The role of low-frequency ultrasound on antibiotic sensitivity and biofilm formation of methicillin-resistant Staphylococcus aureus and Escherichia coli: an in vitro effect study
10.3760/cma.j.cn115530-20250208-00052
- VernacularTitle:低频超声对耐甲氧西林金黄色葡萄球菌和大肠杆菌的抗生素敏感性和生物膜形成的体外作用研究
- Author:
Dewen XUE
1
;
Yicheng LI
1
;
Baochao JI
1
;
Fei WANG
1
;
Xingbu MENG
1
;
Bo LIU
1
;
Li CAO
1
Author Information
1. 新疆医科大学第一附属医院关节外科，新疆地区高发疾病研究教育部重点实验室（新疆医科大学），新疆骨科疾病临床医学研究中心，乌鲁木齐 830011
- Publication Type:Journal Article
- Keywords:
Staphylococcus aureus;
Escherichia coli;
Biofilms;
Low-frequency ultrasound;
Periprosthetic joint infection
- From:
Chinese Journal of Orthopaedic Trauma
2025;27(6):512-520
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the effects of low-frequency ultrasound on antibiotic susceptibility and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli).Methods:After MRSA and E. coli were treated with low-frequency ultrasound with different parameters, they were divided into a group with different ultrasound durations and a group with different ultrasound powers. With the power parameter set at 100%, the former was divided into 5 subgroups: control, 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups. The bacteria were sonicated for 0, 1.0, 2.5, 5.0, 10.0 min, respectively. The group with different ultrasound powers was also divided into 5 subgroups: control, 25% power, 50% power, 75% power, and 100% power subgroups. The bacteria were treated with ultrasonic powers of 0, 25%, 50%, 75%, and 100% for 5.0 min. The MRSA and E. coli corresponded to antibiotic susceptibility testing using vancomycin and meropenem. The number of bacteria surviving was assessed by colony counts. Confocal microscopy was used to observe the changes in biofilms co-cultured with 1/2 minimum inhibitory concentration (MIC) antibiotics after sonication.Results:The E. coli enhanced its susceptibility to meropenem after 5.0 min of high-power sonication while the susceptibility of MRSA to vancomycin was unaffected. The number of E. coli decreased significantly with increasing ultrasound time and power: the numbers of E. coli in the 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups [(51.00±18.73), (30.00±9.17), (5.33±4.04), and (0.23±0.03)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL], and the numbers of E. coli in the 25%, 50%, 75%, and 100% subgroups [(25.00±3.00), (8.00±2.65), (5.00±2.00), and (5.33±4.04)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL] ( P<0.05). However, the number of MRSA was not significantly affected. After treatment with ultrasound combined with 1/2 MIC meropenem, the ratio of live/dead biofilm areas of E. coli decreased significantly with increasing ultrasound time and power: the proportions of E. coli in the 1.0 min, 2.5 min, 5.0 min and 10.0 min subgroups (66.10%±1.78%, 50.84%±7.99%, 60.98%±2.23%, and 29.20%±16.49%) were significantly smaller than those in the control subgroup (93.73%±0.44%), and the proportions of E. coli in the 25%, 50%, 75%, and 100% subgroups (75.23%±2.21%, 65.10%±1.25%, 57.34%±11.21%, and 60.98%±2.23%) were significantly smaller than that in the control subgroup (93.73%±0.44%) ( P<0.05). However, the MRSA live/dead biofilm area ratio was not significantly affected by the treatment with ultrasound combined with 1/2 MIC vancomycin. Conclusions:Low frequency ultrasound can effectively inhibit the growth of E. coli and significantly enhance its sensitivity to antibiotics, and its combination with antibiotics can inhibit the formation of bacterial biofilm. However, low frequency ultrasound or its combination with antibiotics has no significant effect on MRSA.
