Nan Shi1, Yating Gao2, Donghong Yin3, Yan Song4, Jianbang Kang5, Xiaoxia Li6, Zhiqi Zhang7, Xinyuan Feng8, Jinju Duan9. 1. School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: shinan009@126.com. 2. Department of Pharmacy, Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital, Tianjin, PR China. Electronic address: 861878004@qq.com. 3. Department of Pharmacy, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: 13903430239@126.com. 4. Department of Pharmacy, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: songyan009@126.com. 5. Department of Pharmacy, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: kangjianbang0406@163.com. 6. Department of Pharmacy, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: 15834006053@163.com. 7. Department of Pharmacy, First Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: sxzhangzhiqi@163.com. 8. School of Pharmacy, Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: fengxinyuan789@163.com. 9. Department of Pharmacy, Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, PR China. Electronic address: duanjinju@163.com.
Abstract
OBJECTIVE: To explore the effect of sub-minimal inhibitory concentration (sub-MIC) and concentrations within resistant mutation window (MSW) of ciprofloxacin (CIP) on minimal inhibitory concentration (MIC), swimming motility and biofilm formation of Pseudomonas aeruginosa, and also to investigate the correlation between swimming motility and genes expression of lasI, lasR, rhlI, rhlR and pqsR. METHODS: The collected strains were incubated under four different concentrations for 5 days. The MIC and mutant prevention concentration (MPC) were measured by the agar dilution method. The diameter of turbid cycle was used to signify the swimming motility. The biofilm formation was measured by the crystal violet stain method. The genes expression of lasI, lasR, rhlI, rhlR and pqsR were measured by RT-PCR. RESULTS: A total of 11 P. aeruginosa which sensitive to CIP were collected. The incubation within concentrations of MSW made MICs to CIP increased more obviously than under sub-MIC (P < 0.05). The swimming motility showed a trend of being inhibited first and then promoted over time under sub-MIC (P < 0.05), whereas, it was promoted under concentrations within MSW. The biofilm formation was significantly promoted under the concentration of 4×MIC (P < 0.05). Under sub-MIC, the genes expression of rhlR and pqsR had a middle level positive correlation with the promotion of the swimming motility (P < 0.05, r = 0.788 and P < 0.05, r = 0.652, respectively). CONCLUSIONS: Under the concentration of sub-MIC (0.5×MIC) and the concentrations within MSW (1×MIC, 2×MIC and 4×MIC), the effect of CIP on MICs, swimming motility and biofilm formation of P.aeruginosa was quite different. The genes expression of rhlR and pqsR had a middle level positive correlation with the promotion of the swimming motility.
OBJECTIVE: To explore the effect of sub-minimal inhibitory concentration (sub-MIC) and concentrations within resistant mutation window (MSW) of ciprofloxacin (CIP) on minimal inhibitory concentration (MIC), swimming motility and biofilm formation of Pseudomonas aeruginosa, and also to investigate the correlation between swimming motility and genes expression of lasI, lasR, rhlI, rhlR and pqsR. METHODS: The collected strains were incubated under four different concentrations for 5 days. The MIC and mutant prevention concentration (MPC) were measured by the agar dilution method. The diameter of turbid cycle was used to signify the swimming motility. The biofilm formation was measured by the crystal violet stain method. The genes expression of lasI, lasR, rhlI, rhlR and pqsR were measured by RT-PCR. RESULTS: A total of 11 P. aeruginosa which sensitive to CIP were collected. The incubation within concentrations of MSW made MICs to CIP increased more obviously than under sub-MIC (P < 0.05). The swimming motility showed a trend of being inhibited first and then promoted over time under sub-MIC (P < 0.05), whereas, it was promoted under concentrations within MSW. The biofilm formation was significantly promoted under the concentration of 4×MIC (P < 0.05). Under sub-MIC, the genes expression of rhlR and pqsR had a middle level positive correlation with the promotion of the swimming motility (P < 0.05, r = 0.788 and P < 0.05, r = 0.652, respectively). CONCLUSIONS: Under the concentration of sub-MIC (0.5×MIC) and the concentrations within MSW (1×MIC, 2×MIC and 4×MIC), the effect of CIP on MICs, swimming motility and biofilm formation of P.aeruginosa was quite different. The genes expression of rhlR and pqsR had a middle level positive correlation with the promotion of the swimming motility.