Kjetil Klaveness Melby

• Nestegard, Oddmund; Moayeri, Behrouz; Halvorsen, Fred-Arne; Tønnessen, Tor; Sørbye, Sveinung & Paulssen, Eyvind Jakob [Show all 10 contributors for this article] (2022). Helicobacter pylori resistance to antibiotics before and after treatment: Incidence of eradication failure. PLOS ONE. ISSN 1932-6203. 17:e0265322(4), p. 1–8. doi: 10.1371/journal.pone.0265322. Full text in Research Archive Show summary

  Background Increasing prevalence of antibiotic resistance especially to clarithromycin and metronidazole has been observed in Helicobacter pylori (H. pylori). Aim To characterize the antimicrobial resistance pattern of H. pylori before and after treatment in a cohort of patients accumulated over a period of 15 years after an unsuccessful eradication treatment had been given comparing sensitivity data from patients with newly diagnosed H. pylori infection. A specific objective was to look for resistance to levofloxacin. Material and methods Total of 50 patients newly diagnosed for H. pylori infection treated with omeprazole and amoxicillin/clarithromycin and 42 H pylori treatment-resistant patients treated with omeprazole and amoxicillin/levofloxacin were enrolled in this study. Cultures including antibiotic sensitivity testing were conducted according to standard laboratory routines and thus also in keeping with a European study protocol using E-test gradient strips or disc diffusion methods. Results Clarithromycin resistance was more frequently observed in the H. pylori resistant group than in newly diagnosed H. pylori group (39% versus 11%). Regarding metronidazole the distribution was 70% versus 38%, and 8% versus 12% were resistant to tetracycline. No resistance was observed for amoxicillin. After re-treatment of patients belonging to the H. pylori treatment-resistant group, just two patient strains were recovered of which one harbored metronidazole resistance. In the group of newly diagnosed H. pylori, seven patients were culture positive by control after treatment. Two and three patient strains showing resistance to clarithromycin and metronidazole, respectively. None of the strains in our material was classified as resistant to amoxicillin and levofloxacin. Whereas 12% was resistant to tetracycline in the newly diagnosed before treatment. Conclusion Clarithromycin resistance was more frequent in the H. pylori treatment-resistant group than strains from patients with newly diagnosed H. pylori infection. No resistance was observed to amoxicillin and levofloxacin. In such cases Therefore levofloxacin may be used provided in vitro sensitivity testing confirms applicability.

• Nesbakken, Truls; Steinshamn, Håvard; Thomsen, Iben Margrete; Basic, Dean; Klem, Thea B. Blystad & Gifstad, Tron Øystein [Show all 25 contributors for this article] (2022). Importation of roughage to Norway - Implications for plant health, biodiversity, animal and human health. Opinion of the Scientific Committee of the Norwegian Scientific Committee for Food and Environment. VKM Report. ISSN 2535-4019. 2022(02). Full text in Research Archive
• Brigtsen, Anne Karin; Jacobsen, Anne Flem; Dedi, Lumnije; Melby, Kjetil K.; Nygaard, Cathrine Skorpen & Fugelseth, Drude [Show all 7 contributors for this article] (2022). Group B Streptococcus colonization at delivery is associated with maternal peripartum infection. PLOS ONE. ISSN 1932-6203. 17(4). doi: 10.1371/journal.pone.0264309. Full text in Research Archive
• Tranulis, Michael A.; Grahek-Ogden, Danica; Kapperud, Georg; Pahnke, Jens; Aspholm, Marina Elisabeth & Jore, Solveig [Show all 11 contributors for this article] (2021). Oppdatert kunnskap om det zoonotiske potensialet av skrantesjuke ved håndtering av slakt og konsum av kjøtt. Vitenskapelig uttalelse fra faggruppen for hygiene og smittestoffer i Vitenskapskomiteen for mat og miljø . VKM Report. ISSN 2535-4019. 2021(8). Full text in Research Archive
• Megraud, Francis; Bruyndonckx, Robin; Coenen, Samuel; Wittkop, Linda; Huang, Te-Din & Hoebeke, Martin [Show all 42 contributors for this article] (2021). Helicobacter pylori resistance to antibiotics in Europe in 2018 and its relationship to antibiotic consumption in the community. Gut. ISSN 0017-5749. 70(10), p. 1815–1822. doi: 10.1136/gutjnl-2021-324032.
• Stenberg, Johan A.; Melby, Kjetil K.; Magnusson, Christer; Nielsen, Anders; Rydning, Julie & Wendell, Micael [Show all 12 contributors for this article] (2021). Risk assessment of the biocontrol product Nemaslug 2.0 with the active organisms Phasmarhabditis californica (strain P19D) and Moraxella osloensis. VKM Report. ISSN 2535-4019. 2021(16), p. 1–37. Full text in Research Archive Show summary

  Key words: VKM, risk assessment, Norwegian Scientific Committee for Food and Environment, Norwegian Food Safety Authority, biological control, Nematodes, Phasmarhabditis californica, Moraxella osloensis. Parasitic nematodes and associated bacteria are increasingly being used for biocontrol of molluscs. Functionally, it is the bacteria that kill and thus control the targeted pests, but the function of the bacteria is dependent on the nematodes, which should be regarded as vectors of biocontrol. Although the nematodes and the bacteria have a symbiotic relationship within such biocontrol formulations, it should be noted that they are not dependent on each other in the wild, but can establish separate populations which can be free-living or hosted by other organisms. The biocontrol product Nemaslug 2.0 contains the nematode Phasmarhabditis californica (strain P19D) and the bacterial symbiont Moraxella osloensis (unknown strain). The nematode was first described in 2016 and has never been reported in Norway. The lack of reports suggests that it is absent from Norway, but this conclusion comes with a high degree of uncertainty since there have been limited search efforts. The climatic thresholds of the nematode are not known, but its current distribution, spanning widely varying climates, suggests that it could survive and establish in Norway. Natural spread from currently known areas of establishment to natural habitats in Norway is ruled out due to the nematode’s limited dispersal capacity. However, human-assisted spread (e.g. via the use of biocontrol products) and establishment would be likely if Nemaslug 2.0 is allowed for use in open fields in Norway. Use of Nemaslug 2.0 in greenhouses and other enclosed areas is not likely to facilitate spread to natural habitats in Norway provided that residues are properly handled. However, deposition of product residues from greenhouses to outdoor areas may result in local establishment of the nematode in the vicinity of the deposition. Phasmarhabditis californica has a broad host range and may parasitize both rare/endangered and common mollusc species. However, there is no scientific evidence suggesting that the nematode can affect natural populations of molluscs in wild habitats, or otherwise have negative effects on biodiversity. The nematodes’ association with the bacteria Moraxella osloensis is most likely lost, or at least weakened, in natural habitats, suggesting that the nematode becomes less capable of killing its hosts in the wild. Phasmarhabditis californica is not capable of harming or infecting humans. The bacterial species Moraxella osloensis is already present in Norway in a few locations and at a low abundance, and it may be native to Norway. Little is known regarding its distribution in natural environments, but the literature shows that it can infect humans and other mammals. In humans with immunodeficiency or other comorbidities, M. osloensis can cause meningitis, vaginitis, sinusitis, bacteremia, endocarditis, and septic arthritis. The risk of infection in people handling Nemaslug 2.0 can probably be substantially reduced by protective clothing and appropriate handling. We are not aware of any reported health issues arising from use of the previous version of Nemaslug, which also contains M. osloensis. Different strains of M. osloensis are known to vary in their sensitivity to antibiotics, and likely in other traits too. Thus, the lack of information provided about the strain identity and specific characteristics of the strain used in Nemaslug 2.0 generates a high degree of uncertainty regarding its pathogenicity, climate tolerance, sensitivity to antibiotics etc.

