Antimicrobial activity of polyhexamethylene biguanide nanoparticles against mastitis-causing Staphylococcus aureus

Abstract

Polyhexamethylene biguanide (PHMB) nanoparticles (NP) developed for this study presented antimicrobial activity against mastitis-causing Staphylococcus aureus at lower concentrations than PHMB alone, chlorhexidine digluconate, povidone-iodine, and sodium dichloroisocyanurate. Thus, PHMB NP present potential for the development of new dipping solutions. Highlights• The PHMB NP were developed by layer-by-layer assembly.• Mastitis-causing Staph. aureus were inhibited by PHMB NP at low concentrations relative to commonly used teat-dip ingredients. • The NP formulation potentiated the antimicrobial activity of PHMB.

Preparation and Antimicrobial Activity of a Film-Forming Polyhexamethylene Biguanide Teat Disinfectant

“…One research reported that low PHMB concentrations (4 mg/L) killed almost 100% intracellular S. aureus (EMRSA-15 and USA300), and that PHMB entered the keratinocytes, localized with EMRSA-15 and remained continuously over 5 h [30]. One study reported MIC 90 values of PHMB ≥ 0.5 µg/mL against mastitiscausing S. aureus [31]. Another study evaluated the antimicrobial activity of PHMB against mastitis-causing Prototheca spp., and the MIC 90 values of PHMB was 2 µg/mL, which was lower than sodium dichloroisocyanurate (1400 µg/mL) and sodium hypochlorite (2800 µg/mL) against P. bovis isolates [32].…”

Poly(hexamethylene biguanide) hydrochloride (PHMB)-based materials: synthesis, modification, properties, determination, and application

“…PHMB can also be encapsulated into chitosan and alginate by the layer-bylayer self-assembly method. 146 Furthermore, it was reported that PHMB could be immobilized into γ-cyclodextrin (CD) to form inclusion complexes. 147,148 The prepared γ-CD-PHMBcomplexes exhibited a significant antifungal effect against C. albicans and M. pachydermatis.…”

Antibacterial cationic polymers: A novel approach for combating bacterial infections

“…The MIC90 of S. aureus was determined using a microdilution assay. PHMB NP had the lowest MIC value (0.03 g/mL) to inhibit 90% of S. aureus followed by chlorhexidine digluconate (0.25 g/mL) and PHMB (0.5 g/mL) [27]. Anti-biofilm activities were investigated in another investigation by treating S. aureus biofilms and assessing the impact on biofilm mass in vitro.…”

“…PHMB-coupled nanoparticles have an impressive MIC90 of 0.03 g/mL while PHMB alone has a value of 0.5 g/mL in controlling S. aureus infection. Effective Anti-biofilm activity requires a concentration of 15 mg/L [27,28] Polymeric Quaternary Ammonium Compounds (QACs) By quaternary ammonium group modification of polyethyleneimine (PEI) nanoparticles, efficient and longlasting antibacterial effects can be achieved especially in the case of oral bacteria [29,30]…”