• Agnoprotein of polyomavirus BK interacts With proliferating cell nuclear antigen and inhibits DNA replication 

      Gerits, Nancy; Johannessen, Mona; Tümmler, Conny; Walquist, Mari; Kostenko, Sergiy; Snapkov, Igor; van Loon, Barbara; Ferrari, Elena; Hübscher, Ulrich; Moens, Ugo (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-01)
      Background: The human polyomavirus BK expresses a 66 amino-acid peptide referred to as agnoprotein. Though mutants lacking agnoprotein are severely reduced in producing infectious virions, the exact function of this peptide remains incompletely understood. To elucidate the function of agnoprotein, we searched for novel cellular interaction partners. <p>Methods: Yeast-two hybrid assay was performed ...
    • Bacterial interference with canonical NF kappa B signalling 

      Johannessen, Mona; Askarian, Fatemeh; Sangvik, Maria; Sollid, Johanna U. Ericson (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-10)
    • Bacterial membrane-derived vesicles attenuate vancomycin activity against methicillin-resistant staphylococcus aureus 

      Kumaraswamy, Monika; Wiull, Kamilla; Joshi, Bishnu; Sakoulas, George; Kousha, Armin; Vaaje-Kolstad, Gustav; Johannessen, Mona; Hegstad, Kristin; Nizet, Victor; Askarian, Fatemeh (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-29)
      Methicillin-resistant Staphylococcus aureus (MRSA) has evolved numerous antimicrobial resistance mechanisms and is identified as a serious public health threat by the World Health Organization and U.S. Centers for Disease Control and Prevention. The glycopeptide vancomycin (VAN) remains a cornerstone of therapy for severe MRSA infections despite increasing reports of therapeutic failure in hospitalized ...
    • Biofilm Responsive Zwitterionic Antimicrobial Nanoparticles to Treat Cutaneous Infection 

      Obuobi, Sybil Akua Okyerewa; Phung, Anna Ngoc; Julin, Kjersti; Johannessen, Mona; Skalko-Basnet, Natasa (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      To avert the poor bioavailability of antibiotics during S. aureus biofilm infections, a series of zwitterionic nanoparticles containing nucleic acid nanostructures were fabricated for the delivery of vancomycin. The nanoparticles were prepared with three main lipids: (i) neutral (soy phosphatidylcholine; P), (ii) positively charged ionizable (1,2-dioleyloxy-3-dimethylaminopropane; D), and (iii) ...
    • BKV Agnoprotein Interacts with alpha-Soluble N-Ethylmaleimide-Sensitive Fusion Attachment Protein, and Negatively Influences Transport of VSVG-EGFP 

      Johannessen, Mona; Walquist, Mari; Gerits, Nancy; Dragset, Marte Singsås; Spang, Anne; Moens, Ugo (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      The human polyomavirus BK (BKV) infects humans worldwide and establishes a persistent infection in the kidney. The BK virus genome encodes three regulatory proteins, large and small tumor-antigen and the agnoprotein, as well as the capsid proteins VP1 to VP3. Agnoprotein is conserved among BKV, JC virus (JCV) and SV40, and agnoprotein-deficient mutants reveal reduced viral propagation. Studies with ...
    • Chitosan-based delivery system enhances antimicrobial activity of chlorhexidine 

      Hemmingsen, Lisa Myrseth; Panchai, Pimmat; Julin, Kjersti; Basnet, Purusotam; Nystad, Mona; Johannessen, Mona; Skalko-Basnet, Natasa (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-29)
      Infected chronic skin wounds and other skin infections are increasingly putting pressure on the health care providers and patients. The pressure is especially concerning due to the rise of antimicrobial resistance and biofilm-producing bacteria that further impair treatment success. Therefore, innovative strategies for wound healing and bacterial eradication are urgently needed; utilization ...
    • Chitosomes-In-Chitosan Hydrogel for Acute Skin Injuries: Prevention and Infection Control 

      Hemmingsen, Lisa Myrseth; Julin, Kjersti; Ahsan, Luqman; Basnet, Purusotam; Johannessen, Mona; Skalko-Basnet, Natasa (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-12)
      Burns and other skin injuries are growing concerns as well as challenges in an era of antimicrobial resistance. Novel treatment options to improve the prevention and eradication of infectious skin biofilm-producing pathogens, while enhancing wound healing, are urgently needed for the timely treatment of infection-prone injuries. Treatment of acute skin injuries requires tailoring of formulation to ...
    • Comparative exoproteome profiling of an invasive and a commensal Staphylococcus haemolyticus isolate 

