Universidade Federal de Goiás (UFG), Instituto de Patologia Tropical e Saúde Pública, Departamento de Biociências e Tecnologia, Goiânia, GO, Brazil.
Universidade Federal de Goiás (UFG), Hospital das Clínicas, Goiânia, GO, Brazil.
Braz J Infect Dis. 2019 Jan-Feb;23(1):8-14. doi: 10.1016/j.bjid.2018.12.003. Epub 2019 Mar 6.
Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy.
In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis.
Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients.
MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.
细菌性扁桃体炎是一种主要发生在儿童和青少年的上呼吸道感染。金黄色葡萄球菌是扁桃体炎病因学中最常见的病原体之一，其相关性在于其对抗生素的耐药性和在扁桃体内部组织中的持久性。在抗生素治疗多次失败后发生复发性扁桃体炎时，应进行扁桃体切除术。
在这项研究中，我们评估了 123 例来自有复发性扁桃体炎病史的患者的手术切除的扁桃体。对扁桃体进行微生物分析以检测金黄色葡萄球菌。通过 femA 基因的 PCR 鉴定分离株。通过纸片扩散试验测定分离株的药敏性。所有分离株均进行 mecA 和 Panton-Valentine 白细胞毒素（PVL）基因的 PCR 检测。通过脉冲场凝胶电泳确定所有分离株之间的遗传相似性。
从 50 名（40.7%）平均年龄为 11.7 岁的患者中获得了 61 株金黄色葡萄球菌分离株。这些分离株对青霉素表现出高水平耐药性（83.6%），9.8%具有诱导型 MLSb 表型，18.0%被认为是多药耐药（MDR）。在两个分离株中检测到 mecA 基因，在一个分离株中鉴定出编码 PVL 的基因。遗传相似性分析显示分离株之间存在高度多样性。从同一患者中鉴定出多个遗传上不同的分离株，并且从不同患者中获得了相同的分离株。
定植在扁桃体中的 MDR 分离株即使没有感染，也表明细菌的持续存在以及抗菌药物耐药性传播和感染复发的可能性。在金黄色葡萄球菌定植的患者中没有证明存在特定的克隆。
