Transmission risk and resistance characteristics of Streptococcus pneumoniae among preschool children in Foshan

Abstract

Objective To understand the homology and resistance characteristics of Streptococcus pneumoniae (S. pneumoniae) in healthy preschool children, so as to provide basis for disease transmission prevention and rational use of antibiotics.

Methods Stratified cluster random sampling method was used to sample 1 829 healthy children from six kindergartens in Shunde District, Foshan City. Nasal sw-abs were taken and tested for S. pneumoniae. Multi-locus sequence typing was used for homology analysis. The Chi-squared test and random forest analysis were used to explore the resistance characteristics.

Results The nasal carriage rate of S. pneumoniae and multidrug-resistant S. pneumoniae (MDRSP) in children were 22.5% (412/1 829) and 21.3% (390/1 829), respectively. Homology analysis in sequence types showed that the total homology rates of 6 kindergartens were 93.5% (81/93), 91.1%(72/79), 89.2%(58/65), 88.9%(64/72), 86.2%(50/58), 77.8% (35/45), respectively. It was found that the highest homology rate was 82.8% (48/58) within-class and 93.1% (81/87) between classes. S. pneumoniae was mainly resistant to azithromycin (97.1%, 400/412), erythromycin (92.0%, 379/412) and tetracycline (91.5%, 377/412). The dominant multidrug resistance pattern of MDRSP isolates was not sensitive to azithromycin, erythromycin, cotrimoxazole, tetracycline and clindamycin. Random forest analysis indicated that the important phenotypic markers associated with MDRSP were resistance to azithromycin, cotrimoxazole, tetracycline, clindamycin and erythromycin (MDG = 8.94, 6.92, 5.80, 4.84, 2.58).

Conclusion The risk of crosstransmission of S. pneumoniae among preschool children is high, and direct contact is the main way of transmission. Consequently, kindergartens and health departments should take effective measures to effectively prevent and block the spread of Streptococcus pneumoniae.

Abstract

【摘要】 目的 了解健康学龄前儿童肺炎链球菌的同源性和耐药特征, 为阻断疾病传播和指导合理使用抗生素提供依 据。 方法 采用分层整群随机抽样方法, 抽取佛山市顺德区 6 所幼儿园中 1 829 名健康儿童, 进行鼻拭子采样并分离鉴定 肺炎链球菌;采用多位点序列分型进行同源性分析;采用; χ ² 检验、随机森林算法进行耐药特征分析。 结果 儿童鼻腔肺炎 链球菌携带率为22.5%(412 名), 多重耐药肺炎链球菌(MDRSP)的携带率为 21.3%(390 名)。菌株序列型别的同源性分 析显示, 6 所幼儿园菌株的同源率分别为 93.5%(87/93)、91.1%(72/79)、89.2%(58/65)、88.9%(64/72)、86.2%(50/58)、77.8%(35/45); 班级内同源率最髙达 82.8%(48/58), 班级间同源率最髙为 93.1%(81/87)。肺炎链球菌主要对阿奇霉素 (97.1%, 400/412)、红霉素(92.0%, 379/412)、四环素(91.5%, 377/412)耐药; MDRSP 主要耐药谱为同时对阿奇霉素、红霉 素、复方新诺明、四环素及克林霉素不敏感。随机森林分析提示, MDRSP 相关的重要耐药表型变量为阿奇霉素耐药、复方 新诺明耐药、四环素耐药、克林霉素耐药、红霉素耐药(平均不纯度减少值分别为 8.94, 6.92, 5.80, 4.84, 2.58)。 结论 幼儿 园儿童间肺炎链球菌的交叉传播风险较髙, 且直接接触传播是最主要传播途径。幼儿园和相关卫生部门应采取有效措施, 有效预防和阻断肺炎链球菌的传播。