接种13价肺炎球菌结合疫苗对就诊儿童肺炎链球菌血清型和耐药性的影响

Effect of 13-valent pneumococcal conjugate vaccine on serotypes and antibiotic-resistance of streptococcus pneumoniae in children

目的了解就诊儿童肺炎链球菌(Streptococcus pneumoniae,Spn)血清型分布和耐药特征,探索接种13价肺炎球菌结合疫苗(13-valent pneumococcal conjugate vaccine,PCV13)对Spn的影响。方法收集2017—2019年苏州大学附属儿童医院疫苗接种信息明确的就诊儿童的Spn菌株,根据疫苗接种情况进行分组,并采用荚膜肿胀法进行血清分型,E-test法检测菌株抗生素的耐药性,比较是否接种PCV13对Spn血清型和耐药性的差别。结果共收集692株Spn,其中20株分离自接种PCV13儿童。接种组中常见的血清型为19F、6B、19A、23F,对照组中常见的血清型为19F、6B、23F、19A、14,两组血清型分布差别无统计学意义(P=0.868),PCV13血清型覆盖率分别为70.0%和72.4%(P=0.491)。所有菌株对红霉素、四环素、克林霉素高度耐药,且多重耐药率达98.5%。接种组和对照组的Spn菌株对青霉素的不敏感率分别为5.0%和9.1%(P=0.804)。结论苏州大学附属儿童医院监测就诊儿童Spn血清型以PCV13覆盖的血清型为主,菌株对β-内酰胺类抗生素的耐药性有所下降,但对红霉素等其他常用抗菌药物的耐药性依旧严峻,并存在大量的多重耐药情况。尚未观察到接种PCV13对菌株血清型分布及降低抗生素耐药性的明显效果。

Objective To investigate the serotype distribution and antibiotic-resistance of Streptococcus pneumoniae(S.pneumoniae)isolated from medical-visiting children,and to explore the effect of 13-valent pneumococcal conjugate vaccine(PCV13)on pneumococcal isolates.Methods The strains of S.pneumoniae isolated from children with confirmed vaccination information in Soochow University Affiliated Children's Hospital(SCH)from 2017 to 2019 were collected.The strains were grouped according to the vaccination status,used quellung reactions to serotype and employed E-test method to determine the antibiotic resistance of strains,and compared the differences in serotypes and antibiotic-resistance between with and without PCV13 vaccination.Results A total of 692 strains of S.pneumoniae were collected,20 of which were isolated from children vaccinated with PCV13.Serotypes 19F,6B,19A and 23F were prevalent in vaccinated children,while serotypes 19F,6B,23F,19A and 14 were common in unvaccinated children.There was no significant difference between the two groups in serotype distribution(P=0.868),and the PCV13 serotype coverage was 70.0%and 72.4%,respectively(P=0.491).All strains were highly resistant to erythromycin,tetracycline and clindamycin,and the multi-antibiotic resistance rate was 98.5%.The unsusceptible rates of penicillin were 5.0%and 9.1%in the vaccinated and unvaccinated groups,respectively(P=0.804).Conclusions Most S.pneumoniae strains from children in SCH were covered by PCV13 serotypes.The resistance of S.pneumoniae to lactams antibiotics was decreased,but the resistance to other commonly used antibiotics such as erythromycin remained severe,and the multi-antibiotic resistance rate was high.No apparent effect of PCV13 on serotype distribution and antibiotic resistance was observed.