfopristin and linezolid. Subgroups of oxacillin resistant S. aureus and coagulase negative Staphylococcus spp., penicillin non-susceptible S. pneumoniae and vancomycin resistant Enterococcus spp. were specifically included as they are the intended targets for these new drugs. All isolates were susceptible to linezolid (MIC5o and MIC9o 0.25-2.0 mg/l, MIC range 0.12-2 mg/l). Staphylococcal and streptococcal isolates were also susceptible to quinupristin-dalfopristin except for some intermediately susceptible viridans group isolates (MIC54, and MIC90 0.25-2 mg/l, MIC range 0.125-2 mg/l). Enterococcus faecium (MIC90 = 4.0 mg/l) and Enterococcus faecalis (MIC50 = 8.0 mg/l, MIC90 > or = 32 mg/l) were less susceptible to this substance. There was no linkage between reduced susceptibility to linezolid or quinupristin-dalfopristin and resistance to other classes of antimicrobials. The study demonstrated a high prevalence of in vitro susceptibility to linezolid and quinupristin-dalfopristin, which is necessary for their use in the treatment of infections with resistant Gram-positive pathogens. The results were used to evaluate the appropriateness of breakpoints and to define a baseline for monitoring possible future emergence of resistance to quinupristin-dalfopristin and linezolid in Norway.

• Gaustad, Peter; Holter, Ellen & Vege, Åshild (2004). Bacteriological and virological examinations in cases of sudden enexpected deaths in infancy and early childhood. Scandinavian Journal of Forensic Science. ISSN 1503-9552. 3(72). Fulltekst i vitenarkiv
• Klingenberg, C.; Sundsfjord, A; Rønnestad, Arild Erlend; Mikalsen, J; Gaustad, Peter & Flægstad, Trond (2004). Phenotypic and genotypic aminoglycoside resistance in blood culture isolates of coagulase-negative staphylococci from a single neonatal intensive care unit, 1989�2000. Journal of Antimicrobial Chemotherapy. ISSN 0305-7453. 54(5), s. 889–896. doi: 10.1093/jac/dkh453. Fulltekst i vitenarkiv Vis sammendrag

  Objectives: To investigate the prevalence of aminoglycoside resistance and genes encoding aminoglycoside-modifying enzymes (AME) in blood culture isolates of coagulase-negative staphylococci (CoNS) from neonates. Materials and methods: A total of 180 isolates from 148 patients collected in a single neonatal unit over a 12 year period were examined for susceptibility to gentamicin, tobramycin, netilmicin, amikacin and arbekacin by Etest and/or disc diffusion. AME genes were detected by PCR. Results: The overall non-susceptibility rates to gentamicin, tobramycin, netilmicin, amikacin and arbekacin were 66%, 68%, 52%, 38% and 1%, respectively. Gentamicin non-susceptibility rates were 4% and 91% in methicillin-susceptible and -resistant isolates, respectively. aac(6')-Ie-aph(2'')-Ia, aph(3')-IIIa and/or ant(4')-Ia were encountered in 125 (69%), 1 (0.5%) and 30 (16.6%) isolates, respectively. Forty-six (26%) isolates negative for AME genes were susceptible to all aminoglycosides. In contrast, 115 (92%), 91 (73%) and 66 (53%) of aac(6')-Ie-aph(2'')-Ia positive isolates were non-susceptible to gentamicin, netilmicin and amikacin, respectively. Only one isolate showed arbekacin resistance. However, aac(6')-Ie-aph(2'')-Ia positive isolates and isolates with gentamicin MIC 128 mg/L displayed a significant reduction in arbekacin inhibition zones. Conclusions: A high prevalence of aminoglycoside resistance was detected and associated with methicillin resistance. Discrepancies between phenotypic and genetic detection of aminoglycoside resistance were discerned. Gentamicin was the preferred substrate for phenotypic detection of aac(6')-Ie-aph(2'')-Ia. Arbekacin showed favourable antibacterial activity even in aac(6')-Ie-aph(2'')-Ia-positive isolates. We suggest including arbekacin in future clinical trials of empirical treatment of late onset neonatal sepsis.