• Skjerdal, Olaug Taran; Aspholm, Marina Elisabeth; Grahek-Ogden, Danica; Jore, Solveig; Kapperud, Georg & Melby, Kjetil Klaveness [Show all 11 contributors for this article] (2021). Risk ranking and source attribution of food- and waterborne pathogens for surveillance purposes. Opinion of the Panel on Biological Hazards of the Norwegian Scientific Committee for Food and Environment. VKM Report. ISSN 2535-4019. 2021(10), p. 1–252. Full text in Research Archive
• Robertson, Lucy; Grahek-Ogden, Danica; Jore, Solveig; Lund, Vidar; Aspholm, Marina Elisabeth & Kapperud, Georg [Show all 10 contributors for this article] (2020). Giardia og Cryptosporidium i norsk drikkevann. Vitenskapelig uttalelse fra faggruppen for hygiene og smittestoffer i Vitenskapskomiteen for mat og miljø. VKM Report. ISSN 2535-4019. 2020(7), p. 1–38. Full text in Research Archive
• Nilsen, Mariann; Vikanes, Åse Vigdis; Umu, Özgün Candan Onarman; Løvgården, Gunilla; Müller, Fredrik & Melby, Kjetil K. (2020). Differences in composition of gut microbiota in women with and without hyperemesis gravidarum. Microbiota in Health and Disease. ISSN 2704-8845. 2. doi: 10.26355/mhd_20207_316.
• Nestegard, Oddmund; Johnsen, Kay-Martin; Sørbye, Sveinung; Halvorsen, Fred-Arne; Tønnessen, Tor & Paulssen, Eyvind Jakob [Show all 9 contributors for this article] (2020). Clinical characterization of Helicobacter pylori infected patients 15 years after unsuccessful eradication. PLOS ONE. ISSN 1932-6203. 15(9). doi: 10.1371/journal.pone.0238944. Full text in Research Archive
• Melby, Kjetil K.; Carlsen, Karin C. Lødrup; Håland, Geir; Samdal, Helvi Holm & Carlsen, Kai-Håkon (2020). Helicobacter pylori in early childhood and asthma in adolescence. BMC Research Notes. ISSN 1756-0500. 13. doi: 10.1186/s13104-020-04941-6. Full text in Research Archive
• Brigtsen, Anne Karin; Jacobsen, Anne Flem; Dedi, Lumnije; Melby, Kjetil K.; Fugelseth, Drude & Whitelaw, Andrew (2015). Maternal colonization with Group B streptococcus is associated with an increased rate of infants transferred to the neonatal intensive care unit. Neonatology. ISSN 1661-7800. 108, p. 157–163. doi: 10.1159/000434716.
• Brigtsen, Anne Karin; Dedi, Lumnije; Melby, Kjetil K.; Holberg-Petersen, Mona; Radtke, Andreas & Lyng, Randi Valsø [Show all 10 contributors for this article] (2015). Comparison of PCR and serotyping of Group B Streptococcus in pregnant women: The Oslo GBS-study. Journal of Microbiological Methods. ISSN 0167-7012. 108, p. 31–35. doi: 10.1016/j.mimet.2014.11.001.
• Vikanes, Åse Vigdis; Støer, Nathalie; Gunnes, Nina; Grjibovski, Andrej; Samuelsen, Sven Ove & Magnus, Per [Show all 7 contributors for this article] (2013). Helicobacter pylori infection and severe hyperemesis gravidarum among immigrant women in Norway: a case–control study. European Journal of Obstetrics, Gynecology, and Reproductive Biology. ISSN 0301-2115. 167(1), p. 41–46. doi: 10.1016/j.ejogrb.2012.11.007.
• Wester, Astrid Louise; Dunlop, Oona Borghild; Melby, Kjetil K.; Dahle, Ulf R & Wyller, Torgeir Bruun (2013). Age-related differences in symptoms, diagnosis and prognosis of bacteremia. BMC Infectious Diseases. ISSN 1471-2334. 13. doi: 10.1186/1471-2334-13-346. Full text in Research Archive
• Larsen, Astrid Lervik; Ragnhildstveit, Eivind; Moayeri, Behrouz; Eliassen, Lisbeth & Melby, Kjetil K. (2013). Resistance rates of metronidazole and other antibacterials in Helicobacter pylori from previously untreated patients in Norway. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. 121(4), p. 353–358. doi: 10.1111/apm.12009.
• Hjelmevoll, Stig Ove; Olsen, Merethe Elise; Sollid, Johanna U Ericson; Haaheim, Håkon; Melby, Kjetil K. & Moi, Harald [Show all 8 contributors for this article] (2012). Appropriate Time for Test-of-Cure when Diagnosing Gonorrhoea with a Nucleic Acid Amplification Test. Acta Dermato-Venereologica. ISSN 0001-5555. 92(3), p. 316–319. doi: 10.2340/00015555-1275. Full text in Research Archive Show summary

  Culture is commonly regarded as the gold standard for diagnosis of Neisseria gonorrhoeae. However, nucleic acid amplification tests (NAATs) have rapidly replaced culture for diagnostics in many settings. The aim of the present study was to investigate the appropriate time for test-of-cure (TOC) when NAATs are used for diagnosis of gonorrhoea. In total, 30 patients (28 men and 2 women) provided urethral, cervical, rectal or pharyngeal specimens for TOC. All included patients, except one who did not return for second TOC before day 19, tested negative within 2 weeks after treatment with cefixime 400 mg × 1. Antimicrobial susceptibility testing showed that 68% of the culture-positive strains were resistant to ciprofloxacin. Thus, the recommended empirical treatment with ciprofloxacin in Norway should be changed immediately. TOC can be performed 2 weeks after treatment when NAATs are used for diagnosis of gonorrhoea.

