Bacteriological examination of blood and bone marrow specimens

The bacteriological test of blood and bone marrow specimens is to determine the type and type of bacteria contained in the specimen by performing oxidase test, catalase test and nitrate reduction test on blood and bone marrow samples. Specimens collected from patients suspected of bacteremia should generally be collected at the onset of the disease, mostly by the elbow vein. Femoral arterial blood is collected from patients with subacute bacterial endocarditis, and can also be collected near the infected lesion. The blood collection site was first sterilized with iodine and then deiodinated with 75% alcohol. The adult blood collection volume is 5-10 ml each time, and the children 1~2 ml are injected into the magnesium sulfate dextrose broth (aerobic culture) and the sodium thioglycolate broth (anaerobic culture) culture flask, and the intestinal heat caused by Salmonella is suspected. The disease can be injected into the bile glucose broth, gently shake and mix. The ratio of blood to medium should be 1:10, which can fully dilute the antibacterial substances in the blood, such as the original antibiotics, lysozyme, antibodies and complement, and cannot exert antibacterial activity. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Tips: For patients with endocarditis, blood is collected 3 times within 24 hours, each interval is not less than 30 minutes; if necessary, blood is collected 2 times the next day. For patients with unexplained fever, the blood is separated by 60 minutes, and if necessary, the blood is taken 2 times after 24 to 48 hours. Because 1 blood culture is not enough to explain the problem, and the positive result will be missed. Normal value Various pathogenic bacteria tests were negative. Clinical significance Bacterial colony smear, Gram stain, observe bacterial morphology and staining, such as Gram-negative bacilli, oxidase test, catalase test and nitrate reduction test, oxidase negative, catalase test and nitrate reduction test The positive person was initially judged to be Enterobacteriaceae, and inoculated with KIA and MIU medium. The biochemical results on KIA and MIU media were consistent with Salmonella, and the serotype was confirmed by S. aureus diagnostic serum. The biochemical results on KIA and MIU media were consistent with other genus of Enterobacteriaceae, common in blood. Preliminary identification of Gram-negative bacilli and so on. Abnormal results: Symptoms of bacteremia: 1 sudden high fever, can reach 40-41 degrees, or low temperature, acute onset, serious condition, rapid development; 2 headache, dizziness, nausea, vomiting, conscious disturbance; 3 heart rate, pulse fine Speed, shortness of breath or difficulty; 4 liver spleen can be swollen, severe jaundice, subcutaneous bleeding spots and so on. Need to check the crowd: jaundice, subcutaneous bleeding spots, dizziness, nausea, vomiting, high fever and other symptoms of suspected bacteremia. Precautions 1. Generally, blood samples should be collected before the use of antibacterial drugs. If the patient has used antibacterial drugs or the situation is unknown, magnesium sulfate broth enrichment solution should be used to neutralize tetracycline, streptomycin, neomycin, and multi-adhesive. Antibiotics such as bacteriocin, and antibiotic antagonists such as 5% p-aminobenzoic acid (PABA) antagonize sulfonamides, 100 IU / 50 ml penicillinase to destroy penicillin and 0.03% to 0.05, 9/6 sodium polyanisole (SPS) inactivates aminoglycosides and peptide antibiotics. 2. For patients suspected of wave heat, subacute bacterial endocarditis, the culture flask should be incubated until the fourth week, blindly cultivating and sterile growth before reporting negative. 3. In order to find the pathogen as soon as possible, it should be blindly irrigated at least twice during the 7-day incubation period, and the first time after incubation for 12 to 18 hours. During the subsequent incubation period, the changes in the bottle should be observed every day. If there is bacterial growth, timely inoculation and smear staining observation reports are required. There was no evidence of bacterial growth after 7 days of incubation and blind inoculation was performed. Each time the aerobic culture is inoculated, the sheep blood plate and the chocolate agar plate are inoculated; the anaerobic blood agar plate and the sheep blood agar plate are inoculated by anaerobic culture, and aerobic and anaerobic culture are separately carried out. 4. Blood bacteriological culture is the etiological basis for the diagnosis of bacteremia and sepsis. The same bacteria were detected in 2 blood samples of the same patient; or the increase in the corresponding antibody in the serum after 2 to 3 weeks of the patient who detected the bacteria can make a positive pathogenic conclusion. Generally, bacteremia is caused by a kind of bacteria, but there are also mixed infections of two bacteria at the same time, alternating infections of two bacteria or bacteria and fungi, and sometimes uncommon bacteria. These conditions cannot be arbitrarily determined as contaminating bacteria. . 5. The number and interval of blood collection in acute febrile diseases such as meningitis and bacterial pneumonia that require immediate antibacterial therapy; or patients requiring acute surgery such as acute osteomyelitis or septic arthritis should take 2 copies from both arms immediately. Specimens are used for blood bacterial culture. For patients with endocarditis, blood was collected 3 times within 24 hours, each time not less than 30 minutes; if necessary, blood was collected twice the next day. For patients with unexplained fever, the blood draw interval is 60 min; if necessary, blood is taken 2 times after 24 to 48 hours. Because 1 blood culture is not enough to explain the problem, and the positive result will be missed. Inspection process Specimens collected from patients suspected of bacteremia should generally be collected at the onset of the disease, or taken during the period of rising body temperature; in principle, it should be taken before the use of antibiotics, and patients who have started antibiotic treatment can be taken before the next dose; In the elbow vein, femoral artery blood is collected from patients with subacute bacterial endocarditis, and can also be collected near the infected lesion. The blood collection site was first sterilized with iodine and then deiodinated with 75% alcohol. The adult blood collection volume is 5-10 ml each time, and the children 1~2 ml are injected into the magnesium sulfate dextrose broth (aerobic culture) and the sodium thioglycolate broth (anaerobic culture) culture flask, and the intestinal heat caused by Salmonella is suspected. The disease can be injected into the bile glucose broth, gently shake and mix. The ratio of blood to medium should be 1:10, which can fully dilute the antibacterial substances in the blood, such as the original antibiotics, lysozyme, antibodies and complement, and cannot exert antibacterial activity. Not suitable for the crowd No relevant information has been found yet. Adverse reactions and risks No related complications or hazards.

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