• Klingenberg, Claus; Sundsfjord, Arnfinn; Rønnestad, A; Mikalsen, J; Gaustad, P & Flægstad, Trond (2004). Correlation between aminoglycoside resistance phenotype and genotype in blood culture isolates of coagulase negative staphylococci from a single neonatal intensive care unit, 1989-2000. Journal of Antimicrobial Chemotherapy. ISSN 0305-7453. 54(5), s. 889–896. Fulltekst i vitenarkiv
• Rognum, Torleiv Ole; Arnestad, Marianne; Bajanowski, Thomas; Banner, J; Blair, P & Borthne, Arne [Vis alle 26 forfattere av denne artikkelen] (2003). Concensus on diagnostic criteria for the exclusion of SIDS. Nordisk Rettsmedisin. ISSN 0809-1498. 9, s. 62–73. Fulltekst i vitenarkiv
• Warris, Adilia; Klaassen, Corne H.W.; Meis, Jacques F.G.M.; de, Maaike T. Ruiter; de, Hanneke A. Valk & Abrahamsen, Tore G. [Vis alle 8 forfattere av denne artikkelen] (2003). Molecular Epidemiology of Aspergillus fumigatus Isolates Recovered from Water, Air, and Patients Shows Two Clusters of Genetically Distinct Strains. Journal of Clinical Microbiology. ISSN 0095-1137. 41, s. 4101–4106. Fulltekst i vitenarkiv
• Farstad, H; Gaustad, Peter; Kristiansen, P. A.; Perminov, G & Abrahamsen, Tore G (2003). Cerebral venous thrombosis and Escherichia coli infection in neonates. Acta Paediatrica Scandinavica. ISSN 0001-656X. 92(2), s. 254–257. Fulltekst i vitenarkiv Vis sammendrag

  AIM: To present a possible association between cerebral venous thrombosis (CVT) and infection with Escherichia coli. METHODS: Four neonates with deep CVT occurring during an E. coli infection are presented. RESULTS: In these patients the thrombotic disease was found by Doppler ultrasonography. The thrombosis involved at least the sagittal sinus and the transverse sinus according to subsequent MRI scans. The E. coli strains did not produce verotoxin or haemolysin. Disseminated intravascular coagulation was not demonstrated. Three patients presented with seizures. At discharge, all of the patients had signs of neurological damage, but two of them have improved significantly since then. None of the patients has had recurrent (venous) thrombosis. CONCLUSION: E. coli infections in neonates may predispose to CVT, a finding that has clinical implications.