• Holberg-Petersen, Mona; Jenum, Pål Arne; Mannsåker, Turid & Melby, Kjetil K. (2011). Comparison of PCR with culture applied on nasopharyngeal and throat swab specimens for the detection of Bordetella pertussis. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 43(3), p. 221–224. doi: 10.3109/00365548.2010.538855.
• Grub, Carola; Holberg-Petersen, Mona; Medbø, Sverre; Andersen, Bjørg Marit; Syversen, Gaute & Melby, Kjetil K. (2010). A multidrug-resistant, methicillin-susceptible strain of Staphylococcus aureus from a neonatal intensive care unit in Oslo, Norway. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 48(2), p. 148–151. doi: 10.3109/00365540903334401.
• Merckoll, Patricia; Jonassen, Tom Øystein; Vad, Marie Elisabeth; Jeansson, Stig & Melby, Kjetil K. (2009). Bacteria, biofilm and honey: A study of the effects of honey on 'planktonic' and biofilm-embedded chronic wound bacteria. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 41(5), p. 341–347. doi: 10.1080/00365540902849383.
• Hjelmevoll, Stig Ove; Olsen, Merethe Elise; Sollid, johanna u ericson; Haaheim, Håkon; Melby, KK & Moi, H. [Show all 8 contributors for this article] (2008). Clinical validation of a real-time polymerase chain reaction detection of Neisseria gonorrheae porA pseudogene versus culture techniques. Sexually Transmitted Diseases. ISSN 0148-5717. 35, p. 517–520. doi: 10.1097/OLQ.0b013e3181644bc9.
• MENGISTU, ZELALEM; Engh, V; Melby, Kjetil K.; von der Lippe, Elisabeth & Qvigstad, Erik (2007). Postmenopausal vaginal bleeding caused by endometrial tuberculosis. Acta Obstetricia et Gynecologica Scandinavica. ISSN 0001-6349. 86(5), p. 631–632.
• Jørgen, Bente Marie; Merckoll, Patricia & Melby, Kjetil K. (2007). Susceptibility to daptomycin, quinupristin-dalfopristin and linezolid and some other antibiotics in clinical isolates of methicillin resistant and methicillin sensitive S.aureus from the Oslo area. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 39(11), p. 1059–1062.
• Iversen, Bjørn Gunnar; Jacobsen, Trond; Eriksen, Hanne-Merete; Bukholm, Geir; Melby, Kjetil K & Melby, Kjetil K. [Show all 8 contributors for this article] (2007). An outbreak of Pseudomonas aeruginosa infection caused by contaminated mouth swabs. Clinical Infectious Diseases. ISSN 1058-4838. 44(6), p. 794–801. doi: 10.1086/511644.
• Antal, Ellen-Ann; Dietrichs, Espen; Løberg, Else Marit; Melby, Kjetil K. & Mæhlen, Jan (2005). Brain stem encephalitis in listeriosis. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 37(3), p. 190–194. Show summary

  Serious infection with the bacterium L. monocytogenes mainly manifests as sepsis and/or meningitis. A particular entity is Listeria brain stem encephalitis, which is characterized by progressive brain stem deficits. The condition is fatal unless early treated. The purpose of the present study was to assess the incidence of brain stem encephalitis in a population-based listeriosis material. Medical records from 212 of the 240 patients with serious listeriosis reported in Norway from 1977 to 2000, as well as autopsy material from 8 of these patients, were available. This material was searched for clinical and neuropathological evidence of brain stem infection. Findings indicating brain stem encephalitis were present in 19 of the 172 patients with adult listeriosis (11%) but none of the 40 pregnancy-related listeriosis cases. None of the 19 patients had been diagnosed with Listeria brain stem infection originally. We conclude that brain stem encephalitis is relatively common in this Norwegian listeriosis material.

• Simonsen, GS; Bergh, K; Bevanger, L; Digranes, A; Gaustad, Peter & Melby, Kjetil K. [Show all 7 contributors for this article] (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, p. 254–258. Show summary

  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.

• Tveten, Y; Jenkins, A; Digranes, A; Melby, Kjetil K.; Allum, AG & Kristiansen, BE (2004). Comparison of PCR detection of mecA with agar dilution and Etest for oxacillin susceptibility testing in clinical isolates of coagulase-negative staphylococci. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 10(5), p. 462–465. Show summary

  Oxacillin-resistant staphylococci are heterogeneous in their expression of resistance to beta-lactam antibiotics. Different recommendations regarding screening methods for routine use have been published. In this study, the susceptibility to oxacillin of 232 coagulase-negative staphylococci (CoNS) was determined by agar dilution, Etest and presence of the mecA gene. When an oxacillin resistance breakpoint of > or = 0.5 mg/L was used, the sensitivity and specificity for agar dilution were 97.6% and 100%, and those for Etest were 100% and 95.4%. The current National Committee for Clinical Laboratory Standards oxacillin breakpoint recommendation will categorise accurately the CoNS species encountered commonly

• Håland, Geir; Melby, Kjetil K.; Carlsen, Karin C. Lødrup; Skar, Anne Grete; Pettersen, Morten & Carlsen, Kai-Håkon (2004). Are Chlamydia Pneumoniae and Mycoplasma Pheumoniae serum antibodies associated with obstructive airways disease in 2 year old children? American Journal of Respiratory and Critical Care Medicine. ISSN 1073-449X. 169(7).
• Tveten, Y; Jenkins, A; Digranes, A; Melby, KK; Allum, AG & Kristiansen, Bjørn-Erik (2004). Comparison of PCR detection of mecA with agar dilution and Etest for oxacillin susceptibility testing in clinical isolates of coagulase-negative staphylococci. Clinical Microbiology and Infection (CMI). ISSN 1198-743X. 10, p. 462–465.
• Eskild, Anne; Dahl, Gunn Fallås; Melby, Kjetil Klaveness & Nesheim, Britt Ingjerd (2003). Testing for toxoplasmosis in pregnancy: a study of the routines in primary antenatal care. Journal of Medical Screening. ISSN 0969-1413. 10(4), p. 172–175.
• Iversen, PO; Melby, Kjetil Klaveness & Erikstad, TE (2003). Treatment of tuberculosis in three of Oslo's central and eastern parts in 1994-2000. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 123(6), p. 815–817.
• Melby, Kjetil Klaveness (2003). Campylobacter og kinolonresistens. MSIS-rapport. ISSN 1503-1926. Show summary

