Preparation of cefquinome sulfate cationic proliposome and evaluation of its efficacy on Staphylococcus aureus biofilm

Staphylococcus aureus (S. aureus) has the propensity to form biofilms, which eventually cause antibiotic resistance and treatment failure. Cefquinome sulfate (CS) is an animal-specific antibacterial agent for S. aureus infection. In this work, CS cationic proliposomes (CSCPs) were prepared by solid-dispersion method combined with effervescent hydration to eradicate bacterial biofilm and improve the antibacterial effect of the drug. CSCPs were readily dispersed in water, thereby forming CS cationic liposomes (CSCLs) as a white, uniform suspension. The CSCLs had an encapsulation efficiency (EE) of 63.21%, a drug loading of 4.04%, an average particle size of 201.5 nm, and a positive zeta-potential of 65.29 mV. In vitro release studies showed that CSCLs had good sustained-release behavior. The CS and CSCL minimal inhibitory concentration (MIC) of S. aureus type culture strain were 1 and 0.48 g/mL, respectively. The eradication effect of CS on bacterial biofilm (BBF) was relatively weak during culture in drug-containing medium for 8 h-24 h. However, the CSCL eradication effect on BBF increased gradually, and the clearance rate of CSCLs on BBF was about twice that of CS. The clearance rate reached 81.30% with 2.5 x MIC in 24 h. All these results indicated that CSCLs can significantly improve the eradication effect of cefquinome on biofilm to inhibit bacterial growth.