一对紫绀型先天性心脏病患儿肠道菌群动态变化及阴沟肠杆菌耐药性研究

Dynamic changes of the gut microbiota in a pair of newborn twins with cyanotic congenital heart disease and drug resistance of Enterobacter cloacae

摘要:

[目的]观察一对紫绀型先天性心脏病双胞胎新生儿在接受手术及抗生素治疗前后的肠道菌群的动态变化,探究患儿肠道内阴沟肠杆菌在治疗期间耐药性如何发生改变。[方法]通过采集患儿在不同治疗阶段的粪便样本,进行培养组学和16S rRNA基因测序分析。同时,从双胞胎哥哥不同治疗阶段的粪便样本中分离得到10株阴沟肠杆菌进行体外药敏试验。[结果]培养组学结果显示使用抗生素导致术前粪便样本丰富度降低,仅可分离获得肠球菌属、不动杆菌属和肠杆菌属;长期医院环境暴露后,能分离出多种条件致病菌属,包括肠杆菌属、克雷伯菌属、不动杆菌属和假单胞菌属;母乳喂养4个月后,粪便菌群丰富度增加、构成发生改变,可分离获得乳杆菌属和双歧杆菌属等有益细菌。16S rRNA基因测序结果显示,在多种因素影响下不同治疗时间点α多样性指数和相对丰度最高的菌属不同。细菌耐药实验结果显示,治疗期间阴沟肠杆菌对哌拉西林逐渐产生耐药性。[结论]接受抗生素治疗、院内环境暴露和母乳喂养共同影响患儿治疗和康复期间的肠道菌群组成;在不同治疗阶段仅使用一种抗生素,也会导致阴沟肠杆菌对不同药物的耐药性发生改变。

Abstract:

[Objective] To observe the dynamic changes of gut microbiota in a pair of newborn twins with cyanotic congenital heart disease after surgery and antibiotic treatment and explore the variation of drug resistance of Enterobacter cloacae during treatment. [Methods] The fecal samples of the twins were collected at different stages of treatment and analyzed by culturomics and 16S rRNA gene sequencing.The susceptibility of ten Enterobacter cloacae strains isolated from the elder twin at different stages to antibiotics was determined.[Results] Culturomics results suggested that antibiotics decreased the flora richness of fecal samples before surgery and only Enterococcus,Acinetobacter and Enterobacter were isolated.Upon the long-time exposure to the hospital environment,opportunistic pathogens of several genera were isolated,including Enterobacter,Klebsiella,Acinetobacter and Pseudomonas.After 4 months of breast feeding,richness of fecal flora increased and the composition changed.To be specific,probiotics such as Lactobacillus and Bifidobacterium were isolated.16S rRNA gene sequencing results showed that α diversity indexes and the genus with highest relative abundance were different depending on treatment stages under the influence of various factors.The susceptibility tests indicated that E.cloacae strains gradually developed resistance to piperacillin during treatment.[Conclusion]Antibiotic treatment,exposure to hospital environment,and breast feeding all changed the gut microbiota structure of the twins during treatment and recovery.Even if only one antibiotic was used at different stages of treatment,the resistance of E.cloacae to different drugs might change.