Antibacterial Activity of Manuka Honey Against Azithromycin Resistant Extensively Drug Resistant Salmonella Typhi Clinical Isolates: In-Vitro Study

Typhoid fever is a significant health problem in developing countries like Pakistan. Salmonella Typhi the causative agent of typhoid has developed resistant to almost all recommended antibiotics. Emergence of resistance to third generation cephalosporins has further complicated the situation and such strains are called as extensively drug resistant (XDR) Salmonella Typhi. Currently only available options are azithromycin and cabapenems. Recently few reports of azithromycin resistance have emerged from countries like Pakistan, India, Bangladesh and Nepal. As azithromycin is the only oral option available to treat XDR Typhoid, development of resistance may change treatment strategy altogether from out patient management to hospitalization of every patient. This may increase the burden on already weak health care system of countries like Pakistan. So there is dire need to look for the alternative treatment options. Manuka honey is well known for its therapeutic potential against wide range of bacteria including Salmonella Typhimurium. In this study 3 azithromycin resistant isolates were isolated and identified using disc diffusion, E-test and broth micro dilution methods and antibacterial activity, MIC and MBC of manuka honey was performed by agar well diffusion assay and broth micro dilution assay respectively. Manuka honey manifested significant antibacterial activity against all test isolates with zone of inhibition ranging from 7.3mm to 7.5mm, MIC and MBC values were between 10 to 15% v/v Here, we conclude that Manuka honey possess potent antibacterial activity and might be used as an alternative treatment option against azithromycin resistant XDR Typhid. However, further clinical trials are mandatory to validate our initial findings.

A study of The use of Manuka Honey and Methylglyoxal to Impart Antimicrobial Activity to Wool Textiles and Polymers

<p><b>Methylglyoxal (MGO), which is an ingredient in New Zealand Manuka honey (MH) possesses unique antimicrobial properties against a broad range of bacteria. MGO has been determined to have a low minimum inhibitory concentration against bacteria. This provides a new opportunity to develop the use of this compound as a natural antimicrobial agent to impart such antimicrobial properties to wool textiles. This is the focus and detailed research work of this thesis. Also, its application to paper and polymer surfaces has been investigated briefly.</b></p> <p>Due to their protein-based structure and porosity, woollen textiles provide a hospitable host for the growth of microorganisms. This microbial growth on such textiles can pose an undesirable health risk to humans and can negatively affect textile sales. the textile market. Similarly, microbial growth on other substrates such as walls, floors and various equipment can also pose health risks. There are a number of antimicrobial treatments on the market, but with the move to more natural-based antimicrobial agents, there is an opportunity to capture the natural antimicrobial properties of MH and particularly the active ingredient MGO, as a natural antimicrobial agent in wool textiles and paper and polymer substrates.</p> <p>This research developed a novel approach and methodology to incorporate MH and also MGO itself as an isolated component and antimicrobial agent of MH, into the wool fibres and chemically bonding it to the fibre proteins. This approach commenced with determining the extent of uptake of MH, based on its MGO concentration, and MGO itself into wool fibres. The extent of MH and MGO uptake has been determined with High-Performance Liquid Chromatography (HPLC). This uptake was studied over a range of MH and MGO concentrations and temperatures using loose top wool, yarn and finished wool fabric. An increase in temperature from room temperature up to 80 °C resulted in significantly higher amounts of MGO and MH being absorbed by the wool. Also, higher concentrations of the initial MGO and MH solutions accelerated the uptake rates and resulted in higher uptake amounts. The relatively slow diffusion rate of MGO into the wool necessarily required a long period of time, up to 14 days, for the particular uptake to generally reach the saturation level. The maximum amounts of MH and MGO that were incorporated into wool fibres in this study were 21.2 mg g-1 and 299 mg g-1 wool, respectively.</p> <p>The chemical interactions between MGO and MGO in MH with the wool fibres have been characterised by Fourier-Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). FTIR spectra showed that the MGO absorption by the wool changed the intensity of particular peaks between 2,000 and 700 cm-1 characteristic of the wool proteins, and the NH stretching peaks of the wool at 3,270 cm-1. The TGA and DSC analyses showed a thermal stability of the wool after MGO absorption and the likely formation of new bonds, probably H-bonds, between the MGO and the wool. Confirming these findings, the MGOWool and MH-Wool showed a resistance against MGO leaching on washing with water, where less than 1% (relative) of MGO leached out. These results suggest the MGO is likely chemically bound to the wool fibres through hydrogen bonding.</p> <p>The MGO-Wool and also MGO-paper composites produced in a similar way with MGO-Wool, exhibited antimicrobial activities against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The MGO-Wool showed bacteriostatic properties for all composites even after three months of being synthesised. This opens up potential applications for the use of MH and MGO in antimicrobial woollen apparel, medical textiles and bandages.</p> <p>In addition, MGO was incorporated into samples of an acrylic polymer NeoCryl® XK-98 and a polyurethane, Kamthane K-5000, polymer resin, respectively. The interaction of MGO with the respective polymer chains resulted in similar hydrogen bonding between MGO and the polymers. At high MGO concentrations this bonding was confirmed by the presence of a new endothermic peak in the DSC pattern. The addition of MGO also modified the polymer surface and resulted in a more hydrophobic surface with an increased water droplet contact angle of 87.5°. The new polymer compositeswere successfully tested against S. aureus and E. coli microbes and were shown to exhibit antimicrobial properties.</p>

