Bemis David A, Jones Rebekah D, Videla Ricardo, Kania Stephen A
Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, 2407 River Drive, Knoxville, TN 37996, USA.
J Vet Diagn Invest. 2012 Sep;24(5):964-7. doi: 10.1177/1040638712452112. Epub 2012 Jul 11.
Cefoxitin disk diffusion susceptibility testing is a recommended screening method for the detection of methicillin resistance in human isolates of Staphylococcus aureus and coagulase-negative staphylococci. A retrospective analysis of 1,146 clinical isolates of Staphylococcus pseudintermedius from dogs was conducted to determine if screening by the cefoxitin disk method can be similarly useful with S. pseudintermedius. The distribution of cefoxitin growth inhibition zone diameters within this collection was bimodal and correlated well with the results of methicillin resistance gene (mecA) detection by polymerase chain reaction. Of the isolates, 5% had discordant results and, when retested, 84% of these were in agreement. While a greater diversity of isolates and interlaboratory comparisons must be tested, the current study suggests that an epidemiological breakpoint (of approximately ≤ 30 mm = resistant; ≥ 31 = susceptible) can be established to predict methicillin resistance in S. pseudintermedius.
头孢西丁纸片扩散药敏试验是检测金黄色葡萄球菌和凝固酶阴性葡萄球菌人源分离株中耐甲氧西林情况的推荐筛查方法。对1146株犬源中间型葡萄球菌临床分离株进行回顾性分析，以确定头孢西丁纸片法筛查对中间型葡萄球菌是否同样有用。该菌属中头孢西丁生长抑制圈直径分布呈双峰，且与聚合酶链反应检测甲氧西林耐药基因（mecA）的结果相关性良好。这些分离株中，5%的结果不一致，重新检测时，其中84%结果相符。虽然必须检测更多种类的分离株并进行实验室间比较，但目前的研究表明，可以建立一个流行病学界值（约≤30mm为耐药；≥31mm为敏感）来预测中间型葡萄球菌的甲氧西林耐药情况。
