Ulger Toprak Nurver, Rajendram Dunstan, Yagci Aysegul, Gharbia Saheer, Shah Haroun N, Gulluoglu Bahadir M, Akin Levhi M, Demirkalem Pakize, Celenk Tuncay, Soyletir Guner
Medical School, Department of Clinical Microbiology, Marmara University, Haydarpasa, Tibbiye Cad, Istanbul, Turkey.
Anaerobe. 2006 Apr;12(2):71-4. doi: 10.1016/j.anaerobe.2005.11.001. Epub 2005 Dec 13.
Enterotoxigenic Bacteroides fragilis (ETBF) has been implicated in diarrhoeal illness in animals and humans. Recent data suggest that ETBF is associated with flares of inflammatory bowel disease. Toxigenicity is attributed to expression of a toxin referred to as fragilysin, which stimulates fluid accumulation in ligated intestinal segments and alter the morphology of human intestinal cells. Three different isoforms or variants of the enterotoxin gene, designated bft-1, bft-2, and bft-3, have been identified. In this study we investigated the distribution of bft alleles among ETBF strains in stool specimens from patients with colon cancer (n: 31), the control patients (n: 8) and extraintestinal sources (n: 15). We used restriction fragment length polymorphism analysis of the PCR-amplified enterotoxin gene and sequencing the PCR-product to detect the isoforms of bft gene. Among the stool strains, bft-1 was found to be more common than bft-2; as it was detected 27 of 31 strains from colon cancer patients and 7 of 8 control strains. The bft-1 isoform was also found in almost all isolates from extraintestinal sites. No bft-3 subtype was detected among all tested strains.
产肠毒素脆弱拟杆菌（ETBF）与动物和人类的腹泻病有关。最近的数据表明，ETBF与炎症性肠病的发作有关。毒性归因于一种名为脆弱类杆菌毒素的毒素表达，该毒素会刺激结扎肠段中的液体蓄积并改变人类肠道细胞的形态。已鉴定出三种不同的肠毒素基因同工型或变体，分别命名为bft-1、bft-2和bft-3。在本研究中，我们调查了结肠癌患者（n = 31）、对照患者（n = 8）和肠外来源（n = 15）粪便标本中ETBF菌株之间bft等位基因的分布情况。我们对PCR扩增的肠毒素基因进行限制性片段长度多态性分析，并对PCR产物进行测序，以检测bft基因的同工型。在粪便菌株中，发现bft-1比bft-2更常见；在31例结肠癌患者的菌株中有27例以及8例对照菌株中有7例检测到bft-1。在几乎所有肠外部位的分离株中也发现了bft-1同工型。在所有测试菌株中均未检测到bft-3亚型。
