Toxigenic and non-toxigenic patterns I, II and III and biofilm-forming ability in Bacteroides fragilis strains isolated from patients diagnosed with colorectal cancer

Gut Pathogens

Leonardo A. Sechi¹  Zahra Ahmadinejad²  Bizhan Nomanpour³  Seyedesomaye Jasemi⁴  Mohammad Emaneini⁴  Mohammad Mehdi Feizabadi⁴  Mohammad Sadegh Fazeli⁵  Fatemah Sadeghpour Heravi⁶ 

[1] Department of Biomedical Sciences, University of Sassari;Department of Infectious Diseases, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences;Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences;Department of Microbiology, School of Medicine, Tehran University of Medical Sciences;Department of Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences;Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University;

关键词: Enterotoxigenic Bacteroides fragilis;    ETBF;    bft gene;    Biofilm;    Colorectal cancer;    CRC;   

DOI  :  10.1186/s13099-020-00366-5

来源: DOAJ

【 摘 要 】

Abstract Background Enterotoxigenic Bacteroides fragilis (ETBF) associated with the initiation and progression of colorectal cancer (CRC) has been alarmingly reported all over the world. In this study, simultaneous investigation of toxigenic and non-toxigenic patterns I, II and III and biofilm formation ability of Bacteroides fragilis isolated from patients with colorectal cancer was performed. Methods Thirty-one patients diagnosed with CRC and thirty-one control subjects were recruited in this study. Specimens were cultured on BBE and BBA culture media. Classical phenotypic identification tests and PCR was performed to verify Bacteroides fragilis presence. Also, biofilm-forming ability and expression of bft gene were assessed under biofilm and planktonic forms. Results A total of 68 B.fragilis was isolated from all colorectal tissue, of which 13 isolates (19.1%) (11 isolates from CRC and 2 from normal tissue) were positive for bft gene. The abundance patterns of I, II and III were as follow in descending order; pattern I > pattern III > pattern II in CRC subjects and pattern II > pattern III > pattern I in normal tissues. Also, pattern I showed higher biofilm formation ability compared to other patterns. Toxin expression was significantly reduced in biofilm form comparing with planktonic form. Conclusions Based on our findings, there was a difference between the abundance of patterns I, II, and III and biofilm formation in isolates obtained from CRC and normal tissues. Biofilm formation ability and toxin encoding gene (bft) are two main virulence factors in B. fragilis pathogenicity which require more investigation to treat B. fragilis infections effectively.

【 授权许可】

Unknown