      Cavanagh, Jorunn Pauline; Pain, Maria Charlene Ronessen; Askarian, Fatemeh; Bruun, Jack-Ansgar; Urbarova, Ilona; Wai, Sun Nyunt; Schmidt, Frank; Johannessen, Mona (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-22)
      Staphylococcus haemolyticus is a skin commensal emerging as an opportunistic pathogen. Nosocomial isolates of S. haemolyticus are the most antibiotic resistant members of the coagulase negative staphylococci (CoNS), but information about other S. haemolyticus virulence factors is scarce. Bacterial membrane vesicles (MVs) are one mediator of virulence by enabling secretion and long distance delivery ...
    • Comparative exoproteome profiling of an invasive and a commensal Staphylococcus haemolyticus isolate 

      Cavanagh, Jorunn Pauline; Pain, Maria Charlene Ronessen; Askarian, Fatemeh; Bruun, Jack-Ansgar; Urbarova, Ilona; Wai, Sun Nyunt; Schmidt, Frank; Johannessen, Mona (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-22)
      <p><i>Staphylococcus haemolyticus</i> is a skin commensal emerging as an opportunistic pathogen. Nosocomial isolates of <i>S. haemolyticus</i> are the most antibiotic resistant members of the coagulase negative staphylococci (CoNS), but information about other <i>S. haemolyticus</i> virulence factors is scarce. Bacterial membrane vesicles (MVs) are one mediator of virulence by enabling secretion and ...
    • Culturing periprosthetic tissue in BacT/Alert® Virtuo blood culture system leads to improved and faster detection of prosthetic joint infections 

      Sanabria-Moreno, Adriana Maria; Røkeberg, Merethe E.O.; Johannessen, Mona; Sollid, Johanna U Ericson; Simonsen, Gunnar Skov; Hanssen, Anne Merethe (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-10)
      <i>Background</i> - Blood culture bottles (BCBs) provide a semiautomated method for culturing periprosthetic tissue specimens. A study evaluating BCBs for culturing clinical samples other than body fluids is needed before implementation into clinical practice. Our objective was to evaluate use of the BacT/Alert® Virtuo blood culture system for culturing periprosthetic tissue specimens. <p> ...
    • Enterococcus faecium produces membrane vesicles containing virulence factors and antimicrobial resistance related proteins 

      Wagner, Theresa; Joshi, Bishnu; James Peter, Jessin Janice; Askarian, Fatemeh; Skalko-Basnet, Natasa; Hagestad, Ole Christian; Mekhlif, Ahmed; Wai, Sun Nyunt; Hegstad, Kristin; Johannessen, Mona (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-30)
      <i>Enterococcus faecium</i> is a commensal but also a bacteremia causing pathogen, which is inherently resistant to several antimicrobials and has a great ability to acquire new traits. Bacterial membrane vesicles (MVs) are increasingly recognized as a mode of cell-free communication and a way to deliver virulence factors and/or antimicrobial resistance determinants. These features make MVs interesting ...
    • Enterococcus faecium TIR-Domain Genes Are Part of a Gene Cluster Which Promotes Bacterial Survival in Blood 

      Wagner, Theresa; James Peter, Jessin Janice; Paganelli, Fernanda; Willems, Rob J.L.; Askarian, Fatemeh; Pedersen, Torunn Annie; Top, Janetta; de Haas, Carla; van strijp, Jos A. G.; Johannessen, Mona; Hegstad, Kristin (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-03)
      <i>Enterococcus faecium</i> has undergone a transition to a multidrug-resistant nosocomial pathogen. The population structure of <i>E. faecium</i> is characterized by a sharp distinction of clades, where the hospital-adapted lineage is primarily responsible for bacteremia. So far, factors that were identified in hospital-adapted strains and that promoted pathogenesis of nosocomial <i>E. faecium</i> ...
    • Exploring differentially expressed genes of Staphylococcus aureus exposed to human tonsillar cells using RNA sequencing 

      Bastakoti, Srijana; Ajayi, Clement; Julin, Kjersti; Johannessen, Mona; Hanssen, Anne Merethe (Journal article; Tidsskriftartikkel, 2023-07-12)
      Background - The nose and the throat are the most predominant colonizing sites of Staphylococcus aureus, and colonization is a risk factor for infection. Nasal colonization is well described; however, we have limited knowledge about S. aureus throat colonization. The main objective of this study was to explore differentially expressed genes (DEGs) in S. aureus throat isolate TR145 exposed to human ...
    • Flagella-mediated secretion of a novel Vibrio cholerae cytotoxin affecting both vertebrate and invertebrate hosts 

