Fungal enteritis

Introduction to fungal enteritis Fungal enteritis (fungalenteritis) is one of the important types of fungal diseases in the body. The digestive tract is the main route of infection of fungi invading the body, and it poses a greater threat to health and life. In the past, this disease was rare. In recent years, due to a wide range of applications such as broad-spectrum antibiotics, hormones, immunosuppressants, anti-tumor drugs, and radiation therapy, the number of intestinal infections has increased, and the incidence of intestinal fungal infections is 1.6%. The pathogens include Candida and Aspergillus. The fungi causing enteritis in China mainly include Candida, Actinomycetes, Mucor, Aspergillus, and Cryptococcus, among which Candida albicans enteritis is the most common. basic knowledge Sickness ratio: 0.001%-0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: perianal abscess, ischial rectal abscess, constipation

Cause of fungal enteritis

(1) Causes of the disease

The pathogen causing fungal enteritis is mainly Candida, followed by Aspergillus, Mucor, Histoplasma, Paraspora, and Geotrichum, occasionally Coccidioides, Marnifolium and Cryptococcus.

Candida is widely distributed in nature and is one of the normal flora of the human body. It is the main genus of pathogenic fungi, with more than 150 species. Among them, Candida albicans and Candida tropicalis are the most common and have strong pathogenicity. Candida is a biphasic fungus. The yeast is oval or round, with a single blast spore, 2.5 to 5 m in diameter, and can be connected to each other to form pseudohyphae. The mycelium is 5 to 10 m long. The spores can form larger apical thick-walled spores on the medium for 24h, while the buds are formed on the serum-containing sand-salting medium at 37 °C for 1 to 3 hours. The mannoprotein contained in the wall of Candida is serological. Diagnostic target antigen.

Aspergillus belongs to Ascomycota, the spores are ascospores, and the asexual spores are conidia, but some species have asexual reproduction in a single camp. There are 132 species and 18 subspecies of Aspergillus, and the pathogen is mainly Aspergillus fumigatus. 10 species of Aspergillus flavus, Aspergillus niger, etc., the size of Aspergillus spores in the lesion is about 3 ~ 4m, the shape is not complete, densely integrated group, Aspergillus hyphae vary in length, mostly rod-shaped, separated, diameter is larger than spore Slightly larger, the hyphae are branched at an acute angle, and there are multiple hyphae tending to branch in the same direction, and the arrangement is radial or coral-like.

Mucor is a zygomycete, spores are spores, asexual spores are sporangia spores, hyphae are not separated, coarse, and wall thickness is refraction, about 2 to 3 times that of mycelium, at right angles Branches, showing expanded cells and curved hyphae; sporangia stalks grow directly from hyphae, pathogenic bacteria are most common in the three species of Rhizopus, Mucor, and Absidia in Mucoraceae, especially roots. Rhizopus arrhizus and Rhizopus oryzae in the genus Mildew often invade the gastrointestinal tract.

Histoplasma genus is composed of capsular histoplasma and African histoplasma, belonging to the incomplete bacteria sub-gate, a biphasic fungus, yeast type in tissue and 37 ° C medium, diameter 2 ~ 4m; It grows slowly at room temperature and is a white mycelial colony. It has a typical gear-like large conidia, which is separated by hyphae and is highly contagious.

Paraspora is also biphasic. It grows in the natural environment or on the sand-preserving medium at 25 °C. The colonies are small, and the branches are separated by 1 to 2 m wide, and the hyphae are separated. The side has a round or oval shape, about 3 ~ 6m size of the lateral small conidia, in the tissue or on the 37 ° C blood agar on the yeast phase to grow, forming a large oval or spherical yeast body, diameter 10 ~60m, surrounded by a number of bud spores, the small one 1 ~ 2m, the larger one 10 ~ 30m.

Geotrichum candidum is a yeast-like fungus belonging to the genus Insecticidal, Phytophthora, Geotrichum, and feces. After direct smear treatment with 10% potassium hydroxide solution, finely divided hyphae and rectangles can be seen under the microscope. Joint spores, about 4m × 8m size, Gram stain positive, no gap between the two joint spores, sometimes a spore tube in the corner of the joint spores, occasionally round spores, thickening of the cell wall.