A study of The use of Manuka Honey and Methylglyoxal to Impart Antimicrobial Activity to Wool Textiles and Polymers

<p><b>Methylglyoxal (MGO), which is an ingredient in New Zealand Manuka honey (MH) possesses unique antimicrobial properties against a broad range of bacteria. MGO has been determined to have a low minimum inhibitory concentration against bacteria. This provides a new opportunity to develop the use of this compound as a natural antimicrobial agent to impart such antimicrobial properties to wool textiles. This is the focus and detailed research work of this thesis. Also, its application to paper and polymer surfaces has been investigated briefly.</b></p> <p>Due to their protein-based structure and porosity, woollen textiles provide a hospitable host for the growth of microorganisms. This microbial growth on such textiles can pose an undesirable health risk to humans and can negatively affect textile sales. the textile market. Similarly, microbial growth on other substrates such as walls, floors and various equipment can also pose health risks. There are a number of antimicrobial treatments on the market, but with the move to more natural-based antimicrobial agents, there is an opportunity to capture the natural antimicrobial properties of MH and particularly the active ingredient MGO, as a natural antimicrobial agent in wool textiles and paper and polymer substrates.</p> <p>This research developed a novel approach and methodology to incorporate MH and also MGO itself as an isolated component and antimicrobial agent of MH, into the wool fibres and chemically bonding it to the fibre proteins. This approach commenced with determining the extent of uptake of MH, based on its MGO concentration, and MGO itself into wool fibres. The extent of MH and MGO uptake has been determined with High-Performance Liquid Chromatography (HPLC). This uptake was studied over a range of MH and MGO concentrations and temperatures using loose top wool, yarn and finished wool fabric. An increase in temperature from room temperature up to 80 °C resulted in significantly higher amounts of MGO and MH being absorbed by the wool. Also, higher concentrations of the initial MGO and MH solutions accelerated the uptake rates and resulted in higher uptake amounts. The relatively slow diffusion rate of MGO into the wool necessarily required a long period of time, up to 14 days, for the particular uptake to generally reach the saturation level. The maximum amounts of MH and MGO that were incorporated into wool fibres in this study were 21.2 mg g-1 and 299 mg g-1 wool, respectively.</p> <p>The chemical interactions between MGO and MGO in MH with the wool fibres have been characterised by Fourier-Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). FTIR spectra showed that the MGO absorption by the wool changed the intensity of particular peaks between 2,000 and 700 cm-1 characteristic of the wool proteins, and the NH stretching peaks of the wool at 3,270 cm-1. The TGA and DSC analyses showed a thermal stability of the wool after MGO absorption and the likely formation of new bonds, probably H-bonds, between the MGO and the wool. Confirming these findings, the MGOWool and MH-Wool showed a resistance against MGO leaching on washing with water, where less than 1% (relative) of MGO leached out. These results suggest the MGO is likely chemically bound to the wool fibres through hydrogen bonding.</p> <p>The MGO-Wool and also MGO-paper composites produced in a similar way with MGO-Wool, exhibited antimicrobial activities against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). The MGO-Wool showed bacteriostatic properties for all composites even after three months of being synthesised. This opens up potential applications for the use of MH and MGO in antimicrobial woollen apparel, medical textiles and bandages.</p> <p>In addition, MGO was incorporated into samples of an acrylic polymer NeoCryl® XK-98 and a polyurethane, Kamthane K-5000, polymer resin, respectively. The interaction of MGO with the respective polymer chains resulted in similar hydrogen bonding between MGO and the polymers. At high MGO concentrations this bonding was confirmed by the presence of a new endothermic peak in the DSC pattern. The addition of MGO also modified the polymer surface and resulted in a more hydrophobic surface with an increased water droplet contact angle of 87.5°. The new polymer compositeswere successfully tested against S. aureus and E. coli microbes and were shown to exhibit antimicrobial properties.</p>

