Antibacterial and Antivirulence Activity of Manuka Honey against Genetically Diverse Staphylococcus pseudintermedius Strains

Abstract

Staphylococcus pseudintermedius causes opportunistic infections in dogs. It also has significant zoonotic potential, with the emergence of multidrug-resistance leading to difficulty treating both animal and human infections. Manuka honey has previously been reported to inhibit many bacterial pathogens including methicillin resistant Staphylococcus aureus and is successfully utilised in both clinical and veterinary practice. Here we evaluated the ability of manuka honey to inhibit strains of S. pseudintermedius growth alone and in combination with antibiotics, and its capacity to modulate virulence within multiple S. pseudintermedius. All 18 of the genetically diverse S. pseudintermedius strains sequenced and tested were inhibited by ≤ 12% (w/v) medical grade manuka honey, although tolerance to five clinically relevant antibiotics was observed. The susceptibility of the isolates to four of these antibiotics was significantly increased (p ≤0.05) when combined with sub lethal concentrations of honey, although sensitivity to oxacillin was decreased. Virulence (DNase, protease and haemolysin) activity was also significantly reduced (p ≤ 0.05) in over half of isolates when cultured with sub lethal concentrations of honey (13, 9 and 10 isolates respectively). These findings highlight the potential for manuka honey to be utilised against S. pseudintermedius infections. Importance Staphylococcus pseudintermedius is an important member of the skin microbial community in animals and can cause opportunistic infections in both pets and their owners. The high incidence of antimicrobial resistance in S. pseudintermedius highlights that this opportunistic zoonotic pathogen can cause infections which require prolonged and intensive treatment to resolve. Manuka honey has proven efficacy against many bacterial pathogens and is an accepted topical treatment for infections in both veterinary and clinical practice so is a particularly appropriate antimicrobial for use with zoonotic pathogens such as S. pseudintermedius. Here we demonstrate that manuka honey is not only highly potent against novel multi-drug resistant S. pseudintermedius isolates, but also acts synergistically with clinically relevant antibiotics. In addition, manuka honey modulates S. pseudintermedius virulence activity, even at subinhibitory concentrations. In a clinical setting these attributes may assist in controlling infection, allowing a more rapid resolution and reducing antibiotic use.

Sustainable phyto-fabrication of silver nanoparticles using Gmelina arborea exhibit antimicrobial and biofilm inhibition activity

“…Selective binding ability of these polyphenols reduces Ag + ion to provide stability, greater exposed surface area and prevent agglomeration of the synthesised AgNPs 42 – 44 . Application of a combination of an antibiotic with an antibacterial-activity-enhancing agent (such as a plant extract), has been reported to be effective against antibiotic resistant bacteria in the new ‘combinational therapy’ 45 , 46 . Hence, we plan to explore combination of GA-AgNPs with different antibiotics in our future experiments.…”

The Isorhamnetin-Containing Fraction of Philippine Honey Produced by the Stingless Bee Tetragonula biroi Is an Antibiotic against Multidrug-Resistant Staphylococcus aureus

“…The health-promoting properties of honey are associated with plant secondary metabolites that are gathered by honey bees concomitant to the collection of flower nectars or Molecules 2021, 26, 1688. https://doi.org/10.3390/molecules26061688 https://www.mdpi.com/journal/molecules honeydew. In addition to its traditional household use as a sweetener, honey is often recognized as an alternative nutraceutical that exhibits a broad spectrum of in vitro activities such as antibacterial, antioxidant, anti-inflammatory, immunomodulatory, anticancer, anti-glycemic, prebiotic, and antiviral activities [1][2][3][4][5][6][7][8]. Correlated with honey's biological activities is the diversity of its secondary metabolite composition.…”

“…Other bioactive constituents such as organic acids, trace elements, vitamins, amino acids, and proteins were also found [1,2,19]. An abundance of information on the evaluation of honey's antimicrobial and antioxidant properties is available [3,7,8,16,20,23]. However, it is notable that the observed bioactivities are dependent on and as variable as the botanical and geographical origins, and climatic conditions [8][9][10][11]13,14,23].…”

Beehive Products as Antibacterial Agents: A Review

“…As Manuka honey possesses an exceptional antibacterial activity, Brown et al tried it against Staphylococcus pseudintermedius which cause serious infections in domesticated animals and can be transmitted to their owner. They demonstrated that Manuka honey is not just effective against novel multidrug-resistant S. pseudintermedius isolates, but additionally works in tandem with clinically important antibiotics and reduces its virulence [49].…”