The causes of fungal enteritis include:

1. The application of broad-spectrum antibiotics causes intestinal flora imbalance.

2. Glucocorticoids, immunosuppressive drugs, tumor chemotherapy or radiotherapy lead to impaired immune function.

3. There are certain underlying diseases such as chronic liver disease, diabetes, AIDS, etc.

4. Intestinal malnutrition and surgical trauma.

(two) pathogenesis

The pathogenesis of fungal infections is complex and not fully understood. The occurrence of infection is the result of interaction between pathogens and humans.

1. Low immunity in the body, especially impaired cellular immune function, decreased number of phagocytic cells, loss of chemotaxis, decreased bactericidal power, etc., is a major factor in the pathogenesis of fungal enteritis, a feature of conditional fungal infections It is often the case with patients with underlying diseases. What these patients have in common is low immune function.

2. In terms of bacterial cells, the cell wall of Candida albicans contains mannose, which can enhance its adhesion, and Candida albicans is often mycelium in tissues, which is not easily phagocytized by macrophages compared with yeast, and is also like a capsule. After being phagocytosed by macrophages, histoplasma can not be killed, can be propagated in macrophages, causing infection to spread, while Aspergillus endotoxin and lysin (tryptase) can cause tissue necrosis around the infected area. In addition, the number of fungi ingested at one time can also be a determinant of infection. For example, Krause has given 1012 CFU (colony forming unit) of Candida albicans to healthy people. Intestinal infection occurs several hours later, followed by Candida blood. disease.

3. Iatrogenic factors such as the application of broad-spectrum antibiotics leading to intestinal flora imbalance, conditional pathogenic fungi overgrowth, or intestinal surgery increases the chance of infection.

The pathological changes of fungal enteritis are mainly seen in the fungal invasion of various layers of the intestinal wall, Mucor, Aspergillus and a small number of enteritis caused by Candida albicans, but also invading the small inferior and mesenteric arterioles and venules, destroying the tube The wall causes the formation of fungal vasculitis and fungal thrombosis. These lesions are particularly prominent in mucormycosis. The disease can sometimes be mixed with two fungi, such as Candida albicans combined with Mucor, or Candida albicans. Infection, therefore, in pathological examination, it is best to combine fungal culture at the same time, to isolate and identify the pathogenic bacteria, which is conducive to diagnosis, and granuloma and fibrous lesions caused by fungal infection are rare in fungal enteritis, as seen under the microscope: There are focal necrosis and ulcer formation in the intestinal mucosa. Some ulcers are superficial, some are deep into the submucosa, some have pseudomembrane on the surface, and the pseudomembrane has a large number of fungi, fibrin, necrotic tissue and a small amount of inflammatory cells. The layers of the intestinal wall, especially the submucosa, are hyperemia, edema and inflammatory cell infiltration, and the inflammatory cells are different, mainly neutrophils. Monocytes and lymphocytes, can sometimes be seen abscesses.

Fungal enteritis prevention

1. Avoid incentives

First of all, we must control the application of broad-spectrum antibiotics, avoid universal use, and reduce long-term application. It is inevitable that long-term application should be combined with antifungal drugs at a certain stage to prevent the intestinal flora from dysregulating and causing excessive growth of pathogenic fungi. Others such as strengthening nutrition for patients with chronic diseases, improving the body's resistance; using glucocorticoids and immunosuppressive drugs with caution; protecting the integrity of the oral and intestinal mucosal physiological barriers in patients with low immune function, reducing trauma and so on can help prevent fungal enteritis occur.

2. Prevent fungal contamination and treat primary lesions

Malignant tumors and hematological wards should be well ventilated and dry, prevent fungal growth, increase the chance of exogenous infections, detect and treat fungal infections in thrush and other areas in time for patients with AIDS and other immune function suppression, so as not to be secondary Fungal enteritis, for patients undergoing intravenous nutrition, as well as patients undergoing vascular catheterization and surgery, strict aseptic procedures are performed to prevent fungal hospital infections.

