Clinical Features Of Ulcerative Diseases Of Terminal Ileum And Microecological Study Of Chronic Terminal Ileitis

Background & Objectives: Terminal ileum is generally defined as the intestinal tract between ileocecal valve and the anal side of ileum,which is about 30 cm long. Inflammation occurring in terminal ileum involvs in a variety of diseases,the detection rate is different between from 7.8% to 27.3% for the different subjects and objects. At present, its pathogenesis is not yet completely clear, but microbes may play an important role in the pathogenesis of terminal ileitis.Terminal ileitis is usually divided into acute and chronic terminal ileitis, and patients suffering from it usually complain of abdominal pain, abdominal distension, diarrhea or hematochezia. It manifested congestion, erosion, and even ulcers or bleeding under endoscope. Besides, infiltration of inflammatory cells can be seen by biopsy. It had been clear that Salmonella, Klebsiella, Campylobacter jejuni and Yersinia can cause acute inflammation manifested as symptoms of acute gastroenteritis, but there are still some acute enteritis, as well as a large part of chronic terminal ileitis, still can not get diagnosis, which are usually diagnosed as "chronic terminal ileitis (CTI)". The most commom types of CTI are Crohn's disease, tuberculosis and backwash ileitis. The exact pathogenesis of CTI remains unknown. CTI usually makes bad impact on the life quality of patients for its long course, diverse discomfort symptoms and difficult to cure.The Microbial factor in the intestinal inflammation has been pay attention because of the researchs in animal model of CD.The study found that animals in the sterile environment without the occurrence of intestinal inflammation, so-called "no bacteria, no inflammation". Some scholars worked hard trying to find a specific micro-organisms, such as Vice Mycobacterium tuberculosis, and Clostridium difficile. But up until now they have failed to find a specific pathogens can better explain its pathogenesis.Recent studies show that the refrigerator is not " completely safe". It can not completely kill all of bacteria, the bacteria is just grow more slowly in the refrigeration process, and some "Psychrophile" have very strong ability of antifreeze, they can survive in 0℃environment and continue to grow and contaminate food. They has drawn people's attention for they bring a series of diseases. The most common "Psychrophile" is Yersinia enterocolitis (Y.e)and Listeria monocytogenes (LM). Meat, milk and dairy products, soybean products and aquatic products can easily been contaminated. The incidence of Crohn's disease in Nordic region is higher than that in the other areas made people interested in the Nordic climate and Psychrophile. Some scholars have engaged in relationship between CD and psychrophilic bacteria and raised of "cold chain theory".It has been confirmed that Yersinia can cause small enteritis, terminal ileum inflammation and septicemia. Y.e infection is characterized by water-borne diarrhea, and sometimes can cause bloody diarrhoea. However, the adult patients usually resume within one to two weeks. Whether Yersinia bacteria can cause chronic enteritis inflammation still needs further discussion.The LM can cause meningitis, encephalitis or sepsis in adults (non-pregnant), and the elderly or people with weakened immune systems are susceptible. Its incubation period and infection dose is not yet clear, the incubation time has been reported varing from a few days to two to three months. The patients infecting with LM can be observed gastroenteritis symptoms, such as diarrhea and abdominal pain. The infection rate of human and animal varies from 2 percent to 20 percent, thus gastroenteritis should consider the possibility of LM infection and rule it out. LM can be distributed or outbreak, the the major media of which is contaminated food,especially frozen food. The pathogenic mechanism of LM is not clear. And literature seldom touch upon the detection rate of LM in the intestinal mucosa in patients with CTI.There're also some researchers believe that it is not specific bacteria but normal flora change that leads to CTI. And more and more studies have shown that the dynamic balance between host defense response and intestinal microbial (especially commensalisms flora) in the IBD may play a key role during its occurrence and development.The integrity of the intestinal mucosal barrier of the body is very