Corso A, Santos Sanches I, Aires de Sousa M, Rossi A, de Lencastre H
Unidade de Genética Molecular, Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oeiras, Portugal.
Microb Drug Resist. 1998 Winter;4(4):277-88. doi: 10.1089/mdr.1998.4.277.
One hundred forty-eight recent methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from 13 hospitals in Argentina were examined for antibiotic susceptibility and clonal type, using hybridization with DNA probes specific for mecA and Tn554, and pulsed-field gel electrophoresis (PFGE) of chromosomal SmaI digests. The majority of the isolates (62.2%) shared the common PFGE B pattern and carried variants of mecA and Tn554 polymorphs characteristic of an MRSA clone widely spread in Brazilian hospitals. Similarly to the Brazilian isolates, the MRSA clone recovered in the Argentinian hospitals (XI::B::B) and its close relatives (XI::B'::B, XI::AA::B, XI::M::B, XI::omega omega::B, and III::W::B) showed susceptibility to spectinomycin and resistance to numerous antibacterial agents, including beta-lactams, tetracycline, aminoglycosides, macrolides, trimethoprim/sulfamethoxazole, ciprofloxacin, and fosfomycin, and more than 60% of the isolates were also resistant to chloramphenicol and rifampin. The XI::B::B MRSA clone represented the majority of isolates recovered in most of the hospitals, nine of which were located in the city of Buenos Aires, three in the province of Buenos Aires, and one in the province of Tucumán, 1,312 km northwest of the city of Buenos Aires. The observations document further geographic expansion of this South American MRSA clone across national boundaries.
从阿根廷13家医院收集的148株近期耐甲氧西林金黄色葡萄球菌（MRSA）分离株，通过与mecA和Tn554特异性DNA探针杂交以及染色体SmaI酶切片段的脉冲场凝胶电泳（PFGE），检测其抗生素敏感性和克隆类型。大多数分离株（62.2%）具有共同的PFGE B型，携带在巴西医院广泛传播的MRSA克隆特征性的mecA和Tn554多态性变体。与巴西分离株类似，在阿根廷医院分离出的MRSA克隆（XI::B::B）及其近亲（XI::B'::B、XI::AA::B、XI::M::B、XI::ωω::B和III::W::B）对壮观霉素敏感，对多种抗菌药物耐药，包括β-内酰胺类、四环素、氨基糖苷类、大环内酯类、甲氧苄啶/磺胺甲恶唑、环丙沙星和磷霉素，超过60%的分离株还对氯霉素和利福平耐药。XI::B::B MRSA克隆在大多数医院分离出的菌株中占多数，其中9家位于布宜诺斯艾利斯市，3家位于布宜诺斯艾利斯省，1家位于布宜诺斯艾利斯市西北1312公里处的图库曼省。这些观察结果记录了这种南美MRSA克隆在国界之外的进一步地理扩张。
