Department of Clinical Pathology, Cleveland Clinic, 9500 Euclid Avenue, L40, Cleveland, OH 44195, USA.
Antimicrob Agents Chemother. 2011 Sep;55(9):4154-60. doi: 10.1128/AAC.00315-11. Epub 2011 Jun 27.
A Staphylococcus aureus surveillance program was initiated in the United States to examine the in vitro activity of ceftaroline and epidemiologic trends. Susceptibility testing by Clinical and Laboratory Standards Institute broth microdilution was performed on 4,210 clinically significant isolates collected in 2009 from 43 medical centers. All isolates were screened for mecA by PCR and evaluated by pulsed-field gel electrophoresis. Methicillin-resistant S. aureus (MRSA) were analyzed for Panton-Valentine leukocidin (PVL) genes and the staphylococcal cassette chromosome mec (SCCmec) type. All isolates had ceftaroline MICs of ≤2 μg/ml with an MIC(50) of 0.5 and an MIC(90) of 1 μg/ml. The overall resistance rates, expressed as the percentages of isolates that were intermediate and resistant (or nonsusceptible), were as follows: ceftaroline, 1.0%; clindamycin, 30.2% (17.4% MIC ≥ 4 μg/ml; 12.8% inducible); daptomycin, 0.2%; erythromycin, 65.5%; levofloxacin, 39.9%; linezolid, 0.02%; oxacillin, 53.4%; tetracycline, 4.4%; tigecycline, 0%; trimethoprim-sulfamethoxazole, 1.6%; vancomycin, 0%; and high-level mupirocin, 2.2%. The mecA PCR was positive for 53.4% of the isolates. The ceftaroline MIC(90)s were 0.25 μg/ml for methicillin-susceptible S. aureus and 1 μg/ml for MRSA. Among the 2,247 MRSA isolates, 51% were USA300 (96.9% PVL positive, 99.7% SCCmec type IV) and 17% were USA100 (93.4% SCCmec type II). The resistance rates for the 1,137 USA300 MRSA isolates were as follows: erythromycin, 90.9%; levofloxacin, 49.1%; clindamycin, 7.6% (6.2% MIC ≥ 4 μg/ml; 1.4% inducible); tetracycline, 3.3%; trimethoprim-sulfamethoxazole, 0.8%; high-level mupirocin, 2.7%; daptomycin, 0.4%; and ceftaroline and linezolid, 0%. USA300 is the dominant clone causing MRSA infections in the United States. Ceftaroline demonstrated potent in vitro activity against recent S. aureus clinical isolates, including MRSA, daptomycin-nonsusceptible, and linezolid-resistant strains.
一项金黄色葡萄球菌监测计划在美国启动，旨在检测头孢洛林的体外活性和流行病学趋势。对 2009 年从 43 家医疗中心收集的 4210 株临床意义重大的分离株进行了临床和实验室标准协会肉汤微量稀释法的药敏试验。所有分离株均通过 PCR 进行 mecA 筛查，并通过脉冲场凝胶电泳进行评估。耐甲氧西林金黄色葡萄球菌（MRSA）分析了 Panton-Valentine 白细胞毒素（PVL）基因和葡萄球菌盒染色体 mec（SCCmec）类型。所有分离株的头孢洛林 MIC 均≤2μg/ml，MIC（50）为 0.5μg/ml，MIC（90）为 1μg/ml。总的耐药率，以中介和耐药（或不敏感）分离株的百分比表示，如下：头孢洛林 1.0%；克林霉素 30.2%（17.4%MIC≥4μg/ml；12.8%诱导）；达托霉素 0.2%；红霉素 65.5%；左氧氟沙星 39.9%；利奈唑胺 0.02%；苯唑西林 53.4%；四环素 4.4%；替加环素 0%；复方磺胺甲噁唑 1.6%；万古霉素 0%；高水平莫匹罗星 2.2%。53.4%的分离株 mecA PCR 阳性。甲氧西林敏感金黄色葡萄球菌的头孢洛林 MIC（90）为 0.25μg/ml，MRSA 的头孢洛林 MIC（90）为 1μg/ml。在 2247 株 MRSA 中，51%为 USA300（96.9%PVL 阳性，99.7%SCCmec 类型 IV），17%为 USA100（93.4%SCCmec 类型 II）。1137 株 USA300 MRSA 的耐药率如下：红霉素 90.9%；左氧氟沙星 49.1%；克林霉素 7.6%（6.2%MIC≥4μg/ml；1.4%诱导）；四环素 3.3%；复方磺胺甲噁唑 0.8%；高水平莫匹罗星 2.7%；达托霉素 0.4%；头孢洛林和利奈唑胺 0%。USA300 是导致美国耐甲氧西林金黄色葡萄球菌感染的主要克隆。头孢洛林对最近的金黄色葡萄球菌临床分离株具有很强的体外活性，包括耐达托霉素和利奈唑胺的金黄色葡萄球菌。
