Chalmers Gabhan, Kozak Gosia K, Hillyer Elizabeth, Reid-Smith Richard J, Boerlin Patrick
Department of Pathobiology, University of Guelph, Ontario, Canada.
Can J Vet Res. 2010 Apr;74(2):145-8.
Twenty-eight Escherichia coli isolates from various animal and environmental sources with defined tetracycline-resistance genotypes for tet(A), tet(B), and tet(C) were tested for their susceptibility to tetracycline by means of both broth microdilution and Etest. All tet(C)-positive isolates had tetracycline minimum inhibitory concentrations clustering around an intermediate susceptibility range of 2 to 16 microg/mL. Detecting tet(C)-positive isolates by means of susceptibility testing may therefore be difficult with use of the current breakpoint for tetracycline of the Clinical and Laboratory Standards Institute guidelines.
从各种动物和环境来源分离出的28株具有明确tet(A)、tet(B)和tet(C)四环素抗性基因型的大肠杆菌,通过肉汤微量稀释法和Etest法检测其对四环素的敏感性。所有tet(C)阳性菌株的四环素最低抑菌浓度集中在2至16μg/mL的中度敏感范围内。因此,按照临床和实验室标准协会指南中目前四环素的断点,通过药敏试验检测tet(C)阳性菌株可能会有困难。