3. Drug prevention

For high-risk groups such as AIDS patients, intestinal surgery and organ transplant patients, short-term adequate or long-term low-dose prophylaxis can be given.

(1) Patients with hematological diseases and malignant tumors: Nystatin is orally administered 2 million U per day for 5 to 7 days, and can be applied once a month.

(2) AIDS patients: fluconazole or itraconazole 100 ~ 200mg daily orally, 5-7 days a month, or ampoule B weekly 100mg orally added mycomycin suspension mouthwash, 3 times / d Long-term persistence.

(3) Organ transplantation and intestinal surgery patients: nystatin 500,000 U, 3 times / d, oral, or fluconazole 200 mg per day orally, 3 days before surgery and 7 days after surgery.

(4) low-weight newborns or premature infants: fluconazole 12.5mg / kg orally, and even served for 4 to 8 weeks, can prevent neonatal Candida enteritis.

(5) Prevention of recurrence: fungal enteritis, especially parasitic colitis enteritis is easy to relapse after treatment, especially in AIDS patients and other chronic diseases with low immune function, prevention of amphotericin B 50mg, once a week Intravenous infusion, or itraconazole 200mg, 1 time / d, oral, routine check liver function 1 to 2 times during the medication, pay attention to the toxic side effects of the drug.

Fungal enteritis complications Complications perianal abscess sciatic rectal abs constipation

Rectal actinomycetes can form subacute or chronic perianal abscess, ischial rectal abscess or rectal abscess, and lesions around the rectum are often caused by intra-abdominal lesions, manifested as diarrhea, constipation, heavy or thin yellow pus Bloody stools.

Fungal enteritis symptoms Common symptoms Dysentery Low fever Lymph node enlargement Black stool Immunodeficiency Feces with green mucus Painful abdominal pain Bloating diarrhea

1. Candida enteritis

The most common, especially in children, especially malnourished or severely debilitated babies, mainly manifested as diarrhea, stool 10 to 20 times a day, watery or bean curd-like, foam more yellowish green, may be associated with bloating Low fever, even vomiting, but abdominal pain is rare. The iodine smears of the fecal specimens show a large amount of budding yeast and hyphae. The culture is mostly Candida albicans. Children are often accompanied by thrush. Patients with underlying diseases often have application before the onset. In the history of broad-spectrum antibiotics, patients with immunodeficiency are prone to develop disseminated candidiasis. For example, in the treatment of general bacterial enteritis, the symptoms are intensified, and the diarrhea is prolonged, the constant month is not cured, and the recurrence is easy after relapse.

2. Aspergillitis

Occurs in physical labor with basic diseases, mostly caused by Aspergillus fumigatus. Because Fusarium is not a normal intestinal flora, the infection is exogenous, often secondary to pulmonary aspergillosis. Invasion of blood vessels, hyphae can penetrate into the blood vessel wall to cause thrombosis. The clinical manifestations of aspergillitis are mainly abdominal pain and bloody stools, which can cause massive bleeding in the digestive tract, and diarrhea is often atypical and lacks the prolongation of candida enteritis. After invading the blood vessels, it is easy to develop into disseminated aspergillosis.

3. Mucor fungus

Due to the intake of food contaminated by fungal spores, children who develop malnutrition or patients with chronic gastrointestinal diseases, the clinical manifestations vary greatly due to the location of the affected area and the degree of infection, which is characterized by post-vascular embolization. The symptoms of mucosal ulcers and even perforation are often accompanied by stomach infections and gastric ulcers. Abdominal pain, diarrhea, hematemesis and melena, or perforation of the intestines may cause peritonitis, or invading the gastrointestinal blood vessels, causing blood to spread, and the disease progresses rapidly. The rate is high.

4. Histoplasmosis enteritis

Local epidemics, more common in AIDS patients or children, due to inhalation or ingestion of spores from contaminated soil, clinically similar to localized enteritis or ulcerative colitis, slow onset, fever, indigestion, diarrhea, Black stool, abdominal pain, and sometimes vomiting, often accompanied by lung infection, but with enteritis as the main performance.

