Animal model of Acinetobacter baumannii infection
Animal model of Acinetobacter baumannii infection
Acinetolacter baumannii is a gram-negative bacillus that does not ferment sugars, and is widely distributed in nature. Hospitals and human skin, belonging to the conditionally pathogenic bacteria, can cause lung infection, urinary tract, skin, soft tissue, central nervous system and other parts of the infection and sepsis. In recent years, the rate of nosocomial infection caused by it. In recent years, the rate of nosocomial infections caused by A. baumannii and the rate of resistance to antimicrobial drugs including carbapenems have been on the rise, so it is important to construct an animal model of A. baumannii infection to explore its pathogenicity and drug resistance mechanism. Since A. baumannii is easy to invade lung tissue, and the research on its pathogenic mechanism mainly focuses on the epithelial cells of the respiratory tract, the infection pathway is more studied in the lungs, and BALB/C, C3H/HeN mice and rats are suitable for this study.
Principle
The basic principle of the animal model of Acinetobacter baumannii infection is the construction of localized infectious lesions in the lungs of immunosuppressed mice using microtracheal injection or ultrasonic nebulization.
Appliance
The commonly used application areas of animal models of Pseudomonas aeruginosa infection are as follows: it can be used for research on the pathogenic mechanism of multi-drug resistant, pan-resistant Ab infections, drug resistance mechanism, etc., which can be helpful for clinical drug research.
Operation method
Methotrexate immunosuppression in an animal model of Acinetobacter baumannii infection with pneumonia in mice
Principle
Immunosuppressed mice were constructed with localized infectious lesions in the lungs using microtracheal injection or ultrasonic nebulization.
Materials and Instruments
Materials: male mice, ophthalmic surgical instruments Move The basic procedure of methotrexate immunosuppression in an animal model of A. baumannii pneumonia in mice can be divided into the following steps: Caveat Microtracheal injection method. The lung infection rate of immunocompromised BALB/C mice infected by ultrasonic nebulization was 100% (30/30) in all cases. The mortality rates were 100% (10/10) and 33% (3/10), respectively. Bacterial infection in the lungs of mice Ⅱ Neutrophils and lymphocytes were seen in the peribronchiolar and alveolar interstitium 2-24 hours later. Macrophage-dominated inflammatory cell infiltration. In mice infected by microtracheal injection, part of the alveolar tissue was disintegrated, and abscesses and bacterial colonization were seen in the alveolar lumen. In mice infected by ultrasonic nebulization, cellular degeneration was seen in some areas of the lungs at 24 hours, but the bronchial and alveolar tissue structure was basically normal, and the blood vessels of the alveolar wall were mildly dilated with bruising.2-4-48 hours later, the bronchial tubes and peribronchial area were seen to be degenerated, and the blood vessels of part of the lung tissues were highly dilated with edema, and the inflammation gradually recovered at 48 hours. The inflammation gradually recovered after 48 hours. For more product details, please visit Aladdin Scientific website.
Reagents:
① Methotrexate 0.2 mg/d
② 10% chloral hydrate
③ physiological saline
A. The modeling strain was routinely isolated A. baumannii (the concentration of the bacterial fluid was 108 efu/ml), and the modeling animals were selected from 4-week-old BAL.BC clean-grade male mice weighing 13-14 g.
B. The mice were injected with methotrexate 0.2 mg/d intraperitoneally for 2 consecutive days. After 3 days, the mice were anesthetized by intraperitoneal injection of 10% chloral hydrate 0.05 ml, and the lungs were infected with A. baumannii using microtracheal injection or ultrasonic nebulization, and the amount of bacterial fluid was 0.05 ml in both cases.
C. Microtracheal injection: After anesthesia, mice were analyzed and exposed to the trachea with ophthalmologic surgical instruments, and then injected with bacteria or physiological saline using microsyringes, and then immediately suspended vertically for 10 minutes. After the injection, the mice will be suspended vertically for 10 minutes, and then the wound will be sutured and fed in normal cages.
D. Ultrasonic nebulization method: After the mice are anesthetized, they will be placed in a plastic container with 2 ports, and the bacterial solution with a concentration of 108 CFU/ml will be put into an ultrasonic nebulizer, which will be turned on at an atomization rate of 2 ml/min, and the nebulization tube will be inserted into the mouth of the plastic container, and then discharged out the outlet of the other end, and then the mice will be nebulized for 30 minutes. All procedures were performed in a biosafety cabinet.
E. Monitoring of infection rate, mortality, bacterial clearance and lung pathology in mice.