The in vitro antibacterial activity of incomplete iron salt of polyacrylic acid against Pseudomonas aeruginosa, meticillin-resistant Staphylococcus pseudintermedius and meticillin-resistant S. aureus.

Abstract

BACKGROUND: The incomplete iron salt of polyacrylic acid (IIS-PAA) has been used for its haemostatic, wound healing and antibacterial properties in human patients. IIS-PAA is a water-soluble, acidic, hydrophilic polymer that is active at pH 2.9-4.0. HYPOTHESES/OBJECTIVES: To evaluate the antibacterial effect of IIS-PAA against Pseudomonas aeruginosa, meticillin-resistant Staphylococcus pseudintermedius (MRSP) and meticillin-resistant S. aureus (MRSA). METHODS: This was a prospective, nonblinded in vitro study. Sixty canine isolates of P. aeruginosa, MRSP and MRSA were included. Minimum inhibitory concentrations (MICs) of IIS-PAA were determined by agar dilution on Mueller-Hinton agar using testing concentrations ranging from 0.0625-0.4% (raw material 100%) and based on Clinical and Laboratory Standards Institute guidelines. RESULTS: The median MIC for P. aeruginosa was 0.2% (range 0.2-0.3%), mean 0.2% and standard deviation (SD) of 0.018%. The median MIC for MRSP was 0.05% (0.025-0.1%), mean 0.058% and SD 0.022%, and the median MIC for MRSA was 0.1% (0.00625-0.4%), mean 0.126% and SD 0.080%. There were significant differences in MICs between the three bacteria types with MICs highest for Pseudomonas and lowest for MRSP (all P < 0.0001). CONCLUSIONS: IIS-PAA had in vitro antibacterial activity against three important bacterial pathogens. Further studies of IIS-PAA are indicated to assess the potential clinical benefit and in vitro studies to investigate the spectrum of anti-bacterial activity and mode of action.