  Antibiotikaresistensutvikling hos Campylobacter kan oppfattes som indikator for resistensutvikling blant bakterier. Vurderes forbruk av den viktige preparatgruppen kinoloner (nalidiksinsyre, ofloksacin, ciprofloksacin), ser man at kinolonresistens øker med kinolonforbruk. Dersom antibakteriell behandling er indisert, skal campylobacteriose ikke behandles med et fluorokinolon men med et makrolid (f.eks. erytromycin). Også her forekommer resistens, men ytterst sjelden blant norske isolater. Vår undersøkelse indikerer at Campylobacter i den aktuelle tidsperioden har tilpasset seg forbruket av kinoloner (nalidiksinsyre) og tetracykliner. Innen aktuelle områder er derivater av slike stoffer i bruk både i human og veterinærmedisinsk praksis. Det er godt mulig at dette bidrar til at kinolonresistens er så utbredt. Denne undersøkelsen understøtter at pasienter som har ervervet infeksjon utenfor Skandinavia, uavhengig av type, bør antas å være infisert med mikrober som i utgangspunkt er mindre antibiotikafølsomme enn de vi har i Norge. Dette bør medføre at man ikke benytter antibiotika uten etter grundige overveielser, samt kartlegger infeksjonsårsaken og eventuell resistens slik at et målrettet antibiotikavalg finner sted.

• Antal, Ellen-Ann; Løberg, Else Marit; Bracht, Paula; Melby, Kjetil Klaveness & Mæhlen, Jan (2001). Evidence for retrograde intraaxonal spread of listeria monocytogenes. Brain Pathology. ISSN 1015-6305. 11, p. 432–438.
• Lindbæk, Morten; Melby, Kjetil Klaveness; Schøyen, Rolf & Hjortdahl, Per (2001). Bacteriological findings in nasopharynx specimens from patients with a clinical diagnosis of acute sinusitis. Scandinavian Journal of Primary Health Care. ISSN 0281-3432. 19, p. 126–130.
• Satas, Saulius; Hoem, Nils-Ove; Melby, Kjetil K.; Porter, H.; Lindgren, Carl & Whitelaw, Andrew [Show all 7 contributors for this article] (2000). Influence of mild hypothermia after hypoxia-ischemia on the pharmacokinetics of gentamicin in newborn pigs. Biology of the Neonate. ISSN 0006-3126. 77(1), p. 50–57.
• Hansen, S.W.; Melby, Kjetil Klaveness; Aase, Steinar Torbjørn; Jellum, Egil; McColl, K.E.L. & Vollset, Stein Emil (2000). H. pylori infection and smoking have strong joint effects as risk factors of non-cardia gastric cancer but have opposing effects on cardia cancer. Meeting Abstract. Gut. ISSN 0017-5749. 46.
• Lindstedt, Bjørn-Arne; Heir, E.; Vardund, T.; Melby, Kjetil Klaveness & Kapperud, Georg (2000). Comparative fingerprinting analysis of Campylobacter jejuni subsp. jejuni stains by amplified-fragment length polymorphism genotyping. Journal of Clinical Microbiology. ISSN 0095-1137. 38(9), p. 3379–3387.
• Melby, Kjetil Klaveness; Svendby, J. G.; Eggebo, T.; Holmen, L. A.; Andersen, Bjørg Marit & Lind, L. [Show all 8 contributors for this article] (2000). Outbreak of Campylobacter infection in a subartic community. European Journal of Clinical Microbiology and Infectious Diseases. ISSN 0934-9723. 19(7), p. 542–544.
• Hansen, S.W.; Melby, Kjetil Klaveness; Aase, Steinar Torbjørn; Jellum, Egil; McColl, K.E.L. & Vollset, Stein Emil (2000). Role of smoking and Helicobacter pylori infection in aetiology of cardia versus non-cardia gastric cancer. Meeting Abstract. Gastroenterology. ISSN 0016-5085. 118(4).
• Hansen, S.W.; Melby, Kjetil Klaveness; Aase, Steinar Torbjørn; Jellum, Egil & Vollset, Stein Emil (1999). Helicobacter pylori infection and risk of cardia cancer and non-cardia gastric cancer - A nested case-control study. Scandinavian Journal of Gastroenterology. ISSN 0036-5521. 34(4), p. 353–360.
• Holberg-Petersen, Mona; Steinbakk, Martin; Figenschau, K.J.; Jantzen, E.; Eng, J. & Melby, Kjetil Klaveness (1999). Identification of clinical isolates of Mycobacterium spp. by sequence analysis of the 16S ribosomal RNA gene. Experience from a clinical laboratory. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. 107(2), p. 231–239.
• Melby, Kjetil Klaveness; Kvien, Tore Kristian; Glennås, Anne & Anestad, G. (1999). Chlamydia pneumoniae as a trigger of reactive arthritis. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 31(3), p. 327–328.
• Melby, Kjetil Klaveness; Kvien, Tore Kristian & Glennås, Anne (1999). Helicobacter pylori - a trigger of reactive arthritis? Infection. ISSN 0300-8126. 27(4/5), p. 252–255.
• Wyller, V. Bruun; Antal, Ellen-Ann; Bracht, Paula; Løberg, Else Marit; Melby, Kjetil Klaveness & Mæhlen, Jan (1999). Listeria monocytogenes - the perfect parasite? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 119(3), p. 375–379.
• Jenum, Pål Arne; Stray-Pedersen, Babill; Melby, Kjetil Klaveness; Kapperud, Georg; Whilelaw, Andrew & Eskild, Anne [Show all 7 contributors for this article] (1998). Incidence of Toxoplasma gondii Infection in 35,940 pregnant Women in Norway and Pregnancy Outcome for Infected Women. Journal of Clinical Microbiology. ISSN 0095-1137. p. 2900–2906.
• Jenum, Pål Arne; Kapperud, Georg; Stray-Pedersen, Babill; Melby, Kjetil Klaveness; Eskild, Anne & Eng, J. (1998). Prevalence of Toxoplasma gondii specific immunoglobulin G antibodies among pregnant women in Norway. Epidemiology and Infection. ISSN 0950-2688. 120, p. 87–92.
• Gjeruldsen, S.; Syversen, Gaute; Lippe, E. von der & Melby, Kjetil Klaveness (1998). Gule stafylokokker med nedsatt meticillinfølsomhet. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 118, p. 4065–4067.
• Jenum, Pål Arne; Pettersen, M. Holbek; Melby, Kjetil Klaveness & Stray-Pedersen, Babill (1998). Diagnosis of congenital Toxoplasma gondii infection by polymerase chain reaction (PCR) in amniotic fluid samples. APMIS - Journal of Pathologiy, Microbiology and Immunology. ISSN 0903-4641. p. 680–686.
• Bergan, Tom; Bruun, Johan N; Digranes, Asbjørn; Lingaas, Egil; Melby, Kjetil Klaveness & Sander, Jan (1997). Susceptibility testing of bacteria and fungi. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 29(Suppl. 103), p. 1–36.
• Lind, L.; Sjøgren, E.; Melby, Kjetil Klaveness & Kaijser, B. (1996). DNA fingerprinting and serotyping of Campylobacter jejuni isolates from epidemic outbreaks. Journal of Clinical Microbiology. ISSN 0095-1137. 34(4), p. 892–896.
• Kapperud, Georg; Jenum, Pål Arne; Stray-Pedersen, Babill; Melby, Kjetil Klaveness; Eskild, Anne & Eng, J. (1996). Risk factors for Toxoplasma gondii infection in pregnancy. Results of a prospective case-control study in Norway. American Journal of Epidemiology. ISSN 0002-9262. 144(4), p. 405–412.
• Bas, S; Cunningham, T; Kvien, Tore Kristian; Glennås, Anne; Melby, Kjetil Klaveness & Vischer, T. L. (1996). Synovial fluid and serum antibodies against Chlamydia in different forms of arthritis: intra-articular IgA production in Chlamydia sexually acquired reactive arthritis. British Journal of Rheumatology. ISSN 0263-7103. 35(6), p. 548–552.
• Bas, S; Cunningham, T; Kvien, Tore Kristian; Glennås, Anne; Melby, Kjetil Klaveness & Vischer, T. L. (1996). The value of isotype determination of serum antibodies against Chlamydia for the diagnosis of Chlamydia reactive arthritis. British Journal of Rheumatology. ISSN 0263-7103. 35(6), p. 542–547.
• Guy, EC.; Pelloux, H.; Lappalainen, M.; Apöck, H.; Hassel, A. & Melby, Kjetil Klaveness [Show all 10 contributors for this article] (1996). Interlaboratory comparison of polymerase chain reaction for the detection of Toxoplasma gondii DNA added to samples of amniotic fluid. European Journal of Clinical Microbiology and Infectious Diseases. ISSN 0934-9723. 15(10), p. 836–839. Show summary

