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Antibiotic-specific differences in the response of Staphylococcus aureus to treatment with antimicrobials combined with manuka honey.

Liu M, Lu J, Müller P, Turnbull L, Burke CM, Schlothauer RC, Carter DA, Whitchurch CB, Harry EJ - Front Microbiol (2015)

Bottom Line: Previous studies showing synergistic effects between manuka-type honeys and antibiotics have been demonstrated against the growth of one methicillin-resistant S. aureus (MRSA) strain.In some cases when synergism was not observed, there was a significant enhancement in antibiotic susceptibility.Our data also suggest that manuka-type honeys may not work as antibiotic adjuvants for all strains of S. aureus, and this may help determine the mechanistic processes behind honey synergy.

View Article: PubMed Central - PubMed

Affiliation: The ithree institute, University of Technology, Sydney, Sydney, NSW Australia.

ABSTRACT
Skin infections caused by antibiotic resistant Staphylococcus aureus are a significant health problem worldwide; often associated with high treatment cost and mortality rate. Complex natural products like New Zealand (NZ) manuka honey have been revisited and studied extensively as an alternative to antibiotics due to their potent broad-spectrum antimicrobial activity, and the inability to isolate honey-resistant S. aureus. Previous studies showing synergistic effects between manuka-type honeys and antibiotics have been demonstrated against the growth of one methicillin-resistant S. aureus (MRSA) strain. We have previously demonstrated strong synergistic activity between NZ manuka-type honey and rifampicin against growth and biofilm formation of multiple S. arueus strains. Here, we have expanded our investigation using multiple S. aureus strains and four different antibiotics commonly used to treat S. aureus-related skin infections: rifampicin, oxacillin, gentamicin, and clindamycin. Using checkerboard microdilution and agar diffusion assays with S. aureus strains including clinical isolates and MRSA we demonstrate that manuka-type honey combined with these four antibiotics frequently produces a synergistic effect. In some cases when synergism was not observed, there was a significant enhancement in antibiotic susceptibility. Some strains that were highly resistant to an antibiotic when present alone become sensitive to clinically achievable concentrations when combined with honey. However, not all of the S. aureus strains tested responded in the same way to these combinational treatments. Our findings support the use of NZ manuka-type honeys in clinical treatment against S. aureus-related infections and extend their potential use as an antibiotic adjuvant in combinational therapy. Our data also suggest that manuka-type honeys may not work as antibiotic adjuvants for all strains of S. aureus, and this may help determine the mechanistic processes behind honey synergy.

No MeSH data available.


Related in: MedlinePlus

Sensitivity of Staphylococcus aureus strains to antibiotics used alone and in combination with Manuka-type honeys assessed by agar disk diffusion assay. Diameter (in mm) of zones of inhibition around 4 μg-impregnated antibiotic disks on TSA plates without honey (black bar), and in presence of 5% sugar solution (blue bar), 5% manuka honey (purple bar), or 5% Medihoney (red bar). Mean values are presented and error bars indicate one SD. Asterisks above the honey-antibiotic combination treatments indicate statistically significant differences from the antibiotic treatment alone, as determined by ANOVA analysis with a post hoc Dunnett’s test. Data for rifampicin (top left) is copied with permission from Müller et al. (2013).
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Figure 1: Sensitivity of Staphylococcus aureus strains to antibiotics used alone and in combination with Manuka-type honeys assessed by agar disk diffusion assay. Diameter (in mm) of zones of inhibition around 4 μg-impregnated antibiotic disks on TSA plates without honey (black bar), and in presence of 5% sugar solution (blue bar), 5% manuka honey (purple bar), or 5% Medihoney (red bar). Mean values are presented and error bars indicate one SD. Asterisks above the honey-antibiotic combination treatments indicate statistically significant differences from the antibiotic treatment alone, as determined by ANOVA analysis with a post hoc Dunnett’s test. Data for rifampicin (top left) is copied with permission from Müller et al. (2013).

Mentions: Agar diffusion tests were performed to visualize the possible interactions between manuka honey or Medihoney and each antibiotic against each S. aureus strain (Figure 1). Sensitivity was measured based on the diameter of the zone of growth inhibition for antibiotics alone, or in combination with 5% (sub-MIC) manuka honey or Medihoney. A sugar solution made to be isotonic with honey was also used at 5% to examine the sole effect of sugar in combination with antibiotics. Additive effects are indicated by an increase in diameter of the inhibition zone with both antibiotics and honey compared to the use of an antibiotic alone.


