Effect of manuka honey on the expression of universal stress protein A in meticillin-resistant Staphylococcus aureus

Abstract

Staphylococcus aureus is an important pathogen that can cause many problems, from impetigo to endocarditis. With its continued resistance to multiple antibiotics, S. aureus remains a serious health threat. Honey has been used to eradicate meticillin-resistant S. aureus (MRSA) strains from wounds, but its mode of action is not yet understood. Proteomics provides a potent group of techniques that can be used to analyse differences in protein expression between untreated bacterial cells and those treated with inhibitory concentrations of manuka honey. In this study, two-dimensional (2D) electrophoresis was combined with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) to determine the identities of proteins whose levels of expression were changed at least two-fold following treatment with manuka honey. Protein extracts were obtained from cells grown in tryptone soy broth (with or without manuka honey) by mechanical disruption and were separated on 2D polyacrylamide gels. A protein was isolated in gels prepared from untreated cell extract that was absent from gels made using honey-treated cell extract. Using MALDI-TOF MS, the protein was identified as universal stress protein A (UspA). Downregulation of this protein was confirmed by real-time polymerase chain reaction (PCR), which showed a 16-fold downregulation in honey-treated cells compared with untreated samples. This protein is involved in the stress stamina response and its downregulation could help to explain the inhibition of MRSA by manuka honey.

Specific non-peroxide antibacterial effect of manuka honey on the Staphylococcus aureus proteome

“…This mechanism is supported by the downregulation of EF-Tu and further downregulation of five other translation factors and ribosomal proteins. This stress response is in agreement with a recent study identifying the universal stress protein (UspA) [26] as being significantly downregulated after treatment with manuka honey. In contrast, the stress response protein CspC was upregulated in this study, which may reflect an initial response to treatment with manuka honey (25 min) compared with a longer-term (4 h) response [26].…”

Phytochemical screening and antimicrobial activity of apiary honey produced by honey bee (Apis mellifera) on clinical strains of Staphylococcus aureus, Escherichia coli and Candida albicans

“…It is indeed of paramount importance to unveil new therapies directed at novel targets as budding to alternatives to antibiotics as well as validation of traditional remedies (Jenkins et al, 2011). Plethora of studies has emerged towards natural products in addressing the dearth and limitations of current therapies.…”

“…In the modern era, the different biological, chemical and physical properties of honey have revealed several beneficial claims through different techniques. The multi facet properties of honey anchored in the scientific world is regarded as a sweetener, functional food, antioxidant, antimicrobial, antiseptic, prebiotics, probiotics, immunomodulatory, antiinflammatory, anti-tumor and anti-cancer effect amongst others (Jenkins et al, 2011;Conway et al, 2010;Fauzi et al, 2011). Above and beyond its therapeutic effects or medicinal attributes (Mohapatra et al, 2011;Conti et al, 2007), it is also of potential use as bio-indicators for environmental contamination (Celechovska and Vorlova, 2001).…”

Are there feasible prospects for manuka honey as an alternative to conventional antimicrobials?

“…In methicillin-resistant S. aureus (MRSA), the failure of daughter cells to separate towards the end of the cell cycle was explained by the loss of activity of autolysins, which normally cleave peptidoglycan [10]. Manuka honey has also been shown to elicit downregulation of a universal stress protein in MRSA, which compromises its ability to overcome environmental insults [11]; another effect of manuka honey on MRSA has been to reverse oxacillin resistance [12]. These multiple inhibitory effects of manuka honey on MRSA strengthen claims that it may play an important clinical role in decontaminating colonized patients, limiting cross-infection and preventing infection in colonized wounds.…”