Vindel Ana, Cuevas Oscar, Cercenado Emilia, Marcos Carmen, Bautista Verónica, Castellares Carol, Trincado Pilar, Boquete Teresa, Pérez-Vázquez Maria, Marín Mercedes, Bouza Emilio
Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
J Clin Microbiol. 2009 Jun;47(6):1620-7. doi: 10.1128/JCM.01579-08. Epub 2009 Apr 1.
In a point-prevalence study performed in 145 Spanish hospitals in 2006, we collected 463 isolates of Staphylococcus aureus in a single day. Of these, 135 (29.2%) were methicillin (meticillin)-resistant S. aureus (MRSA) isolates. Susceptibility testing was performed by a microdilution method, and mecA was detected by PCR. The isolates were analyzed by pulsed-field gel electrophoresis (PFGE) after SmaI digestion, staphylococcal chromosomal cassette mec (SCCmec) typing, agr typing, spa typing with BURP (based-upon-repeat-pattern) analysis, and multilocus sequence typing (MLST). The 135 MRSA isolates showed resistance to ciprofloxacin (93.3%), tobramycin (72.6%), gentamicin (20.0%), erythromycin (66.7%), and clindamycin (39.3%). Among the isolates resistant to erythromycin, 27.4% showed the M phenotype. All of the isolates were susceptible to glycopeptides. Twelve resistance patterns were found, of which four accounted for 65% of the isolates. PFGE revealed 36 different patterns, with 13 major clones (including 2 predominant clones with various antibiotypes that accounted for 52.5% of the MRSA isolates) and 23 sporadic profiles. Two genotypes were observed for the first time in Spain. SCCmec type IV accounted for 6.7% of the isolates (70.1% were type IVa, 23.9% were type IVc, 0.9% were type IVd, and 5.1% were type IVh), and SCCmec type I and SCCmec type II accounted for 7.4% and 5.2% of the isolates, respectively. One isolate was nontypeable. Only one of the isolates produced the Panton-Valentine leukocidin. The isolates presented agr type 2 (82.2%), type 1 (14.8%), and type 3 (3.0%). spa typing revealed 32 different types, the predominant ones being t067 (48.9%) and t002 (14.8%), as well as clonal complex 067 (78%) by BURP analysis. The MRSA clone of sequence type 125 and SCCmec type IV was the most prevalent throughout Spain. In our experience, PFGE, spa typing, SCCmec typing, and MLST presented good correlations for the majority of the MRSA strains; we suggest the use of spa typing and PFGE typing for epidemiological surveillance, since this combination is useful for both long-term and short-term studies.
在2006年于145家西班牙医院开展的一项现患率研究中，我们在一天内收集了463株金黄色葡萄球菌分离株。其中，135株（29.2%）为耐甲氧西林金黄色葡萄球菌（MRSA）分离株。采用微量稀释法进行药敏试验，通过聚合酶链反应（PCR）检测mecA。分离株经SmaI酶切后采用脉冲场凝胶电泳（PFGE）分析、葡萄球菌染色体盒式mec（SCCmec）分型、agr分型、基于重复模式（BURP）分析的spa分型以及多位点序列分型（MLST）。135株MRSA分离株对环丙沙星耐药率为93.3%，对妥布霉素耐药率为72.6%，对庆大霉素耐药率为20.0%，对红霉素耐药率为66.7%，对克林霉素耐药率为39.3%。在对红霉素耐药的分离株中，27.4%表现为M表型。所有分离株对糖肽类均敏感。发现了12种耐药模式，其中4种模式的分离株占65%。PFGE显示36种不同模式，有13个主要克隆（包括2个具有不同抗菌型的优势克隆，占MRSA分离株的52.5%）和23个散发病例谱型。两种基因型在西班牙首次被观察到。SCCmecⅣ型占分离株的6.7%（Ⅳa型占70.1%，Ⅳc型占23.9%，Ⅳd型占0.9%，Ⅳh型占5.1%），SCCmecⅠ型和SCCmecⅡ型分别占分离株的7.4%和5.2%。1株无法分型。仅1株分离株产生杀白细胞素。分离株呈现agr 2型（82.2%）、1型（14.8%）和3型（3.0%）。spa分型显示32种不同类型，优势类型为t067（48.9%）和t002（14.8%），通过BURP分析克隆复合体067占78%。序列类型125和SCCmecⅣ型的MRSA克隆在西班牙最为常见。根据我们的经验，对于大多数MRSA菌株，PFGE、spa分型、SCCmec分型和MLST呈现出良好的相关性；我们建议使用spa分型和PFGE分型进行流行病学监测，因为这种组合对长期和短期研究均有用。
