Abstract

Objective Haemophilus influenzae type b (Hib) is the most virulent serotype that colonizes the upper respiratory tract of children. After introducing Hib conjugate vaccine, Hib has become almost entirely replaced by nontypeable H. influenzae (NTHi) strains. This study investigated the incidence of NTHi, which may cause serious sporadic body infections.

Methods A total of 300 nasal and throat swab samples were obtained from children aged 6 to 60 months, who visited outpatient pediatric clinics of Jordan University Hospital and Al-Bashir Hospital, Amman, Jordan. Colonies resembling H. influenzae were tested by conventional laboratory tests including Gram staining and antibiotic susceptibility. The 16S rRNA and bexA (capsulation gene) were amplified from the extracted DNA. Swabs (n = 100) were delivered to the laboratory in transport media. After initial culture, DNA was extracted directly and tested by conventional polymerase chain reaction (PCR) employing actin beta primers for assessing the housekeeping gene, followed by quantitative PCR (qPCR) against Hib-specific primers.

Results A total of 31/300 (10.33%) of H. influenzae isolates were recovered by culture and confirmed by PCR for 16S rRNA; 96.77% (30/31) were NTHi, and only one isolate was Hib. This isolate was confirmed by detection region II of the cap locus of Hib gene by qualitative TaqMan real-time qPCR. Antibiotic resistance among NTHi to ampicillin and erythromycin was 50.0 and 20.0%, respectively.

Conclusion The conjugated Hib vaccine almost eliminated the occurrence of Hib in the upper respiratory tract of the Jordanian children, while NTHi colonization was found in 10% of them.

Publication History

Received: 10 December 2019

Accepted: 13 July 2020

Publication Date:
31 August 2020 (online)

Georg Thieme Verlag KG
Stuttgart · New York

中文翻译：

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约旦儿童流感嗜血杆菌与Hib疫苗的呼吸运输。

摘要

目的 乙型流感嗜血杆菌（Hib）是在儿童上呼吸道定殖的最强毒力血清型。引入Hib结合疫苗后，Hib已几乎完全被不可分型的流感嗜血杆菌（NTHi）菌株取代。这项研究调查了NTHi的发生率，它可能导致严重的零星身体感染。

方法 从约旦大学医院和约旦安曼市的Al-Bashir医院门诊儿科门诊的6至60个月大的儿童中获得300份鼻和咽拭子样本。通过常规实验室测试（包括革兰氏染色和抗生素敏感性）对类似于流感嗜血杆菌的菌落进行了测试。的16S rRNA基因和bexA（封装基因）从提取的DNA进行扩增。拭子（n  = 100）以运输介质的形式送到实验室。初始培养后，直接提取DNA，并通过常规聚合酶链反应（PCR）使用肌动蛋白β进行测试 用于评估管家基因的引物，然后针对Hib特异性引物进行定量PCR（qPCR）。

结果培养的流感嗜血杆菌分离物 总数为31/300（10.33％），并经PCR确证16S rRNA ; NTHi为96.77％（30/31），只有一种分离物为Hib。通过定性TaqMan实时qPCR通过检测Hib基因的帽位点区域II证实了该分离株。NTHi对氨苄西林和红霉素的抗生素耐药性分别为50.0％和20.0％。

结论 结合的Hib疫苗几乎消除了约旦儿童上呼吸道的Hib发生，而NTHi的定植在其中的占10％。

出版历史

收到：2019年12月10日

接受：2020年7月13日

发布日期：
2020年8月31日（在线）

Georg Thieme Verlag KG
斯图加特·纽约