Antibiotic-specific differences in the response of Staphylococcus aureus to treatment with antimicrobials combined with manuka honey.

Liu M, Lu J, Müller P, Turnbull L, Burke CM, Schlothauer RC, Carter DA, Whitchurch CB, Harry EJ - Front Microbiol (2015)

Sensitivity of Staphylococcus aureus strains to antibiotics used alone and in combination with Manuka-type honeys assessed by agar disk diffusion assay. Diameter (in mm) of zones of inhibition around 4 μg-impregnated antibiotic disks on TSA plates without honey (black bar), and in presence of 5% sugar solution (blue bar), 5% manuka honey (purple bar), or 5% Medihoney (red bar). Mean values are presented and error bars indicate one SD. Asterisks above the honey-antibiotic combination treatments indicate statistically significant differences from the antibiotic treatment alone, as determined by ANOVA analysis with a post hoc Dunnett’s test. Data for rifampicin (top left) is copied with permission from Müller et al. (2013).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307217&req=5

Figure 1: Sensitivity of Staphylococcus aureus strains to antibiotics used alone and in combination with Manuka-type honeys assessed by agar disk diffusion assay. Diameter (in mm) of zones of inhibition around 4 μg-impregnated antibiotic disks on TSA plates without honey (black bar), and in presence of 5% sugar solution (blue bar), 5% manuka honey (purple bar), or 5% Medihoney (red bar). Mean values are presented and error bars indicate one SD. Asterisks above the honey-antibiotic combination treatments indicate statistically significant differences from the antibiotic treatment alone, as determined by ANOVA analysis with a post hoc Dunnett’s test. Data for rifampicin (top left) is copied with permission from Müller et al. (2013).
Mentions: Agar diffusion tests were performed to visualize the possible interactions between manuka honey or Medihoney and each antibiotic against each S. aureus strain (Figure 1). Sensitivity was measured based on the diameter of the zone of growth inhibition for antibiotics alone, or in combination with 5% (sub-MIC) manuka honey or Medihoney. A sugar solution made to be isotonic with honey was also used at 5% to examine the sole effect of sugar in combination with antibiotics. Additive effects are indicated by an increase in diameter of the inhibition zone with both antibiotics and honey compared to the use of an antibiotic alone.

Bottom Line: Previous studies showing synergistic effects between manuka-type honeys and antibiotics have been demonstrated against the growth of one methicillin-resistant S. aureus (MRSA) strain.In some cases when synergism was not observed, there was a significant enhancement in antibiotic susceptibility.Our data also suggest that manuka-type honeys may not work as antibiotic adjuvants for all strains of S. aureus, and this may help determine the mechanistic processes behind honey synergy.

View Article: PubMed Central - PubMed

Affiliation: The ithree institute, University of Technology, Sydney, Sydney, NSW Australia.

ABSTRACT
Skin infections caused by antibiotic resistant Staphylococcus aureus are a significant health problem worldwide; often associated with high treatment cost and mortality rate. Complex natural products like New Zealand (NZ) manuka honey have been revisited and studied extensively as an alternative to antibiotics due to their potent broad-spectrum antimicrobial activity, and the inability to isolate honey-resistant S. aureus. Previous studies showing synergistic effects between manuka-type honeys and antibiotics have been demonstrated against the growth of one methicillin-resistant S. aureus (MRSA) strain. We have previously demonstrated strong synergistic activity between NZ manuka-type honey and rifampicin against growth and biofilm formation of multiple S. arueus strains. Here, we have expanded our investigation using multiple S. aureus strains and four different antibiotics commonly used to treat S. aureus-related skin infections: rifampicin, oxacillin, gentamicin, and clindamycin. Using checkerboard microdilution and agar diffusion assays with S. aureus strains including clinical isolates and MRSA we demonstrate that manuka-type honey combined with these four antibiotics frequently produces a synergistic effect. In some cases when synergism was not observed, there was a significant enhancement in antibiotic susceptibility. Some strains that were highly resistant to an antibiotic when present alone become sensitive to clinically achievable concentrations when combined with honey. However, not all of the S. aureus strains tested responded in the same way to these combinational treatments. Our findings support the use of NZ manuka-type honeys in clinical treatment against S. aureus-related infections and extend their potential use as an antibiotic adjuvant in combinational therapy. Our data also suggest that manuka-type honeys may not work as antibiotic adjuvants for all strains of S. aureus, and this may help determine the mechanistic processes behind honey synergy.

No MeSH data available.


Related in: MedlinePlus