Chmelar Dittmar, Vrtný Jirí
Department of Examination Methods and Medical Biology, Faculty of Health Studies, University of Ostrava, Ostrava.
Klin Mikrobiol Infekc Lek. 2010 Jun;16(3):97-102.
Members of the Bacteroides fragilis group are the most frequently isolated anaerobic bacteria causing a wide range of severe anaerobic infections. In spite of the high frequency of their occurrence, their presence in clinical specimens is underestimated or even disregarded. The article warns of the severity of these anaerobic pathogens, particularly if detected in clinical samples from the abdominal area. It was hypothesized that there is a correlation between the presence of the bacteria in patients preferring high-meat diet and cancers of the small intestine and especially the colon and rectum [10]. Endotoxins of the bacteria contribute to weakening the patient's immune system damaged by cancer and play a significant role in the progression of small intestine and colon cancer.
Endotoxin production was determined in 140 strains of the Bacteroides fragilis group (B. fragilis, B. thetaiotaomicron, B. distasonis, B. vulgatus) isolated from patients with 7 cancerous and non-cancerous diseases (5 strains of each type of Bacteroides spp. for each diagnosis), using the Pyrosate LAL (limulus amoebocyte lysate) assay.
A statistically significant difference in the production of endotoxins isolated from strains of the Bacteroides fragilis group was found between cancerous and non-cancerous diseases.
All four bacterial species produced significantly more endotoxins in cancer than in non-cancerous diseases, with the lowest production in skin abscess (F2,134 = 170, p < 0.0001). Statistically significant differences in the production of endotoxins were also found between the individual members of the Bacteroides fragilis group. B. fragilis and B. vulgatus produced significantly more of (twice as much) endotoxin than B. distasonis and B. thetaiotaomicron (post hoc t-tests, p < 0.00001).
脆弱拟杆菌群成员是最常分离出的厌氧细菌，可引发多种严重的厌氧感染。尽管它们出现的频率很高，但在临床标本中的存在却被低估甚至忽视。本文警告了这些厌氧病原体的严重性，尤其是在腹部临床样本中检测到它们时。据推测，偏好高肉饮食的患者体内存在这些细菌与小肠癌，尤其是结肠癌和直肠癌之间存在关联[10]。这些细菌的内毒素会导致因癌症而受损的患者免疫系统减弱，并在小肠癌和结肠癌的进展中发挥重要作用。
使用Pyrosate LAL（鲎试剂）检测法，对从7种癌症和非癌症疾病患者中分离出的140株脆弱拟杆菌群（脆弱拟杆菌、多形拟杆菌、解脲拟杆菌、普通拟杆菌）进行内毒素产生情况的测定（每种诊断的每种拟杆菌属菌株各5株）。
在癌症和非癌症疾病之间，从脆弱拟杆菌群菌株中分离出的内毒素产生情况存在统计学上的显著差异。
所有四种细菌在癌症患者体内产生的内毒素均显著多于非癌症疾病患者，在皮肤脓肿患者体内产生的内毒素最少（F2,134 = 170，p < 0.0001）。在脆弱拟杆菌群的各个成员之间，内毒素产生情况也存在统计学上的显著差异。脆弱拟杆菌和普通拟杆菌产生的内毒素显著更多（多出两倍），比解脲拟杆菌和多形拟杆菌多（事后t检验，p < 0.00001）。
