Effects of simulated microgravity on the phenotype of extensively drug-resistant Acinetobacter baumannii exstracted from sputum specimens of elderly patients with hospital-acquired pneumonia
10.3760/cma.j.issn.0254-9026.2020.03.003
- VernacularTitle:模拟微重力对医院获得性肺炎老年患者痰标本中泛耐药鲍曼不动杆菌表型的影响
- Author:
Bin ZHANG
1
;
Changting LIU
Author Information
1. 南开大学医学院，天津 300071
- From:
Chinese Journal of Geriatrics
2020;39(3):259-263
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of simulated microgravity on the phenotype of extensively drug-resistant Acinetobacter baumannii extracted from sputum specimens of elderly patients with hospital-acquired pneumonia. Methods:A strain of A. baumannii grown in simulated microgravity was constructed by a three-dimensional rotary cell culture system, and a strain of A. baumannii grown in normal gravity was prepared as a control group.The growth rates of the two strains were detected by the Bioscreen system, colony numbers were measured by the plate colony-counting method, oxidative stress was analyzed by observing the survival rate in phosphate buffer saline(PBS) with 5 mmol/L H 2O 2, biofilm formation ability was determined by crystal violet staining, and antibiotic susceptibility was measured by the K-B method. Results:Compared with the normal gravity strain, the simulated microgravity strain was associated with a significantly slower growth rate, especially after 10 h( P<0.05), a decreased number of bacterial colonies[(2.33±0.61)×10 13CFU/L vs.(4.87±0.63)×10 13CFU/L, t=4.865, P=0.040], lower survival rates in PBS solution with H 2O 2[(51.43±0.97)% vs.(56.53±2.54)%, t=4.715, P=0.042], reduced biofilm formation ability( A570), [(0.449±0.014) vs.(0.506±0.024), t=8.692, P=0.013], and an increased inhibition zone diameter of amikacin[(15.17±0.21) mm vs.(13.77±0.15) mm, t=6.725, P=0.021]. Conclusions:Simulated microgravity changes the growth rate, biofilm formation ability, oxidative stress and antibiotic susceptibility of extensively drug-resistant A. baumannii, potentially providing a new treatment strategy for extensively drug-resistant A. baumannii-associated hospital-acquired pneumonia in the elderly.