      Dongre, Mitesh; Singh, Bhupender; Aung, Kyaw Min; Larsson, Per; Miftakhova, Regina; Persson, Karina; Askarian, Fatemeh; Johannessen, Mona; Hofsten, Jonas von; Persson, Jenny L.; Erhardt, Marc; Tuck, Simon; Uhlin, Bernt Eric; Wai, Sun Nyunt (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-07)
      Using <i>Caenorhabditis elegans</i> as an infection host model for <i>Vibrio cholerae</i> predator interactions, we discovered a bacterial cytotoxin, MakA, whose function as a virulence factor relies on secretion via the flagellum channel in a proton motive force-dependent manner. The MakA protein is expressed from the polycistronic <i>makDCBA</i> (<i>m</i>otility-<i>a</i>ssociated <i>k</i>illing ...
    • Genetic variability in the sdrD gene in Staphylococcus aureus from healthy nasal carriers 

      Ajayi, Clement; Åberg, Espen; Askarian, Fatemeh; Sollid, Johanna U Ericson; Johannessen, Mona; Hanssen, Anne Merethe (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-16)
      <p><i>Background</i>: <i>Staphylococcus aureus</i> cell wall anchored Serine Aspartate repeat containing protein D (<i>sdrD</i>) is a member of the microbial surface component recognising adhesive matrix molecules (MSCRAMMs). It is involved in the bacterial adhesion and virulence. However the extent of genetic variation in <i>S. aureus sdrD</i> gene within isolates from healthy carriers are not ...
    • Host and microbe determinants that may influence the success of S. aureus colonization 

      Johannessen, Mona; Sollid, Johanna U Ericson; Hanssen, Anne-Merethe (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Staphylococcus aureus may cause serious skin and soft tissue infections, deep abscesses, endocarditis, osteomyelitis, pneumonia, and sepsis. S. aureus persistently colonizes 25–30% of the adult human population, and S. aureus carriers have an increased risk for infections caused by the bacterium. The major site of colonization is the nose, i.e., the vestibulum nasi, which is covered with ordinary ...
    • The interaction between Staphylococcus aureus SdrD and desmoglein 1 is important for adhesion to host cells 

      Askarian, Fatemeh; Ajayi, Clement; Hanssen, Anne-Merethe; Van Sorge, Nina M.; Pettersen, Ingvild; Diep, Dzung Bao; Sollid, Johanna U. Ericson; Johannessen, Mona (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)
      <i>Staphylococcus aureus</i> is known as a frequent colonizer of the skin and mucosa. Among bacterial factors involved in colonization are adhesins such as the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Serine aspartate repeat containing protein D (SdrD) is involved in adhesion to human squamous cells isolated from the nose. Here, we identify Desmoglein 1 ...
    • Liposomal delivery of antibiotic loaded nucleic acid nanogels with enhanced drug loading and synergistic anti-inflammatory activity against S. aureus intracellular infections 

      Obuobi, Sybil Akua Okyerewa; Julin, Kjersti; Fredheim, Elizabeth G. Aarag; Johannessen, Mona; Skalko-Basnet, Natasa (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-07)
      The persistence of <i>Staphylococcus aureus</i> has been accredited to its ability to escape immune response via host cell invasion. Despite the efficacy of many antibiotics against <i>S. aureus</i>, the high extracellular concentrations of conventional antibiotics required for bactericidal activity is limited by their low cellular accumulation and poor intracellular retention. While nanocarriers ...
    • Liposomes-in-hydrogel delivery system enhances the potential of resveratrol in combating vaginal chlamydia infection 

      Jøraholmen, May Wenche; Johannessen, Mona; Gravningen, Kirsten Midttun; Puolakkainen, Mirja; Acharya, Ganesh; Basnet, Purusotam; Skalko-Basnet, Natasa (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-11)
      <i>Chlamydia trachomatis</i> is the most common cause of bacterial sexually transmitted infections and causes serious reproductive tract complications among women. The limitations of existing oral antibiotics and treatment of antimicrobial resistance require alternative treatment options. We are proposing, for the first time, the natural polyphenol resveratrol (RES) in an advanced delivery system ...
    • Localization of Staphylococcus aureus in tissue from the nasal vestibule in healthy carriers 

      Hanssen, Anne-Merethe; Kindlund, Bert; Stenklev, Niels Christian; Furberg, Anne-Sofie; Fismen, Silje; Olsen, Renate Slind; Johannessen, Mona; Sollid, Johanna U Ericson (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-05)
      <p><b>Background:</b> Colonization of the body is an important step in Staphylococcus aureus infection. S. aureus colonizes skin and mucous membranes in humans and several animal species. One important ecological niche of S. aureus is the anterior nares. More than 60% of the S. aureus in the nose are found in vestibulum nasi. Our aim was to describe the localization of S. aureus in nasal tissue ...