Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center Rotterdam, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
Clevergene Biocorp Private Limited, Bangalore, India.
Microbiome. 2017 Nov 9;5(1):147. doi: 10.1186/s40168-017-0363-6.
It is clear that specific intestinal bacteria are involved in the development of different premalignant conditions along the gastrointestinal tract. An analysis of the microbial constituents in the context of pancreatic cystic lesions has, however, as yet not been performed. This consideration prompted us to explore whether endoscopically obtained pancreatic cyst fluids (PCF) contain bacterial DNA and to determine the genera of bacteria present in such material.
Total DNA was isolated from 69 PCF samples. Bacterial 16S rRNA gene-specific PCR was performed followed by Sanger sequencing and de novo deep sequencing for the V3-V4 variable region of 16S rRNA gene.
We observed that 98.2% of the samples were positive in conventional PCR, and that 100% of selected PCF samples (n = 33) were positive for bacterial microbiota as determined by next generation sequencing (NGS). Comprehensive NGS data analysis of PCF showed the presence of 408 genera of bacteria, of which 17 bacterial genera were uniquely abundant to PCF, when compared to the Human Microbiome Project (HMP) database and 15 bacterial microbiota were uniquely abundant in HMP only. Bacteroides spp., Escherichia/Shigella spp., and Acidaminococcus spp. which were predominant in PCF, while also a substantial Staphylococcus spp. and Fusobacterium spp. component was detected.
These results reveal and characterize an apparently specific bacterial ecosystem in pancreatic cyst fluid samples and may reflect the local microbiota in the pancreas. Some taxa with potential deleterious functions are present in the bacterial abundance profiles, suggesting that the unique microbiome in this specific niche may contribute to neoplastic processes in the pancreas. Further studies are needed to explore the intricate relationship between pathophysiological status in the host pancreas and its microbiota.
显然，特定的肠道细菌参与了胃肠道不同癌前状态的发展。然而，目前尚未对胰腺囊性病变中的微生物成分进行分析。考虑到这一点，我们探讨了经内镜获取的胰腺囊液（PCF）是否含有细菌 DNA，并确定了此类物质中存在的细菌属。
从 69 份 PCF 样本中提取总 DNA。进行细菌 16S rRNA 基因特异性 PCR，随后进行 Sanger 测序和 16S rRNA 基因 V3-V4 可变区的从头深度测序。
我们观察到常规 PCR 中 98.2%的样本为阳性，通过下一代测序（NGS）确定 100%的选定 PCF 样本（n=33）存在细菌微生物群。PCF 的综合 NGS 数据分析显示存在 408 个细菌属，与人类微生物组计划（HMP）数据库相比，PCF 中 17 个细菌属具有独特的丰富度，而在 HMP 中仅 15 个细菌属具有独特的丰富度。拟杆菌属、大肠埃希氏菌/志贺氏菌属和酸氨基球菌属在 PCF 中占优势，同时也检测到大量的葡萄球菌属和梭杆菌属成分。
这些结果揭示并描述了胰腺囊液样本中明显特异的细菌生态系统，并可能反映了胰腺中的局部微生物群。一些具有潜在有害功能的分类群存在于细菌丰度图谱中，这表明这个特定生态位中的独特微生物组可能有助于胰腺的肿瘤发生过程。需要进一步研究来探索宿主胰腺的病理生理状态与其微生物群之间的复杂关系。