  To investigate the accuracy of the polymerase chain reaction (PCR) method for the detection of Toxoplasma gondii in clinical specimens, aliquots of amniotic fluid to which known amounts of Toxoplasma gondii DNA had been added were tested by five European Centres. Four laboratories were able to detect DNA at levels equivalent to ten tachyzoites or less, including two that detected DNA equivalent to a single parasite. Two laboratories erroneously found one of eight negative control samples to be positive. These findings confirm that the high level of sensitivity associated with the PCR method can be readily achieved under routine laboratory conditions, but they also underscore the potential for both false-positive and false-negative findings to occur. Furthermore, the results confirm the urgent need for an external quality assurance scheme to support laboratories employing PCR in a clinical context for the detection of Toxoplasma gondii.

• Dunlop, Oona; Rootwelt, V.; Sannes, Mette; Goplen, Anne Kristin; Abdelnoor, Michel & Skaug, Kjell [Show all 11 contributors for this article] (1996). Risk of toxoplasmic encephalitis in AIDS patients: indications for prophylaxis. Scandinavian Journal of Infectious Diseases. ISSN 0036-5548. 28, p. 71–73.
• Kvien, Tore Kristian; Glennås, Anne & Melby, Kjetil Klaveness (1996). Prediction of diagnosis in acute and sub acute oligoarthritis of unknown origin. British Journal of Rheumatology. ISSN 0263-7103. 35(4), p. 359–363.

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• Melby, Kjetil Klaveness; Lundin, Knut & Ness-Jensen, Eivind (2022). Possible interference of infection with Helicobacter pylori with the onset of coeliac disease.
• Brigtsen, Anne Karin; Jacobsen, Anne Flem; Dedi, Lumnije; Melby, Kjetil K.; Espeland, Cathrine Nygaard & Fugelseth, Drude [Show all 7 contributors for this article] (2019). Maternal peripartum infection in women colonized with group B Streptococcus at delivery: a prospective cohort study.
• Steinbakk, Martin; Moayeri, Behrouz & Melby, Kjetil K. (2019). Antibiotic sensitivity pattern in Helicobacter pylori from previously untreated patients in South-Eastern Norway 2018.
• Melby, Kjetil K.; Nissen-Meyer, Lise Sofie Haug & Lundin, Knut Erik Aslaksen (2019). Helicobacter pylori in patients with coeliaci compared to healthy blood donors.
• Melby, Kjetil K.; Carlsen, Karin C. Lødrup; Haaland, Geir; Samdal, Helvi Holm; Mowinckel, Petter & Carlsen, Kai Håkon (2017). Antistoffnivåer mot Helicobacter pylori ved 16 års alder relatert til Astma.
• Melby, Kjetil K.; Carlsen, Karin C. Lødrup; Håland, Geir; Samdal, Helvi Holm; Mowinckel, Petter & Carlsen, Kai-Håkon (2017). Antibody levels to Helicobacter pylori infections at 16 years of age in relation to allergic disease. Helicobacter. ISSN 1083-4389. 22, p. 114–114.
• Melby, Kjetil K.; Carlsen, Karin C. Lødrup; Håland, Geir; Samdal, Helvi Holm; Mowinckel, Petter & Carlsen, Kai-Håkon (2017). Cod liver oil consumption and prevalence of Helicobacter pylori (HP) infections at 2, 10 and 16 years of age. Helicobacter. ISSN 1083-4389. 22, p. 96–97. doi: 10.1111/hel.12416.
• Melby, Kjetil K.; Vikanes, Åse Vigdis; Nilsen, Mariann & Müller, Fredrik (2015). Hyperemesis grvidarum and Helicobacter pylori. .
• 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. ISSN 0029-2001. 134(5), p. 507–508. doi: 10.4045/tidsskr.14.0033.
• Brigtsen, Anne Karin; Dedi, Lumnije; Melby, Kjetil K.; Fugelseth, Drude ; Flem-Jacobsen, Anne & Lindemann, Rolf (2012). High Prevalence of Group B Streptococcus Serotype IX in the Norwegian Population.
• Vikanes, Åse Vigdis; Stoer, NC; Gunnes, Nina; Grjibovski, Andrei M.; Samuelsen, Sven Ove & Magnus, Per [Show all 7 contributors for this article] (2012). Helicobacter pylori and severe hyperemesis gravidarum by IgG, virulence factors and feces antigens; an institution-based case-control study among immigrant women in Norway. European Journal of Public Health. ISSN 1101-1262. 22, p. 240–240.
• Melby, Kjetil K.; Carlsen, KL; Haaland, G; Carlsen, KH; Munthe-Kaas, MC & Devulpallli, CS [Show all 8 contributors for this article] (2007). Prevalence of Helicobacter pylori (HP) infection at two and ten years of age.
• Antal, Ellen-Ann; Løberg, Else Marit; Dietrichs, Espen; Melby, Kjetil K. & Mæhlen, Jan (2005). Patogenesen for hjernestammelisteriose; observasjoner på mus og menneske. Show summary