5. Paraspora enteritis

Secondary to the infection of the lungs or infection by blood, the disease is also endemic, mainly found in the central plateau of Brazil, people who are often exposed to the soil are more susceptible to the disease, the lesions are mostly in the ileocecal area, causing abscess The ulcerative granuloma formed, the pathogen can spread to the local lymph nodes through the lymph, liver, spleen, the main symptoms are abdominal pain, the right lower quadrant can touch the mass, accompanied by diarrhea, vomiting, often due to ascites and abdominal lymphadenopathy is easily misdiagnosed as Tuberculosis or tumor.

6. Geositic enteritis

Geositic bacterium is similar to Candida, and it is an endogenous conditional pathogen. Geositic colitis is more common in chronically ill patients with immunodeficiency and immunosuppressive drugs, antibiotics or glucocorticoids. Symptoms include abdominal pain and diarrhea. Pus and blood or mucus, similar to dysentery, but a large number of genus and rectangular joint spores can be found in pus and blood, patients with oral filariasis, similar to thrush.

Examination of fungal enteritis

Pathogen examination

Because fungi are widely distributed in nature, even spores are often found in the air. In the collection of manure specimens and inspection operations, pollution should be minimized. Specimens should be fresh. Some fungi are highly contagious, such as capsular histoplasma. Safety protection so as not to cause infection in laboratory personnel.

(1) Direct microscopy specimens: 10% potassium hydroxide or normal saline tablets, a large number of hyphae and spores are found to have diagnostic significance under high magnification. For biphasic fungi, only spores may be found to be normal carriers, fungal. The six common pathogens of enteritis can be identified by direct microscopic examination, but spores, hyphae and other background substances are sometimes confused and difficult to identify.

1 hyphae and spores: the mycelium is the same thickness, except for the mold, there are branches, the branches of different angles are visible, the cytoplasm is uniform, and the granules of different sizes are contained. The spores are mostly round or oval, and most of them are the same size. The edges are neat and the cell structure is visible.

2 Cell wall: In the sample treated with potassium hydroxide solution, the cell wall is often widened and connected in an arc shape, similar to hyphae, but the structure of the sterile silk.

3 asbestos body: finer than hyphae, no segmentation, sterile silk particles.

4 plant fiber: undigested food residue, uneven edges, no branches.

5 fat cells: round, fuzzy structure, no cell wall.

6 phospholipid beads: different sizes, irregular shape, no cell structure.

7 Potassium hydroxide crystal: snowflake or coral, with a zigzag edge and strong refractive index.

8 small blisters: round, translucent, cell-free structure.

(2) Dyeing methods commonly used in staining microscopy:

1 Gram stain: suitable for Candida, spores, hyphae dyed blue, but uneven coloration.

2 Periodic acid iodine staining (PA5): fungal spores, hyphae are dyed red.

3 acridine orange staining: fungal spores were bright green under fluorescence microscope.

4 Giemsa staining and Reiter staining: suitable for capsular histoplasma, fixed with methanol before dyeing, stained with red under the oil microscope, budding at the smaller end, and a capsular-like structure around the bacteria. The cell wall of this bacterium is usually located in macrophages or monocytes, and a few are located outside the cell.

5 lactic acid phenol cotton blue dyeing: suitable for a variety of fungal culture smear, the bacteria stained blue.

(3) Fungal culture: Direct microscopic examination of fecal specimens is usually not easy to determine the species. It is necessary to refer to the results of fecal culture, observe the colony morphology, and then pick up the microscopic examination after colony staining. Commonly used sand preservation medium and blood agar medium, for double Phase-type fungi also need to be cultured separately at different temperatures (25 ° C or 37 ° C) in order to observe their morphological changes.

1 large culture: It is one of the main methods for identifying fungi. The growth of colonies can be observed. According to the growth rate, shape and color of the colonies, the strains are initially identified.

A. Test tube bevel: Puncture the agar plane with a platinum ring, inoculate the specimen on the slant medium of the test tube at 3 o'clock. This method is not easy to be contaminated, but the colony is small.

