Fachbereich Veterinärmedizin



    Antimicrobial susceptibilities and occurrence of resistance genes in bovine Helcococcus ovis isolates (2011)

    Zeitschriftenartikel / wissenschaftlicher Beitrag
    Bilk, Sabine
    Nordhoff, Marcel
    Schulze, Christoph
    Wieler, Lothar H
    Kutzer, Peter
    Veterinary Microbiology; 149(3/4) — S. 488–491
    ISSN: 0378-1135
    DOI: 10.1016/j.vetmic.2010.11.012
    Pubmed: 21131144
    Institut für Mikrobiologie und Tierseuchen

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    Abstract / Zusammenfassung

    The aim of the study was to investigate antimicrobial susceptibilities of bovine Helcococcus ovis isolates and to detect genes encoding for H. ovis erythromycin and tetracycline resistance. Twenty-nine isolates were included and the minimal inhibitory concentrations (MICs) of seven antimicrobials were determined using test conditions as given in an approved CLSI guideline for the pyridoxal-dependent Abiotrophia spp. and Granulicatella spp. Furthermore, the macrolide resistance phenotype was examined by the erythromycin-clindamycin double-disk test (D-zone test). Erythromycin MICs of ≥ 8 μg/ml were found in three (10%) isolates which also presented the macrolide, lincosamide, and streptogramin B (MLS(B)) resistance phenotype, either constitutive or inducible. The erm(B) gene was detected in one of these isolates. Increased tetracycline MICs (≥ 8 μg/ml) were obtained for 24 (83%) isolates, mostly associated with the tet(M) gene alone (n=21) or both the tet(L) and tet(M) genes (n=2). The MICs determined for penicillin, ampicillin, amoxicillin-clavulanic acid, and cephalothin did not indicate resistance to these antimicrobials. The study suggests that resistance to MLS(B) antimicrobials and tetracycline is frequent in H. ovis. Moreover, this is the first report about occurrence of the resistance genes erm(B), tet(L), and tet(M) in the Helcococcus genus.