  Listeriose er matvarebåren infeksjon med bakterien Listeria monocytogenes. Sykdommen har høy dødelighet og rammer særlig predisponerte individer inkludert immunsvekkede, eldre og gravide. Sykdommen opptrer sporadisk eller i epidemier, og er meldepliktig til MSIS. En spesielt alvorlig manifestasjon er hjernestammelisteriose. Denne tilstanden er vanlig hos husdyr, men forekommer også hos menneske. I det norske listeriosematerialet (MSIS) fra perioden 1977-2000 fant vi at udiagnostisert klinisk hjernestammelisteriose må ha vært tilstede hos minst 11% av pasientene (1). Ved nevropatologisk undersøkelse av 9 pasienter med hjernestammelisteriose fant vi at bakterieholdige betennelsesinfiltrater var lokalisert langs forløpet av hjernenerver som innerverer munnhulen og svelget; trigeminus-, vagus-, glossopharyngeus- og hypoglossusnervene (2). Disse funnene korrelerer med histologiske og radiologiske observasjoner vi har gjort av bakterietransport langs hjernenerver i en musemodell for hjernestammelisteriose (3). Til sammen passer observasjonene på mus og menneske med at hjernestammelisteriose oppstår ved at matbårne Listeriabakterier krysser slimhinnen i munnhulen, transporteres retrograd langs hjernenerver og translokeres til hjernenervekjerner i den forlengede marg. Referanser: 1) Brain stem encephalitis in listeriosis. Antal EA, Løberg EM, Dietrichs E, Mæhlen J. Scandinavian Journal of Infectious Diseases 2005; 37: 190-194. 2) Neuropathological findings in 9 cases of Listeria monocytogenes brain stem encephalitis Antal EA, Løberg EM, Dietrichs E, Mæhlen J. Brain Pathology 2005; 15: 187-191. 3) Evidence for axonal transport of Listeria monocytogenes. Antal EA, Bracht P, Løberg EM, Melby KK, Mæhlen J. Brain Pathology 2001; 11: 432-8.

• ULVMOEN, AINA & Melby, Kjetil K. (2005). Gonokokker i Oslo området - oversikt over antibiotika resistens med særlig vekt på fluorokinoloner.
• Jørgen, Bente; Merckoll, Patricia & Melby, Kjetil K. (2005). How effective is the new antibiotic Daptomycin against MRSA and Methicillin-sensitive Staphylococcus aureus in the Oslo area?
• Jørgen, Bente; Holberg-Petersen, Mona; Syversen, Gaute; Andresen, Lise & Melby, Kjetil K. (2004). METHICILLINRESISTENTE STAPHYLOCOCCUS AUREUS - KLONALITET OG RESISTENS MØNSTER I OSLO-OMRÅDET. Show summary

  Hensikt: Kartlegge variasjon i pulsfelt gelelektroforese-mønster (PFGE) hos tilfeldig utvalgte isolater av meticillinresistente Staphylococcus aure us (MRS A) fra Oslo-området, og sammenligne deres anbiotikafølsomhet. Materiale: I perioden mai 1995 til mai 2004 ble 425 MRSA-isolater funnet i prøver analysert ved vår avdeling. Fra denne databasen ble 85 isolater tilfeldig utvalgt og videre undersøkt. Metode: Alle kliniske isolater ble undersøkt i samsvar med gjeldende retningslinjer, med konvensjonell testing av antibiotikafølsomhet ved diskdiffusjon (AB Biodisk, Stockholm, Sverige), påvisning av mecA-gen med PCR og karakterisering med makrorestriksjonsanalyse av Smal-kuttet genomisk DNA separert ved PFGE. PFGE-profilene ble analysert med Molecular Analyst Software Fingerprinting, vl.6 (Applied Maths, Belgium). Klonalitet ble satt ved 80% likhet. Tilleggsundersøkelse av antibiotikafølsomhet ble gjort med Etest (Biodisk, Stockholm) i følge leverandørens instruksjoner. Resultater: De 85 isolatene ble undersøkt for følsomhet overfor 17 forskjellige antibiotika. Blant de 85 undersøkte PFGE-profilene var det stor klonal variasjon. 7 clustere inneholdt ~4 isolater og omfattet 55 (ca. 64%) av isolatene. Bare 5 clustere inneholdt ~ 5 isolater. To av de større clusterene hadde isolater fra samme klonale gruppe som ble isolert under to MRSA-utbrudd ved et sykehus i vår region i 1999 og 2000. Et isolat i en annen stor cluster var lik den epidemiske (E)MRSA-15 fra Storbritannia og et isolat i en annen relatert til EMRSA-16.Generelt var antibiotikafølsomheten jevnt fordelt mellom PFGE- clusterene. Fucidinresistens så ut til å være lokalisert til to av de store clusterene og bare sjelden i de sporadiske isolatene. Tilsvarende trend så ut til å gjelde klindamycin og aminoglykosider. Rifampicinresistens fantes nesten utelukkende i de sporadiske isolatene. Konklusjon: Molekylære overvåkningsstudier har dokumentert en stor spredning av klonalitet blant MRSA-isolater.Antibiotikaresistens synes å være jevnt distribuert mellom klanene unntatt fucidinresistens. Disse trendene bør fortsatt overvåkes nøye.