• Vege, Åshild; Arnestad, Marianne; Bajanowski, Thomas; Gaustad, Peter; Holter, Ellen & Krous, Henry F [Vis alle 10 forfattere av denne artikkelen] (2003). Autopsy protocols for diagnostic purposes -Extensiveness of sampling - interpretation of findings. Nordisk Rettsmedisin. ISSN 0809-1498. 9(3/4), s. 71–72. Fulltekst i vitenarkiv
• Warris, A.; Netea, M.G.; Wang, Jacob Edward; Kullberg, B.J.; Gaustad, Peter & Verweij, P. E. [Vis alle 7 forfattere av denne artikkelen] (2003). Cytokine release in healthy donors and patients with chronic granulomatous disease upon stimulation with Aspergillus fumigatus. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 35, s. 482–487. Fulltekst i vitenarkiv
• Synnestvedt, Marit; Muller, Fredrik; Gaustad, Peter & Bucher, Aira (2003). Recurrent Group A Streptococcal Genital Infection after Puerperal Sepsis. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 35, s. 509–510. Fulltekst i vitenarkiv
• Ween, Ola; Teigen, Svanhild; Gaustad, Peter; Kilian, Mogens & Håvarstein, Leiv Sigve (2002). Competence without a competence pheromone in a natural isolate of Streptococcus infantis. Journal of Bacteriology. ISSN 0021-9193. 184(13), s. 3426–3432. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Booth, James; Suganthan, Rajikala; Gaustad, Peter & Bjørås, Magnar (2015). Development of DinQ from Escherichia coli as an anti-cell-envelope antibiotic. International Journal of Antimicrobial Agents. ISSN 0924-8579. 45(2), s. 196–197. doi: 10.1016/j.ijantimicag.2014.10.005. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne Karin; Ingebretsen, André; Ørtengren, Ulf Thore & Gaustad, Peter [Vis alle 7 forfattere av denne artikkelen] (2014). Phenotypic characterization of Candida glabrata from blood, respiratory and gastrointestinal tracts. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne Karin; Ingebretsen, André; Ørtengren, Ulf Thore & Gaustad, Peter [Vis alle 7 forfattere av denne artikkelen] (2014). Phenotypic Characterization of Candida glabrata from Blood, Respiratory and Gastrointestinal Tracts. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne Karin; Ingebretsen, André; Ørtengren, Ulf Thore & Gaustad, Peter [Vis alle 7 forfattere av denne artikkelen] (2014). Phenotypic Characterization of Candida glabrata from Blood, Respiratory and Gastrointestinal Tracts. Poster presentation. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne Karin; Ingebretsen, André; Ørtengren, Ulf Thore & Gaustad, Peter [Vis alle 7 forfattere av denne artikkelen] (2014). Phenotypic Characterization of Candida glabrata from Blood, Respiratory and Gastrointestinal Tracts. Oral Presentation. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne Karin; Ingebretsen, André; Ørtengren, Ulf Thore & Gaustad, Peter [Vis alle 7 forfattere av denne artikkelen] (2014). Phenotypic diversity among clinical Candida glabrata strains in Norwegian health care unit. Oral presentation. Fulltekst i vitenarkiv
• Melby, Kjetil K.; Olsen, Anne Olaug; Dedi, Lumnije; Gaustad, Peter; Syversen, Gaute & Moi, Harald (2014). Resistensutvikling må overvåkes – gonokokken som eksempel. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 134(5), s. 507–508. doi: 10.4045/tidsskr.14.0033. Fulltekst i vitenarkiv
• Berents, Teresa Løvold; Carlsen, Karin C. Lødrup; Mowinckel, Petter; Skjerven, Håvard Ove; Kvenshagen, Bente & Rolfsjord, Leif Bjarte [Vis alle 9 forfattere av denne artikkelen] (2013). Staphylococcus aureus colonization and skin barrier function in infants with and without eczema - a cross-sectional cohort study. Allergy. European Journal of Allergy and Clinical Immunology. ISSN 0105-4538. 68, s. 159–159. Fulltekst i vitenarkiv
• Hesstvedt, Liv; Gaustad, Peter; Hannula, Raisa; Larssen, Kjersti Wik; Friman, Nina Christine & Mylvaganam, Haima [Vis alle 10 forfattere av denne artikkelen] (2013). Invasive candidemia in Norway- a comparison of 2 decades. Mycoses (Berlin). ISSN 0933-7407. 56, s. 52–52. Fulltekst i vitenarkiv
• Andersen, C T; Bechensteen, Anne Grete; Hesstvedt, Liv & Gaustad, Peter (2012). Multiple brain abscesses caused by Aspergillus viridinutans in a leukemic child. Mycoses (Berlin). ISSN 0933-7407. 55(supp. 4), s. 75–75. Fulltekst i vitenarkiv
• Andersen, Kari-Mette; Enersen, Morten; Kristoffersen, Anne-Karin; Gaustad, Peter; Ørtengren, Ulf Thore & Olsen, Ingar (2012). Phenotypic and genotypic characterization of Candida glabrata. Fulltekst i vitenarkiv
• Haakensen, Lene; Lindstad, Belinda Langnes & Gaustad, Peter (2012). Emergining fluconazole resistant pathogen; first described cases of candidemi caused by Issatchenkia occidentalis. Mycoses (Berlin). ISSN 0933-7407. 55, s. 294–294. Fulltekst i vitenarkiv
• Zinöcker, Severin; Wang, Mengyu; Gaustad, Peter; Kvalheim, Gunnar; Rolstad, Bent & Vaage, John Torgils (2010). Mesenchymal Stem Cell Therapy for Graft-versus-Host Disease. Fulltekst i vitenarkiv
• Erofeev, Alexander; Reikvam, Dag Henrik; Gaustad, Peter; Grzyb, Krzysztof; Sandvik, Anders & Jahnsen, Frode Lars [Vis alle 7 forfattere av denne artikkelen] (2009). Role of secretory antibodies and commensal microbiota in DSS-induced colitis. Fulltekst i vitenarkiv
• Nordøy, Ingvild; Nordøy, I; Gaustad, P & Sandven, Per (2009). Candidemia in Norway: a 5 year follow-up of a nationwide study. Mycoses (Berlin). ISSN 0933-7407. 52, s. 66–67. doi: 10.1111/j.1439-0507.2009.01782.x. Fulltekst i vitenarkiv
• Kolstad, A.; Holte, Harald; Fosså, A.; Lauritzen, G.F.; Gaustad, Peter & Torfoss, Dag (2007). Pneumocystis jirovecii pneumonia in B-cell lymphoma patients treated with the rituximab-CHOEP-14 regimen. Haematologica. ISSN 0390-6078. 92, s. 139–140. Fulltekst i vitenarkiv
• Rognum, Torleiv Ole; Vege, Åshild & Gaustad, Peter (2006). Clues pointing to the possibility of bacterial involvement in SIDS. Fulltekst i vitenarkiv
• Hansen, GA; Sandven, P & Gaustad, P (2006). Late recurrant Candidemia: microbiology,clinical manifestations and molecular epidemiology. Fulltekst i vitenarkiv
• Hansen, Gorm A.; Sandven, Per & Gaustad, Peter (2006). Late Recurrent Candidemia: Microbiology, Clinical Manifestions and Molecular Epidemiology. Fulltekst i vitenarkiv
• Sandven, Per & Gaustad, Peter (2005). Har faget medisinsk mykologi en fremtid i Norge. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 125(5), s. 621–621. Fulltekst i vitenarkiv
• Gaustad, Peter; Backe, Elin Friis & Sandven, Per (2005). Candida glabrata, Candida krusei and Candida norvegensis: species with decreased susceptibiltity to fluconazole. Cross-resistance to other antifungals. Fulltekst i vitenarkiv
• Gaustad, Peter & Sandven, Per (2005). Candida strains with decreased susceptibility to fluconazole. Cross-resistance to other azoles and activity of other antimycotic agents. Fulltekst i vitenarkiv
• Klingenberg, C.; Sundsfjord, A; Rønnestad, Arild Erlend; Mikalsen, J; Gaustad, Peter & Flægstad, Trond (2004). Phenotypic and genotypic aminoglycoside resistance in blood culture isolates of coagulase-negative staphylococci from a single neonatal intensive care unit, 1989�2000. Pediatric Research. ISSN 0031-3998. 56(3), s. 464–464. Fulltekst i vitenarkiv Vis sammendrag

