用免疫磁珠分离法结合选择性厌氧菌琼脂从人粪便中分离具核梭杆菌。

Isolation of Fusobacterium nucleatum from human feces using immunomagnetic separation coupled with fastidious anaerobe agar.

机构信息

Department of General Surgery, The Third Affiliated Hospital of Chongqing Medical University (Gener Hospital), Shuanghu Road, Chongqing 401120, China.

Department of Laboratory Medicine, The 956th Hospital of Chinese People's Liberation Army (PLA), Linzhi, 860114, China.

出版信息

J Appl Microbiol. 2023 Feb 16;134(2). doi: 10.1093/jambio/lxac058.

DOI:10.1093/jambio/lxac058

PMID:36724265

Abstract

AIM

Fusobacterium nucleatum (F. nucleatum) is associated with the initiation, development, and metastasis of colorectal cancer. However, it is difficult to isolate F. nucleatum from clinical specimens. In this study, we aimed to develop an effective and rapid method for isolating F. nucleatum from human feces using polyclonal antibody (PAB)-coated immunomagnetic beads (IMBs) with selective media.

METHODS AND RESULTS

IMBs conjugated with PAB were prepared and used to isolate F. nucleatum from human feces, and the bacteria were cultured with selective culture media (fastidious anaerobe agar + nalidixic acid + vancomycin). Under optimized experimental conditions, IMBs could selectively recover F. nucleatum from fecal microbiota samples spiked with Peptostreptococcus or Bacteroides fragilis. In artificial fecal samples, the detection sensitivity of IMBs for F. nucleatum was 103 CFU mL-1. In addition, IMBs combined with selective media could rapidly isolate F. nucleatum from human feces.

CONCLUSIONS

This study successfully established an effective method for the rapid isolation of F. nucleatum from human feces by IMBs. The whole procedure requires 2-3 days, and has a sensitivity of 103 CFU mL-1 feces.

摘要

目的

具核梭杆菌（Fusobacterium nucleatum，F. nucleatum）与结直肠癌的发生、发展和转移有关。然而，从临床标本中分离 F. nucleatum 较为困难。本研究旨在开发一种使用多克隆抗体（polyclonal antibody，PAB）包被免疫磁珠（immunomagnetic beads，IMBs）结合选择性培养基从人粪便中有效、快速分离 F. nucleatum 的方法。

方法和结果

制备了与 PAB 偶联的 IMBs，用于从人粪便中分离 F. nucleatum，并使用选择性培养培养基（苛养厌氧菌琼脂+萘啶酸+万古霉素）培养细菌。在优化的实验条件下，IMBs 可从添加消化链球菌或脆弱拟杆菌的粪便微生物群样本中选择性回收 F. nucleatum。在人工粪便样本中，IMBs 对 F. nucleatum 的检测灵敏度为 103 CFU mL-1。此外，IMBs 与选择性培养基相结合可从人粪便中快速分离 F. nucleatum。