• Melby, Kjetil K. & Skar, Anne Grete (2004). Guillain Barre syndrom (GBS) etter dokumentert infeksjon med Campylobacter Jejuni/Coli - Muligheter for et nasjonal studie? Show summary

  Guillain-Barre syndrom (GBS) er en alvorlig komplikasjon etter gjennomgått infeksjonssykdom. I ca 30% av tilfellene forteller pasientene om gastrointestinal infeksjon og i tilsvarende omfang om forutgående luftveisinfeksjon. På VVS ses årlig 5-10 slike tilfelle. Prognosen er vanligvis god men forverres med økende alder. Hensikten denne presentasjonen er å gjøre oppmerksom på denne potensielt alvorlige men heldigvis sjeldne komplikasjon som kan opptre etter gjennomgått infeksjonssykdom. Siden 1980 årene er det ikke foretatt noen landsomfattende undersøkelser med hensyn på utløsende årsaker til Guillain Barre syndrom. En studie hvor fokus særlig er på Campyloba:cter jejuni/coli som mulig utløser vil derfor være av interesse. Materiale og metoder. Sekvensielle sera fra 2 pasienter - begge pasientene innlagt i VVS og utredet i henhold til standard kriterier for slike pasienter -var tilgjengelig for undersøkelse i tillegg til sera fra dyrkningspositive pasienter. Feces dyrkning med hensyn på C.jejuni/coli ble utført med konvensjonell metodikk på et modifisert Skirrows medium. Spesifikke antistoffer (IgG, IgM og IgA) i serum ble påvist ved en in house diffusjon i gel ELISA teknikk med en etanolinaktivert multireagerende C.jejuni stamme som antigen samt en kommersiell Campylobacter ElA IgG/lgNlgM (Virion) som synes å ha en sensitivitet i forhold til dyrkning på ~ 65% (spesifikt IgG). Resultater. Begge pasientene var infisert med Campylobacter jejuni/coli. Fra begge pasienter var tilgjengelig sera tatt 14 dager etter sykdomsdebut og opptil 12 uker etter start av infeksjonen. Hos begge pasientene ble påvist til dels sterkt forhøyete IgG antistoff nivåer spesifikt rettet mot en multireagerende C.jejuni stamme (B14363/8l). Kommeutarer og konklusjoner. Blant GBS pasienter finnes de som har Campylobacter jejuni/coli som årsak til enteritt. Hos GBS pasienter vil påvisning av spesifikke antistoffer være nyttig for å sannsynliggjøre CJ betydning som utløsende årsak på samme måte som denne mikroben er knyttet til re aktiv artritt (ReA). De mikrobiologiske avdelinger oppfordres til å ta vare på serum og eventuelle isolater fra GBS pasienter. Campylobacter infeksjonen har økt forekomst i Norge og relasjonen til GBS er fortsatt uklar. Siden forekomsten anslås å være 1/100000 individer er helst en landsomfattende studie nødvendig for å sikre tilstrekkelig materiale. Om ønskelig kan stammer/sera sendes til Mikrobiologisk avdeling, VVS.

• Eskild, Anne; Dahl, Gunn Fallås; Melby, Kjetil Klaveness & Nesheim, Britt Ingjerd (2003). Testing for toxoplasmosis in pregnancy: a study of the routines in primary antenatal care.
• Melby, Kjetil Klaveness (2003). Increasing Antibiotic Resistance in Campylobacter ssp Recovered over a Ten Year Period from Patients residing in The Oslo Area. Show summary

  Introduction. Campylobacter jejuni/coli is regarded as a leading cause of gastroenteritis. Aim of the study was to analyse the antibiotic sensitivity pattern of Campylobacter ssp detected in our department during the period 1988 -2000 with reference to where the infection was contracted. Materials and methods. Antibiotic sensitivity testing was done by disc diffusion. Results Altogether 2489 Campylobacter sp were reported. Both an increase in number of Campylobacter sp and their resistance to nalidixic acid (NalR), tetracycline and erythromycin was observed. The resistance (NalR) increased from 1988 to 2000. An increase in total nalidixic acid resistance (TotalNalR) was found among isolates from patients contracting their disease in South East Asia or the Iberian peninsula. A trend towards smaller zone of inhibition was observed for all antibiotics tested during the period 1991 - 1999. In Campylobacter ssp nalidixic acid resistance predicted fluoroquinolone resistance. Comments and conclusions. Studies have shown that quinolone resistance may be related to quinolone usage for a variety of infections including travellers diarrhoea and usage in veterinary medicine. Fluoroquinolone therapy for campylobacteriosis should be avoided as quionolone resistance may quickly emerge during therapy. The increase in macrolide resistance is worrying as this is the drug of choice. The increase in antibiotic resistance among Campylobacter ssp may be regarded as an indicator of level of resistance among other enteric pathogens for instance Salmonella sp in which nalidixic acid resistance may predict therapeutic failure when using ciprofloxacin even though the strain may be in vitro sensitive. However, nalidixic acid resistant Campylobacter ssp appeared also resistant to ciprofloxacin. The occurrence varied apparently according to antibiotic consumption in the area.

• Melby, Kjetil Klaveness (2003). Økt forekomst av antistoffer mot Helicobacter pylori hos pasienter med 1. gangs hjerteinfarkt behandlet med percutan coronar intervensjon.
• Melby, Kjetil Klaveness (2003). Hyperemesis Gravidarum is not linked to the presence of antibodies to Helicobacter pylori in Norwegian pregnant women but is so in patients of African descent.
• Melby, Kjetil Klaveness (2003). Prevalence of Helicobacter pylori infections and sensitisation at 2 years of age.
• Antal, Ellen-Ann; Dietrichs, Espen; Løberg, Else Marit; Melby, Kjetil Klaveness & Mæhlen, Jan (2002). 5) Brain stem infection is common in listeriosis. Eur Jrn Neurol Oct 2002, 9 (Suppl.2), 17. Show summary

  Introduction: Infection by the bacterium Listeria monocytogenes occurs sporadically (1,2-2,5:100.000/yr) or in regular epidemics (1). In adults, listeriosis mainly occurs as sepsis or meningitis, but a particularly serious syndrome; brain stem encephalitis with progressive brain stem deficits and coma, also occurs. The frequency of this syndrome has never been determined, but a review from 1992 identified only 62 cases reported in world literature (2). We here present a retrospective study of the frequency of brain stem infection in adult, non-pregnancy-related listeriosis. Materials & methods: 247 cases of listeriosis were nominally reported in Norway in the period 1977-2000. 133 patients had definite adult listeriosis. The other cases were pregnancy-related, or data were unavailable. We studied medical records, laboratory results and (in 6 cases) autopsy material. Brain stem infection was identified by clinical and/or histopathological criteria. Results: Although brain stem infection had not been diagnosed in any of the patients during their illness, symptoms and signs of brain stem infection were recorded in 20 of the 133 adult listeriosis cases. Their clinical pictures varied widely. Moreover, autopsy demonstrated brain stem infection in some patients in which no neurological deficits had been recorded. Conclusion: Brain stem infection is frequently present in adult listeriosis. Neurological examination should therefore be performed on all listeriosis patients. Also, listeriosis should always be considered when brain stem deficits from an unknown cause are in progress. 1) Lorber B. Listeriosis. Clin Infect. Dis, 1997;24:1-11 2) Armstrong RW, Fung PC. Brainstem encephalitis (rhombencephalitis) due to Listeria monocytogenes: case report and review. Clin Infect Dis 1993;16:689-702

• Melby, Kjetil Klaveness; Wethe, Marianne; Hansen, Svein; Skar, Anne Grete & Gjønnæss, Halvard Alf (2002). Hyperemesis gravidarum ¿ relation to Helicobacter pylori. A serological study on sera from pregnant women in Oslo. Show summary

  Hyperemesis gravidarum is most likely not linked to the presence of Helicobacter pylori in a Scandinavian setting.

