In vitro antibacterial activity of biapenem against adherent bacteria

Abstract

Biofilm bacteria are highly resistant to antibiotics. Moreover, bacteria simply adhered to a solid surface, before forming a biofilm, are also resistant to a killing effect of antibiotics. It is, hence, of importance to know antibacterial activity against adherent bacteria when evaluate antibiotics in vitro. We studied antibacterial activity of biapenem (BIPM), a newly developed carbapenem, to bacteria adherento a solid surface.
BIPM demonstrated the same MBC^AD (MBC for adherent bacteria) as IPM for Staphylococcus aureus, though the MIC^AD (MIC for adherent bacteria) was higher than that of IPM. BIPM showed excellent but slightly higher MBCA^AD than IPM for Staphylococcus epidermidis, and slightly higher MBC^AD than PAPM for Streptococcus pneumoniae. For Pseudomonas aeruginosa, BIPM demonstrated the lowest MBC^AD among four carbapenems. For Enterobacter cloacae, Serratia marcescensand Escherichia coli, BIPM showed MBC^AD slightly higher than MEPM but far lower than IPM and PAPM.
Results obtained in this study suggest that BIPM is a potent carbapenem even against adherent bacteria.