Severe Acute Otitis Media Caused by Mucoid Streptococcus Pyogenes in a Previously Healthy Adult
Severe Acute Otitis Media Caused by Mucoid Streptococcus Pyogenes in a Previously Healthy Adult
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DOI：
10.1620/tjem.232.301
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发表时间：
2014-04-01
影响因子：
2.2
通讯作者：
Katori, Yukio
中科院分区：
文献类型：
--
作者：
Kakuta, Risako;Yano, Hisakazu;Katori, Yukio
化脓性链球菌是引起学龄儿童咽扁桃体炎的最常见病原体。在日本，黏液性肺炎链球菌是众所周知的严重急性中耳炎（AOM）的病原体；然而，粘液样化脓性链球菌鲜有报道。据我们所知，这是日本首例由黏液化脓链球菌引起的急性中耳炎病例。一名36岁健康女性，因鼓膜切开术后耳痛加重伴头痛，疑似脑脊液耳漏而转诊至我院。对羊的中耳分泌物进行细菌培养，在羊血琼脂上产生被完全溶解带包围的粘液样菌落。抗原凝集试验结果化脓性链球菌阳性，给予帕尼培南-倍他米龙2.0 g/d治疗，连用10天，症状基本消失。研究了该菌株的细菌学特征。确定化脓性葡萄球菌主要毒力因子emm基因编码的m蛋白基因型为emm75。一般来说，化脓性葡萄球菌形成菌落具有非黏液光泽的外观，基于羊血琼脂的β -溶血。粘液样表型是由于透明质酸荚膜多糖的大量产生，这是一个关键的毒力决定因素。Emm75常见于非侵袭性疾病，但在侵袭性疾病中较少见。总之，粘液样化脓性链球菌即使在以前健康的人中也可引起严重感染。今后应监测黏液性化脓性链球菌的出现情况及耐药趋势。
Streptococcus (S.) pyogenes is well recognized as the most common pathogen causing pharyngotonsillitis in school-age children. In Japan, mucoid Streptococcus pneumoniae is well known as a causative agent of severe acute otitis media (AOM); however, mucoid S. pyogenes has rarely been reported. To the best of our knowledge, this is the first report of an AOM patient caused by mucoid S. pyogenes in Japan. A 36-year-old previously healthy female was referred to our hospital with suspicion of cerebrospinal otorrhea due to increasing otalgia accompanied by headache following myringotomy. Bacterial cultures of middle ear secretions were performed, and mucoid-form colonies surrounded by zones of complete beta-hernolysis were produced on sheep's blood agar. Antigen-agglutination test results were positive for S. pyogenes, and thus the patient received treatment with panipenem-betamipron 2.0 g/day for 10 days, which resolved nearly all symptoms. The bacteriological features of this strain were then investigated. The M-protein genotype encoded by the emm gene, the major virulence factor of S. pyogenes, was determined to be emm75. Generally, S. pyogenes forms colonies having non-mucoid matt appearances based on beta-hemolysis of sheep's blood agar. The mucoid phenotype results from abundant production of hyaluronic acid capsular polysaccharide, a key virulence determinant. emm75 is common in noninvasive, but less common in invasive disease. In conclusion, mucoid S. pyogenes can cause severe infection even in previously healthy persons. Emergence of mucoid S. pyogenes and drug resistance trends should be monitored in the future.