  ESPR EUROPEAN SOCIETY FOR PEDIATRIC RESEARCH: Stockholm, Sweden September 19-22, 2004

• Warris, A.; Netea, M.G.; Gaustad, Peter; Kullberg, B.J.; Verweij, P. E. & Abrahamsen, Tore G (2003). Aspergillus fumigatus induces Amphotericin A (AmB) tolerance and inhibits AmB induced cytokine release. Fulltekst i vitenarkiv
• Denning, David; Lortholary, Olivier & Gaustad, Peter (2003). ESCMID Fungal Infection Study Group (EFISG). Fulltekst i vitenarkiv
• Dahle, Dag Olav; Aasen, Kaj Robert; Axelsen, Anne Kilsund & Gaustad, Peter (2003). Vancomycin susceptibility still prevails in Norwegian enterococcal bacteremias. Fulltekst i vitenarkiv
• Walberg, Mette; Mørk, Cato; Sandven, Per; Jorde, A. T.; Bjørås, Magnar & Gaustad, Peter (2003). 18S rRNA sekvensering av neglprøver i diagostikk av onychomykose. Fulltekst i vitenarkiv
• Walberg, Mette; Mørk, Cato; Sandven, Per; Jorde, A. T.; Andersen, M.I. & Bjørås, Magnar [Vis alle 7 forfattere av denne artikkelen] (2003). 18S rDNA sekvensensering av negprøver i diagnostikk av onychomykose. Fulltekst i vitenarkiv
• Walberg, Mette; Bøvre, Magli; Gaustad, Peter; Bjørneklett, Arvid & Brinch, Lorentz (2002). Screening for circulating galactomannan as a marker for invasive aspergillosis in patients with hematological disease. Fulltekst i vitenarkiv
• Steinbakk, Martin; Sandven, Per; Andersen, Cecilie Torp; Gaustad, Peter & Larssen, Kjersti Wik (2015). Soppinfeksjoner. Strategimøte nr 27, 2013. Folkehelseinstituttet, Smittevern, miljø og helse. ISSN 9788280827029. Fulltekst i vitenarkiv
• Sandven, Per; Steinbakk, Martin; Bjørnholt, Jørgen V; Gaustad, Peter; Mengshoel, Anne Torunn & Thilesen, Carina Merethe (2010). Anaerob diagnostikk : Strategimøte nr. 23, 2009. Folkehelseinstituttet. ISSN 9788280824226. Fulltekst i vitenarkiv
• Lassen, Jørgen Fredrik; Sandven, Per; Vik, Einar; Bevanger, Lars; Gaustad, Peter & Høiby, Arne (2003). Streptokokker (Gruppe A og B). Strategimøte nr 15, 2001. Folkehelseinstituttet. Fulltekst i vitenarkiv
• Høiby, E.A. & Gaustad, Peter (2003). Streptococcus pyogenes i dyrkningsmedtoder, identifikasjon og resistensbestemmelse. Folkehelseinstituttet. Fulltekst i vitenarkiv
• Høiby, E.A.; Lermark, G.; Martin, P.; Hasseltvedt, V. & Gaustad, Peter (2003). Gruppe A-streptokokker. Folkehelseinstituttet. Fulltekst i vitenarkiv
• Høiby, E.A. & Gaustad, Peter (2003). Prøvetaking for å påvise GAS ved dyrkning. Folkehelseinstituttet. Fulltekst i vitenarkiv

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