important, a study found that there were abnormalities in intestinal epithelial permeability and other genetic defects in CD patients. The normal intestinal epithelial can stop infiltration of macromolecules and decomposition of bacteria. Damage to the intestinal barrier could lead to ectopia of bacteria, and finally result of the occurrence of intestinal inflammation, which may explain why in some mouse model, we even used single the traditional bacteria regarded normal bacteria in human being can trigger ulcers, for example, Bacteroides vulgatus enable ordinary IL-10-deficient mice occurred ulcer. In addition, the number of flora may also be related to the occurrence of CTI. Due to the specific anatomy, colon contents can reflow into ileum, which may result in bacteria transplantation, as well as ectopic increase in the number of bacteria, so it is necessary to approach the membrane flora of patients with CTI.On one hand, the study was to approach clinical features of ulcerative diseases of terminal ileum,and on the other hand to explore the flora changes in the membrane flora of CTI patients. Finally we plan to detect two common Psychrophile (Y.e and LM) in ileal mucosa, trying to explore the pathogenesis of CTI on microecological perspective.Materials and Methods1. Fifty-five inpatients of Nan-fang hospital detected with ulcerative diseases of terminal ileum from Jan. 2000 to Oct. 2007 were enrolled. Their clinical manifestations, diagnosis and treatment were retrospectively analyzed.2. 30 cases of CTI patients confirmed by endoscopic biopsy, from Digestive Endoscopy Center of Nanfang Hospital between May 2007 to Feb.2008, aged between from 18 to 50, did not use hormones or antibiotics in the past month, 30 cases of healthy people, respectively collected ileal mucosa for 2～4 pieces.3. Mucosa collected from the ileal is weighted immediately,and washed 3 times with cleanning solution. Put it into homogenizer for grinding, subculturing the homogenate on 5 kinds of selective culture medium,each of the medium contain 6 kinds of concentration(3 drops). They were cultured respectively under aerobic and anaerobic environment for 24～48 h, then the number of coenobiums and the mean value are counted. The purpose of bacteria contains two kinds of aerobic bacteria (Escherichia coli, Enterococcus) and three kinds of anaerobic bacteria (B. Lactobacillus, Bifidobacterium). Homogenate from another part is noculated on Listeria monocytogenes color medium and Yersinia selective medium (CIN medium).4. 24 or 48 h later ,count the colony on selective medium and then smear, stain and to observe under microscope, sequentially biochemical identification was operated.5. Firstly, we design primers of Y.e and LM specific coding sequences, then pick the colony suspected Y.e or LM, extract it's DNA for PCR amplification. Finally gel electrophoresis analysis and sequencing were carried out.6. Statistical analysis.Results1. Clinical features of ulcerative diseases of terminal ileum:Multiple ulcer were more common than solitary ulcer. The most common gastrointestinal symptoms of these patients were abdominal pain and hematochezia. The detection rate of crohn's disease and intestinal tuberculosis were 60.0% and 10.9% respectively.2. Conventional bacteria:Through the qualitative and quantitative of Escherichia coli, enterococci, B. Bifidobacterium and Lactobacillus, the results showed that the number of Lactobacillus of patient group was significantly reduce compared to the control group ,and was statistically significant difference (Z= -3.048, P = 0.002).However, there was no significant difference in other bacteria.3. Psychrophile: By PCR and direct sequencing , 3 cases of patients with LM positive, as well as 2 cases positive in control group. Comparing the two group there was no significant difference(x~2=0.000, P=1.000). 5 cases with Y.e positive in both of the case group and control group, and there was no significant difference between the 2 groups.Conclusions:1. It is hard to discriminate them from each other for there is no specificity in ulcerative diseases of terminal ileum. So diagnosis of chronic ulcerative diseases of terminal ileum should be judged by the history, clinical manifestations and auxiliary examination.2. The number of Lactobacillus decreases in ileal mucosa may result in decline of ability to inhibit intestinal bacteria, and finally lead to CTI.3. LM and Y.e may not afford to be a major role in the pathogenesis of CTI.