Departments of Pediatrics,
Departments of Pediatrics.
Pediatrics. 2019 Oct;144(4). doi: 10.1542/peds.2019-1642. Epub 2019 Sep 5.
pneumonia is prevalent in children and can be followed by upper airway carriage for months. Treatment of pneumonia with macrolides is widespread and can lead to the development of macrolide resistance. The clinical consequences of chronic carriage are unknown. In this article, we describe a child with acute lymphoblastic leukemia who developed macrolide-susceptible pneumonia confirmed by nasopharyngeal secretions polymerase chain reaction and culture with good response to azithromycin. Five months later, the patient developed another pneumonia that was diagnosed with positive macrolide-resistant polymerase chain reaction and culture from the bronchoalveolar lavage. The child responded well to fluoroquinolones and eventually was discharged from the hospital. The recovered from the second pneumonia is a novel strain and is genetically identical to the that caused the first pneumonia, apart from the macrolide-resistance 23S ribosomal RNA gene. Both isolates are identical in both P1 (subtype 2 with a novel variant, 2bv) and multiple-locus variable number tandem repeat analysis type (53662). This is indicative of chronic carriage with de novo macrolide-resistance mutation and subsequent breakthrough pneumonia that is reported for the first time here. Children with immunosuppression may be at increased risk of life-threatening macrolide-resistant pneumonia after carriage. Further studies are required to evaluate the impact of this phenomenon. This will then guide strategies to limit the associated morbidity, such as testing for macrolide resistance, treatment of pneumonia in high-risk children with bactericidal antibiotics (such as fluoroquinolones), and possibly eradication protocols of carriage to prevent subsequent life-threatening infections.
肺炎在儿童中较为普遍，并可在上呼吸道携带数月。大环内酯类药物治疗肺炎较为广泛，可能导致大环内酯类耐药的产生。慢性携带的临床后果尚不清楚。本文描述了一例急性淋巴细胞白血病患儿，其通过鼻咽分泌物聚合酶链反应（PCR）和培养证实为对大环内酯类敏感的肺炎，对阿奇霉素反应良好。5 个月后，患儿发生另一次肺炎，经支气管肺泡灌洗培养和聚合酶链反应（PCR）检测，诊断为阳性的大环内酯类耐药。患儿对氟喹诺酮类药物反应良好，最终出院。从第二次肺炎中分离出的菌株是一种新型菌株，除了 23S 核糖体 RNA 基因的大环内酯类耐药突变外，与引起第一次肺炎的菌株在遗传上完全相同。两种分离株在 P1（亚型 2 带有新型变异体 2bv）和多位点可变数目串联重复分析型（53662）上完全相同。这表明存在慢性携带并出现新大环内酯类耐药突变，随后发生突破性肺炎，这是首次在此报道。免疫抑制的儿童在发生携带后可能面临危及生命的大环内酯类耐药性肺炎的风险增加。需要进一步研究来评估这种现象的影响。这将有助于制定相关策略，以限制相关发病率，例如进行大环内酯类耐药性检测、用杀菌抗生素（如氟喹诺酮类）治疗高危儿童的肺炎，以及可能制定清除携带方案以预防随后发生危及生命的感染。