• Jørgen, Bente; Syversen, Gaute & Melby, Kjetil Klaveness (2002). Fucidinresistente Staphylococcus aureus hos impetigopasienter fra Oslo området. Show summary

  Bakgrunn:Impetigo er en velkjent overflatisk hudinfeksjon som i den senere tid har fått endel oppmerksomhet. Siden flere institusjoner har rapportert økende forekomst av denne tilstanden har vi ved mikrobiologisk avdeling, Ullevål universitetssykehus gjort en liten retrospektiv analyse av våre funn ved impetigo. Materiale og metode: Fra vår database ble fucidinfølsomhet hos Staphylococcus aureus i perioden juli-august i 2001 og 2002 beregnet. I tillegg gjennomgikk vi 1500 polikliniske pussprøver sendt til avdelingen juli- august 2002. Klinikk: Fra remisser der det var angitt mistanke om brennkopper/impetigo registrerte vi mikrobiologisk funn og fucidinfølsomheten hos S. aureus der dette ble funnet. Konklusjon:Årets utbrudd av impetigo preges i stor grad av monoinfeksjon med Staphylococcus aureus, i motsetning til det tidligere mer Streptococcus pyogenes-dominerte bildet. I tillegg ses en stor økning av fucidinresistente S.aureus-isolater, hele 75% i vårt materiale. Dette har gjort at den vanlige lokalbehandling i mange tilfeller ikke har ført fram, og sykdomsvarighet og mulighet for videre smitte har økt. På bakgrunn av dette er det grunn til å fraråde bruk av fucidin ved impetigo inntil svar på dyrkning og resistensbestemmelse foreligger. Ved lokalbehandling kan bacimycin være et alternativ.

• Melby, Kjetil Klaveness & Mannsåker, Turid (2001). Antibiotikafølsomhet for campylobacter ssp isolert fra Oslopasienter over en 10 års periode.
• Holberg-Petersen, Mona; Mannsåker, Turid; Jenum, Pål Arne & Melby, Kjetil Klaveness (2001). Clinical experience of PCR, culture, and serology for detection of Bordetella pertussis.
• Melby, Kjetil Klaveness & Mannsåker, Turid (2001). Antibiotic sensitivity pattern of campylobacter ssp. Recovered over a ten year period from patients residing in the Oslo area.
• Melby, Kjetil Klaveness (2000). Epidemiologi og resistens overfor antibakterielle midler blant Salmonella sp og Campylobacter sp - Et 10-årsmateriale.
• Melby, Kjetil Klaveness (2000). Etiologi og resistensforhold ved urinveisinfeksjoner.
• Melby, Kjetil Klaveness (2000). Experience in diagnosing Borreliosis in the Department of Microbiology, Ullevaal University Hospital.
• Mannsåker, Turid; Syversen, Gaute; Lippe, Bent von der & Melby, Kjetil Klaveness (2000). Occurence of MRSA and BORSA in blood cultures from 1998 and 1999 in a large teaching hospital.
• Holberg-Petersen, Mona; Mannsåker, Turid; Jenum, Pål Arne & Melby, Kjetil Klaveness (1999). Kikhostediagnostikk ved PCR-En sammenligning med serologi og dyrkning-videre studier.
• Melby, Kjetil Klaveness (1999). Etiologi ved bakteriemi/sepsis-erfaringer fra Ullevål sykehus.
• Melby, Kjetil Klaveness (1999). Salmonella og campylobacter infeksjoner.
• Hansen, S.W.; Melby, Kjetil Klaveness; Aase, Steinar Torbjørn; McColl, K.E.L. & Vollset, Stein Emil (1999). Røyking, helicobacter pylori-infeksjon og kreft i magesekk.
• Melby, Kjetil Klaveness (1999). Anitbiotikaresistens hos salmonella og campylobacter sp-erfaringer fra perioden 1988-98.
• Hansen, S.W.; Melby, Kjetil Klaveness; Aase, Steinar Torbjørn; Jellum, Egil; Mccoll, K. E. L. & Vollset, E. E. (1999). H. pylori infection and smoking have strong joint effects as risk factors of non-cardia gastric cancer but have opposing effects on cardia cancer.
• Melby, Kjetil Klaveness (1998). Campylobacter jejuni/coli - Kliniske og serologiske erfaringer fra vannbårne utbrudd i Norge.
• Hansen, S.W.; Vollset, Stein Emil; Ardill, J.E.S.; El-Omar, E.; Melby, Kjetil Klaveness & Aase, Steinar Torbjørn [Show all 8 contributors for this article] (1997). Hypergastrinaemia is a strong predictor of distal gastric adenocarcinoma among helicobacter pylori infected persons.
• Hansen, S.W.; Vollset, Stein Emil; Ardill, J.E.S.; El-Omar, E.; Melby, Kjetil Klaveness & Aase, Steinar Torbjørn [Show all 8 contributors for this article] (1997). Hypergastrinaemia is a strong predictor of distal gastric adenocarcinoma among Helicobacter Pylori infected persons.
• Hansen, S.W.; Vollset, Stein Emil; Ardill, J.E.S.; El-Omar, E.; Melby, Kjetil Klaveness & Aase, Steinar Torbjørn [Show all 8 contributors for this article] (1997). Hypergastrinaemia is a strong predictor of distal gastric adenocarcinoma among helicobacter pylori infected persons.
• Skjerdal, Olaug Taran; Aspholm, Marina; Grahek-Ogden, Danica; Jore, Solveig; Møretrø, Trond & Kapperud, Georg [Show all 9 contributors for this article] (2019). Listeria monocytogenes i sushi - vurdering av helseråd til gravide og andre utsatte grupper. Vitenskapelig uttalelse fra faggruppe for hygiene og smittestoffer i Vitenskapskomiteen for mat og miljø. Vitenskapskomiteen for mat og miljø (VKM). ISSN 978-82-8259-324-3.
• Ytrehus, Bjørnar; Grahek-Ogden, Danica; Strand, Olav; Tranulis, Michael A.; Mysterud, Atle & Aspholm, Marina [Show all 13 contributors for this article] (2018). Factors that can contribute to spread of CWD – an update on the situation in Nordfjella, Norway. Opinion of the Panel on biological hazards of the Norwegian Scientific Committee for Food and Environment. Norwegian Scientific Committee for Food and Environment (VKM). ISSN 978-82-8259-316-8.

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