Biofilm or persister cells formed by Staphylococcus
aureus are closely related to pathogenicity. However,
no antimicrobials exist to inhibit biofilm formation or persister
cells induced by S. aureus in clinical
practice. This study found that pinaverium bromide had antibacterial
activity against S. aureus, with the
MIC50/MIC90 at 12.5/25 μM, respectively.
Pinaverium bromide (at 4 × MIC) showed a rapid bactericidal effect
on S. aureus planktonic cells, and
it was more effective (at least 1-log10 cfu/mL) than linezolid,
vancomycin, and ampicillin at 4 h of the time-killing test. Pinaverium
bromide (at 10 × MIC) significantly inhibited the formation of S. aureus persister cells (at least 3-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 24, 48, 72,
96, and 120 h of the time-killing test. Biofilm formation and adherent
cells of S. aureus isolates were significantly
inhibited by pinaverium bromide (at 1/2 or 1/4 × MICs). The fluorescence
intensity of the membrane polarity of S. aureus increased with the treatment of pinaverium bromide (≥1 ×
MIC), and the MICs of pinaverium bromide increased by 4 times with
the addition of cell membrane phospholipids, phosphatidyl glycerol
and cardiolipin. The cell viabilities of human hepatocellular carcinoma
cells HepG2 and Huh7, mouse monocyte-macrophage cells J774, and human
hepatic stellate cells LX-2 were slightly inhibited by pinaverium
bromide (<50 μM). There were 54 different abundance proteins
detected in the pinaverium bromide-treated S. aureus isolate by proteomics analysis, of which 33 proteins increased,
whereas 21 proteins decreased. The abundance of superoxide dismutase
sodM and ica locus proteins icaA and icaB decreased. While the abundance
of global transcriptional regulator spxA and Gamma-hemolysin component
B increased. In conclusion, pinaverium bromide had an antibacterial
effect on S. aureus and significantly
inhibited the formation of biofilm and persister cells of S. aureus.