脆弱类杆菌(Bacteroides fragilis)是革兰氏阴性无芽孢厌氧杆菌,主要存存于大肠、阴道和口腔等处。Finegold(1975)研究25名健康成人大肠中的正常菌群,发现每克于粪中约有10~(10～11)个本组细菌,比大肠杆菌约高100～1000倍。临床细菌检验发现无芽孢厌氧杆菌在各种感染性标本中检出率较高,其中脆弱类杆菌占首位。在厌氧菌菌血症中,脆弱类杆菌 Bacteroides fragilis is Gram-negative non-Bacillus anaerobic bacteria, mainly stored in the large intestine, vagina and mouth and so on. Finegold (1975) studied normal flora in 25 healthy adult large intestine and found that about 10-10 (10-11) of the group of bacteria per gram in feces was about 100-1000 times higher than that of E. coli. Clinical Bacteria Test found that non-spore-forming anaerobic bacteria in a variety of infectious specimens detected in a higher rate, Bacteroides fragilis accounted for the first place. In anaerobic bacteremia, Bacteroides fragilis