Alginate oligomers inhibit growth of bacteria causing bovine mastitis and potentiate the activity of antibiotics commonly used for treatment of the disease

J. Adv. Dairy Res. 2017 5:186. doi: 10.4172/2329-888X.1000186 [in press]. Tøndervik A, et al.

Abstract

Alginate oligomers have been shown to disrupt microbial biofilms and reduce minimum inhibitory concentrations (MIC) for many clinically relevant antibiotics to a range of human pathogens. The antibiofilm and potentiating effects of alginate oligomers has previously been focussed on bacterial and fungal strains that play significant roles in chronic human infections. This study on the effects of an alginate oligomer (OligoG CF-5/20) on bacteria that cause bovine mastitis is the first report that investigates a significant disease in animal health. The effect of OligoG CF-5/20 on the inhibitory concentrations of ampicillin, erythromycin, cephalothin and lincomycin to a test panel of nine bacterial strains associated with bovine mastitis were investigated. Two different media were used for cultivation, the standard Mueller-Hinton normally used for bacterial MIC determination, and a skimmed milk medium to mimic the native growth conditions for mastitis bacteria. OligoG CF-5/20 was shown to inhibit growth of all strains tested, and demonstrated a 2 to 8 fold reduction in MICs for erythromycin, cephalothin and lincomycin. The data highlights a potential role for alginate oligomers in potentiating the efficacy of antibiotics, and thereby potentially reducing antibiotic use, in the treatment of mastitis in dairy cattle.