Piper betle extract and its application in bovine teat dipping solution inhibit and eliminate biofilms in bovine mastitis-inducing staphylococci

Abstract

Background and Aim: Staphylococci, including Staphylococcus aureus, Staphylococcus chromogenes, and Staphylococcus haemolyticus, are significant bacteria that induce bovine mastitis, primarily because they can form biofilms in bovine teat canals. This study aimed to investigate the efficacy of Piper betle extract and a bovine teat dipping solution containing P. betle extract (BSP) against these mastitis-causing staphylococci. Materials and Methods: BSP was prepared using P. betle extract as the bioactive compound. The antibacterial activity of the plant extract and BSP against the pathogens was investigated using a broth microdilution method. The activity of the extract and BSP against the pathogen biofilms was also determined. A stability test was performed to observe the pH, color, turbidity, homogeneity, precipitation, and separation of BSP stored at 4°C and 25°C for up to 4 weeks. Results: The extract exhibited potent antibacterial activity against S. aureus and S. haemolyticus, with similar values for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging from 0.03 mg/mL to 0.125 mg/mL. The MIC and MBC values of the extract against S. chromogenes were 0.5-1 mg/mL and 0.5-2 mg/mL, respectively. Moreover, BSP exhibited MIC and MBC values of 12.5–50 v/v against all tested staphylococci isolates. When used at 1/2 and 1/4 × MIC, the extract and BSP significantly inhibited the formation of staphylococcal biofilms (p < 0.05) in the tested strains. The results indicated that treatment with 1/2 × MIC of the extract and BSP resulted in biofilm inhibition ranging from 30%–66% and 19%–39%, respectively. Furthermore, the extract at 16 × MIC eliminated 54%-86% of established mature isolate biofilms, whereas BSP removed 41%-61% of mature biofilm viability. Storage of BSP at 4°C did not change the factors associated with stability from the 1st to 4th week. Conclusion: These findings suggest that BSP may exhibit potential medicinal benefits in inhibiting the growth and biofilm formation of mastitis-inducing staphylococci in bovines. Keywords: antibacterial activity, biofilms, bovine teat dipping solution, Piper betle extract, staphylococci.