Identification of components in Kazakhstan honeys that correlate with antimicrobial activity against wound and skin infecting microorganisms

Background Antimicrobial drug resistance is a major public health threat that can render infections including wound and skin infections untreatable. The discovery of new antimicrobials is critical. Approaches to discover novel antimicrobial therapies have included investigating the antimicrobial activity of natural sources such as honey. In this study, the anti-microbial activity and chemical composition of 12 honeys from Kazakhstan and medical grade manuka honey were investigated. Methods Agar well diffusion and broth culture assays were used to determine anti-microbial activity against a range of skin and wound infecting micro-organisms. Folin-Ciocalteu method was used to determine the total phenol content of the honeys and non-targeted liquid chromatography analysis was performed to identify components that correlated with antimicrobial activity. Results In the well diffusion assay, the most susceptible micro-organisms were a clinical isolate of Methicillin resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis (ATCC 19433). Buckwheat & multi-floral honey from Kazakhstan demonstrated the highest antimicrobial activity against these two micro-organisms. Kazakhstan honeys with a buckwheat floral source, and manuka honey had the highest total phenol content. Non-targeted liquid chromatography analysis identified components that correlated with anti-microbial activity as hydroxyphenyl acetic acid, p-coumaric acid, (1H)–quinolinone, and abscisic acid. Conclusions The Kazakhstan honeys selected in this study demonstrated antimicrobial activity against wound and skin infecting micro-organisms. Compounds identified as correlating with antimicrobial activity could be considered as potential bioactive agents for the treatment of wound and skin infections.

Exploration of the antimicrobial synergy between selected natural substances on Streptococcus mutans to identify candidates for the control of dental caries

Dental caries is caused by dental plaque, a community of micro-organisms embedded in an extracellular polymer matrix as a biofilm on the tooth surface. Natural products that are widely available could be used as an alternative or adjunctive anti-caries therapy. Sometimes, when two products are used together, they yield a more powerful antimicrobial effect than the anticipated additive effect. These synergistic combinations are often better treatment options because individual agents may not have sufficient antimicrobial action to be effective when used alone. Cranberries contain phenolic compounds like proanthocyanidins (PAC) that disrupt biofilm formation. Manuka honey has high concentrations of the agent methylglyoxal, which is cariostatic. Because these agents have varied modes of antimicrobial action, they show potential for possible synergistic effects when paired. Various cranberry extracts were tested pairwise with manuka honey or methylglyoxal by well-diffusion assays and 96-well checkerboard assays in the presence of Streptococcus mutans to test for synergy. Synergy was demonstrated in two of the cranberry extracts paired with manuka honey. The synergistic combinations found in this research thus can be considered as candidates for the formulation of a dentifrice that could be used to inhibit the formation of dental plaque and thereby avoid the development of caries.

The Identification of Multidrug Resistant Microorganisms Including Bergyella Zoohelcum Acquired from the Skin/Prosthetic Interface of Amputees and Their Susceptibility to Medihoney™ and Garlic Extract (Allicin)

