局部使用抗生素对拟行玻璃体内注射患者眼表微生物群落影响的自身前后对照研究

目的　针对拟接受玻璃体内注射患者，研究眼局部使用抗生素对眼表微生物群落的影响。方法　收集2018年9月至2019年1月在眼科就诊需行玻璃体内注射患者结膜囊拭子，分别在眼局部抗生素给药前（未用药组）与给药后（用药组）进行采样，建立自身对照。采用Miseq PE301+8+8+301平台进行细菌16S rDNA 基因 V3-V4 区双端测序，分析比较使用抗生素滴眼前后眼表微生物群落构成差异。并进行OTUs聚类、物种丰度分析、多样性分析、物种组成分类分析等生物信息学分析。结果　本研究共纳入30例（43眼）患者，获得86例标本，成功建库41例标本，可形成自身前后比较的患者7例，共14例标本。该14例标本共获得607 362条有效序列及869个OTUs。OTUs分析显示，用药组眼表微生物OTUs数量明显较未用药组减少。Alpha和Beta多样性分析结果均显示，用药组与末用药组眼表微生物群落差异均无统计学意义（均为P>0.05）。物种分类组成分析显示，未用药组与用药组比较核心关键菌具有明显差异，在属水平，未用药组主要为放线菌、棒状杆菌、表皮葡萄球菌，用药组主要为α-变形菌、鞘脂单胞菌、链球菌。Lefse分析显示，经过抗生素处理后的结膜囊菌群发生显著变化。结论　眼局部抗生素使用会明显影响拟行玻璃内注射患者的眼表微生物群落构成，尤其结膜囊内一些对维持眼表稳态有意义的重要“核心菌”。

A self-controlled study on influnence of topical antibiotics to ocular surface microbiome in the patients undergoing intravitreal injection

Objective　To investigate the effect of topical antibiotics on the microbiome of ocular surface in patients who received intravitreal injection.Methods　Conjunctival sac swabs of patients who received intravitreal injection from September 2018 to January 2019，samples were taken before and after local antibiotic administration of the eyes (untreated group and treated group, respectively) to establish self-control study. MiseqPE301+8+8+301 platform was applied to carry double-terminal sequencing of bacterial 16S rDNA gene in V3-V4 region, and compare the differences of microbial community composition in the two groups. OTUs clustering, species abundance analysis, diversity analysis, species composition classification analysis and other bioinformatics analysis were conducted.Results　All the patients signed the informed consent. A total of 30 patients (43 eyes) and 86 samples were collected, and 41 samples were successfully sequenced, and the proper comparison was 7 patients (14 samples). During the detection, 607 362 valid sequences and 869 OTUs were obtained, respectively. OTUs analysis showed that the number of ocular surface microbe OTUs in the treated group was significantly lower than that in the untreated group. Both Alpha and Beta diversity analysis showed that there was no significant difference in ocular surface microbial communities between the treated group and the untreated group (both P>0.05). Lefse analysis showed that there were significant differences in the core bacteria composition between the treated group and the untreated group. The untreated group was mainly actinomycetes, corynebacterium and staphylococcus epidermidis, while the treated group was mainly α-variant bacteria, spatholipidomonas and streptococcus.Conclusion　Topical administration of antibiotics can significantly influence microbiome of ocular surface, especially some important “core bacteria” in the conjunctival sac which are important for maintaining ocular homeostasis.