Providencia isolates carrying bla (PER-1) and bla (VIM-2) genes: biofilm-forming capacity and biofilm inhibitory concentrations for carbapenem antibiotics.

Multidrug-resistant clinical isolates of Providentia carrying bla (PER-1) and bla (VIM-2) were evaluated for the abilities to form biofilm and high biofilm forming capacity was demonstrated in them. Minimum biofilm inhibitory concentrations (MBICs), minimum biofilm eradication concentrations (MBECs), and minimum inhibitory concentrations (MICs) for imipenem and meropenem were also determined. In all tested strains, the MBICs were higher than the MICs for both drugs. Interestingly, the MBICs and the MBEC(50) for meropenem were lower than those for imipenem in the isolates producing high amounts of biofilm, suggesting that meropenem is superior to imipenem in the growth inhibition and eradication of biofilm forming Providentia strains.