BackgroundUsers of prosthetic devices face the accumulation of potentially drug-resistant pathogenic bacteria on the skin/prosthesis interface. In this study, we took surface swabs of the skin/prosthesis interface of eleven disabled athletes to identify microorganisms present. In addition to determining their antimicrobial resistance profile, we assessed their sensitivity to Manuka honey and Garlic extract (allicin) MethodsEleven volunteers were directed to swab the skin at the skin/prosthesis interface. After initial isolation of microorganisms we employed the following general microbiological methods; Gram stain, Catalase test, Oxidase test, lactose fermenting capability, haemolytic capability, Staphaurex, mannitol fermenting capability, Streptex; API Staph, 20E, Candida, and BBL crystal identification system tests. Once identified, isolates were analysed for their sensitivity to penicillin, erythromycin. ampicillin, vancomycin, ceftazidime, ciprofloxacin, gentamicin and colistin-sulphate. Isolates were also analysed for their sensitivity to allicin (Garlic Extract (GE)) and Manuka honey (Medihoney™) (MH). ResultsEleven isolates were identified, Bacillus cereus, Staphylococcus haemolyticus, Staphylococcus aureus, Micrococcus luteus, Pseudomonas oryzihabitans, Micrococcus spp., Bacillus subtilis, Group D Streptococcus, Pantoea spp., Enterobacter cloacae and Bergyella zoohelcum. All Gram-positive organisms were resistant to 1.5 units of penicillin and 10 μg of ampicillin, and two Gram-negatives Pseudomonas oryzihabitans and Bergyella zoohelcum were resistant to 10 μg ceftazidime, whilst Bergyella zoohelcum, was also resistant to 10 μg of gentamicin. In comparison, all organisms were sensitive to Manuka honey and nine sensitive to Allicin. ConclusionsThis study highlights the prevalence of uncommon drug resistant microorganisms on the skin within a vulnerable population, highlighting the potential for MH or GE intervention.

Evaluation of antiviral activity of Manuka honey against SARS-CoV-2.

Background and aims: In 2020 a global pandemic was declared caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). The pandemic is still ongoing and continues to cause considerable mortality and morbidity world-wide and new variants of the virus are emerging. Rapid development and rollout of vaccines for SARS-CoV-2 is in progress to counter the pandemic but has been tempered by the emergence of new SARS-CoV-2 variants, many of which exhibit reduced vaccine effectiveness. To date there is no approved antiviral treatment for coronavirus disease 2019 (COVID-19). Several studies have shown that Manuka honey has virucidal/antiviral effect. Methylglyoxal (MG), a bioactive component in Manuka honey, has antiviral activity in vitro. MG may modify arginine residues in the functional domains of viral spike and nucleocapsid proteins, resulting in loss of charge, protein misfolding and inactivation. The aim of this study was to characterize the antiviral activity of Manuka honey against SARS-CoV-2 in vitro Materials and methods: Wild-type SARS-CoV-2 with titers of multiplicities of infection (MOI) 0.1 and 0.05 were incubated with 2-fold serial dilutions of 250+ Manuka honey (equivalent to 250 to 31 µM) in infection medium (Dulbecco's Modified Eagle Medium + 2% fetal bovine serum + 100 units/ml penicillin + 100 µg/ml streptomycin) for 3 h. Manuka honey treated and untreated control SARS-CoV-2 was incubated with confluent cultures of Vero cells in vitro for 1 h, cultures washed with phosphate-buffered saline and incubated in fresh infection medium at 37°C for 4 - 5 days until 70% of virus control cells displayed cytopathic effect. We also studied the effect of scavenging MG in Manuka Honey with aminoguanidine (AG; 500 µM) on virucidal activity. The antiviral activity of MG was judged by median tissue culture infectious dose (TCID50) assays. Data analysis was by logistic regression. TCID50 (mean ± SD) was deduced by interpolation. Results: Diluted Manuka honey inhibited SARS-CoV-2 replication in Vero cells. SARS-CoV-2 was incubated in diluted Manuka honey in medium at 37°C for 3 h before adding to Vero cells. Manuka honey dilutions down to 125 µM MG equivalents completely inhibited cytopathic effect of SARS-CoV-2 whereas 31.25 µM and 62.5 µM MG equivalents had limited effect. Logistic regression and interpolation of the cytopathic effect indicated that the TCID50 = 72 ± 2 µM MG equivalents for MOI of 0.1. Prior scavenging of MG by addition of AG resulted in virus replication levels equivalent to those seen in the virus control without AG. Conclusion: Manuka honey has antiviral activity against SARS-CoV-2 when incubated with the virus in cell-free media at no greater than ca. 40-fold dilutions of 250+ grade. Anti-viral activity was inhibited by AG, consistent with the anti-viral effect being mediated by MG. Manuka honey dilutions in MG equivalents had similar antiviral effect compared to authentic MG, also consistent with MG content of Manuka honey mediating the antiviral effect. Whilst Manuka honey may inactivate SARS-CoV-2 in cell-free culture medium, its antiviral activity in vivo for other than topical application may be limited because of the rapid metabolism of MG by the glyoxalase system and limited bioavailability of oral MG.