Department of Dermatology,Venereology and Andrology, Medical School, Alexandria University, Egypt.
Braz J Infect Dis. 2012 Sep-Oct;16(5):426-31. doi: 10.1016/j.bjid.2012.08.004. Epub 2012 Sep 7.
Staphylococcus aureus has been recognized as an important pathogen associated with inpatients and community infections. Community-acquired methicillin-resistant S. aureus (CA-MRSA) infections commonly present as skin and soft-tissue infections (SSTIs). Treatment often includes incision and drainage with or without adjunctive antibiotics.
This study aimed to identify CA-MRSA infections both phenotypically and genotypically, to determine their spectrum of antibiotic resistance, and to establish the best scheme for molecular distinction between hospital-acquired MRSA (HA-MRSA) and CA-MRSA by staphylococcal cassette chromosome mec (SCCmec) typing and detection of Panton Valentine leukocidin (PVL).
50 swabs, from skin and soft tissue of infected lesions of outpatients attending the dermatology department of the Medical School, Alexandria University, were collected. Additionally, a nasal swab was taken from every participant.
Collection of swabs from the infected skin and soft tissues, followed by laboratory testing to phenotypically and genotypically identify MRSA. Also, nasal swabs were taken from every patient to identify MRSA colonization.
Staphylococcus aureus strains were identified in 38 (76%) of the 50 clinical isolates. 18 (47.37%) out of the 38 S. aureus strains were resistant to oxacillin and cefoxitin discs, were penicillin binding protein 2a (PBP2a) producers, and were initially diagnosed as MRSA. All of the 18 strains were definitively diagnosed as MRSA by mecA gene detection using real time PCR, while only six (33.33%) strains were PVL positive. Using the sets of primers of Zhang et al.: nine (50%) out of the 18 CA-MRSA strains were SCCmec type V, and one (5.56%) was SCCmec type IVc. Then, using the set of primers by Oliveira et al., two (25%) out of the eight untypable MRSA strains were found to be SCCmec type IV, and six (75%) remained untypable.
CA-MRSA must be considered when treating skin and soft tissue infections, especially in developing countries. Empirical use of agents active against CA-MRSA is warranted for patients presenting with serious SSTIs.
金黄色葡萄球菌已被认为是与住院患者和社区感染相关的重要病原体。社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）感染通常表现为皮肤和软组织感染（SSTIs）。治疗通常包括切开引流，辅以或不辅以抗生素。
本研究旨在通过表型和基因分型鉴定 CA-MRSA 感染，确定其抗生素耐药谱，并通过葡萄球菌盒染色体 mec（SCCmec）分型和检测杀白细胞素（PVL）来建立区分医院获得性 MRSA（HA-MRSA）和 CA-MRSA 的最佳分子方案。
收集了来自亚历山大大学医学院皮肤科门诊感染性皮损的 50 个拭子，此外，还从每位患者采集了一个鼻腔拭子。
采集感染皮肤和软组织的拭子，然后进行实验室检测，以表型和基因分型鉴定 MRSA。还从每位患者采集鼻腔拭子，以鉴定 MRSA 定植。
在 50 株临床分离株中，鉴定出金黄色葡萄球菌 38 株（76%）。38 株金黄色葡萄球菌中，18 株（47.37%）对苯唑西林和头孢西丁纸片耐药，青霉素结合蛋白 2a（PBP2a）产生，初步诊断为 MRSA。所有 18 株均通过实时 PCR 检测 mecA 基因确诊为 MRSA，而只有 6 株（33.33%）为 PVL 阳性。使用 Zhang 等人的引物组：18 株 CA-MRSA 中有 9 株（50%）为 SCCmec 型 V，1 株（5.56%）为 SCCmec 型 IVc。然后，使用 Oliveira 等人的引物组，在 8 株无法定型的 MRSA 菌株中，有 2 株（25%）为 SCCmec 型 IV，6 株（75%）仍无法定型。
在治疗皮肤和软组织感染时，必须考虑 CA-MRSA，特别是在发展中国家。对于出现严重 SSTIs 的患者，应经验性使用针对 CA-MRSA 的有效药物。
