Thick or purulent sputum with a fishy odor

Introduction It is often sticky or purulent, and it can be a symptom of clinical diagnosis of Escherichia coli pneumonia. Escherichia co1i (also known as Escherichia coli) pneumonia has increased significantly in recent years, is the second most common pathogen of Klebsiella pneumoniae, which is the second most common pathogen of Klebsiella pneumoniae, which causes community-acquired Gram-negative bacilli pneumonia. 12% to 45% of pneumonia, accounting for 2.0% to 3.3% of all pneumonia pathogens. It is one of the main pathogens of acquired pneumonia in hospitals, with an incidence of 4.2 to 9.0/10,000, accounting for 9.0% to 15.0% of Gram-negative bacilli pneumonia. In the 1960s, the mortality rate of the disease was as high as 60%, and it dropped significantly after the 1980s, with a report of 29%. It mainly occurs in elderly debilitated patients, all kinds of chronic basic diseases, critically ill patients, tracheal intubation, long-term treatment with corticosteroids and other immunosuppressive agents, long-term use of antibiotics and dysbacteriosis, and various immune balls. Patients with protein defects, etc., are susceptible to this disease.

Cause

(1) Causes of the disease

Escherichia coli was discovered in 1885 by German scientist Es-cherich, belonging to the family Enterobacteriaceae, Escherichia, Gram-negative, facultative anaerobic, with a cell size of (1.0 to 1.5) m × (2.0 to 6.0) Mm, no capsule, most strains have flagella, 4-6, are flagella, do not spore, can decompose glucose and other sugars, so that fermentation produces acid and gas, nitrate reduction test positive, oxidase negative , produces sputum, does not use citric acid. It has low nutrient requirements and grows well on common medium. The optimum growth temperature is 37 ° C, and it can grow at 42-44 ° C. The bacteria is a normal intestinal flora, which is abundant in human and animal feces and is widely distributed in nature. Containing plasmids encoding antibiotic resistance, colon toxin, enterotoxin, pili, etc., with O, H, K antigens on the surface, has been found to inhibit the drug and other flora, since the 1980s, Escherichia coli produced super wide The proportion of spectrum -lactamases (ESBLs) increased rapidly. The rate of ESBLs production in foreign countries was 2.2% to 28%, and that in China was 5% to 32.4%.

(two) pathogenesis

Escherichia coli is a conditional pathogen. The cause of the disease is the decline of the body's immune defense function, inhalation of oropharyngeal colonization bacteria or infection by abdominal organs such as the gastrointestinal tract and genitourinary tract, and transmission through blood. It mainly occurs in elderly debilitated patients, all kinds of chronic basic diseases, critically ill patients, tracheal intubation, long-term use of corticosteroids and other immunosuppressive drugs, long-term use of antibiotics and dysbacteriosis, and various immune balls. Patients with protein defects, etc., are susceptible to this disease. In general hospitals such as teaching hospitals, the spread of Escherichia coli containing multidrug resistance genes carried in specimens such as feces, urine and oropharyngeal secretions of patients causes difficulties in treatment.

The pathology of Escherichia coli pneumonia is similar to that of other Gram-negative bacteria pneumonia, mainly showing changes in bronchial pneumonia in the lower lobe of the lung. Patients with a course of more than 6 days often have small abscesses of the lungs, pleural effusion and even empyema. Inflammation involves less tracheal-bronchial mucosa, probably because most E. coli pneumonia is caused by a blood-borne pathway. There is a slurry in the alveoli and a moderate amount of monocyte filling. Red blood cell exudation is common in the early stage of the disease, and neutrophils and macrophages can be seen in the later stage. There may be thickening of the alveolar wall and necrotic lesions. Some cases may be associated with lesions such as cholecystitis, pyelonephritis or meningitis caused by Escherichia coli.

an examination

Related inspection

Pulmonary function test lung volume determination lung examination lung biopsy

The clinical manifestations of Escherichia coli pneumonia are similar to those of general acute pneumonia, which can be manifested as chills, fever, cough, cough, chest pain, cyanosis and difficulty breathing. It is often sticky or purulent and can have a bad smell. Some cases have gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea. In severe cases, there may be disturbances of consciousness such as lethargy and peripheral circulatory disorders. Pulmonary signs may have bilateral lower respiratory tract sounds and wet sounds, and lung consolidation signs are rare. 40% of patients may be accompanied by empyema and corresponding signs, which occur on the severe side of the lesion.

There are many kinds of Gram-negative bacilli that can cause pneumonia, the clinical manifestations are similar, and the auxiliary examination lacks specificity. Therefore, the diagnosis of Escherichia coli pneumonia requires clinical combination of pathogens. Symptoms of pneumonia, the original chronic disease, long-term use of antibiotics or the history of the use of immunosuppressants, accompanied by gastrointestinal symptoms, and even mental symptoms, the disease progresses quickly and can be complicated by empyema, should consider this disease. The sputum smear test can distinguish whether the pathogen is Gram-negative bacilli, and the sputum culture positive should exclude the contamination of the oropharyngeal colonization bacteria. Therefore, the qualified sputum specimen should be taken first, that is, the proportion of leukocytes and epithelial cells in the sputum smear is more than 2.5. . Escherichia coli can confirm the disease. Diagnosis can also be established by the culture of Escherichia coli in pleural fluid and blood samples. DNA probes or PCR methods can be used wherever possible. If pneumonia secondary to urinary tract infection, and urinary tract and sputum culture Escherichia coli are positive, there is also diagnostic value.

Differential diagnosis

The differential diagnosis of this disease and other bacterial pneumonia mainly depends on the establishment of pathogens, and sometimes it is difficult to identify clinical manifestations alone.

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