B. Petri dish: The specimen was inoculated into the center of the plate medium at 3 o'clock, inverted and placed in an incubator for cultivation, and the colony growth was observed once every 3 days.

2 Small culture: Colonies with better growth in large culture were inoculated on a slide medium, and after 1 to 3 days of culture, the characteristics of the cells were observed under a microscope.

A. Point method: firstly form a small amount of medium in the center of the slide, then inoculate the strain on the edge of the medium, cover the cover glass, place it in a glass plate with a U-shaped tube, and culture at different times. Remove the microscopic observation or staining microscopy.

B. Tableting method: Inoculate the strain on the test tube slant or plate medium, cover a cover glass, so that the bacteria grow on the cover glass, and then take it out on the glass slide at the appropriate time for microscopic examination.

2. Histopathological examination

Some fungi belong to the normal flora of human intestinal tract, such as Candida albicans, and fungal contamination problems are widespread. Therefore, the diagnostic value of the pathological examination of fecal specimens is limited, and sometimes combined with the results of colonoscopy biopsy.

(1) Pathological changes in Aspergillus infection: have diagnostic significance, including:

1 inflammation: acute exudative inflammation.

2 ulcer formation: due to the invasion of blood vessels by Aspergillus, causing blood vessel destruction, thrombosis and tissue necrosis; ulcers vary in size and shape, can reach the muscular layer, rough and uneven bottom surface, purulent exudation.

3 granuloma: composed of epithelial cells and macrophages, accompanied by neutrophils, lymphocytes or plasma cells infiltration.

4 suppurative changes: submucosal small abscess formation, a large number of neutrophil infiltration, which can be seen hyphae.

(2) Fungal spores and hyphae are found in pathological sections, which is direct evidence of invasive enteritis and has a positive diagnostic significance. The staining methods include:

1 tin iodate staining: the fungus is red.

2 Urotropine silver staining: the fungus is black.

3 acridine orange fluorescent staining: the fungus is yellow or red fluorescent.

3. Immunological examination

(1) Mycotoxin skin test: using a fungal bacterium or vaccine of Candida, Aspergillus, Histoplasma, Paraspora, etc., skin allergy test according to different dilution ratios, diameter greater than 5mm after 48h Induration or erythema is positive, and has a reference value for the diagnosis of patients with atypical clinical symptoms.

(2) Detection of serum antigen: After the pathogenic fungi are degraded by human phagocytic cells, the cell wall and cytoplasmic antigen are released in the blood circulation, and those who have not been cleared may be subjected to enzyme immunoassay (EIA), indirect hemagglutination test, immunoblotting, etc. Detection, heating shock protein belongs to fungal cytoplasmic antigen, Walsh et al. on the tumor with invasive candidiasis, 50% positive within 24h after onset, specificity up to 96%, and the serum of Aspergillus enteritis detected by ElA method The cell wall antigen and the antigen associated with Concanavalin A have early diagnostic value. When the antigen level is 100 g/ml, the negative fungal culture can be diagnosed.

(3) Serum antibody detection: The complement fixation test has certain value for the diagnosis of histoplasmosis enteritis. The skin test results can be comprehensively judged to exclude false positives. The indirect fluorescein labeled antibody quantitative test can be used to diagnose Candida enteritis. There are common methods such as convective immunoelectrophoresis, latex agglutination test, ELA, etc., the latter is most sensitive, but for patients with AIDS and other immune function inhibition, antibody detection is prone to false negative.

(4) cumping reaction: a patient with candidiasis has a sputum-collecting factor and an inhibitor of sputum-collecting. The former can inhibit the activity of Candida in the test tube, and the serum sputum response is normal. It is ubiquitous, but after infection with Candida, the phenomenon of sputum is suppressed due to the increase of interference.

4. Animal inoculation test

For the colony of the culture of the fecal specimen fungus, its pathogenicity can be further identified by animal inoculation.

(1) Inoculation method: scrape the colonies on the culture medium, grind it, add a little saline to shake, filter the hyphae, and make a spore suspension, the concentration is about 108/ml, and inject into the animal, according to the animal The size and route of inoculation, ranging from 0.2 to 1.0 ml, can be repeated multiple times to enhance the pathogenicity of the animal.

