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    Probiotic Escherichia coli Nissle 1917 reduces growth, Shiga toxin expression, release and thus cytotoxicity of enterohemorrhagic Escherichia coli (2015)

    Art
    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Autoren
    Mohsin, Mashkoor
    Guenther, Sebastian (WE 7)
    Schierack, Peter
    Tedin, Karsten (WE 7)
    Wieler, Lothar H (WE 7)
    Quelle
    International journal of medical microbiology; 305(1) — S. 20–26
    ISSN: 1438-4221
    Sprache
    Englisch
    Verweise
    DOI: 10.1016/j.ijmm.2014.10.003
    Pubmed: 25465158
    Kontakt
    Institut für Mikrobiologie und Tierseuchen

    Robert-von-Ostertag-Str. 7-13
    Gebäude 35
    14163 Berlin
    Tel.+49 30 83 8-518 40/518 43 Fax.+49 30 838 45 18 51
    email:mikrobiologie@vetmed.fu-berlin.de

    Abstract / Zusammenfassung

    Due to increased release or production of Shiga toxin by Enterohemorrhagic Escherichia coli (EHEC) after exposure to antimicrobial agents, the role of antimicrobial agents in EHEC mediated infections remains controversial. Probiotics are therefore rapidly gaining interest as an alternate therapeutic option. The well-known probiotic strain Escherichia coli Nissle 1917 (EcN) was tested in vitro to determine its probiotic effects on growth, Shiga toxin (Stx) gene expression, Stx amount and associated cytotoxicity on the most important EHEC strains of serotype O104:H4 and O157:H7. Following co-culture of EcN:EHEC in broth for 4 and 24 h, the probiotic effects on EHEC growth, toxin gene expression, Stx amount and cytotoxicity were determined using quantitative real time-PCR, Stx-ELISA and Vero cytotoxicity assays. Probiotic EcN strongly reduced EHEC numbers (cfu) of O104:H4 up to (68%) and O157:H7 to (72.2%) (p<0.05) in LB broth medium whereas the non-probiotic E. coli strain MG1655 had no effect on EHEC growth. The level of stx expression was significantly down-regulated, particularly for the stx2a gene. The stx down-regulation in EcN co-culture was not due to reduced numbers of EHEC. A significant inhibition in Stx amounts and cytotoxicity were also observed in sterile supernatants of EcN:EHEC co-cultures. These findings indicate that probiotic EcN displays strong inhibitory effects on growth, Shiga toxin gene expression, amount and cytotoxicity of EHEC strains. Thus, EcN may be considered as a putative therapeutic candidate, in particular against EHEC O104:H4 and O157:H7.