Duarte Maria J, Kozin Elliott D, Bispo Paulo J M, Mitchell Andreas H, Gilmore Michael S, Remenschneider Aaron K
Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA.
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA.
World J Otorhinolaryngol Head Neck Surg. 2017 Nov 23;4(4):246-252. doi: 10.1016/j.wjorl.2017.09.003. eCollection 2018 Dec.
Otologic methicillin-resistant (MRSA) infection has historically been rare, but given the rise in community-acquired MRSA carriage and infection at other body sites, prevalence rates may be changing. The goal of this study was to determine the prevalence of MRSA in recent otologic cultures from patients with acute otitis externa (AOE).
Retrospective review of an institutional microbiologic database.
A retrospective analysis was performed on serial culture isolates taken from the ear at a quaternary care hospital from January 2014 to April 2016. The causative pathogen and antibiotic sensitivity was determined by culture isolation and end point mean inhibitory concentration (MIC) testing. Medical records were reviewed to document patient characteristics, chronicity of infection, symptomatology, and previous treatments.
Over the study period, 173 patients were diagnosed with AOE and underwent otologic cultures of the ear. Fifty-three (30.6%) of cultures grew (SA). Of SA infections, 15 (28.3%) were identified as MRSA. MRSA patients were typically older than patients with methicillin-sensitive SA (MSSA) (mean age 46.7 ± 17.9 29 ± 19.4, = 0.003) and had more medical comorbidities (4 1.7, = 0.001). Compared to patients with MSSA, patients with MRSA were significantly more likely to have had prior ototopical antibiotic exposure (37% 73%, = 0.019).
Contemporary ear culture isolates at quaternary care center show higher rates of MRSA compared to historical reports in the literature. Clinicians should consider ear cultures to identify MRSA AOE.
IV.
耳部耐甲氧西林金黄色葡萄球菌（MRSA）感染在历史上较为罕见，但鉴于社区获得性MRSA携带率及其他身体部位感染率的上升，其患病率可能正在发生变化。本研究的目的是确定近期急性外耳道炎（AOE）患者耳部培养物中MRSA的患病率。
对机构微生物数据库进行回顾性分析。
对2014年1月至2016年4月在一家四级医疗中心从耳部采集的系列培养分离株进行回顾性分析。通过培养分离和终点平均抑制浓度（MIC）检测确定致病病原体和抗生素敏感性。查阅病历以记录患者特征、感染慢性化情况、症状及既往治疗情况。
在研究期间，173例患者被诊断为AOE并接受了耳部培养。53份（30.6%）培养物培养出金黄色葡萄球菌（SA）。在SA感染中，15份（28.3%）被鉴定为MRSA。MRSA患者通常比甲氧西林敏感SA（MSSA）患者年龄更大（平均年龄46.7±17.9岁对29±19.4岁，P = 0.003）且合并症更多（4对1.7，P = 0.001）。与MSSA患者相比，MRSA患者既往耳部局部使用抗生素的可能性显著更高（37%对73%，P = 0.019）。
与文献中的历史报告相比，当代四级医疗中心的耳部培养分离株显示出更高的MRSA发生率。临床医生应考虑进行耳部培养以识别MRSA所致的AOE。
IV级