(2) Selection of animals and route of inoculation: Due to different strains, the infectivity of animals is also different. Appropriate animals and different inoculation routes should be selected:

1 Candida albicans: intravenous injection of rabbit or intraperitoneal injection of mice.

2 Aspergillus: Rabbits are used, and chickens are injected intravenously or intraperitoneally.

3 mucor: intravenous injection of rabbits.

4 histoplasma: bacteriological fluid plus 5% gastric mucin, intraperitoneal injection of rats or mice.

5 coccidioides: intratesticular injection of guinea pigs.

6 Geotrichum: no disease to animals.

(3) Animal dissection: Before dissection, the animals were placed in a 5% phenol solution for disinfection, and then the corresponding tissues, pathological changes of the organs were examined under aseptic conditions, and the lesion materials were taken for direct smear and fungal culture, and the anatomized animals were observed. The corpse should be cremated and should not be buried to prevent the spread of pathogenic fungi.

Determination of the concentration of fungal metabolites or decomposition products in serum by gas chromatography has certain reference value for the diagnosis of invasive fungal enteritis. For example, mannan polysaccharides on the cell wall of Candida are hydrolyzed to produce mannose, and the serum concentration is in Candida. Bacteremia is often greater than 800g/ml, Candida enteritis is between 600 and 800g/ml, and normal people are less than 600 g/ml. The rapid development of modern molecular biology technology has opened up new avenues for the diagnosis of deep mycosis. Nuclear hybrid probe hybridization and PCR technology can be used to determine the specific gene fragments of fungi. It is sensitive and rapid. It has been carried out at home and abroad. For example, Buchman et al. reported the coding gene of Candida lanosterol demethylase, which is fungi-specific. Sex gene fragments can be used for clinical diagnosis of deep mycosis by PCR.

Diagnosis and diagnosis of fungal enteritis

diagnosis

The diagnosis of fungal enteritis is difficult. Most of the clinical cases are missed or misdiagnosed. Some are not discovered until autopsy. First, the clinical symptoms are generally not serious, lacking characteristic manifestations, and few even have no obvious diarrhea, such as Aspergillitis; Because there are not many projects with diagnostic significance in laboratory tests, some projects are difficult to promote and apply. Therefore, the diagnosis of fungal enteritis requires a variety of methods, combined with clinical experience for comprehensive analysis.

Clinical diagnosis

Histoplasma and paraspora enteritis have local epidemics. Most patients are residents of endemic areas or have traveled to endemic areas. Conditional pathogenic fungi do not cause disease under normal conditions, only when the body's immune function is low. Onset, such as Candida, Aspergillus, if the clinical manifestations can not be explained by bacterial or viral infections, antibiotic treatment will intensify the symptoms, diarrhea prolonged, and there are basic diseases or other incentives related to low immune function. For the application of broad-spectrum antibiotics and immunosuppressive drugs, the possibility of fungal enteritis should be considered. The pathogen examination or colonoscopy should be performed in time for patients with diarrhea and thrush. If necessary, antifungal drugs should be used. Diagnostic treatment.

2. Pathogenic diagnosis

Including fungal morphological examination and fungal culture, if a large number of hyphae and spores are found by direct microscopic examination of the fecal specimen, and the contamination factor can be diagnosed as fungal enteritis, only a small number of spores may be normal carriers, meaning little, fungal culture needs Three consecutive positive and the same strain, combined with clinical diagnosis, for biphasic fungi, need to be cultured at 25 ° C and 37 ° C and stained microscopic examination to identify fungal morphology, or further animal inoculation test Identify the pathogenicity of the fungus.

3. Pathological diagnosis

Colonoscopy is the last resort for patients who cannot be diagnosed by clinical diagnosis and pathogenic diagnosis. The hyphae and spores are found in pathological sections, which is direct evidence of fungal infection, and the pathological changes of fungal infections such as Aspergillus and Mucor. It is characterized and has diagnostic significance. The results of intestinal biopsy can also be confirmed by similar pathological changes in animal vaccination tests.

