I. Purpose
1. Understand the wide distribution of bacteria in nature and normal human body, and establish the concept of "bacteria", so as to understand the importance of aseptic operation for microbiology and medical practice.
2. Understand that there are many kinds of bacteria living in normal people, which will not cause human diseases under normal circumstances, and are called normal flora.
3, familiar with the influence of external factors on bacteria, learn common disinfection and sterilization methods.
4. Understand that different bacteria have different resistance to external factors.
Second, the normal throat bacteria examination
Materials: Blood agar plate culture medium, sterilized cotton swab, inoculation ring and alcohol lamp.
Methods: Take a sterile cotton swab, gently rub it on the throat of the examinee, then apply it on one side of blood agar medium, and then use a sterile inoculation ring to separate and mark the inoculation. Cover the Petri dish and incubate at 37℃ for 24 hours (or cough method).
Results: There were colonies growing on the surface of agar plate. Among them, the dominant one is a small colony surrounded by a grass-green incomplete hemolytic ring. This is the normal flora of the throat-Streptococcus A.
Third, surface water bacteria inspection?
Materials: surface water (river water, well water or pond water), advanced agar medium, 1ml sterile pipette, sterile Petri dish.
Method:
1. Suck 1ml of ground water with a sterile straw and add it to a sterilized Petri dish.
2. Pour the high-grade agar that has been melted and cooled to about 45℃ into the above dish, cover it and shake it gently, so that the water and agar are fully mixed and let stand.
3、37℃? After 24 hours, take it out for observation and count the colonies.
Extended data:
When pathogenic bacteria are detected in throat swab secretion, it is regarded as respiratory tract infection. Can be combined with other examinations (X-ray fluoroscopy, B-ultrasound, etc. ) to diagnose respiratory tract infection. If yeast-like bacteria are cultivated, it is necessary to consider whether antibiotics are used improperly or excessively during infection. Antibiotics should be stopped immediately and antifungal drugs such as amphotericin B, griseofulvin and clotrimazole should be used instead.
Common pathogens are:
1, Gram-positive bacteria: Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus beta hemolyticus, Corynebacterium diphtheriae, Candida, etc.
2. Gram-negative bacteria: Neisseria meningitidis, Neisseria gonorrhoeae, Moraxella, Catalan, Bordetella pertussis, Enterobacter, Pseudomonas aeruginosa, Alcaligenes, etc. If tuberculosis is cultivated, it is tuberculosis.
3. The corresponding bacteria can be isolated from the pharynx of patients with pertussis and diphtheria. The nasal abscess of acute pharyngolaryngitis is mainly caused by Staphylococcus aureus, Streptococcus hemolyticus and Pseudomonas aeruginosa. Many throat infections are caused by anaerobic bacteria.
Baidu encyclopedia-throat swab