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Synergism between Medihoney and rifampicin against methicillin-resistant Staphylococcus aureus (MRSA).

Müller P, Alber DG, Turnbull L, Schlothauer RC, Carter DA, Whitchurch CB, Harry EJ - PLoS ONE (2013)

Bottom Line: Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance.Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin.Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections.

View Article: PubMed Central - PubMed

Affiliation: The ithree institute, University of Technology Sydney (UTS), Sydney, New South Wales, Australia.

ABSTRACT
Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections.

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Related in: MedlinePlus

Growth curves of S. aureus NCTC8325 in CaMHB.Bacteria were incubated with (A) 70 µg/ml MGO, 0.2 µg/ml rifampicin, or both, or with (B) 70 µg/ml MGO (in CaMHB with 7% sugar solution, MGOS), 0.2 µg/ml rifampicin, or both. A growth control using just CaMHB is included as indicated. Rif is rifampicin.
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pone-0057679-g002: Growth curves of S. aureus NCTC8325 in CaMHB.Bacteria were incubated with (A) 70 µg/ml MGO, 0.2 µg/ml rifampicin, or both, or with (B) 70 µg/ml MGO (in CaMHB with 7% sugar solution, MGOS), 0.2 µg/ml rifampicin, or both. A growth control using just CaMHB is included as indicated. Rif is rifampicin.

Mentions: The synergistic effect of MGO and rifampicin was also examined using time-kill assays. A concentration of 70 µg/ml MGO (corresponding to the concentration of MGO in 7% (w/v) manuka honey) inhibited growth of S. aureus NCTC8325 for up to 8 h. However, after 8 h, growth of bacteria occurred and at 48 h, the CFU/mL count increased to levels of growth similar to that observed in the untreated culture (Fig. 2A). When combined with rifampicin, an increase in the antimicrobial activity could be detected, but after 12 h the CFU/mL count reached the level of the no-treatment control. S. aureus isolates originating from that sample and subsequently cultured in the presence of rifampicin were no longer susceptible to rifampicin at all tested concentrations (0–20 µg/ml) (data not shown). MGO in CaMHB medium supplemented with sugar equivalent to that present in 7% honey (MGOS) had reduced antimicrobial activity compared to MGO in CaMHB (Fig. 2B).


Synergism between Medihoney and rifampicin against methicillin-resistant Staphylococcus aureus (MRSA).

Müller P, Alber DG, Turnbull L, Schlothauer RC, Carter DA, Whitchurch CB, Harry EJ - PLoS ONE (2013)

Growth curves of S. aureus NCTC8325 in CaMHB.Bacteria were incubated with (A) 70 µg/ml MGO, 0.2 µg/ml rifampicin, or both, or with (B) 70 µg/ml MGO (in CaMHB with 7% sugar solution, MGOS), 0.2 µg/ml rifampicin, or both. A growth control using just CaMHB is included as indicated. Rif is rifampicin.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585195&req=5

pone-0057679-g002: Growth curves of S. aureus NCTC8325 in CaMHB.Bacteria were incubated with (A) 70 µg/ml MGO, 0.2 µg/ml rifampicin, or both, or with (B) 70 µg/ml MGO (in CaMHB with 7% sugar solution, MGOS), 0.2 µg/ml rifampicin, or both. A growth control using just CaMHB is included as indicated. Rif is rifampicin.
Mentions: The synergistic effect of MGO and rifampicin was also examined using time-kill assays. A concentration of 70 µg/ml MGO (corresponding to the concentration of MGO in 7% (w/v) manuka honey) inhibited growth of S. aureus NCTC8325 for up to 8 h. However, after 8 h, growth of bacteria occurred and at 48 h, the CFU/mL count increased to levels of growth similar to that observed in the untreated culture (Fig. 2A). When combined with rifampicin, an increase in the antimicrobial activity could be detected, but after 12 h the CFU/mL count reached the level of the no-treatment control. S. aureus isolates originating from that sample and subsequently cultured in the presence of rifampicin were no longer susceptible to rifampicin at all tested concentrations (0–20 µg/ml) (data not shown). MGO in CaMHB medium supplemented with sugar equivalent to that present in 7% honey (MGOS) had reduced antimicrobial activity compared to MGO in CaMHB (Fig. 2B).

Bottom Line: Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance.Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin.Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections.

View Article: PubMed Central - PubMed

Affiliation: The ithree institute, University of Technology Sydney (UTS), Sydney, New South Wales, Australia.

ABSTRACT
Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections.

Show MeSH
Related in: MedlinePlus