4. Immunological diagnosis

In order to detect fungal circulating antigens, the most diagnostic significance, but often due to cross-reaction, can not determine the species, the test positive indicates that the infection has been applied to epidemiological investigation, the diagnosis of acute infection is of little value, the specific detection is often due to patients With false immunodeficiency and false negatives, the scope of application is limited.

Differential diagnosis

Fungal enteritis

Identification of common diarrheal diseases Bacterial dysentery is one of the most common intestinal infectious diseases. Geositic colitis is difficult to distinguish. Localized enteritis and ulcerative colitis are easily confused with histoplasmosis.

(1) Cholera: Pandemic is now rare, mostly local outbreaks, patients with severe vomiting and diarrhea, vomiting and diarrhea are rice sputum or yellow water, no abdominal pain, no fever, often rapid dehydration and microcirculation failure, vomiting and diarrhea A direct microscopic examination revealed a large number of Vibrio species that were fish-like.

(2) Bacterial dysentery: all year round, most common in summer and autumn, the main lesion is suppurative inflammation of the colon, patients with less vomiting, often fever, diarrhea with abdominal pain, urgency and weight, left lower abdomen tenderness, stool mixed with pus, Microscopic examination revealed red blood cells, pus cells and macrophages, and the growth of dysentery bacilli was cultured.

(3) Amoebic dysentery: mainly distributed, patients often concealed onset, diarrhea is different, less toxemia, abdominal pain and urgency is not obvious, similar to fungal enteritis, but feces and pus without mixing The typical one is jam-like, stinking, and the red blood cells are mainly microscopic examination. The amoebic trophozoites consuming red blood cells and the Charcot-Ryden crystals can be seen. The sigmoid colonoscopy shows that the intestinal mucosa is scattered in the ulcer, the edges are neat, the congestion is elevated, and the ulcers are between. Mucosal normal, ulcer smear or biopsy visible trophozoites.

(4) Typhoid fever and paratyphoid fever: Paratyphoid fever can be a gastroenteritis type episode, but the course of disease is short, the prognosis is good, and it recovers within 3 to 5 days. Typhoid and paratyphoid A, B with high fever, systemic toxemia symptoms Lord, may be associated with abdominal pain, but less diarrhea, blood or bone marrow culture can be confirmed by typhoid or paratyphoid bacillus growth.

(5) Crohn's disease: or Crohn's disease, usually a long history, with obvious onset and remission. X-ray barium meal shows lesions mainly at the end of the ileum, with line-like shadows with marginal incompleteness. In between, the expansion of the intestines, the so-called missing signs.

(6) ulcerative colitis: clinical manifestations of recurrent diarrhea, pus and blood, may be associated with fever, lesions with sigmoid colon, the most serious rectum, or involving the entire colon, colonoscopy can be seen intestinal mucosal congestion, edema and ulcer formation, The mucous membrane is brittle and easy to bleed, and there is no pathogenic bacteria growth in the fecal culture. In the advanced case, the X-ray barium meal shows that the colonic bag disappears and the intestinal tube shows a lead-like change.

(7) Clostridium difficile enteritis: both often appear after the application of antibiotics, and Clostridium difficile causes pseudomembranous colitis, which is characterized by necrotic inflammation in the colonic mucosa and exudation Spots or large patches of pseudomembrane can be identified by pathogenic detection.

(8) Other diarrhea: Allergic diarrhea has a history of eating fish and shrimp or exposure to allergens, and there is a history of taking drug-like diarrhea with laxatives; enzyme-deficient diarrhea has a family history of hereditary diseases, through detailed medical history, combined with fecal etiology Inspection is not difficult to identify.

It is worth noting that for bacterial enteritis and viral enteritis, the pathogen is usually found in the fecal specimen as the main basis for identification. For fungal enteritis, even if there is fungal growth in the fecal culture, it is difficult to diagnose because the fecal specimen is easily infected by fungi. Contamination, and some fungi belong to the normal intestinal flora.

2. Different types of fungal enteritis

The identification of histoplasma and paraspora enteritis is an endemic epidemic, which is rare in China and has little significance.

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